Vom Fachbereich Chemie. der. Universität Duisburg-Essen. zur Erlangung des akademischen Grades eines Doktors der Naturwissenschaften

Size: px
Start display at page:

Download "Vom Fachbereich Chemie. der. Universität Duisburg-Essen. zur Erlangung des akademischen Grades eines Doktors der Naturwissenschaften"

Transcription

1 An Innovative Method to Generate Iodine(V and III)-Fluorine Bonds and Contributions to the Reactivity of Fluoroorganoiodine(III) Fluorides and Related Compounds Vom Fachbereich Chemie der Universität Duisburg-Essen zur Erlangung des akademischen Grades eines Doktors der Naturwissenschaften genehmigte Dissertation von Anwar Abo-Amer aus Irbid / Jordanien Referent: Prof. Dr. H.-J. Frohn Korreferent: Prof. Dr. G. Geismar Tag der mündlichen Prüfung:

2 Die experimentellen Arbeiten wurden in der Zeit von Juli 2001 bis April 2004 unter Anleitung von Herrn Prof. Dr. H.-J. Frohn im Fach Anorganische Chemie des Fachbereiches Chemie am Campus Duisburg der Universität Duisburg-Essen durchgeführt.

3 ACKNOWLEDGMENTS I would like to thank my supervisor Prof. Dr. Hermann-Josef Frohn (Distinguished Professor Inorganic Chemistry), for his guidance, encouragement, support throughout my graduate study, his willingness to share his technical knowledge and for having patience with me. He acted as the driving force behind this research. He provided his knowledge and expertise. He spent many time for constructive discussion, which enriched my knowledge, skill and my experience. I sincerely thank Prof. Dr. G. Geismar, the Korreferent, for his encouragement, support and constructive discussion. Also, I m very grateful to Prof. Dr. Vadim Bardin for many fruitful discussions concerning topics in fluorine and boron chemistry. I have to thank my colleague Dr. Nicolay Adonin for helpful discussions. He provided not only scientific, but also moral support, and most of all friendship, throughout my study and research. I am also grateful to many other persons and I would like to acknowledge their significant contributions to my study: - Karsten Koppe, who has provided me with constant support, kind guidance and significant contribution, not only on my academic life but also on my personal life. - Wassef Al Sekhaneh, who inspired my research with his incredible knowledge. - Dietmar Jansen, Petra Fritzen, Christoph Steinberg, Andre Wenda, and Oliver Brehm, which all inspired my research with their incredible knowledge and helped for a warm and supportive environment. Special thanks are given to many faculty and staff members of the chemistry department (Duisburg-Essen Universität) for their assistance during my graduate study. In particular, thanks are pressed to Dr. Ulrich Flörke for the X-Ray crystallographic work. Special thanks to Mrs. Beate Römer and Mr. Manfred Zähres for NMR spectrometric measurements. My utmost appreciation and thanks are given to my wife, Eman Abu-Jadoua, for her love and support throughout my graduate career. I also thank my daughter, Mimas, and my son, Yamen, for bringing so much joy the moment they joined into my life in Germany. I warmly thank my parents, brothers and sisters for continuous inspiration and encouragement. The support of many friends through out my research (Prof. Dr. Alaa Hassan, Prof. Dr. Mohammad Shabat) has also been much appreciated.

4 After great pain, a formal feeling comes Emily Dickinson

5 Dedicated to My Daughter Mimas, My Son Yamen, My Wife Eman, My Mother and Father

6 Table of Contents I Table of Contents 1 Introduction Bonding and Structure in Polyvalent Iodine Compounds (Difluoroiodo)arenes (Tetrafluoroiodo)arenes and (Difluorooxoiodo)arenes (Tetrafluoroiodo)arenes (Difluorooxoiodo)arenes Iodine Pentafluoride Iodonium Salts Diaryliodonium Salts Alkenyl(aryl)iodonium Salts 12 2 Objectives Preparative Aspects Iodine Pentafluoride (Tetrafluoroiodo)arenes (Difluorooxoiodo)arenes (Difluoroiodo)arenes Iodonium Salts Reactivity, Structure, and Spectroscopy 17 3 Results and Discussion Preparation of Iodine Pentafluoride (IF 5 ) by a New Methodological Approach Introduction Relevant Reactivities of I(V)-F and I(V)-O Bonds The Reaction of I(V)-O Compounds with ahf in a Two Phase System The Important Steps in the Preparation of IF The Influence of the HF Concentration on the IF 5 Formation 21

7 Table of Contents II Fluoro-1-(tetrafluoroiodo)benzene by Oxygen-Fluorine Substitution Fluoro-1-(difluorooxoiodo)benzene (p-c 6 H 4 FIOF 2 ) by Treat- ment of 4-Fluoro-iodylbenzene with Hydrofluoric Acid (Difluoroiodo)arenes (ArIF 2 ) by Oxygen-Fluorine Substitution on ArIO with Hydrofluoric Acid as Reagent 25 The Influence of the HF Concentration on the Formation of (Difluoroiodo)arenes (ArIF 2 ) A Convenient Route to (Difluoroiodo)benzenes (ArIF 2 ) Directly from (Diacetoxyiodo)benzenes Iodonium Salts The Synthesis of Diaryliodonium Salts Starting from (Difluoroiodo)arenes The Synthesis of Alkenyl(aryl)iodonium Salts Starting from (Difluoroiodo)arenes trans-1,2,3,3,3-pentafluoroprop-1-enyl(fluorophenyl)iodonium Tetrafluoroborates trans-1,2,3,3,3-pentafluoroprop-1-enyl(pentafluorophenyl)iodonium Tetrafluoroborate Preparation of Trifluorovinyl(fluorophenyl)iodonium Tetrafluoroborates Preparation of Trifluorovinyl(pentafluorophenyl)iodonium Tetrafluoroborate Selected Reactivities of Fluoro(difluoroiodo)benzenes C 6 H 4 FIF Reactivities with Nucleophiles and Lewis Bases The Reaction of p-c 6 H 4 FIF 2 with Trimethylsilylacetate The Interaction of ArIF 2 with 2,2 -Bipyridine The Interaction of ArIF 2 with (C 6 H 5 ) 3 PO The Reaction of ArIF 2 with [NMe 4 ]F 37

8 Table of Contents III The Reaction of p-c 6 H 4 FIF 2 with [N(CH 3 ) 4 ]F (1 : 1) in Dichloromethane The 1 : 2 Reaction of p-c 6 H 4 FIF 2 with [N(CH 3 ) 4 ]F in Dichloromethane The 1 : 0.5 Reaction of p-c 6 H 4 FIF 2 with [N(CH 3 ) 4 ]F in Dichloromethane The Reaction of p-c 6 H 4 FIF 2 with [N(CH 3 ) 4 ]F (1 : 1) in Acetonitrile The Reaction of p-c 6 H 4 FIF 2 with [N(CH 3 ) 4 ]F (1 : 3) in Dichloromethane The 1 : 2 Reaction of o-c 6 H 4 FIF 2 with [N(CH 3 ) 4 ]F in Dichloromethane The 1 : 2 Reaction of m-c 6 H 4 FIF 2 with [N(CH 3 ) 4 ]F in Dichloromethane The Reaction of p-c 6 H 4 FIF 2 with CsF The Reaction of p-c 6 H 4 FIF 2 with CsF (1 : 1) in Acetonitrile The Reaction of p-c 6 H 4 FIF 2 with CsF (1 : 2) in Acetonitrile Reactions of C 6 H 4 FIF 2 with Lewis and Brønsted Acids The Reaction of p-c 6 H 4 FIF 2 with C 6 H 5 PF The Reactions of p-c 6 H 4 FIF 2 with Alcohols (MeOH, EtOH, CF 3 CH 2 OH) The Reaction of p-c 6 H 4 FIF 2 with CF 3 CO 2 H The Reaction of p-c 6 H 4 FIF 2 with ahf Selected Reactivities of Iodonium Salts Reactions with Lewis Bases The Reaction of [p-c 6 H 4 F(CF 2 =CF)I][BF 4 ] with Naked Fluoride The Reaction of [p-c 6 H 4 F(C 6 H 5 )I][BF 4 ] with Naked Fluoride The 1 : 1 Reaction of [p-c 6 H 4 F(C 6 H 5 )I]F with Naked Fluoride in Dichloromethane Reactions with Nucleophiles The Reaction of [p-c 6 H 4 F(trans-CF 3 CF=CF)I][BF 4 ] with (p-c 6 H 4 F) 3 As in CH 2 Cl The Reaction of [p-c 6 H 4 F(trans-CF 3 CF=CF)I][BF 4 ] with (p-c 6 H 4 F) 3 P in CH 2 Cl The Reaction of [p-c 6 H 4 F(trans-CF 3 CF=CF)I][BF 4 ] with 2,2 -Bipyridine in CH 2 Cl The Attempted Reaction of [p-c 6 H 4 F(CF 2 =CF)I][BF 4 ] with (p-c 6 H 4 F) 3 P in ahf 58

9 Table of Contents IV 3.9 The Results of 1 H, 13 C, and 19 F NMR Spectroscopic Studies F NMR Spectroscopic Studies of IF The NMR Spectroscopic Studies of 4-Fluoro-1-(tetrafluoroiodo)benzene (p-c 6 H 4 FIF 4 ) The NMR Spectroscopic Studies of 4-Fluoro-1-(difluorooxoiodo)benzene (p-c 6 H 4 FIOF 2 ) The NMR Spectroscopic Comparison of C 6 H 4 XI, C 6 H 4 XI(OAc) 2, and C 6 H 4 XIF 2 (X = o-, m-, and p-f) The Temperature Dependence of 19 F NMR Chemical Shifts in Monofluoro(difluoroiodo)benzenes NMR Spectroscopic Studies on Iodonium Salts Asymmetric Diaryliodonium Tetrafluoroborates trans-1,2,3,3,3-pentafluoroprop-1-enyl(fluorophenyl)iodonium Tetrafluoroborates Trifluorovinyl(fluorophenyl)iodonium Tetrafluoroborates Alkenyl(pentafluorophenyl)iodonium Tetrafluoroborates Thermal Stabilities of Selected (Difluoroiodo)benzenes and Aryl-Containing Iodonium Salts X-Ray Crystal Structure Analysis The Crystal Structures of p-c 6 H 4 FIF 2 and o-c 6 H 4 FIF The Crystal Structure of [m-c 6 H 4 F(C 6 H 5 )I][BF 4 ] The Crystal Structure of [p-c 6 H 4 F(trans-CF 3 CF=CF)I][BF 4 ] The Crystal Structure of p-c 6 H 4 FIOF The Inductive and Resonance Parameters of Selected I(III)- Substituents in Iodonium Salts Using Taft`s Method Experimental Section Materials, Apparatus, and Methods General Methods Spectroscopic, Physical, and Analytical Measurements 105

10 Table of Contents V NMR Spectroscopy H NMR Spectroscopy B NMR Spectroscopy F NMR Spectroscopy C NMR Spectroscopy Differential Scanning Calorimetry (DSC) Measurements Melting Point Measurements X-Ray Single Crystal Measurements Weighing of Electrostatic Materials Solvents, Chemicals, and Starting Compounds Solvents Chemicals Available in the Laboratory Commercially Available Chemicals Starting Compounds The Preparation of (Diacetoxyiodo)arenes ArI(O 2 CCH 3 ) The Preparation of Iodosylbenzenes ArIO The Preparation of p-fluoroiodylbenzene p-c 6 H 4 FIO The Preparation of Phenyldifluoroborane The Preparation of Perfluorovinyldifluoroborane The Preparation of Potassium Perfluorovinyltrifluoroborate The Preparation of Lithium Perfluorovinyltrimethoxyborate The Preparation of trans-1,2,3,3,3-pentafluoroprop-1-enyldifluoroborane The Preparation of Potassium trans-1,2,3,3,3-pentafluoroprop-1- enyltrifluoroborate The Preparation of Lithium trans-1,2,3,3,3-pentafluoroprop-1- enyltrimethoxyborate The Preparation of trans-1,2,3,3,3-pentafluoropropene Synthetic Procedures and Spectroscopic Data An Innovative Preparation of Iodine Pentafluoride Starting from Iodine(V) Oxide Starting from Sodium Iodate 124

11 Table of Contents VI The Influence of the HF Concentration on the IF 5 Formation: Reaction of NaIO 3 with ahf The Preparation of 4-Fluoro-1-(tetrafluoroiodo)benzene The Preparation of 4-Fluoro-1-(difluorooxoiodo)benzene The Preparation of (Difluoroiodo)benzenes from Iodosylbenzenes 128 The Influence of the HF Concentration on the Formation of (Difluoroiodo)arenes (ArIF 2 ) A Convenient Route to (Difluoroiodo)benzenes ArIF 2 Directly from (Diacetoxyiodo)benzenes The Preparation of Monofluorophenyl(phenyl)iodonium Tetrafluoroborates The Preparation of trans-1,2,3,3,3-pentafluoroprop-1-enyl(monofluorophenyl)iodonium Tetrafluoroborates The Preparation of trans-1,2,3,3,3-pentafluoroprop-1-enyl(pentafluorophenyl)iodonium Tetrafluoroborate The Preparation of Trifluorovinyl(monofluorophenyl)iodonium Tetrafluoroborates The Preparation of Trifluorovinyl(pentafluorophenyl)iodonium Tetrafluoroborate Selected Reactivities of Fluoro(difluoroiodo)benzenes C 6 H 4 FIF Reactivities with Nucleophiles and Lewis Bases The Reaction of p-c 6 H 4 FIF 2 with Trimethylsilylacetate The Interaction of ArIF 2 with 2,2 -Bipyridine The Interaction of ArIF 2 with (C 6 H 5 ) 3 PO The Reaction of p-c 6 H 4 FIF 2 with [NMe 4 ]F The Reaction of p-c 6 H 4 FIF 2 with [N(CH 3 ) 4 ]F (1 : 1) in Dichloromethane The Reaction of p-c 6 H 4 FIF 2 with [N(CH 3 ) 4 ]F (1 : 2) in Dichloromethane The Reaction of p-c 6 H 4 FIF 2 with [N(CH 3 ) 4 ]F (1 : 0.5) in Dichloromethane The Reaction of p-c 6 H 4 FIF 2 with [N(CH 3 ) 4 ]F (1 : 1) in Acetonitrile The Reaction of p-c 6 H 4 FIF 2 with [N(CH 3 ) 4 ]F (1 : 3) in CH 2 Cl The Reaction of m-c 6 H 4 FIF 2 with [N(CH 3 ) 4 ]F (1 : 2) in Dichloromethane 154

12 Table of Contents VII The Reaction of o-c 6 H 4 FIF 2 with [N(CH 3 ) 4 ]F (1 : 2) in Dichloromethane The Reaction of p-c 6 H 4 FIF 2 with CsF The Reaction of p-c 6 H 4 FIF 2 with CsF (1 : 1) in Acetonitrile The Reaction of p-c 6 H 4 FIF 2 with CsF (1 : 2) in Acetonitrile Reactions of C 6 H 4 FIF 2 with Lewis and Brønsted Acids The Reaction of p-c 6 H 4 FIF 2 with C 6 H 5 PF The Reactions of ArIF 2 with Alcohols (MeOH, EtOH, CF 3 CH 2 OH) The Reaction of p-c 6 H 4 FIF 2 with CF 3 CO 2 H The Reaction of p-c 6 H 4 FIF 2 with ahf Selected Reactivities of Iodonium Salts Reactions with Lewis Bases The Reaction of [p-c 6 H 4 F(CF 2 =CF)I][BF 4 ] with Naked Fluoride in CH 2 Cl The Reaction of [p-c 6 H 4 F(C 6 H 5 )I][BF 4 ] with Naked Fluoride in CH 2 Cl The 1 : 1 Reaction of [p-c 6 H 4 F(C 6 H 5 )I]F with Naked Fluoride in CH 2 Cl Reactions with Nucleophiles The Reaction of [p-c 6 H 4 F(trans-CF 3 CF=CF)I][BF 4 ] with (p-c 6 H 4 F) 3 As in CH 2 Cl The Reaction of [p-c 6 H 4 F(trans-CF 3 CF=CF)I][BF 4 ] with (p-c 6 H 4 F) 3 P in CH 2 Cl The Reaction of [p-c 6 H 4 F(trans-CF 3 CF=CF)I][BF 4 ] with 2,2 -Bipyridine in CH 2 Cl The Attempted Reaction of [p-c 6 H 4 F(CF 2 =CF)I][BF 4 ] with (p-c 6 H 4 F) 3 P in ahf The Determination of the Inductive and Resonance Parameters of Selected I(III)-Substituents in Iodonium Salts Using Taft`s Method Summary Generation of Iodofluorides and Organoiodofluorides Iodine Pentafluoride (Tetrafluoroiodo)arenes 171

13 Table of Contents VIII (Difluorooxoiodo)arenes (Difluoroiodo)arenes The First Synthesis of Perfluoroalkenyl(aryl)iodonium Tetrafluoroborate Salts Reactivity, Structure, and Spectroscopy of Monofluoro(difluoroiodo)benzenes General Reactivities of Perfluoroalkenyl(aryl)iodonium Tetrafluoroborate Salts References Appendix NMR Spectroscopic Data of I-F and Related Compounds Solubility of ArIF 2 in Different Solvents Solubility of HF in Methylene Chloride The Interatomic Distances and Angles of p-c 6 H 4 FIF 2, o-c 6 H 4 FIF 2, [m-c 6 H 4 F(C 6 H 5 )I][BF 4 ], p-c 6 H 4 FIOF 2 [p-c 6 H 4 F(trans-CF 3 CF=CF)I][BF 4 ] List of Figures List of Schemes List of Tables List of Symbols and Abbreviations List of Publications, Presentations and Conferences 201 Curriculum Vitae

14 Introduction 1 1 Introduction 1.1 Bonding and Structure in Polyvalent Iodine Compounds The concept of hypervalency was introduced by Musher [1] in By definition in hypervalent molecules the octet rule is not obeyed, that means that there are more than four pairs of electrons around the central atom in the conventional Lewis formula. More simply, hypervalent molecules or ions are containing central atoms of group 15 18, non-metals of groups V VIII of the main groups, in a higher valency than the stable one given by the valency rule 8 group number. In such compounds the central atom uses a p-orbital to form a linear bond to two ligands. Such bonds, termed "hypervalent", are longer and weaker than [2, 3, 4, 5] (normal) two-centre two-electron covalent bonds. The description of such bonding systems by molecular orbital theory led to the concept of 3- [6, 7] center-4-electron or similar poly-centre bonds (hypervalent bonds). Supported by [8, 9] computational work this concept is now accepted. The most common hypervalent iodine compounds are aryl λ 3 iodanes (ArIL 2 ) with a decet structure and pseudotrigonal bipyramidal geometries (T-shaped molecules) and aryl-λ 5 iodanes (ArIL 4 ) with a dodecet structure and square pyramidal geometries. Bonding in ArIL 2 compounds uses essentially a pure 5p orbital in the linear L-I-L bond, the hypervalent three-centre-four-electron bond (3c-4e bond), with two electrons from the doubly occupied 5p orbital of iodine and one electron from each p-orbital of the ligands L. The least electronegative ligand in ArIL 2, the aryl group, is bound by a normal two-centre-two-electron covalent bond with C(sp 2 ) hybridization in the C Ar I σ-bond. [10, 11] In the MO-scheme of the IL 2 subunit with three molecular orbitals the two molecular orbitals of lower energy, bonding and nonbonding orbitals, are filled (Fig. 1). Partial positive charge has to be assigned to the central iodine atom (ca a.u.), [8] while partial negative charge on both apical heteroatom ligands (L = F: ca. 0.5 a.u.). [8] The filled nonbonding molecular orbital has a node at the central iodine atom. The partial positive charge on iodine in the highly polarised 3c 4e bond makes the aryl-λ 3 -iodane an electrophilic agent. The inherent nature of the 3c 4e bond explains the preferred orientation of more electronegative ligands in the apical positions. For non-metals of the same group more electropositive central atoms are energetically favoured for hypervalent species: thus in general, λ 3 -iodanes are more stable than analogous λ 3 - bromanes and λ 3 [10, 11] -chloranes.

15 Introduction 2 L antibonding : Ar I nonbonding : L bonding L I L Figure 1: Molecular orbital scheme for the three centre-four electron bond in the IL 2 group. For the designation of hypervalent compounds the Martin Arduengo [N-X-L] notation is usually used [12], in which N is the number of valence electrons surrounding the central atom X and L is the number of ligands bonded to the X-atom. According to this designation, six structural types of polyvalent iodine species (1 6) are the most common. The first two species, 8-I-2 (1) and 10-I-3 (2), called λ 3 -iodanes, are conventionally considered as derivatives of iodine(iii), whereas the next two, 10-I-4 (3) and 12-I-5 (4) λ 5 -iodanes, represent the most typical structural types of pentavalent iodine. [13].. L L L O L : L L L L L L L I R I : I I I L I.. L L : L L L L L L L L L.. L L 8-I-2 10-I-3 10-I-4 12-I-5 14-I-6 14-I Species 1 4 are common in organic chemistry. The 10-I-3 species have an approximately T- shaped structure with a collinear arrangement of the most electronegative ligands. Including the free electron pairs, the ψ-geometry of iodine is a distorted trigonal bipyramide. 8-I-2 species (iodonium cations) (1) are usually considered as cationic part of salts with pseudotetrahedral geometry of the central I-atom. Caused by the positive partial charge on iodine and the open moiety of iodine, additional contacts to basic sites of the anion are observed. [14, 15] The I-C distances in both species 1 and 2 are approximately equal to the sum of the covalent radii of iodine and carbon, ranging generally from 2.00 to 2.10 Å. Compounds of iodine(iii) with one carbon ligand are represented by organic iodosyl compounds (RIO, where R is usually aryl) and their derivatives (RIX 2, where X represents an electronegative ligand). The second iodine(iii) class with two carbon ligands on iodine includes various iodonium salts (R 2 I + X ). The overwhelming majority of known, stable organic compounds of polyvalent iodine belong to these two classes. The two heteroatom ligands X attached to iodine in RIX 2 are commonly represented by fluorine, chlorine, O-, N-, and strongly electronegative C-substituents. In general, only RIX 2 derivatives bearing the

16 Introduction 3 [13, 14] most electronegative substituents X are sufficiently stable. The bonding in iodine(v) compounds containing divalent ligands such as oxygen may also be described in terms of hypervalency. Two singly occupied atomic orbitals of oxygen interact with a doubly occupied 5p orbital of iodine forming three molecular orbitals: one bonding (doubly occupied), one nonbonding localised on oxygen (doubly occupied), and one antibonding (unoccupied). The result is a highly polarised I O bond with considerable positive partial charge on iodine and negative partial charge on oxygen. Such hypervalent bonds are designated as 2c 4e bonds (fig. 2). [11] On the other hand, compounds of the IOL 3 type are constructed from three different bonds. In PhIOF 2 there is one 2c 2e I C bond, one 3c 4e IF 2 bond, and one 2c 4e I O bond. [16] C... O. : I C O.... I : ψ 3 antibonding ψ 2 ψ 1 nonbonding bonding I O Figure 2: The molecular orbital scheme for the hypervalent 2c-4e I-O bond. The bonding in iodine(v) compounds, IL 5, with a square pyramidal structure may be described in terms of one 2c 2e bond between iodine and the ligand in the apical position, trans to the lone pair, and two orthogonal, hypervalent 3c 4e bonds, accommodating four [17, 18a] ligands. Aryl-λ 5 -iodanes ArIL 4 have a square pyramidal structure with the aryl group in the apical position and four ligands in basal positions. L L Ar I..: L L A very high fugalibility (leaving group ability) of iodanyl groups (λ 1 ) is among the most

17 Introduction 4 important features of iodonium salts, often describes as λ 3 -iodanes [18b], which makes it possible to generate highly reactive species such as carbenes, nitrenes, cations, and arynes under mild conditions. Furthermore λ 3 -iodanes, RIX 2, are suitable oxidizing agents and allow the transformation of a wide range of functionalities such as alcohols, amines, sulfides, alkenes, alkynes, and carbonyl groups. [10] 1.2 (Difluoroiodo)arenes Actually (difluoroiodo)arenes have received a widespread practical application in organic synthesis as versatile fluorination reagents. Generally, they are more reactive than the analogous bromides and chlorides. [19] There is a considerable number of different methods of synthesis for this widely applied class. [20] (Difluoroiodo)arenes were synthesised for the first time by Dimroth and Bockemüller from iodosylbenzenes and 40 % aqueous hydrogen fluoride as impure products in 1931: [21] ArIO + 2 HF K[HF 2 ] CHCl 3 ArIF 2 + H 2 O Garvey, Halley, and Allen used a mixture of 46 % aqueous HF and glacial acetic acid: [22] (1) ArIO + 2 HF / CH 3 CO 2 H ArIF 2 + H 2 O (2) In 1966, Carpenter reported a method, which can be described as chlorine-fluorine substitution on (dichloroiodo)arene using HF in the presence of mercury(ii) oxide: [23] ArICl HF / HgO ArIF 2 + HgCl 2 + H 2 O (3) The isolation of readily hydrolysible (difluoroiodo)arenes is the mean problem in all above mentioned methods owing to the fact that the reaction mixture contains water. To overcome this disadvantage, Schmidt and Meinert proposed the electrochemical oxidation of iodoarenes in acetonitrile solution in the presence of silver fluoride as supporting electrolyte and fluoride source giving the pure (difluoroiodo)arenes. [24] For a high yield the electrochemical preparation of para-substituted (difluoroiodo)arenes [25, 26] Et 3 N n HF was recently used as reagent. Moreover, (difluoroiodo)arenes are formed readily when the corresponding iodosyl or bis(trifluoracetoxy)iodoarenes are treated with sulfur tetrafluorid at 20 C. [27] All the by-

18 Introduction 5 products in this reaction are volatile and can be removed by evaporation. (Difluoroiodo)arenes are afforded in high purity: ArIO + SF 4-20 C ArIF 2 + SOF 2 (4) ArI(O 2 CCF 3 ) SF 4-20 C ArIF SOF CF 3 COF (5) Schmeißer reported for the first time the oxidative addition of fluorine to C 6 F 5 I. C 6 F 5 IF 2 was [28, 29] obtained by using elemental fluorine at low temperature: -100 C Ar f I + F 2 CCl 3 F Ar f IF 2 (6) Xenon difluoride was also used to obtain (difluoroiodo)arenes: [30] ArI + XeF C ArIF 2 + Xe (7) The fluorination of various iodoarenes with elemental fluorine, diluted with nitrogen to avoid the fluorination of the aromatic ring which contained donating substituents, have been [31, 32] published: -100 C ArI + F 2 CCl 3 F ArIF 2 (8) A modified three step method for preparing (difluoroiodo)arenes from iodoarenes in a pure form was reported parallel to this work. (Dichloroiodo)arenes were prepared by the reaction of iodoarenes with chlorine gas (eq. 9). The products were hydrolysed to form the corresponding iodosylarenes (eq. 10), which were treated after purification with 46 % aqueous HF to produce (difluoroiodo)arenes (eq. 11): [33] ArI + Cl 2 ArICl NaOH ArIO + 2 HF ArICl 2 ArIO + H 2 O + 2 NaCl ArIF 2 + H 2 O (9) (10) (11)

19 Introduction (Tetrafluoroiodo)arenes and (Difluorooxoiodo)arenes (Tetrafluoroiodo)arenes The chemistry of iodine(v) compounds or λ 5 -iodanes is substantially less developed in comparison with the chemistry of I(III). Recently there has been an increasing interest in I(V) especially in their fluorinated compounds. [34] Iodine(V) compounds may have the general formula IL 5, IZL 3, and IZ 2 L where L is a monovalent and Z a divalent ligand. The bonding system of IL 5 can be described in terms of one 2c 2e bond I L apical and two orthogonal 3c 4e bonds, accommodating the basal IF 2 subunits. In the case of RIF 4, the R-ligand is placed in [19, 35] the apical position. The oxidative fluorination of organoiodides can be used to prepare (tetrafluoroiodo)arenes (RIF 4 ). This method produces very often RIF 4 in mixtures with (difluoroiodo)arenes, and their separation is difficult. The first reported method for the preparation of ArIF 4 used the fluorination of ArI by nitrogen-diluted F 2 in CCl 3 F. In the first step ArI reacts with F 2 at 100 C giving slightly soluble ArIF 2 in CCl 3 F, which can - as far as dissolved - further interact with F 2 at 40 C and form ArIF 4. [36-38] Fluorination of iodoarenes with an excess of one of the following fluorinating agents XeF 2, ClF 3, BrF 3, BrF 5, C 6 F 5 BrF 2 and C 6 F 5 BrF 4 led to the corresponding (tetrafluoroiodo)arene compounds: [27, 30, 37, 39 41] C 3 ArI + 4 ClF 3 3 ArIF Cl 2 (12) Another approach to ArIF 4 preferentially developed for aryl groups with electronwithdrawing substituents is the nucleophilic substitution on IF 5. Arylsilanes and arylmetal [19a, 42 46] compounds of thalium, lead, bismuth, and cadmium have been used: PhSiF 3 + IF Py PhIF 4 + SiF 4 2 Py (13) Si(C 6 F 5 ) IF Py 4 C 6 F 5 IF 4 + SiF 4 2 Py (14) Cd(C 6 F 5 ) IF 5 2 C 6 F 5 IF 4 + CdF 2 (15) Ar f IF 4 can be produced by electrophilic substitution using the highly electrophilic [IF 4 ] + cation [47a]. No Ar f IF 4 was formed by oxidative fluorination between iodoarenes Ar f I and IF 5 under non-acidic conditions: [47b]

20 Introduction 7 Ar f H + [IF 4 ] + Ar fif 4 + H + (16) (Tetrafluoroiodo)arenes were obtained in quantitive yield also by heating iodylarenes with [48, 49] sulphur tetrafluoride: ArIO SF 4 ArIF SOF 2 (17) (Difluorooxoiodo)arenes react in the same manner with SF 4, moreover their use is safer [27, 37, 45, 50] because they are less explosive than iodylarenes: ArIOF 2 + SF 4 ArIF 4 + SOF 2 (18) (Difluorooxoiodo)arenes (Difluorooxoiodo)arenes were obtained by dissolving iodylarenes in hot 40 % aqueous [51 53] hydrofluoric acid: ArIO HF ArIOF 2 + H 2 O (19) Alternative procedures are the reaction of (tetrafluoroiodo)arenes with equivalent amounts of hexamethylsiloxane (eq. 20) or simply with water (eq. 21) or iodylarenes (eq. 22): [49] ArIF 4 + ( (CH 3 ) 3 Si) 2 O ArIOF (CH 3 ) 3 SiF (20) ArIF 4 + H 2 O ArIOF HF (21) ArIF 4 + ArIO 2 2 ArIOF 2 (22) 1.4 Iodine Pentafluoride Iodine pentafluoride, IF 5, is the only known binary interhalogen compound of iodine(v). Iodine pentafluoride is a colourless liquid with a melting point of 9.6 C and a boiling point of 98 C.

21 Introduction 8 Iodine pentafluoride is a versatile and well-known fluorinating agent. It can be used, for example, to prepare fluorohydrocarbons and fluoroalkyl sulfides, to form adducts with oxides of nitrogen and to convert metals to fluorides. [56] IF 5 was first prepared in 1862 by heating of iodine with silver fluoride: [54] 3 I AgF IF AgI (23) Thirty years later, Moissan reported the direct synthesis using iodine and elemental fluorine. [55] It has been found that iodine(v) fluoride can be prepared by reacting iodine oxygen compounds with sulfur tetrafluoride. Such I-O starting materials are iodine oxides (I 2 O 5 ), alkali metal iodates (NaIO 3, KIO 3 ) and alkaline earth metal iodates (Mg(IO 3 ) 2, Ca(IO 3 ) 2, Ba(IO 3 ) 2 ). The reactants must be used in anhydrous form, because water reacts as well with sulfur tetrafluoride as with iodine pentafluoride: [56] I 2 O SF 4 2IF SOF 2 (24) In 1963, Fawcett reported a new method of preparing iodine pentafluoride by fluorinating anhydrous iodine pentaoxide (I 2 O 5 ) with pure carbonyl fluoride at high temperature: [57] I 2 O COF 2 2IF CO 2 (25) The reaction between iodine and fluorine is primarily a heterogeneous solid-gas reaction. Because of the high reaction enthalpy iodine sublimates and reacts instantaneously with fluorine in the gas phase. At a temperature above 250 C IF 7 becomes the favoured product. Therefore it is useful in the direct synthesis of IF 5 to look for homogeneous and moderate temperature conditions. Principally the presence of an inert solvent may be useful. In the technical process IF 5 itself is used as slightly dissolving medium for I 2 : [58] IF 5 as solvent I F 2 2 IF C (26) In a modified method molten iodine was reacted with gaseous fluorine at C (eq. [59, 60] 27):

AP Chemistry A. Allan Chapter 8 Notes - Bonding: General Concepts

AP Chemistry A. Allan Chapter 8 Notes - Bonding: General Concepts AP Chemistry A. Allan Chapter 8 Notes - Bonding: General Concepts 8.1 Types of Chemical Bonds A. Ionic Bonding 1. Electrons are transferred 2. Metals react with nonmetals 3. Ions paired have lower energy

More information

CHAPTER 6 Chemical Bonding

CHAPTER 6 Chemical Bonding CHAPTER 6 Chemical Bonding SECTION 1 Introduction to Chemical Bonding OBJECTIVES 1. Define Chemical bond. 2. Explain why most atoms form chemical bonds. 3. Describe ionic and covalent bonding.. 4. Explain

More information

S block elements p block elements and chemical bonding -1

S block elements p block elements and chemical bonding -1 S block elements p block elements and chemical bonding -1 1.Group I elements do not occur free (native state) in the nature because a. They are unstable b. Their compounds with other elements are highly

More information

Theme 3: Bonding and Molecular Structure. (Chapter 8)

Theme 3: Bonding and Molecular Structure. (Chapter 8) Theme 3: Bonding and Molecular Structure. (Chapter 8) End of Chapter questions: 5, 7, 9, 12, 15, 18, 23, 27, 28, 32, 33, 39, 43, 46, 67, 77 Chemical reaction valence electrons of atoms rearranged (lost,

More information

Chemistry Assessment Unit AS 1

Chemistry Assessment Unit AS 1 Centre Number 71 Candidate Number ADVANCED SUBSIDIARY (AS) General Certificate of Education January 2011 Chemistry Assessment Unit AS 1 assessing Basic Concepts in Physical and Inorganic Chemistry [AC111]

More information

Questions on Chapter 8 Basic Concepts of Chemical Bonding

Questions on Chapter 8 Basic Concepts of Chemical Bonding Questions on Chapter 8 Basic Concepts of Chemical Bonding Circle the Correct Answer: 1) Which ion below has a noble gas electron configuration? A) Li 2+ B) Be 2+ C) B2+ D) C2+ E) N 2-2) Of the ions below,

More information

Chapter 11. Chemical Bonds: The Formation of Compounds from Atoms

Chapter 11. Chemical Bonds: The Formation of Compounds from Atoms Chapter 11 Chemical Bonds: The Formation of Compounds from Atoms 1 11.1 Periodic Trends in atomic properties 11.1 Periodic Trends in atomic properties design of periodic table is based on observing properties

More information

In the box below, draw the Lewis electron-dot structure for the compound formed from magnesium and oxygen. [Include any charges or partial charges.

In the box below, draw the Lewis electron-dot structure for the compound formed from magnesium and oxygen. [Include any charges or partial charges. Name: 1) Which molecule is nonpolar and has a symmetrical shape? A) NH3 B) H2O C) HCl D) CH4 7222-1 - Page 1 2) When ammonium chloride crystals are dissolved in water, the temperature of the water decreases.

More information

Question 4.2: Write Lewis dot symbols for atoms of the following elements: Mg, Na, B, O, N, Br.

Question 4.2: Write Lewis dot symbols for atoms of the following elements: Mg, Na, B, O, N, Br. Question 4.1: Explain the formation of a chemical bond. A chemical bond is defined as an attractive force that holds the constituents (atoms, ions etc.) together in a chemical species. Various theories

More information

Chemistry Assessment Unit AS 1

Chemistry Assessment Unit AS 1 Centre Number 71 Candidate Number ADVANCED SUBSIDIARY (AS) General Certificate of Education January 2014 Chemistry Assessment Unit AS 1 assessing Basic Concepts in Physical and Inorganic Chemistry AC112

More information

CHAPTER NOTES CHAPTER 16. Covalent Bonding

CHAPTER NOTES CHAPTER 16. Covalent Bonding CHAPTER NOTES CHAPTER 16 Covalent Bonding Goals : To gain an understanding of : NOTES: 1. Valence electron and electron dot notation. 2. Stable electron configurations. 3. Covalent bonding. 4. Polarity

More information

Bonds. Bond Length. Forces that hold groups of atoms together and make them function as a unit. Bond Energy. Chapter 8. Bonding: General Concepts

Bonds. Bond Length. Forces that hold groups of atoms together and make them function as a unit. Bond Energy. Chapter 8. Bonding: General Concepts Bonds hapter 8 Bonding: General oncepts Forces that hold groups of atoms together and make them function as a unit. Bond Energy Bond Length It is the energy required to break a bond. The distance where

More information

Chapter 2 Polar Covalent Bonds: Acids and Bases

Chapter 2 Polar Covalent Bonds: Acids and Bases John E. McMurry www.cengage.com/chemistry/mcmurry Chapter 2 Polar Covalent Bonds: Acids and Bases Modified by Dr. Daniela R. Radu Why This Chapter? Description of basic ways chemists account for chemical

More information

Health Science Chemistry I CHEM-1180 Experiment No. 15 Molecular Models (Revised 05/22/2015)

Health Science Chemistry I CHEM-1180 Experiment No. 15 Molecular Models (Revised 05/22/2015) (Revised 05/22/2015) Introduction In the early 1900s, the chemist G. N. Lewis proposed that bonds between atoms consist of two electrons apiece and that most atoms are able to accommodate eight electrons

More information

pre -TEST Big Idea 2 Chapters 8, 9, 10

pre -TEST Big Idea 2 Chapters 8, 9, 10 Name: AP Chemistry Period: Date: R.F. Mandes, PhD, NBCT Complete each table with the appropriate information. Compound IMF Compound IMF 1 NiCl 3 7 ClCH 2 (CH 2 ) 3 CH 3 2 Fe 8 H 2 CF 2 3 Ar 9 H 2 NCH 2

More information

Sample Exercise 8.1 Magnitudes of Lattice Energies

Sample Exercise 8.1 Magnitudes of Lattice Energies Sample Exercise 8.1 Magnitudes of Lattice Energies Without consulting Table 8.2, arrange the ionic compounds NaF, CsI, and CaO in order of increasing lattice energy. Analyze From the formulas for three

More information

Copyright 2014 Edmentum - All rights reserved. Chemistry Chemical bonding, molecular structure and Gases Blizzard Bag 2014-2015

Copyright 2014 Edmentum - All rights reserved. Chemistry Chemical bonding, molecular structure and Gases Blizzard Bag 2014-2015 Copyright 2014 Edmentum - All rights reserved. Chemistry Chemical bonding, molecular structure and Gases Blizzard Bag 2014-2015 1. Which of the following is a unit of pressure? A. newton-meters per second

More information

SOME TOUGH COLLEGE PROBLEMS! .. : 4. How many electrons should be shown in the Lewis dot structure for carbon monoxide? N O O

SOME TOUGH COLLEGE PROBLEMS! .. : 4. How many electrons should be shown in the Lewis dot structure for carbon monoxide? N O O SME TUGH CLLEGE PRBLEMS! LEWIS DT STRUCTURES 1. An acceptable Lewis dot structure for 2 is (A) (B) (C) 2. Which molecule contains one unshared pair of valence electrons? (A) H 2 (B) H 3 (C) CH 4 acl 3.

More information

Candidate Style Answer

Candidate Style Answer Candidate Style Answer Chemistry A Unit F321 Atoms, Bonds and Groups High banded response This Support Material booklet is designed to accompany the OCR GCE Chemistry A Specimen Paper F321 for teaching

More information

Chapter 7. Comparing Ionic and Covalent Bonds. Ionic Bonds. Types of Bonds. Quick Review of Bond Types. Covalent Bonds

Chapter 7. Comparing Ionic and Covalent Bonds. Ionic Bonds. Types of Bonds. Quick Review of Bond Types. Covalent Bonds Comparing Ionic and Covalent Bonds Chapter 7 Covalent Bonds and Molecular Structure Intermolecular forces (much weaker than bonds) must be broken Ionic bonds must be broken 1 Ionic Bonds Covalent Bonds

More information

Chapter 6 Assessment. Name: Class: Date: ID: A. Multiple Choice Identify the choice that best completes the statement or answers the question.

Chapter 6 Assessment. Name: Class: Date: ID: A. Multiple Choice Identify the choice that best completes the statement or answers the question. Name: Class: Date: ID: A Chapter 6 Assessment Multiple Choice Identify the choice that best completes the statement or answers the question. 1. When an atom loses an electron, it forms a(n) a. anion. c.

More information

Start: 26e Used: 6e Step 4. Place the remaining valence electrons as lone pairs on the surrounding and central atoms.

Start: 26e Used: 6e Step 4. Place the remaining valence electrons as lone pairs on the surrounding and central atoms. Section 4.1: Types of Chemical Bonds Tutorial 1 Practice, page 200 1. (a) Lewis structure for NBr 3 : Step 1. The central atom for nitrogen tribromide is bromine. 1 N atom: 1(5e ) = 5e 3 Br atoms: 3(7e

More information

Chapter 8 Concepts of Chemical Bonding

Chapter 8 Concepts of Chemical Bonding Chapter 8 Concepts of Chemical Bonding Chemical Bonds Three types: Ionic Electrostatic attraction between ions Covalent Sharing of electrons Metallic Metal atoms bonded to several other atoms Ionic Bonding

More information

Chapter 5 Classification of Organic Compounds by Solubility

Chapter 5 Classification of Organic Compounds by Solubility Chapter 5 Classification of Organic Compounds by Solubility Deductions based upon interpretation of simple solubility tests can be extremely useful in organic structure determination. Both solubility and

More information

Chapter 1 The Atomic Nature of Matter

Chapter 1 The Atomic Nature of Matter Chapter 1 The Atomic Nature of Matter 6. Substances that cannot be decomposed into two or more simpler substances by chemical means are called a. pure substances. b. compounds. c. molecules. d. elements.

More information

Packet 4: Bonding. Play song: (One of Mrs. Stampfel s favorite songs)

Packet 4: Bonding. Play song:  (One of Mrs. Stampfel s favorite songs) Most atoms are not Packet 4: Bonding Atoms will, or share electrons in order to achieve a stable. Octet means that the atom has in its level. If an atom achieves a stable octet it will have the same electron

More information

ch9 and 10 practice test

ch9 and 10 practice test 1. Which of the following covalent bonds is the most polar (highest percent ionic character)? A. Al I B. Si I C. Al Cl D. Si Cl E. Si P 2. What is the hybridization of the central atom in ClO 3? A. sp

More information

Bonding in Elements and Compounds. Covalent

Bonding in Elements and Compounds. Covalent Bonding in Elements and Compounds Structure of solids, liquids and gases Types of bonding between atoms and molecules Ionic Covalent Metallic Many compounds between metals & nonmetals (salts), e.g. Na,

More information

Sample Exercise 8.1 Magnitudes of Lattice Energies

Sample Exercise 8.1 Magnitudes of Lattice Energies Sample Exercise 8.1 Magnitudes of Lattice Energies Without consulting Table 8.2, arrange the following ionic compounds in order of increasing lattice energy: NaF, CsI, and CaO. Analyze: From the formulas

More information

Assessment Schedule 2015 Chemistry: Demonstrate understanding of bonding, structure, properties and energy changes (91164)

Assessment Schedule 2015 Chemistry: Demonstrate understanding of bonding, structure, properties and energy changes (91164) NCEA Level 2 Chemistry (91164) 2015 page 1 of 7 Assessment Schedule 2015 Chemistry: Demonstrate understanding of bonding, structure, properties and energy changes (91164) Evidence Statement Q Evidence

More information

Self Assessment_Ochem I

Self Assessment_Ochem I UTID: 2013 Objective Test Section Identify the choice that best completes the statement or answers the question. There is only one correct answer; please carefully bubble your choice on the scantron sheet.

More information

Exam 2 Chemistry 65 Summer 2015. Score:

Exam 2 Chemistry 65 Summer 2015. Score: Name: Exam 2 Chemistry 65 Summer 2015 Score: Instructions: Clearly circle the one best answer 1. Valence electrons are electrons located A) in the outermost energy level of an atom. B) in the nucleus of

More information

Which substance contains positive ions immersed in a sea of mobile electrons? A) O2(s) B) Cu(s) C) CuO(s) D) SiO2(s)

Which substance contains positive ions immersed in a sea of mobile electrons? A) O2(s) B) Cu(s) C) CuO(s) D) SiO2(s) BONDING MIDTERM REVIEW 7546-1 - Page 1 1) Which substance contains positive ions immersed in a sea of mobile electrons? A) O2(s) B) Cu(s) C) CuO(s) D) SiO2(s) 2) The bond between hydrogen and oxygen in

More information

But in organic terms: Oxidation: loss of H 2 ; addition of O or O 2 ; addition of X 2 (halogens).

But in organic terms: Oxidation: loss of H 2 ; addition of O or O 2 ; addition of X 2 (halogens). Reactions of Alcohols Alcohols are versatile organic compounds since they undergo a wide variety of transformations the majority of which are either oxidation or reduction type reactions. Normally: Oxidation

More information

Solid Type of solid Type of particle

Solid Type of solid Type of particle QUESTION (2015:3) Complete the table below by stating the type of solid, the type of particle, and the attractive forces between the particles in each solid. Solid Type of solid Type of particle Cu(s)

More information

Carboxylic Acids When a carbonyl carbon also bears a hydroxyl group, then these compounds are appreciably acidic, and are called carboxylic acids.

Carboxylic Acids When a carbonyl carbon also bears a hydroxyl group, then these compounds are appreciably acidic, and are called carboxylic acids. Carboxylic Acids When a carbonyl carbon also bears a hydroxyl group, then these compounds are appreciably acidic, and are called carboxylic acids. R Carboxylic acids are classified according to the substituent

More information

Molecular Geometry and VSEPR We gratefully acknowledge Portland Community College for the use of this experiment.

Molecular Geometry and VSEPR We gratefully acknowledge Portland Community College for the use of this experiment. Molecular and VSEPR We gratefully acknowledge Portland ommunity ollege for the use of this experiment. Objectives To construct molecular models for covalently bonded atoms in molecules and polyatomic ions

More information

Chemistry. The student will be able to identify and apply basic safety procedures and identify basic equipment.

Chemistry. The student will be able to identify and apply basic safety procedures and identify basic equipment. Chemistry UNIT I: Introduction to Chemistry The student will be able to describe what chemistry is and its scope. a. Define chemistry. b. Explain that chemistry overlaps many other areas of science. The

More information

TRENDS IN ATOMIC PROPERTIES: THE PERIODIC TABLE

TRENDS IN ATOMIC PROPERTIES: THE PERIODIC TABLE TRENDS IN ATOMIC PROPERTIES: THE PERIODIC TABLE Electron configurations determine organization of the periodic table Next properties of elements and their periodic behavior Elemental properties determined

More information

Chapter 4: Structure and Properties of Ionic and Covalent Compounds

Chapter 4: Structure and Properties of Ionic and Covalent Compounds Chapter 4: Structure and Properties of Ionic and Covalent Compounds 4.1 Chemical Bonding o Chemical Bond - the force of attraction between any two atoms in a compound. o Interactions involving valence

More information

EXPERIMENT 17 : Lewis Dot Structure / VSEPR Theory

EXPERIMENT 17 : Lewis Dot Structure / VSEPR Theory EXPERIMENT 17 : Lewis Dot Structure / VSEPR Theory Materials: Molecular Model Kit INTRODUCTION Although it has recently become possible to image molecules and even atoms using a high-resolution microscope,

More information

The Periodic Table: Periodic trends

The Periodic Table: Periodic trends Unit 1 The Periodic Table: Periodic trends There are over one hundred different chemical elements. Some of these elements are familiar to you such as hydrogen, oxygen, nitrogen and carbon. Each one has

More information

CHAPTER 6 REVIEW. Chemical Bonding. Answer the following questions in the space provided.

CHAPTER 6 REVIEW. Chemical Bonding. Answer the following questions in the space provided. Name Date lass APTER 6 REVIEW hemical Bonding SETIN 1 SRT ANSWER Answer the following questions in the space provided. 1. a A chemical bond between atoms results from the attraction between the valence

More information

5. Which of the following subatomic particles are most important in determining the chemical reactivity and physical properties of an atom?

5. Which of the following subatomic particles are most important in determining the chemical reactivity and physical properties of an atom? 1. For the following compounds draw the Lewis Structure and determine: (a) The # of Bonding Pairs (b) The # of Lone pairs (c) The electron domain shape (d) The molecular shape (e) Hybridization (f) Whether

More information

A mutual electrical attraction between the nuclei and valence electrons of different atoms that binds the atoms together is called a(n)

A mutual electrical attraction between the nuclei and valence electrons of different atoms that binds the atoms together is called a(n) Chemistry I ATOMIC BONDING PRACTICE QUIZ Mr. Scott Select the best answer. 1) A mutual electrical attraction between the nuclei and valence electrons of different atoms that binds the atoms together is

More information

An alkyne is a hydrocarbon that contain a Carbon carbon triple bond. Acetylene, the simplest alkyne, widely used in industry for the synthesis of

An alkyne is a hydrocarbon that contain a Carbon carbon triple bond. Acetylene, the simplest alkyne, widely used in industry for the synthesis of Alkynes An alkyne is a hydrocarbon that contain a Carbon carbon triple bond. Acetylene, the simplest alkyne, widely used in industry for the synthesis of acetaldehyde, acetic acid, vinyl chloride O O H

More information

Exercises Topic 2: Molecules

Exercises Topic 2: Molecules hemistry for Biomedical Engineering. Exercises Topic 2 Authors: ors: Juan Baselga & María González Exercises Topic 2: Molecules 1. Using hybridization concepts and VSEPR model describe the molecular geometry

More information

Alkynes: An Introduction to Organic Synthesis

Alkynes: An Introduction to Organic Synthesis Alkynes: An Introduction to Organic Synthesis Alkynes Hydrocarbons that contain carbon-carbon triple bonds Acetylene, the simplest alkyne is produced industrially from methane and steam at high temperature

More information

CHAPTER 10: INTERMOLECULAR FORCES: THE UNIQUENESS OF WATER Problems: 10.2, 10.6,10.15-10.33, 10.35-10.40, 10.56-10.60, 10.101-10.

CHAPTER 10: INTERMOLECULAR FORCES: THE UNIQUENESS OF WATER Problems: 10.2, 10.6,10.15-10.33, 10.35-10.40, 10.56-10.60, 10.101-10. CHAPTER 10: INTERMOLECULAR FORCES: THE UNIQUENESS OF WATER Problems: 10.2, 10.6,10.15-10.33, 10.35-10.40, 10.56-10.60, 10.101-10.102 10.1 INTERACTIONS BETWEEN IONS Ion-ion Interactions and Lattice Energy

More information

IB Chemistry. DP Chemistry Review

IB Chemistry. DP Chemistry Review DP Chemistry Review Topic 1: Quantitative chemistry 1.1 The mole concept and Avogadro s constant Assessment statement Apply the mole concept to substances. Determine the number of particles and the amount

More information

CHEMISTRY BONDING REVIEW

CHEMISTRY BONDING REVIEW Answer the following questions. CHEMISTRY BONDING REVIEW 1. What are the three kinds of bonds which can form between atoms? The three types of Bonds are Covalent, Ionic and Metallic. Name Date Block 2.

More information

Chapter 2 Polar Covalent Bonds; Acids and Bases

Chapter 2 Polar Covalent Bonds; Acids and Bases John E. McMurry http://www.cengage.com/chemistry/mcmurry Chapter 2 Polar Covalent Bonds; Acids and Bases Javier E. Horta, M.D., Ph.D. University of Massachusetts Lowell Polar Covalent Bonds: Electronegativity

More information

Chemistry 151 Final Exam

Chemistry 151 Final Exam Chemistry 151 Final Exam Name: SSN: Exam Rules & Guidelines Show your work. No credit will be given for an answer unless your work is shown. Indicate your answer with a box or a circle. All paperwork must

More information

Bonding Practice Problems

Bonding Practice Problems NAME 1. When compared to H 2 S, H 2 O has a higher 8. Given the Lewis electron-dot diagram: boiling point because H 2 O contains stronger metallic bonds covalent bonds ionic bonds hydrogen bonds 2. Which

More information

Lab Manual Supplement

Lab Manual Supplement Objectives 1. Learn about the structures of covalent compounds and polyatomic ions. 2. Draw Lewis structures based on valence electrons and the octet rule. 3. Construct 3-dimensional models of molecules

More information

A pure covalent bond is an equal sharing of shared electron pair(s) in a bond. A polar covalent bond is an unequal sharing.

A pure covalent bond is an equal sharing of shared electron pair(s) in a bond. A polar covalent bond is an unequal sharing. CHAPTER EIGHT BNDING: GENERAL CNCEPT or Review 1. Electronegativity is the ability of an atom in a molecule to attract electrons to itself. Electronegativity is a bonding term. Electron affinity is the

More information

Bonding & Molecular Shape Ron Robertson

Bonding & Molecular Shape Ron Robertson Bonding & Molecular Shape Ron Robertson r2 n:\files\courses\1110-20\2010 possible slides for web\00bondingtrans.doc The Nature of Bonding Types 1. Ionic 2. Covalent 3. Metallic 4. Coordinate covalent Driving

More information

INTERMOLECULAR FORCES

INTERMOLECULAR FORCES INTERMOLECULAR FORCES Intermolecular forces- forces of attraction and repulsion between molecules that hold molecules, ions, and atoms together. Intramolecular - forces of chemical bonds within a molecule

More information

Lecture 22 The Acid-Base Character of Oxides and Hydroxides in Aqueous Solution

Lecture 22 The Acid-Base Character of Oxides and Hydroxides in Aqueous Solution 2P32 Principles of Inorganic Chemistry Dr. M. Pilkington Lecture 22 The Acid-Base Character of Oxides and Hydroxides in Aqueous Solution Oxides; acidic, basic, amphoteric Classification of oxides - oxide

More information

7.4. Using the Bohr Theory KNOW? Using the Bohr Theory to Describe Atoms and Ions

7.4. Using the Bohr Theory KNOW? Using the Bohr Theory to Describe Atoms and Ions 7.4 Using the Bohr Theory LEARNING TIP Models such as Figures 1 to 4, on pages 218 and 219, help you visualize scientific explanations. As you examine Figures 1 to 4, look back and forth between the diagrams

More information

Chemistry Workbook 2: Problems For Exam 2

Chemistry Workbook 2: Problems For Exam 2 Chem 1A Dr. White Updated /5/1 1 Chemistry Workbook 2: Problems For Exam 2 Section 2-1: Covalent Bonding 1. On a potential energy diagram, the most stable state has the highest/lowest potential energy.

More information

Writing a Correct Mechanism

Writing a Correct Mechanism Chapter 2 1) Balancing Equations Writing a Correct Mechanism 2) Using Arrows to show Electron Movement 3) Mechanisms in Acidic and Basic Media 4) Electron rich Species: Nucleophile or Base? 5) Trimolecular

More information

2C Intermolecular forces, structure and properties:

2C Intermolecular forces, structure and properties: Electronegativity and polarity Polar and non-polar bonds: 1) Non-Polar bonds: 2C Intermolecular forces, structure and properties: A covalent bond shares an electron pair: In a hydrogen molecule, the electrons

More information

EXPERIMENT 9 Dot Structures and Geometries of Molecules

EXPERIMENT 9 Dot Structures and Geometries of Molecules EXPERIMENT 9 Dot Structures and Geometries of Molecules INTRODUCTION Lewis dot structures are our first tier in drawing molecules and representing bonds between the atoms. The method was first published

More information

Chapter 13 - LIQUIDS AND SOLIDS

Chapter 13 - LIQUIDS AND SOLIDS Chapter 13 - LIQUIDS AND SOLIDS Problems to try at end of chapter: Answers in Appendix I: 1,3,5,7b,9b,15,17,23,25,29,31,33,45,49,51,53,61 13.1 Properties of Liquids 1. Liquids take the shape of their container,

More information

A REVIEW OF GENERAL CHEMISTRY: ELECTRONS, BONDS AND MOLECULAR PROPERTIES

A REVIEW OF GENERAL CHEMISTRY: ELECTRONS, BONDS AND MOLECULAR PROPERTIES A REVIEW OF GENERAL CEMISTRY: ELECTRONS, BONDS AND MOLECULAR PROPERTIES A STUDENT SOULD BE ABLE TO: 1. Draw Lewis (electron dot and line) structural formulas for simple compounds and ions from molecular

More information

Chapter 2 The Chemical Context of Life

Chapter 2 The Chemical Context of Life Chapter 2 The Chemical Context of Life Multiple-Choice Questions 1) About 25 of the 92 natural elements are known to be essential to life. Which four of these 25 elements make up approximately 96% of living

More information

Name: Class: Date: 2 4 (aq)

Name: Class: Date: 2 4 (aq) Name: Class: Date: Unit 4 Practice Test Multiple Choice Identify the choice that best completes the statement or answers the question. 1) The balanced molecular equation for complete neutralization of

More information

Brønsted-Lowry Acids and Bases

Brønsted-Lowry Acids and Bases Brønsted-Lowry Acids and Bases 1 According to Brønsted and Lowry, an acid-base reaction is defined in terms of a proton transfer. By this definition, the reaction of Cl in water is: Cl(aq) + Cl (aq) +

More information

Periodic Table Questions

Periodic Table Questions Periodic Table Questions 1. The elements characterized as nonmetals are located in the periodic table at the (1) far left; (2) bottom; (3) center; (4) top right. 2. An element that is a liquid at STP is

More information

Chem101: General Chemistry Lecture 9 Acids and Bases

Chem101: General Chemistry Lecture 9 Acids and Bases : General Chemistry Lecture 9 Acids and Bases I. Introduction A. In chemistry, and particularly biochemistry, water is the most common solvent 1. In studying acids and bases we are going to see that water

More information

BRØNSTED ACIDS & BASES

BRØNSTED ACIDS & BASES ACIDS & BASES BRØNSTED ACIDS & BASES BRØNSTED ACIDS & BASES Brønsted acids are proton donors. Brønsted bases are proton acceptors. Amphoteric species can act as either an acid or a base, depending on the

More information

7. 2. KOH (you need an acid or a base, this is a base) 8. 1. 76. All gold atoms have 79 protons and electrons, this is a +3 cation.

7. 2. KOH (you need an acid or a base, this is a base) 8. 1. 76. All gold atoms have 79 protons and electrons, this is a +3 cation. IB/SL Chemistry Name ANSWERS Test; Past Chemistry Regents Exams Most Frequently Missed Questions 1. 1. A HIGH PROBABLITY OF FINDING AN ELECTRON 2. 3. +8 (every atom of oxygen in the universe) 3. 2. LOW

More information

Covalent Bonding & Molecular Compounds Multiple Choice Review PSI Chemistry

Covalent Bonding & Molecular Compounds Multiple Choice Review PSI Chemistry Covalent Bonding & Molecular Compounds Multiple Choice Review PSI Chemistry Name 1) Which pair of elements is most apt to form a molecular compound with each other? A) aluminum, oxygen B) magnesium, iodine

More information

Question Bank Electrolysis

Question Bank Electrolysis Question Bank Electrolysis 1. (a) What do you understand by the terms (i) electrolytes (ii) non-electrolytes? (b) Arrange electrolytes and non-electrolytes from the following substances (i) sugar solution

More information

H 2O gas: molecules are very far apart

H 2O gas: molecules are very far apart Non-Covalent Molecular Forces 2/27/06 3/1/06 How does this reaction occur: H 2 O (liquid) H 2 O (gas)? Add energy H 2O gas: molecules are very far apart H 2O liquid: bonding between molecules Use heat

More information

EXPERIMENT 1: Survival Organic Chemistry: Molecular Models

EXPERIMENT 1: Survival Organic Chemistry: Molecular Models EXPERIMENT 1: Survival Organic Chemistry: Molecular Models Introduction: The goal in this laboratory experience is for you to easily and quickly move between empirical formulas, molecular formulas, condensed

More information

5s Solubility & Conductivity

5s Solubility & Conductivity 5s Solubility & Conductivity OBJECTIVES To explore the relationship between the structures of common household substances and the kinds of solvents in which they dissolve. To demonstrate the ionic nature

More information

Electrophilic Aromatic Substitution

Electrophilic Aromatic Substitution Electrophilic Aromatic Substitution Electrophilic substitution is the typical reaction type for aromatic rings. Generalized electrophilic aromatic substitution: E E Electrophile Lewis acid: may be or neutral.

More information

(1) e.g. H hydrogen that has lost 1 electron c. anion - negatively charged atoms that gain electrons 16-2. (1) e.g. HCO 3 bicarbonate anion

(1) e.g. H hydrogen that has lost 1 electron c. anion - negatively charged atoms that gain electrons 16-2. (1) e.g. HCO 3 bicarbonate anion GS106 Chemical Bonds and Chemistry of Water c:wou:gs106:sp2002:chem.wpd I. Introduction A. Hierarchy of chemical substances 1. atoms of elements - smallest particles of matter with unique physical and

More information

Chemistry Notes for class 12 Chapter 13 Amines

Chemistry Notes for class 12 Chapter 13 Amines 1 P a g e Chemistry Notes for class 12 Chapter 13 Amines Amines constitute an important class of organic compounds derived by replacing one or more hydrogen atoms ofnh 3 molecule by alkyl/aryl group(s).

More information

Sharing of Electrons. Covalent Bonding Chapter 8. Ch. 8 Vocabulary OBJECTIVES. Exothermic Reaction Structural Formula (Ch. 8.3) Polar Covalent Bond

Sharing of Electrons. Covalent Bonding Chapter 8. Ch. 8 Vocabulary OBJECTIVES. Exothermic Reaction Structural Formula (Ch. 8.3) Polar Covalent Bond Ch. 8 Vocabulary 2 Covalent Bonding Chapter 8 Covalent bond Molecule Lewis Structure Sigma bond Pi bond Bond Dissociation Energy Endothermic Reaction Exothermic Reaction Structural Formula (Ch. 8.3) Polar

More information

Nucleophilic Substitution and Elimination

Nucleophilic Substitution and Elimination Nucleophilic Substitution and Elimination What does the term "nucleophilic substitution" imply? A nucleophile is an the electron rich species that will react with an electron poor species A substitution

More information

The elements of the second row fulfill the octet rule by sharing eight electrons, thus acquiring the electronic configuration of neon, the noble gas o

The elements of the second row fulfill the octet rule by sharing eight electrons, thus acquiring the electronic configuration of neon, the noble gas o 2. VALENT BNDING, TET RULE, PLARITY, AND BASI TYPES F FRMULAS LEARNING BJETIVES To introduce the basic principles of covalent bonding, different types of molecular representations, bond polarity and its

More information

Chapter 8: Chemical Equations and Reactions

Chapter 8: Chemical Equations and Reactions Chapter 8: Chemical Equations and Reactions I. Describing Chemical Reactions A. A chemical reaction is the process by which one or more substances are changed into one or more different substances. A chemical

More information

Acids and Bases: A Brief Review

Acids and Bases: A Brief Review Acids and : A Brief Review Acids: taste sour and cause dyes to change color. : taste bitter and feel soapy. Arrhenius: acids increase [H ] bases increase [OH ] in solution. Arrhenius: acid base salt water.

More information

It does not react N.R.

It does not react N.R. Benzene versus yclohexene versus yclohexadiene 1 l l cyclohexene l l cyclohexadiene l Expect this to react similarly "cyclohexatriene" It does not react l N.R. benzene Benzene is resonance stabilized,

More information

CHEM 1301 SECOND TEST REVIEW. Covalent bonds are sharing of electrons (ALWAYS valence electrons). Use Lewis structures to show this sharing.

CHEM 1301 SECOND TEST REVIEW. Covalent bonds are sharing of electrons (ALWAYS valence electrons). Use Lewis structures to show this sharing. CEM 1301 SECOND TEST REVIEW Lewis Structures Covalent bonds are sharing of electrons (ALWAYS valence electrons). Use Lewis structures to show this sharing. Rules OCTET RULE an atom would like to have 8

More information

Since we will be dealing with aqueous acid and base solution, first we must examine the behavior of water.

Since we will be dealing with aqueous acid and base solution, first we must examine the behavior of water. Acids and Bases Know the definition of Arrhenius, Bronsted-Lowry, and Lewis acid and base. Autoionization of Water Since we will be dealing with aqueous acid and base solution, first we must examine the

More information

Name: Class: Date: 3) The bond angles marked a, b, and c in the molecule below are about,, and, respectively.

Name: Class: Date: 3) The bond angles marked a, b, and c in the molecule below are about,, and, respectively. Name: Class: Date: Unit 9 Practice Multiple Choice Identify the choice that best completes the statement or answers the question. 1) The basis of the VSEPR model of molecular bonding is. A) regions of

More information

Chapter 16 Acid-Base Equilibria

Chapter 16 Acid-Base Equilibria Chapter 16 Acid-Base Equilibria Learning goals and key skills: Understand the nature of the hydrated proton, represented as either H + (aq) or H 3 O + (aq) Define and identify Arrhenuis acids and bases.

More information

Type of Chemical Bonds

Type of Chemical Bonds Type of Chemical Bonds Covalent bond Polar Covalent bond Ionic bond Hydrogen bond Metallic bond Van der Waals bonds. Covalent Bonds Covalent bond: bond in which one or more pairs of electrons are shared

More information

UNIT TEST Atomic & Molecular Structure. Name: Date:

UNIT TEST Atomic & Molecular Structure. Name: Date: SCH4U UNIT TEST Atomic & Molecular Structure Name: _ Date: Part A - Multiple Choice Identify the letter of the choice that best completes the statement or answers the question. 1. Who postulated that electrons

More information

Chemistry B2A Chapter 12 Chemical Bonding

Chemistry B2A Chapter 12 Chemical Bonding Chemistry B2A Chapter 12 Chemical Bonding Octet rule-duet role: when undergoing chemical reaction, atoms of group 1A-7A elements tend to gain, lose, or share sufficient electrons to achieve an electron

More information

Ionic and Metallic Bonding

Ionic and Metallic Bonding Ionic and Metallic Bonding BNDING AND INTERACTINS 71 Ions For students using the Foundation edition, assign problems 1, 3 5, 7 12, 14, 15, 18 20 Essential Understanding Ions form when atoms gain or lose

More information

Lewis Dot Notation Ionic Bonds Covalent Bonds Polar Covalent Bonds Lewis Dot Notation Revisited Resonance

Lewis Dot Notation Ionic Bonds Covalent Bonds Polar Covalent Bonds Lewis Dot Notation Revisited Resonance Lewis Dot Notation Ionic Bonds Covalent Bonds Polar Covalent Bonds Lewis Dot Notation Revisited Resonance Lewis Dot notation is a way of describing the outer shell (also called the valence shell) of an

More information

Protonation. favored H 3 O + R O O H

Protonation. favored H 3 O + R O O H arboxylic Acids arboxylic acids have one property that distinguishes them from most other organic compounds they re acidic. Now not as acidic as fuming sulfuric acid, but still pretty darned acidic. The

More information

B) atomic number C) both the solid and the liquid phase D) Au C) Sn, Si, C A) metal C) O, S, Se C) In D) tin D) methane D) bismuth B) Group 2 metal

B) atomic number C) both the solid and the liquid phase D) Au C) Sn, Si, C A) metal C) O, S, Se C) In D) tin D) methane D) bismuth B) Group 2 metal 1. The elements on the Periodic Table are arranged in order of increasing A) atomic mass B) atomic number C) molar mass D) oxidation number 2. Which list of elements consists of a metal, a metalloid, and

More information

Chemical Reactions in Water Ron Robertson

Chemical Reactions in Water Ron Robertson Chemical Reactions in Water Ron Robertson r2 f:\files\courses\1110-20\2010 possible slides for web\waterchemtrans.doc Properties of Compounds in Water Electrolytes and nonelectrolytes Water soluble compounds

More information

CHEMISTRY STANDARDS BASED RUBRIC ATOMIC STRUCTURE AND BONDING

CHEMISTRY STANDARDS BASED RUBRIC ATOMIC STRUCTURE AND BONDING CHEMISTRY STANDARDS BASED RUBRIC ATOMIC STRUCTURE AND BONDING Essential Standard: STUDENTS WILL UNDERSTAND THAT THE PROPERTIES OF MATTER AND THEIR INTERACTIONS ARE A CONSEQUENCE OF THE STRUCTURE OF MATTER,

More information