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  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.),  while partial negative charge on both apical heteroatom ligands (L = F: ca. 0.5 a.u.).  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 , 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. .. 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).  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.  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.  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.  There is a considerable number of different methods of synthesis for this widely applied class.  (Difluoroiodo)arenes were synthesised for the first time by Dimroth and Bockemüller from iodosylbenzenes and 40 % aqueous hydrogen fluoride as impure products in 1931:  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:  (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:  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.  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.  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:  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):  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.  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):  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.  IF 5 was first prepared in 1862 by heating of iodine with silver fluoride:  3 I AgF IF AgI (23) Thirty years later, Moissan reported the direct synthesis using iodine and elemental fluorine.  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:  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:  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 :  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 8.1 Types of Chemical Bonds A. Ionic Bonding 1. Electrons are transferred 2. Metals react with nonmetals 3. Ions paired have lower energy
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
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
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,
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]
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
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.
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
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
Name: Thursday, February 14, 2008 Test 8: Review Questions 1. Based on bond type, which compound has the highest melting point? 1. CH OH 3. CaCl 3 2 2. C H 4. CCl 6 14 4 2. Which compound contains ionic
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
1. If the electronegativity difference between the elements in compound NaX is 2.1, what is element X? bromine fluorine chlorine oxygen 2. Which bond has the greatest degree of ionic character? H Cl Cl
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
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
1. Balance the following equation. What is the sum of the coefficients of the reactants and products? 1 Fe 2 O 3 (s) + _3 C(s) 2 Fe(s) + _3 CO(g) a) 5 b) 6 c) 7 d) 8 e) 9 2. Which of the following equations
Class: Date: Chapter 9-10 practice test Multiple Choice Identify the choice that best completes the statement or answers the question. 1. Which one of the following is most likely to be an ionic compound?
(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
EXAM 4 CH101.004 (Blackstock) November 30, 2006 Student name (print): honor pledge: 1. Which of these choices is the general electron configuration for the outermost electrons of elements in the alkaline
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
INTRODUCTORY CHEMISTRY Concepts and Critical Thinking Sixth Edition by Charles H. Corwin Chapter 13 Liquids and Solids by Christopher Hamaker 1 Chapter 13 Properties of Liquids Unlike gases, liquids do
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
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
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.
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.
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
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
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
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.
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
Chapter 8 Basic Concepts of Chemical Bonding Why do TiCl 4 and TiCl 3 have different colors?... different chemical properties?... different physical states? Chemical Bonding and Properties Difference in
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
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
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
1 Lewis Structures. Sections 3.3-3.7 Learning goals: (1) Writing valid Lewis structures for the constitutional structure of molecular substances for a given composition. (2) Predicting molecular geometry
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
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
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
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,
Name: Intermolecular Forces Practice Exam Date: 1. At STP, fluorine is a gas and bromine is a liquid because, compared to fluorine, bromine has 1) stronger covalent bonds 2) stronger intermolecular forces
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.
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
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
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
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
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
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
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,
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
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
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
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
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
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
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
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
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
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
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
Question Bank Periodic Table and Periodic Properties 1. Name the following with reference to the elements of Modern Periodic Table. (1 26) (a) An alkali metal in period 2. Ans. Lithium (b) A halogen in
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
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
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
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.
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
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
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
: 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
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
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
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
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.
VSEPR Theory, Valence Bond Theory, Characteristic of Covalent Compounds. VSEPR theory was proposed by Gillespie and Nyholm to explain the shapes of molecules and ions.. The orbital which contains the bonded
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
Models Models are attempts to explain how nature operates on the microscopic level based on experiences in the macroscopic world. Fundamental Properties of Models A model does not equal reality. Models
COVALENT BONDING [MH5; Chapter 7] Covalent bonds occur when electrons are equally shared between two atoms. The electrons are not always equally shared by both atoms; these bonds are said to be polar covalent.
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
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
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
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
Benzene 1 NT 87 90 ompound 87 has the formula 6 6, is known as benzene, and it is a hydrocarbon derived from petroleum distillates. Benzene is the parent compound for a class of compounds known as aromatic
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,
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
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.
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
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).
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
Name Date STUDY GUIDE CHAPTER 1 ATOMS AND ELEMENTS 1) DESCRIBE THE RUTHERFORD-BOHR ATOMIC MODEL All matter is made of small particles called atoms. An atom is the smallest unit of matter that retains the
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
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