VIBRATIONAL SPECTROSCOPIC STUDY OF TRANSITION

Transcription

1 VIBRATIONAL SPECTROSCOPIC STUDY OF TRANSITION AND RARE EARTH METAL COMPLEXES PhD Theses Written by: László Hajba chemical engineer Supervisor: Prof. Dr. János Mink full professor Made in the Environmental Sciences Doctoral School University of Pannonia Veszprém 2008

2 INTRODUCTION, AIMS Transition metal complexes are of great importance in basic research and in industrial processes as catalysts. Knowledge of the molecular structures and bonding properties are crucial in understanding the chemical behaviour of the complexes. Vibrational spectroscopy, i.e., infrared and Raman spectroscopy, play a major role together with X-ray diffraction in structure determination. Moreover, force constant calculations can provide additional information about the nature of the chemical bonds and the bond strengths. The infrared, far infrared and Raman spectra of several transition metal complexes (tetraacetato-complexes containing metal-metal bonds, metal-aqua complexes and metal carbonyl clusters) were recorded during this thesis work. Experimental difficulties in obtaining the far-infrared spectra and the technique used for the Raman spectroscopic measurements are described in the experimental section of the thesis. Raman microscopy proved to be invaluable, especially for the thermal- or photosensitive and fluorescent samples, since the sample size can be reduced drastically. The main aim of the research was to complete the existing spectroscopic data of the selected complexes, therefore new infrared and Raman spectra were recorded in all cases with modern infrared and Raman instrumentation (FT-IR, FT-FIR, FT-Raman, Raman microscope). Complete assignments of the vibrational spectra and force constant calculations were performed. Furthermore, a number of useful correlations have been established between the bonding parameters e.g. between bond length, stretching force constants, and stretching wavenumbers. 2

3 THESES I. Vibrational spectroscopy of dimetal-acetato complexes I/1. Complete assignment of the vibrational spectra was performed for the M 2 (O 2 CCH 3 ) 4 X 2 (M = Re(VII), Os(III)) type molecules and infrared and Raman spectra of the Re 2 (O 2 CCD 3 ) 4 Cl 2 deuterated species were recorded and studied for the first time. I/2. It was shown that the so-called diatomic and other simplified approximations in most cases overestimate the metal metal stretching force constants. Only the full normalcoordinate calculation (considering the full coordination sphere geometry) gives realistic force constants for the metal-metal stretching. I/3. It was shown that the metal metal bond strength increases as ReCl < ReBr < OsCl, while the metal oxygen stretching force constant values exhibit an opposite tendency. I/4. An empirical correlation was established between the metal-metal stretching wavenumbers and force constants. With the help of this correlation, the metal-metal stretching force constants can be predicted from the stretching wavenumbers for analogous Re-Re complexes (18 complexes). The predicted force constants correlate well with the result of the full normal coordinate calculations. The established correlations can be used also to predict the metal-metal bond lengths either from the metal-metal stretching wavenumbers or from the force constants. II. Vibrational spectroscopy of metal-aqua complexes II/1. Infrared, far-infrared and Raman spectra were measured for aqua-complexes in solid state and also in aqueous solution. The dominated literature Raman data were completed with the measured far-infrared wavenumbers to perform a full assignment of the vibrational spectra. II/2. On the basis of the full vibrational spectra normal coordinate calculations were performed for the aqua-complexes. Force constant calculations were carried out for several nonaaqua lanthanide species for the first time. II/3. For the M(OH 2 ) 2+/3+ 6 type complexes a satisfactory linear correlations were found between both the averaged metal oxygen stretching wavenumbers and force constants and the parameter Z 1/2 /R 2 0, which characterises the ion dipole moment interaction, where Z is the charge of the metal ion and R 0 the M O bond length. Better 3

4 correlations have been obtained with the parameter Z 1/2 /R 2 0 as there were published before due to our new results based on IR, FIR and Raman spectroscopic data. II/4. It was shown that the correlation between the Ln O stretching force constants and Ln O bond distances is lineary increasing with the increase in atomic number in the series of lanthanoide ions. It clearly displays the effect of the lanthanoide contraction in the series of hydrated ions. III. Vibrational spectroscopy of metal-carbonyl clusters III/1. Infrared, far-infrared and Raman spectra were recorded for several metal-carbonyl clusters. The assignments were completed with our measured new spectral data and the assignments for cluster frame vibrations published in the literature have been slightly modified. The full assignment of vibrational spectrum was performed for the Co 3 (CO) 9 (µ 3 -S) cluster for the first time. III/2. It was shown that the symmetry properties are clearly reflected by the vibrational spectra. In the case of the cobalt cluster with the bulky and planar pentafluoro-benzene ligand due to the lower symmetry (C S ), the degenerate stretching mode of the M 3 (trimetal) frame splits into a doublet. III/3. Force constant calculations were performed with different set of internal coordinates and with different types of geometric models for the cluster frame. It can be concluded that only the full normal coordinate calculations give more realistic force constants, but the calculations with a simplified model can also offer relevant structural information about metal-clusters with analogous structure. III/4. Based on the force constant calculations the following increasing order of bond strength can be set up for the sulphur containing metal clusters: Trends for metal-metal bonds: Co 3 S(CO) 9 < FeCo 2 S(CO) 9 < Co 3 S(CO) 8 (C 6 F 5 ) Trends for metal-sulphur bonds: Co 3 S(CO) 9 < Co 3 S(CO) 8 (C 6 F 5 ) < FeCo 2 S(CO) 9 The correlation between the calculated metal-metal force constants and the bond distances can be useful to predict the force constant from the bond distance in other analogous carbonyl clusters, or vice versa. 4

5 PUBLICATIONS RELATED TO THE DISSERTATION 1. F.E. Kühn, I.S. Gonçalves, A.D. Lopes, C.C. Romo, W. Wachter, J. Mink, L. Hajba, A.J. Parola, F. Pina, J. Sotomayor: Dirhenium Tetracarboxilato Complexes Linked by Cyano Bridges with Axial Metal Pentacarbonyl Ligands Syntesis and Characterisation European Journal of Inorganic Chemistry, (1999) J. Mink, Cs. Németh, L. Hajba, M. Sandström, P.L. Goggin: Infrared and Raman spectroscopic and theoretical studies of hexaaqua metal ions in aqueous solution Journal of Molecular Structure, 661, (2003) J. Mink, M.Y. Skripkin, L. Hajba, Cs. Németh, A. Abbasi, M. Sandström: Infrared and Raman spectroscopic and theoretical studies of nonaaqua complexes of trivalent rare earth metal ions Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 61 (7), (2005) L. Hajba, J. Mink, F.E. Kühn, I.S. Gonçalves: Raman and infrared spectroscopic and theoretical studies of dinuclear rhenium and osmium complexes, M 2 (O 2 CCH 3 ) 4 X 2 (M = Re, Os; X = Cl, Br) Inorganica Chimica Acta, 359, (2006) Hajba L., Bencze É., Tóth K., Kocsis L., Mink J., Markó L., Vastag S.: Vibrational Spectra and Force Constant Calculations of Cobalt Carbonyl Cluster Complexes Containing µ 3 -bridging Sulfur Journal of Raman Spectroscopy, (in preparation) OTHER PUBLICATIONS 6. L. Jánosi, T. Kégl, L. Hajba, Z. Berente, L. Kollár: Platinum complexes of (R)-N,N-bis(2-(diphenylphosphino)ethyl)-1-phenyl-ethylamine: their synthesis and characterisation Inorganica Chimica Acta, 316, (2001) D.K. Breitinger, H. -H. Belz, L. Hajba, V. Komlósi, J. Mink, G. Brehm, D. Colognesi, S.F. Parker, R.G. Schwab: Combined vibrational spectra of natural wardite Journal of Molecular Structure, 706 (1-3), (2004) E. Bellis, L. Hajba, B. Kovács, K. Sándor, L. Kollár, G. Kokotos: Three generations of,-diaminobutyric acid modified poly(propyleneimine) dendrimers and their cisplatin-type platinum complexes Journal of Biochemical and Biophysical Methods, 69 (1-2), (2006)

6 9. J. Mihály, S. Sterkel, H.M. Ortner, L. Kocsis, L. Hajba, É. Furdyga, J. Mink: FTIR and FT-Raman Spectroscopic Study on Polymer Based High Pressure Digestion Vessels Croatica Chemica Acta, 79, (2006) Mihály Judith, Mink János, Hajba László: Vértesszlsi, alsó paleolit korból származó állatcsontok vizsgálata FTIR és FT-Raman spektroszkópiai módszerekkel / FTIR and FT-Raman spectroscopical study of Lower Palaeolithic bones from Vértesszls Archeometriai Mhely, 2006/ L.V. Stepakova, M.Yu. Skripkin, L.V. Chernykh, G.L. Starova, L. Hajba, J. Mink, M. Sandström: Vibrational spectroscopic and force field studies of copper(ii) chloride and bromide compounds, and crystal structure of KCuBr 3 Journal of Raman Spectroscopy, 39 (1), (2008) F.Z. Zakaria, J. Mihály, I. Sajó, R. Katona, L. Hajba, F.A. Aziz, J. Mink: FT-Raman and FTIR spectroscopic characterization of biogenic carbonates from Philippine venus seashell and Porites sp. coral (p n/a) Journal of Raman Spectroscopy, Published Online: Mar :09AM; DOI: /jrs

7 PRESENTATIONS 1. L. Hajba, J. Mink, É. Bencze, K. Tóth, L. Kocsis, L. Markó, Low-frequency Vibrational Spectra of Cobalt Cluster Complexes Containing µ 3 -bridging Sulphur Ligands. 3 rd International Symposium on Advanced Infrared and Raman Spectroscopy, 5-9 July 1998, Vienna, Austria. 2. L. Hajba, A.D, Lopez, I.S. Gonçalves, F.E. Kühn, J. Mink, Vibrational Spectroscopic and Theoretical Study of 2,2 -Dipyridil and 2,2 -Dipyrimidine Molybdenium Complexes. 7 th Austrian Hungarian International Conference on Vibrational Spectroscopy, április 7-9., Balatonfüred, Magyarország. 3. J. Mihály, S, Sterkel, H.M. Ortner, L. Kocsis, L. Hajba, É. Furdiga, J. Mink, Study of Surface Degradation on High pressure Digestion Vessels by FTIR and FT-Raman Spectroscopies. 7 th Austrian Hungarian International Conference on Vibrational Spectroscopy, április 7-9., Balatonfüred, Magyarország. 4. Hajba L., Mink J., Többmagvú fémklaszterek rezgési spektroszkópiai szerkezetvizsgálata. MTA Spektrokémiai Munkabizottságának Ülése, március , Veszprém, Magyarország. 5. Hajba L., Bencze É., Tóth K., Kocsis L., Mink J., Markó L., Vastag S., Heteroatomot tartalmazó kobalt karbonil klaszterek rezgési spektroszkópiai vizsgálata és erállandó számítása. 45. Magyar Spektrokémiai Vándorgyülés, július 1-3., Siófok, Magyarország. 6. Hajba L., Mink J., Kühn F.E., Herrmann W.A., Kétmagú fém-klaszterek fém-fém kötéseinek rezgési spektroszkópiai tanulmányozása 46. Magyar Spektrokémiai Vándorgylés, június 30 július 2., Szeged, Magyarország. 7. L. Hajba, É. Bencze, K. Tóth, L. Kocsis, J. Mink, L. Markó, S. Vastag, Low Frequency Vibrational Spectra and Force Constant Calculalations of Cobalt Carbonyl Cluster Complexes Containing µ 3 -bridging Sulfur. XVIII th International Conference on Raman Spectroscopy, August 2002 Budapest, Hungary. 8. L. Hajba, J. Mink, F.E. Kühn, W.A. Herrmann, Raman and Infrared Spectroscopic and Theoretical Study of Re-Re Containing Acetates. XVIII th International Conference on Raman Spectroscopy, August 2002, Budapest, Hungary. 9. D.K. Breitinger, L. Hajba, V. Komlósi, J. Mink, G. Brehm, D. Colognesi, S.F. Parker, H. Schukow, R.G. Schwab, Vibrational Dynamics in Wardite-type Minerals. XVIII th International Conference on Raman Spectroscopy, August 2002, Budapest, Hungary. 10. D.K. Breitinger, L. Hajba, V. Komlósi, J. Mink, G. Brehm, D. Colognesi, S.F. Parker, H. Schukow, R.G. Schwab, Vibrational Dynamics in Wardite-type Minerals. XXVI th European Congress on Molecular Spectroscopy, 1-6 September 2002, Lille, France. 7

8 11. Mink J., Komlósi V., Hajba L., Hren B., Pap T., Khirer A., FTIR mikroszkópia az orvosi diagnosztikában. 46. Magyar Spektrokémiai Vándorgylés, június 30 július 2., Szeged, Magyarország. 12. Hajba L., Mink J., Kühn F.E., Kétmagú fém-klaszterek fém-fém kötéseinek rezgési spektroszkópiai tanulmányozása. 46. Magyar Spektrokémiai Vándorgylés, június 30 július 2., Szeged, Magyarország. 13. Mihály J., Kocsis L., Hajba L., Ortner H., Sterkel S., Mikrohullámú feltáró edények felületi degradációjának FTIR és FT-Raman spektroszkópiai vizsgálata. 46. Magyar Spektrokémiai Vándorgylés, június 30 július 2., Szeged, Magyarország. 14. L. Hajba, J. Mink, M. Sandström, A. Molla-Abbassi, M. Skripkin, Vibrational spectroscopic and force field study of hydrated lanthanides. 28 th International Conference on Solution Chemistry, augusztus , 2003, Debrecen, Magyarország. 15. L. Hajba, J. Mink, Cs. Németh, M. Sandström and P.L. Goggin, Infrared and Raman Spectroscopic and Theoretical Studies of Hexaaqua Metal Ions in Aqueous Solution. 2 nd International Conference on Advanced Vibrational Spectroscopy, August 2003, Nottingham, UK. 16. Zoltán Bacsik, László Hajba, Gábor Jancsó, János Mink, Detection of 2,4-dichlorophenol by open path Fourier transform infrared spectrometry. ICAVS-2, August Nottingham, UK. 17. J. Mink, Z. Bacsik, Cs. Németh, L. Hajba, Y. Zhang, F.E. Kühn, A.M. Santos, W.A. Herrmann, Raman, Infrared, Far-infrared and Theoretical Studies of Octahedral Acetonitrile Complexes of Cu(I) and Ag(I). XXVII European Congress on Molecular Spectroscopy, 5-10 September 2004, Krakow, Poland. 18. J. Mink, Cs. Németh, L. Hajba, M. Sandström, F. Jalilehvand, A. Molla-Abbassi, M.Yu. Skripkin, L.V. Stepakova, Comprehensive Infrared, Raman and Theoretical Studies of Hexa- and Nona-Aqua Complexes of Different Metals. 29th International Conference on Solution Chemistry, August 2005, Portoroz, Slovenia. 19. J. Mink, J. Mihály, V.T. Dobosi, K.T. Biro, and L. Hajba, Raman and FTIR spectroscopic studies of lower palaeolithic archaeological animal bones from Vertesszolos (Hungary). 20th International Conference on Raman Spectroscopy (ICORS), August 2006, Yokohama, Japan. 20. J. Mihály, V. Gombás, L. Hajba, A. Afishah, F.A. Aziz, J. Mink, FT-Raman spectroscopic investigation on human dental enamel. 4th ICAVS, June 2007, Corfu, Greece. 8