Experimental Electronic Structure of Coordination Compounds

Jozef Kožišek, Peter Herich, Marek Fronc

Department of Physical Chemistry, Slovak Technical University, Bratislava, Slovakia. jozef.kozisek@stuba.sk

Introduction

Properties of compounds are determined by their electronic structure. From the chemical point of view, the precise knowledge of the electronic structure of molecules is crucial to explain their possible reactivity, chemical and transport properties in various surroundings. Thus the experimental (such as ESR, voltammetry, electron spectroscopy, precise X-ray measurements) and theoretical (high-level quantum-chemical calculations) methods of the study of an exact electron density distribution in molecules are of increasing importance in recent studies in addition to common methods for determining their chemical structure (such as X-ray diffraction, NMR and vibrational spectroscopy, mass spectrometry).

Standard X-ray crystallography gives an information about the geometrical structure of the molecule under study. Over 500 000 crystal structures of organic and organometallic compounds in Cambridge Crystallographic Database have been solved using the software based on the spherical model of the atomic electron density. In the real compounds it is not adequate and the spherical part is only the 'core' of the atom. From the chemical point of view, the most interesting part of the electron density is the asymmetric one which reflects the changing electron density distribution (EDD) due to the creation of chemical bonds. The EDD and its subsequent topological analysis is a powerful tool for the experimental study of the electronic structure (ES) of molecules in solid state [1].

Experimental

For study of experimental electron density distribution (EEDD) of some coordination compounds the GEMINI R data at 100K will be used. Theoretical study will be performed by a quantum-chemical software. The results of topological analysis both experimental and theoretical will be discussed [2-4].

This work has been supported by Slovak Grant Agency APVV and VEGA (APVV-0202-10 and 1/0679/11).

References

1. M. Benard, P. Coppens,M.L. DeLucia, E.D. Stevens, Inorg.Chem. ,19 (1980), 1924.

2. J. Kožíšek, N.K. Hansen, H. Fuess, Acta Cryst. B58, 463-470 (2002).

3. J. Kožíšek, M. Fronc, P. Skubák et al., Acta Cryst. A60, 510-516 (2004).

4. J. Kožíšek, L. Perašínova, M. Breza, XXIth IUCr Congress, Osaka 2008, p. C128, Japan.