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Crystal‐field splittings and optical spectra of transition‐metal mixed‐ligand complexes by effective Hamiltonian method
Author(s) -
Soudackov A. V.,
Tchougreeff A. L.,
Misurkin I. A.
Publication year - 1996
Publication title -
international journal of quantum chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.484
H-Index - 105
eISSN - 1097-461X
pISSN - 0020-7608
DOI - 10.1002/(sici)1097-461x(1996)57:4<663::aid-qua13>3.0.co;2-1
Subject(s) - ligand field theory , tetragonal crystal system , crystal field theory , chemistry , hamiltonian (control theory) , degenerate energy levels , ground state , transition metal , spectral line , crystallography , metal , ligand (biochemistry) , crystal structure , atomic physics , physics , quantum mechanics , ion , mathematical optimization , biochemistry , receptor , mathematics , organic chemistry , catalysis
Many of the important properties of transition‐metal complexes depend on the low‐energy excitation spectrum formed by d ‐electrons of the central transition‐metal atom. The spectra of this type are usually fit to the well‐known crystal field theory or to the angular overlap model. The result of the fitting is a set of parameters which are considered as characteristics of the electronic structure of the complex such as strength of the ligand field or types and extent of metal‐ligand bonding. We present here a short account of the effective Hamiltonian method recently developed to calculate the splitting of the d ‐levels by the ligands and the resulting d ‐ d spectra of transition‐metal complexes together with some results of its application to the mixed‐ligand complexes with the general formula ML 4 Z 2 , where M = V, Co, Ni; L = H 2 O, NH 3 , Py; and Z = H 2 O, NCS−,C −l. Particular attention is paid to the V(H 2 O) 4 Cl 2 and Co(H 2 O) 4 Cl 2 compounds. The former seems to have tetragonal structure, whereas for the latter, our method predicts a spatially degenerate ground state for the tetragonal arrangement of the ligands. That must lead to the Jahn‐Teller distortion, which is actually observed. © 1996 John Wiley & Sons, Inc.