A theoretical rationale for the formation, structure and spin state of pentacyanochromate(II)
Deeth, Robert J.. (2006) A theoretical rationale for the formation, structure and spin state of pentacyanochromate(II). EUROPEAN JOURNAL OF INORGANIC CHEMISTRY (13). pp. 2551-2555. ISSN 1434-1948Full text not available from this repository.
Official URL: http://dx.doi.org/10.1002/ejic.200600137
The pentacyanochromate(II) complex is unusual in two respects. Firstly, it is one of the few homoleptic cyanide species with a high-spin ground state. Secondly, it was synthesised during an attempt to make the hexacoordinate complex. A combination of qualitative ligand field theory and quantitative density functional theory including solvation effects is applied to rationalise these observations. The spin state depends on the d orbital energy differences and how the promotion energy, PE, associated with a change in spin state compares to the d-d spin pairing energy, SPE. The calculations show that PE > SPE for octahedral [Cr-II(CN)(6)](4-), hence it has a spin triplet S = 1 ground state, while PE < SPE for [Cr-II(CN)(5)](3-), hence it is high spin with S = 2. The hexacyanide is stabilised in aqueous solution by solvation. In less polar solvents such as acetonitrile, the unfavourable electrostatic interactions dominate and the reaction stops at the pentacyano complex. In both complexes, the cyanide behaves as a strong-field ligand and is both a good sigma donor and pi acceptor.
|Item Type:||Journal Article|
|Subjects:||Q Science > QD Chemistry|
|Journal or Publication Title:||EUROPEAN JOURNAL OF INORGANIC CHEMISTRY|
|Publisher:||WILEY-V C H VERLAG GMBH|
|Date:||3 July 2006|
|Number of Pages:||5|
|Page Range:||pp. 2551-2555|
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