Five-coordinate transition metal complexes and the value of τ5: observations and caveats.
Dalton Trans
; 49(42): 14798-14806, 2020 Nov 03.
Article
em En
| MEDLINE
| ID: mdl-33044477
ABSTRACT
The τ5 parameter, first proposed by Addison and coworkers, is the principal measure of the geometry of five-coordinate transition metal complexes, with τ5 = 0 said to describe a perfect square pyramidal geometry and τ5 = 1 a perfect trigonal pyramidal geometry. Therefore, the geometries of all five-coordinate complexes are assumed to lie on a continuum between these two extremes. Herein we show that there are a significant number of examples of transition metal complexes having τ5 > 1, leading to an equatorially distorted trigonal bipyramidal geometry with the transition metal ion lying out of the plane of the equatorial donor atoms. We also show that complexes having τ5 = 0 and displaying perfect square pyramidal geometry are very much the exception, and that the majority of complexes for which τ5 = 0 have the metal ion sitting above the mean plane of the donor atoms in the square plane, in a basally distorted square pyramidal geometry. Density functional theory computations on a number of these complexes show that the structural distortions are inherent features of the complexes, and not merely the result of intermolecular interactions.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Idioma:
En
Revista:
Dalton Trans
Assunto da revista:
QUIMICA
Ano de publicação:
2020
Tipo de documento:
Article
País de afiliação:
Nova Zelândia