The experimental M-A and M-B distances in several series of [MAnBm-n]-type complexes have been studied by DFT. Many of the structural features of the series, such as trans influences and sterically induced bond elongations, are not reproduced correctly in gas-phase DFT calculations. However, the correct trends are recovered by explicitly including environmental effects via the COSMO solvation model. These observations imply that the condensed-phase environment plays a critical role in determining the geometric structure of coordination complexes. Thus, any apparently satisfactory reproduction of the condensed-phase structure by an in vacuo calculation may mask an incorrect treatment of the interplay between different ligands attached to the same metal center.
CHMR, School of Chemistry, The University of Sydney, 2006, Australia, Department of Chemistry, University of Warwick, Coventry, UK. rosalie.hocking@csiro.au