Vibrational and Mossbauer spectra of M-n(Fe(CN)(5)NO)(m) complexes (M = Sc-III, Y-III, La-III, Fe-II). A normal coordinate treatment

The influence of the outer sphere cations (Sc. Y, La, Fe) on the position a nd intensity of the [Fe(CN)(5)NO](2-) vibrational bands as well as on the M ossbauer parameters is explored with ab initio calculations and normal coor dinate analysis (NCA). The B3LYP calculations show redistribution of the el ectron density caused by the second coordination sphere of Fe. Changes in t he force field and in the vibrational eigenvectors are obtained with NCA. B oth the theoretical and experimental results are combined in order to prese nt a coherent picture of the role of the second coordination sphere. (C) 20 01 Elsevier Science B.V. All rights reserved.