文档介绍：CROATICA CHEMICA ACAA 72 (2–3) 663¿672 (1999)
ISSN-0011-1643
CCA-2604 Original Scientific Paper
Fourier Transform Infrared Study
of Dichlorodioxochromium(VI),
Dichlorodioxomolybdenum(VI)
and Dichlorodioxotungsten(VI) Complexes
with 2,2’-Bipyridine*
Bojan [optrajanov,a,b,** Mira Trpkovska,a and Ljup~o Pejova
a Institut za hemija, PMF, Univerzitet »Sv. Kiril i Metodij«, . Box 162,
91001 Skopje, Macedonia
b Makedonska akademija na naukite i umetnostite, Skopje, Macedonia
Received November 6, 1998; revised April 25, 1999; accepted April 29, 1999
The Fourier transform infrared spectra of the 2,2’--
plexes of dichlorodioxochromium(VI), dichlorodioxomolybdenum(VI)
and dichlorodioxotungsten(VI) were studied in the 4000 to 400
cm–1 region. The assignment of the bands originating from vibra-
tions mainly localized in the bipyridine ligand is relatively
straightforward. The essentially pure MO2 stretching vibrations
give rise to very strong bands, the separation of which increases in
the order Cr < Mo < W as a consequence of the greater sensitivity
of the antisymmetric stretching O–M–O vibration to the changes
in the mass of the M atoms. For this to be true, the symmetric
stretching vibration should have a higher frequency than the anti-
symmetric one. The results of the preliminary ab initio HF SCF
calculations on simple model structures