Vibrational spectra and normal coordinate analysis of the tetrahalogeno-closo-1,2-diphosphahexaboranes P2B4X4, X = Cl, Br

Publication Type
Journal contribution
Authors
Lorenzen, V.; Preetz, W.; Keller, W.; Haubold, W.
Year of publication
1999
Published in
Z. Naturforsch., B: Chem. Sci.
Band/Volume
54/10
ISBN / ISSN / eISSN
0932-0776
DOI
10.1515/znb-1999-1003
Page (from - to)
1229-1234
Abstract

High-resoln. vibrational spectra of the tetrahalogeno-closo-1,2- diphosphahexaboranes P2B4X4, X = Cl, Br were measured at low temps. (20-60 K). The B-halogen stretching vibrations are obsd. below 370 cm-1 while the P-P valence vibrations are found at 414 (Cl) and 372 cm-1 (Br). Due to the presence of the B isotopes 10B and 11B and P-P stretching vibrations and the cage modes in the region of 550-1200 cm-1 are split. Based on the crystallog. data of P2B4Cl4 normal coordinate analyses were performed. Using a set of 16 force consts. (e.g. fd(PP) = 1.35 (X = Cl) and 1.20 (Br), fd(BB) = 1.30/1.65 (Cl) and 1.45/1.60(Br), fd(BX) = 4.40(Cl) and 3.53(Br) mdyn/.ANG.) a good agreement of obsd. and calcd. frequencies was achieved.

Involved persons

Involved institutions