title: [Study on the infrared spectra of metallic clusters containing R2dtc ligand and V = O group].
abstract: This paper reports the features and regularities of the infrared spectra for two kinds of complexes containing R2dtc ligand. The cubane-like clusters containing R2dtc ligand possess weak and wide peaks at 400-500 cm-1 assigned to M-mu 3S vibration, while the peaks at 330-380 cm-1 and 1,470-1,510 cm-1 can be assigned to M-Sdtc and C-N vibrations, respectively. The nu(C-N) and nu(C = S) vibrations for Me2dtc-cubane cluster exhibit blue shift and red shift, respectively, when compared with those of other R2dtc ones. This would be attributed to the strong super-conjugation of the methyl group. The M-mu 3S vibrations for both types of complexes [V2Cu2S4(R2dtc)2(PhS)2]2- and [VCu4S4(R2dtc)n(PhS)4-n]3- (n = 0, 1, 2) occur at 480 and 465 cm-1, respectively. This small difference becomes a useful indication to distinguish the two types of clusters. Cluster complexes containing (R2dtc)2V2O2(mu-S)2 structural unit show the V = O vibration in the range of 844-970 cm-1. It is noted that (Et4N)[V3S2O3(Et2dtc)3] contains two sets of the V = O bonds corresponding to two sets of V = O vibrations at 970 and 844 cm-1. An additional coordination of the V = O bond to another metal atom obviously weakens the V = O bond to give rise to the red shift of the infrared frequency. Similar red shifts were also observed for other complexes and were discussed.
authors.affiliation: State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, 350002 Fujian.
authors.forename: H
authors.initials: H
authors.lastname: Zhu
authors.forename: C
authors.initials: C
authors.lastname: Chen
authors.forename: Y
authors.initials: Y
authors.lastname: Yang
authors.forename: Y
authors.initials: Y
authors.lastname: Deng
authors.forename: Y
authors.initials: Y
authors.lastname: Zhang
authors.forename: Q
authors.initials: Q
authors.lastname: Liu