系列异金属类立方烷原子族化合物的振动光谱

通过振动光谱和Ｘ－射线结构分析数据的结合，归属了系列具有「Ｍ３ＹＳ３Ｍ′」（Ｍ＝Ｍｏ，Ｗ；Ｙ＝Ｏ，Ｓ；Ｍ′＝Ｃｕ，Ｓｎ，Ｓｂ，Ｐｂ，Ｂｉ）簇芯的异金属四核类立方烷原子簇化合物的主要振动谱峰。讨论了五种结构类型的光谱特征和成键状态，Ｍ′的加入使ｖＭ－（μ３－Ｙ）和ＶＭ－ｓ频率下降。当Ｍ′为过渡金属，例如Ｃｕ时，Ｃｊ与「Ｍ３ＹＳ３」结合紧密造成了Ｃｕ－Ｓ共价键相当的ｖＣｕ－ｓ振动频率，而当Ｍ′为主族金属时，ＶＭ′－ｓ远小于相应共价键的振动频率值。文中还对ｖＭ－Ｍ振动进行若干论述。

Vibrational spectroscopic investigation of a series of heterometallic cubane-like M'-Mo (W) cluster compounds]

By combining the results of IR spectroscopic experiments with the molecular structures, the main stretching vibrations of a series of the heterometallic tetranuclear cluster compounds with M3YS3M'] cluster core (M = Mo, W; Y = O, S; M' = Cu, Sn, Pb, Sb, Bi) have been assigned. The characteristic features and the bonding situations of the five configuration types are discussed. It is shown from the IR and Raman spectra that when M' is a transition metal such as Cu, the nu M's frequency of the M3YS3M'] core has a value comparable to that of corresponding M'-S covalent bond thus indicating a close combination of M' with M3YS3]. Whereas when M' is a main group metal, the nu M'-s vibration is always observed in a lower region than of the M'-S covalent bond because of a loose combination of M' withM3YS3]. However, remarkable enhancement of M-M band strength due to the addition of M' is demonstrated by Raman spectra. Some comments for the M-M vibration of various structures of these compounds are also described.