混合价簇合物[Et4N]2{(CO)4M}xM'S4][x=1,2; M=Mo(0)或W(0); M'=Mo(VI)或W(VI)]的共振Raman光谱及IR光谱研究

研究了{CO)4M}xM'S4]^2^-x=1,2; M=Mo(0), W(0); M'=Mo(VI), W(VI)]系列簇合物共振Raman(RR)光谱及红外(IR)光谱。除了对^νc-o, ^νM(VI)-s(b)S(b):桥基S], ^νM(VI)-s(t)S(t): 端基S], ^νM(0)-c, ^δM(0)-c-o进行归属外, 着重讨论^νM(0)-s(b), ^νM(0)-M(VI)的归属。研究了IR谱中Δν^νM(VI)-s(b)─^νM(0)-s(b)]与M(0)→M(VI)电荷迁移的关系。RR谱研究结果表明, 在(CO)4^-MS2MoS2]^2^-, (CO)4MoS2MoS2Mo(CO)4]^2^-中S(b)→M(0)电荷迁移与M(0)→Mo(VI)电荷迁移之间有较明显的相互偶合; 在(CO)4MS2WS2]^2^-中S(b)→W(VI)与M(0)→W(VI)电荷迁移、S(t)→W(VI)与M(0)→W(VI)电荷迁移之间也分别存在明显的相互偶合, 说明了它们存在强的电子离域。本系列簇合物中二核簇的电子离域程度比三核簇强。

Studies on the resonance-raman and infrared spectra of cluster compounds with mixed-valence Mo(W) atoms, [Et4N]2{(CO)4M}xM'S4] [x=1 or 2, M=Mo(0) or W(0), M'=Mo(VI) or W(VI)]

The Resonance-Ramsn and Infrared spectra of series of cluster compounds, {CO)4M}xM'S4]^2^-x=1 or 2; M=Mo(0) or W(0); M'=Mo(VI) or W(VI)] have been investigated. Besides the characteristic frequencies of ^νco, ^νM(VI)-s(b), ^νc-o, ^νM(VI)-s(t), ^νM(0)-c, and ^δM(0)-c-o were assigned. The assignment of ^νM(0)-s(b) and ^νM(0)-M(VI) were emphatically discussed. The relationship between Δν^νM(VI)-s(b) ─^ν ,(0)-s(b)] and M(0)→M(VI) charge transfer were demonstrated by their IR spectra. The results from the studies on the Resonance-Raman spectra indicate that there evidently are couplings between the S(b)→ Mo(0) charge transfer and M(0)→Mo(VI) charge transfer in (CO)4MS2WS2]^2^- and (CO)4MoS2MoS2Mo(CO)4]^2^-, between S(b)→W(VI) and M(0)→W(VI) charge transfer and between S(t)→W(VI) and M(0)→W(VI) charge transfer in (CO)4MS2WS2]^2^-. T his implies that the extensive electron delocalization exists in these cluster compounds with mixed-valence metal atoms and the electron delocalization in the dinuclear clusters is stronger than that in the trinuclear clusters.