簇合物[(C_2H_5)_4N]_3[W_2FeS_6(SCH_2CH_2S)_2]的合成、结构和性质研究

Studies on Synthesis, Structure and Properties of Cluster Compound [(C_2H_5)_4N]_3[W_2FeS_6(SCH_2CH_2S)_2]

用两种不同的合成路线制备了标题化合物单晶,该化合物晶体为P2_1/c空间群,α=1.4256(5)nm,b=3.6007(9)nm,c=1.8075(4)nm,β=99.15(2)°,Z=8,对结构精修得到最后的一致性因子R=0.069,在[W_2FeS_6(SCH_2CH_2S)_2]^(3-)中存在端基双键S、端基单键螯合配位S和桥μ_2—S。Fe通过桥S分别与两个W相连,构成双齿非线型的W—Fe—W硫桥式结构。用EHMO方法对簇合物的电子结构进行了量子化学计算得到了与结构研究一致的规律。对簇合物进行了红外光谱、紫外可见光谱和电化学研究,并与所合成的其它化合物进行比较。

The crystal of [(C_5H_5)_4N]_3[W_2FeS_6(SCH_2CH_2S)_2] were prepared in two routes. It crystal lizes in space group P2_1/c with a=1. 4256(5)nm, b=3. 6007(9)nm, c=1. 8075(4)nm, β=99. 15(2)°, Z=8. The final agreement factor R=0.069 was gained by refining all structural parameters to 10168 unique reflections (1>2. 5σ(Ⅰ)). The structural analysis shows that there are a double bond S (terminal), a single bond S (terminal) and μ_2—S bridge in the anion [W_2FeS_6(SCH_2CH_2S)_2]^(3-). The W atom and the other five S atoms coordinated to it constitute a proximate tetraangle awl with terminal double S being the top of the awl. The Fe atom connects with two W atoms and four μ_2—S constructing the four nonlinear S bridging structure W—Fe—W. The electronic structure of the compound was calculated with EHMO. In this structrue, the change of W=S (terminal)<W—μ_2—S<W—S(terminal) in bond length has shown no difference to change of W =S(terminal)>W—μ_2--S>W—S (terminal) in bond order. The measurements of IR and UV spectra and determination of electric chemistry of the cluster compound were carried out.The structure and properties of this compound are compared to those of [(C_2H_5)_4N]_3[Mo_2FeS_6(SCH_2CH_2S)_2]·(1/4)CH_3CN in this paper.