Synthesis and Structural Characterization of an Unusual Oxygen-Linked Double Cubane-Like Cluster {[Mo3PbOS3](OAc)2(py)3(dtp)2O}2

Abstract

The unusual oxygen-linked double cubane-like cluster compound {[Mo(3)PbOS(3)](OAc)(2)(py)(3)(dtp)(2)O}(2) (A) (dtp = S(2)P(OEt(2))(-), OAc = CH(3)COO(-), py = C(5)H(5)N) was obtained for the first time by the reaction of the mixed S/O-bridged cluster [Mo(3)(&mgr;(3)-O)(&mgr;-S)(3)(dtp)(4)H(2)O] (B) with Pb(OAc)(2).3H(2)O in the presence of excess CH(3)COOH and pyridine. It has been characterized by IR, Raman, UV-vis, and X-ray structure analysis. The molecule contains a crystallographic center of inversion and can be viewed as consisting of two [Mo(3)PbOS(3)](6+) cubane-like cores linked through a pair of oxygen bridges with Mo-(&mgr;-O) bond lengths of ca. 1.89 Å. The cell dimensions are a = 11.705(8) Å, b = 19.527(8) Å, c = 20.670(9) Å, beta = 98.14(4) degrees, V = 4677(8) Å(3), Z = 2 in the space group P2(1)/n. The final R = 0.056, R(w) = 0.068 for 5424 reflections with I >/= 3sigma(I). The average Mo-Mo bond distance is 2.613(1) Å and the nonbonding Mo-Pb distances lie in the range from 3.997(1) to 4.090(1) Å. The spectra of IR, Raman, and UV-vis spectra are also shown in this paper.