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A tetranuclear molybdenum cluster compound{Mo_4(μ_3-S)_3(μ_3-O)[S_2P(OEt)_2]_6}·3CH_3CN was obtained by the reaction of MoCl_3·3H_2O with P_2S_5 in ethanol and then recrystallizationfrom acetonitrile.The compound crystallizes in the trigonal system belonging to the space groupR3 with the following cell dimensions:a=b=c=12.852(3)■,a=β=γ=108.37(2)°,V=1697.3■~3,Z=1,D_c=1.693g·cm~(-3).The structure was solved by heavy atom method and refined by full-matrixleast-squares to R=0.072 for 1781 reflections with I≥3σ(I).The results of the structure determinationindicate that the cluster skeleton possesses a cubanelike cluster core formed by four Mo atoms locatedin a distored tetrahedron with three S atoms and one O atom as its triple bridging atoms.There aretwo sets of bond distances,i.e.2.700(1)and 2.831(1)■ in the six Mo-Mo bonds.Taking the Mocluster core as a whole,it has a formal oxidation state of+14,leaving ten electrons to form the metal-metal bonds.Thus each Mo-Mo bond has an average bond order of 5/6.
A tetranuclear molybdenum cluster compound {Mo_4 (μ_3-S) _3 (μ_3-O) [S_2P (OEt) _2] _6} · 3CH_3CN was obtained by the reaction of MoCl_3 · 3H_2O with P_2S_5 in ethanol and then recrystallizationfrom acetonitrile.The compound crystallizes in the trigonal system belonging to the space group R3 with the following cell dimensions: a = b = c = 12.852 ■ a = β = γ = 108.37 (2) °, V = 1697.3 ■ ~ 3, Z = The structure was solved by heavy atom method and refined by full-matrix least-squares to R = 0.072 for 1781 reflections with I ≧ 3σ (I). The results of the structure determinationindicate that the cluster skeleton possesses a cubanelike cluster core formed by four Mo atoms located in a distored tetrahedron with three S atoms and one O atom as its triple bridging atoms. There aretwo sets of bond distances, ie. 2.700 (1) and 2.831 (1) ■ in the six Mo-Mo bonds.Taking the Mocluster core as a whole, it has a formal oxidation state of +14, leaving ten electrons to form the metal-metal bonds.Thus each Mo-Mo bond ha s an average bond order of 5/6.