Preparation and characterization of the osmium cluster complexes H2Os3(CO)8L(EtFcPCMe) (L = CO or PEt2Fc) and H2Os3(CO)8[(η-C5H3PEt2)Fe(η-C5H4)]

Abstract

Thermolysis of Os3(CO)11(PEt2Fc) (Fc = (η-C5H4)Fe(η-C5H5)) in octane for 8 h affords H2Os3(CO)9(EtFcPCMe), 10, and H2Os3(CO)8[(η-C5H3PEt2)Fe(η-C5H4)], 9e, in 15 and 65% yield, respectively. Heating Os3(CO)12 and PEt2Fc in 1:2 molar ratio in xylene for 10 h gives two isomers of H2Os3(CO)8(PEt2Fc)(EtFcPCMe), 11, in about 40% yield. Two crystalline modifications of the complex 9e have been obtained from the same solvent: 9eA, triclinic, a = 15.653(1), b = 15.799(1), c = 11.257(1) Å, α = 90.388(7)°, β = 109.740(6)°, γ = 82.445(6)°, Z = 4 (two molecules per asymmetric unit), space group [Formula: see text]; and 9eB, monoclinic, a = 9.889(2), b = 13.632(3), c = 18.927(4) Å, β = 97.36(2)°, Z = 4, space group P21/n. The structures were solved by heavy atom methods and were refined by full-matrix least-squares procedures to R = 0.033 and 0.037 for 8131 and 5145 reflections with I ≥ 3σ(I), respectively.