The Reactivity of Molybdenum Pentachloride with Ester Molecules: Ester Activation, Metal Reduction and Synthesis of 1D Coordination Polymers

The reactions of MoCl5, 1, with stoichiometric amounts of a variety of molecules containing the ester functionality, in anhydrous non-coordinating solvent, afforded metal compounds which were isolated in the solid state and characterized. The 1:2 molar reactions of 1 with methyl formate (HCO2Me), methylmethoxyacetate (MeOCH2CO2Me) and methyl-D,L-lactate (D,L-HOCH(Me)CO2Me) gave respectively the dinuclear complex [MoOCl3{O=C(H)OMe}]2, 2, and the mononuclear MoOCl3[2-O=C(OMe)CH2OMe], 6a, and MoOCl3[2-O=C(OMe)CH(Me)OH], 6b. According to NMR/GC-MS analyses, activation of the ester moiety in part of the organic material took place in the distinct cases. The molybdenum(IV) 1D coordination polymers [MoCl4-2-{trans-(CO2R)CH=CH(CO2R)}]n (R = Me, 3a; R = Et, 3b) were prepared by treatment of 1 with one equivalent of alkyl-fumarates. Instead the mononuclear Mo(IV) complexes MoCl4[2-CH2(CO2Me)2], 4, and MoCl4[2-{cis-(CO2Me)CH=CH(CO2Me)}], 5, were obtained from 1/CH2(CO2Me)2 and 1/cis-maleate, respectively. The molecular structures of 2, 3a, 3b, 4, 6a and 6b were ascertained by X-ray diffraction studies.