Synthesis and characterization of a series of novel polyoxometalate-supported carbonyl manganese derivatives†
Abstract
Four novel heteropolytungstate-supported carbonyl manganese derivatives [(M4(H2O)10)(XW9O33)2{Mn(CO)3}2]n− (X = Sb/Bi; M = Mn/Mn3.5W0.5) have been successfully synthesized and characterized by single crystal X-ray diffraction crystallography, IR and UV spectroscopy, representing the first examples of structurally characterized transition metal substituted sandwich-type tungsto-antimonates/bismutates incorporated with carbonyl manganese groups. The organic–inorganic hybrids are composed of two {Mn(CO)3} groups attached to a dimeric heteropolytungstate {M4(B-β-XW9O33)2} unit via six MnI–O–W bonds. The {M4(B-β-XW9O33)2} unit is built up of a central symmetric parallelogram-like tetra-MnII cluster sealed into two identical [B-β-XW9O33]9− fragments through MnII–O–W bonds. Furthermore, polyanions 1 and 2 proved to be efficient for the electrocatalytic reduction of NO2−. Magnetic measurements on these complexes were also investigated.