SYNTHESIS AND CHARACTERIZATION OF MANGANESE(II) CHALCOGENOLATO COMPLEXES - CRYSTAL AND MOLECULAR-STRUCTURE OF [(MN(MU-SEC(6)H(2)ME(3)-2,4,6)(2))())(INFINITY)]

A series of manganese(II) complexes [{Mn(EC(6)H(2)R'(3)-2,4,6)(2)}] (E = Se, R' = Me or Bu(t); E = Te, R' = Me) have been prepared by protol ysis of [Mn{N(SiMe(3))(2)}(2)(thf)] (thf = tetrahydrofuran) with the c orresponding sterically demanding arenechalcogenols 2,4,6-R'(3)C(6)H(2 )EH. Complexes with R' = Me form co-ordination polymers which are solu ble only in strongly co-ordinating solvents. while complexes with R' = Bu(t) are dimeric and readily dissolve in less polar solvents such as toluene. The complexes react with Lewis bases (PMe(3), 2,2'-bipyridyl ) to form tetrahedral or octahedral adducts, depending on the steric r equirements of the arenechalcogenolate ligands. The structure of [{Mn( mu-SeC(6)H(2)Me(3)-2,4,6)(2)}infinity] was determined by X-ray diffrac tion. The compound forms a one-dimensional infinite chain with bridgin g selenolate ligands which surround the metal centre in a flattened te trahedral geometry.