Synthesis and characterisation of manganese(II) chalcogenolato complexes. Crystal and molecular structure of [{Mn(µ-SeC6H2Me3-2,4,6)2}∞]

Abstract

A series of manganese(II) complexes [{Mn(EC₆H₂R′₃-2,4,6)₂}](E = Se, R′= Me or Bu^t., E = Te, R′= Me) have been prepared by protolysis of [Mn{N(SiMe₃)₂}₂(thf)](thf = tetrahydrofuran) with the corresponding sterically demanding arenechalcogenols 2,4,6-R′₃C₆H₂EH. Complexes with R′= Me form co-ordination polymers which are soluble 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 (PMe₃,2,2′-bipyridyl) to form tetrahedral or octahedral adducts, depending on the steric requirements of the arenechalcogenolate ligands. The structure of [{Mn(µ-SeC₆H₂Me₃-2,4,6)₂}_∞] was determined by X-ray diffraction. The compound forms a one-dimensional infinite chain with bridging selenolate ligands which surround the metal centre in a flattened tetrahedral geometry.