Versatility of the co-ordination behaviour of 1-methylpyrimidine-2-thione towards metal ions of the first transition series

Abstract

The preparations are reported of complexes of 1-methylpyrimidine-2-thione (L) with Mn^II, Co^II, Ni^II, Cu^II, and Zn^II A combination of X-ray, electronic spectral, i.r., and e.s.r. studies has been employed to deduce the co-ordination geometries. The complexes [ML₄][ClO₄]₂·2Me₂CO (M = Mn, Co, or Zn) contain tetrahedral [ML₄]²⁺ ions with L co-ordinated via N. Zero-field splitting parameters have been evaluated for the manganese complex. The thione ligand chelates via N and S in a range of complexes such as [CoL₃][ClO₄]₂, [CuLX₂](X = Cl or Br) and, with varying degrees of distortion, in metal halide complexes ML₂X₂(M = Mn, Co, or Ni). Copper(II) perchlorate or tetrafluoroborate are reduced by L to give Cu^I₂L₃X₂(X = ClO₄ or BF₄).