The multidentate chemistry of manganese(II). II. Six and eight coordinate compounds with bidentate ligands

Abstract

The existence of colourless, pure manganese(II) complexes containing four molecules of 1:10-phenanthroline (phen) per manganese atom has been substantiated, and some new compounds of this type prepared to extend the range of known compounds to the following: Mn(phen) 4X 2.nH 2O (where X = a weakly or non-coordinating anion such as BPh 4, I or 2-bromocamphor-π-sulphonate; n = 2, 4 or 6 depending upon X). A number of yellow compounds possessing three or two molecules of phen per manganese atom have also been prepared for comparison with tetrakis-phen compounds, as have also the colourless complexes M(phen) 4(ClO 4) 2.nH 2O (where M = Sr, Ba or Pb; n = 0, 4 or 5). Two other bidentate ligands with rigid chelate rings, viz. o-phenylenediamine and 8-aminoquinoline, have also been shown to yield 8-coordinate tetrakis-ligand manganese(II) perchlorate complexes, as well as octahedral compounds of the types [Mn(ligand) 3](ClO 4) 2 and [Mn(ligand) 2X 2], (where X = Cl or Br). On the other band, bidentate nitrogenous ligand with more flexible chelate rings have been shown to yield tris- and bis-ligand octahedral complexes of the types [Mn(ligand) 3](ClO 4) 2 and [Mn(ligand) 2X 2] (where X = Cl or Br).