• Magnesium;
  • Gallium;
  • Redox-active ligands;
  • Disulfides;
  • Reduction


The reactions of (dpp-bian)Mg(thf)3 (1) {dpp-bian = 1,2-bis[(2,6-diisopropylphenyl)imino]acenaphthene} with 0.5 molar equivalents of RS–SR (R = Bz, sBu, C(S)NMe2) occur with a cleavage of the S–S bond to afford monosulfide complexes (dpp-bian)Mg(SBz)(dme) (2), (dpp-bian)Mg[S(sBu)](dme) (3), and (dpp-bian)Mg[SC(S)NMe2](thf) (4). Compounds 2, 3, and 4 are paramagnetic due to the presence of dpp-bian radical-anions that are formed in the course of one-electron transfer from the dpp-bian dianion in 1 to the sulfur-containing substrate. Reduction of BzS–SBz with gallane (dpp-bian)Ga–Ga(dpp-bian) (5) gives a mononuclear GaIII complex with the dpp-bian radical-anion, (dpp-bian)Ga(SBz)2 (6). The reaction of 5 with RS–SR (R = C(S)NMe2) proceeds with a cleavage of the S–S and Ga–Ga bonds and affords (dpp-bian)Ga[SC(S)NMe2] (7), in which the dpp-bian ligand retains its dianionic state. Complexes 2, 3, 4, and 6 have been characterized by ESR and IR spectroscopy, and complex 7 has been studied by 1H MNR spectroscopy. The molecular structures of 24, 6, and 7 have been determined by X-ray crystallography. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)