Mono- and Dinuclear Coordination Compounds with Directional Bis(bidentate) Ligands

The benzene-o-dithiol/salicylimine (S-S/N-O) ligands H-3-1 and H-3-2 have been synthesized, representing the first examples of a new type of polydentate heterodonor ligands. Schiff-base condensation of salicylaldehyde with an amine linked to a benzene-o-dithiol donor group leads to the formation of the ligands. Bis(cyclopentadienyl) titanium dichloride reacts selectively at the S-S donor groups of H-3-1 and H-3-2 to yield complexes [CP2Ti(H-1)] and [Cp2Ti(H-2)], respectively. Ligand H-3-1 reacts with [Ni(OAc)(2)]center dot 4H(2)O to yield the mononuclear complex (BU4N)(2)[Ni(H-1)(2)] or the dinuclear complex (BU4N)(2)[Ni-2(1)(2)] depending on the stoichiometric conditions employed. While (BU4N)(2[)Ni(H-1)(2)] possesses a nickel(II) center with an S-4 coordination environment, the double-stranded dinuclear complex (BU4N)(2)[Ni-2(1)(2)] contains two {(Ni2NO)-N-II} centers and shows an antiparallel orientation of the ligand strands. ((C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)