Synthesis and structures of mono and binuclear nickel(II) thiolate complexes of a dicompartmental pseudo-macrocycle with N(imine)_2S _2 and N(oxime)_2S_2 metal-binding sites

摘要

The reaction of [Ni(pftp)] [pftp = N,N-propane-1,3-diyl-(6-formyl-4- methyliminatothiophenolato)] with hydroxylamine hydrochloride in the presence potassium acetate in MeOH resulted in the formation of the complex [Ni(LH 2)] [L = N,N-propane-1,3-diyl-(4-methyl-2-methyliminato-6- methyloxime-thiophenolato)] in good yield. A single crystal X-ray diffraction structural determination showed a mononuclear nickel(II) complex with the new acyclic ligand LH2 that had been functionalised with two oxime groups containing an empty N(oxime)_2S_2 pocket to which another metal ion could be added. A further reaction of [Ni(LH_2)] with NiCl_2·6H_2O, triethylamine and ammonium hexafluorophosphate in MeOH gave a dark red product that yielded red crystals of [Ni_2(LH)]PF_6·DMF via slow recrystallisation from a DMF/PriOH solvent mixture. A single crystal X-ray diffraction study of these crystals confirmed the presence of a dinuclear nickel(II) complex linked by a dithiolato-bridge. Both nickel(II) ions exhibited square-planar geometry where the metal centres are coordinated in two distinct cis-S _2N(imine)_2 and cis-S_2N(oxime)_2 binding sites provided by the new dicompartmental oxime/thiolate-containing ligand LH.