STABILIZATION OF UNUSUAL SUBSTRATE COORDINATION MODES IN DINUCLEAR MACROCYCLIC COMPLEXES

Abstract

The steric protection offered by the macrobinucleating hexaazaditiophenolate ligand (L) allows for the preparation of the first stable dinuclear nickel(II) borohydride bridged complex, which reacts rapidly with elemental sulphur producing a tetranuclear nickel(II) complex [{(L)Ni2}2(μ-S6)]2+ bearing a helical μ4-hexa- sulfide ligand. The [(L)CoII 2]2+ fragment have been able to trap a monomethyl orthomolybdate in the binding pocket. Unusual coordination modes of substrate in dinuclear macrocyclic compounds was demonstrated.

Keywords

• coordination chemistry
• borohydride
• hexasulphide
• molybdate
• amino-thiophenolate ligands