Synthesis and characterisation of novel dipyridine and pyridinyl benzoquinoline complexes of zinc and nickel

Abstract

Dipyridine and pyridinyl benzoquinoline ligands and their coordination chemistry with nickel and zinc are described. The pyridinyl benzoquinoline ligand was synthesised through the photochemical Mallory reaction of the dipyridine ligand. The zinc complexes adopt distorted tetrahedral geometries, featuring one coordinated dipyridine or pyridinyl benzoquinoline ligand, with two chlorides completing the first coordination sphere. In contrast, the nickel complexes adopt octahedral geometries with two bidentate ligands and two coordinating chlorides per metal centre. Using cyclic voltammetry, the redox behaviour of all complexes was investigated, revealing both ligand- and metal-based reduction, as well as surprising catalytic reactivity with DCM. Together, this work explores the synthesis and coordination chemistry of two new ligands of the uncommon dipyridine family.