Bis-nickel-bridged p-terphenyl dianion - Synthesis and structures

Abstract

In this paper we present the synthesis and characterisation of novel bisnickelacyclic complexes. We carried out the reaction between 2,2′,2″,5′-tetralithio-1,1′,4′,1″-terphenyl and nickelocene in which bisnickelacyclic-dilithium complex was formed. It represented the contact ion pair that consisted of nickelacyclic dianion (the first of it's kind) and lithium cations. Exchange of solvent from diethyl ether to DME (1,2-dimethoxyethane) afforded solvent separated ionic pair. Both of these complexes exhibited paramagnetic behaviour, so structural investigations had to be carried out by means of X-ray diffraction. DFT calculations were employed for better understanding of electronic structure of these complexes.