Impact of nuclearity and topology on the single molecule magnet behaviour of hexaazatrinaphtylene-based cobalt complexes

Abstract

A hexaazatrinaphtylene-based transition metal complex that exhibits single molecule magnet (SMM) behaviour is reported herein. Both monometallic (1) and bimetallic (2) Co^II complexes with distorted octahedral geometries could be obtained through a straightforward change in synthetic conditions. Field induced SMM behaviour was exhibited by 1, with a D value of −60 cm⁻¹ and U_eff = 17 K originating from the unquenched orbital angular momentum of the octahedral Co^II (d⁷) centre. On the other hand, 2 exhibits weak antiferromagnetic interactions with a positive D value, thus preventing the observation of SMM behaviour. This investigation reveals the influence of both nuclearity and topology on the magnetic properties of HATN based complexes.