A Literature Survey on Homo-and Hetero-metallic Complexes of Manganese Exhibiting SMM Behavior

Abstract

Single molecule magnets (SMMs) have been extensively studied in last few years due to their wide range of potential applications in information storage, molecular electronics and quantum computing. In the early 1990s the storage of information at the molecular level became certainly feasible owing to the discovery of multinuclear transition-metal complexes acting as SMMs. Among them, clusters containing Mn(III) often have abnormally large spin ground states and this, in combination with the anisotropy derived from a Jahn–Teller distorted ion, result in Mn(III) to be an excellent candidate for building new SMMs or Single chain magnets (SCMs). Owing to coordination labile sites the magnetic properties of the Mn(III) salen-type complexes can be regulated by modulating the Schiff base ligand and thus they can act as coordination-acceptor building blocks. As a result, most fascinating linear type 1D chain complexes have been developed by using quasi-planar chelating Mn(III) salen compounds along with bridging co-ligands. Introduction of heteroatom e.g. sodium, cobalt, nickel etc. in Mn(III) salen complexes either enable the orbital overlap leading to antiferromagnetic coupling or an electron spin polarization leading to a ferromagnetic coupling. Some heterometallic complexes of lanthanides and manganese possess frequency-dependent magnetic properties, exhibiting single-molecule magnet behavior. In this literature review the synthetic strategies, diverse structural and magnetic properties of twenty two homo- and hetero-metallic complexes containing manganese have been discussed. Homometallic manganese complexes are classified into two groups e.g. discrete Mn complexes, one-dimensional chains and their magneto-structural correlations are also been highlighted.