MnIII(tetra-biphenyl-porphyrin)–TCNE Single-Chain Magnet via Suppression of the Interchain Interactions

A single-chain magnet (SCM) of [Mn­(TBPP)­(TCNE)]·4m-PhCl2 (1), where TBPP2– = meso-tetra­(4-biphenyl)­porphyrinate; TCNE• – = tetracyanoethenide radical anion; m-PhCl2 = meta-dichlorobenzene, was prepared via suppression of interchain interactions. 1 has a one-dimensional alternating MnIII(porphrin)–TCNE• –chain structure similar to those of a family of complexes reported by Miller and co-workers. From a comparison of the static magnetic properties of 1 with other MnIII(porphyrin)–TCNE• – chains, a magneto-structural correlation between the intrachain magnetic exchange and both the dihedral angle between the mean plane on [Mn­(TBPP)­(TCNE)] and Mn–NC was observed. The ac magnetic susceptibility data of 1 could be fit with the Arrhenius law, indicating that slow magnetic relaxation and ruling out three-dimensional long-range ordering and spin-glass-like behavior. The Cole–Cole plot for 1 was semicircular, verifying that it is an SCM. Therefore, 1 is an ideal single-chain magnet with significantly strong intrachain magnetic exchange interactions beyond the Ising limit.