Five new Mn(II) complexes based on flexible bis(imidazole) ligands: Synthesis, structure and magnetic properties

Abstract

Five new Mn(II) complexes, namely, Mn(bimb)0.5(mb)2 (1), Mn(bimb)0.5(mob)2 (2), Mn3(bimh)(mb)6 (3), Mn3(bimb)3(H2O)4(btc)2 (4) and [Mn3(bimh)3(H2O)2(btc)2]·2H2O (5) (mb=4-methylbenzoate, mob=4-methoxylbenzoate, btc=1,3,5-benzenetricarboxylate, bimb=1,4-bis(imidazol-1-yl)-butane and bimh=1,6-bis(imidazol-1-yl)-hexane) were synthesized hydrothermally and characterized by IR spectroscopy, elemental analyses and X-ray diffraction techniques. Compounds 1–3 are all chain structures. The formation of 1–2 are based on the linkage between the paddle-wheel shaped secondary building block units (SBUs) through bimb ligands, whereas 3 is composed of trinuclear Mn3 clusters linked by the longer bimh ligands. Compounds 4 and 5 are both 3D complicated frameworks with different topologies. The structure characteristics of flexible bis(imidazole) ligands and organic counteranions play a key role on the ultimate framework. Furthermore, compound 1 exhibits ferrimagnetic-like behavior, while compounds 2–5 display antiferromagnetic behaviors.