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

Five new Mn(II) complexes, namely, Mn(bimb)(0.5)(mb)(2) (1), Mn(bimb)(0.5)(mob)(2) (2), Mn-3(bimh)(mb)(6) (3), Mn-3(bimb)(3)(H2O)(4)(btc)(2) (4) and [Mn-3(bimh)(3)(H2O)(2)(btc)(2)].2H(2)O (5) (mb = 4-methylbenzoate, mob = 4-methoxylbenzoate, btc = 1,3,5-benzenetricarboxylate, bimb = 1,4-bis(imidazol-1-y1)-butane and bimh 1,6-bis(imidazol-1-y1)-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. (C) 2014 Elsevier Ltd. All rights reserved.