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This paper reports the first systemic investigation on the bimetallic ring coordination polymers based on two structure-related flexible bis(imidazole) ligands, bimb as well as bix [bimb = 1, 4-bis(imidazol-1-yl)-butane, bix = 1, 4-bis(imidazol-1-yl-methylene)-benzene)]. As expected, six new cobalt complexes were generated, namely, [Co2(SCN)4(bimb)2] ( 1), [Co2(L1)2(bimb)2Cl2] ( 2), [Co2(L2)4(bix)2] ( 3), [Co(SCN)2(bimb)2] ( 4), {Co[N(CN)2]2(bimb)2} ( 5), and [Co(L3)(bix)] ( 6) (HL1 = 4-aminobenzoic acid, HL2 = 4-nitrobenzoic acid, and H2L3 = succinic acid). The structures of 1- 3 are three discrete dinuclear ring motifs. Especially, 1 is the first example of 1D pseudo-polyrotaxane formed by S ···S strong interactions based on bis(imidazole) ligands. 4 and 5 exhibit 1D meso-helical chain architecture, in spite of their different space groups. In 6, the discrete dinuclear ring motifs, traversed by μ2-η3-chelating L3 anions, are interconnected by another μ2-η1-bridging L3 anions to form 2D (4, 4) network. The formation of these compounds should be undoubtedly attributed to the preference for cis-bis(imidazole) ligands crystallization resulting in various ring architectures. In addition, compound 6 exhibits antiferromagnetic behavior. [ABSTRACT FROM AUTHOR]

The self-assembly reactions of transition metal ions and 1,3,5-benzenetricarboxylic acid (H3btc) in the presence of auxiliary aromatic bidentate ligands 1,10-phenanthroline (1,10-phen) or 4,4′-bipyridine- N, N′-dioxide (4,4′-bpdo) have isolated four coordination polymers [Co18(btc)10(H2O)6(OH)6(1,10-phen)6] ·14H2O ·3DMF ( 1) and [ M3(btc)2(H2O)4(4,4′-bpdo)] ·2H2O ·2DMF [ M = Co ( 2), Mn ( 3), Ni ( 4)]. Single-crystal X-ray diffraction analysis revealed that the M3 clusters in the structure of 1- 4 are connected by hydroxyl group oxygen atoms (or oxygen atoms from 4,4′-bpdo ligands) and carboxyl groups to generate a three-dimensional framework. The network of final assemblies can be adjusted by varying the type of auxiliary ligands (1,10-phen, 4,4′-bpdo). In addition, the gas adsorption properties of 2 are also investigated. [ABSTRACT FROM AUTHOR]

Three two-dimensional coordination polymers {[Zn(H-3, 3-bpma)(1, 2,4-btc)] ·H2O} n ( 1), {[Cu2(H-3, 3-bpma)2(1, 2,4-btc)(H-1, 2,4-btc)(H2O)2] ·ClO4 ·7.75H2O} n ( 2), and {[Cd4(H-3, 3-bpma)2(1, 3,5-btc)3Cl(H2O)7] ·12.75H2O} n ( 3) [3, 3-bpma = N, N′-bis(3-pyridylmethyl)amine, H3-1, 2,4-btc = 1, 2,4-benzenetricarboxylic acid, and H3-1, 3,5-btc = 1, 3,5-benzenetricarboxylic acid] were synthesized and characterized by X-ray crystallography. The complexes are all two-dimensional layer networks with diverse topologies bridged by mixed flexible bis(pyridylmethyl)amine and auxiliary rigid aromatic multicarboxylate ligands. The H-3, 3-bpma ligands adopt different conformations, whereas the aromatic multicarboxylates show various binding modes in the complexes. The magnetic, photoluminescence and thermal properties for complexes 1 and 2 were investigated. [ABSTRACT FROM AUTHOR]