Novel Metal-Organic Frameworks with Specific Topology from New Tripodal Ligands: 1,3,5-Tris (1-imidazolyl)benzene and 1,3-Bis(1-imidazolyl)-5-(imidazol-1-ylmethyl)benzene

Reactions of two new tripodal ligands 1,3,5-tris(1-imidazolyl)benzene (4) and 1,3-bis(1-imidazolyl)-5-(imidazol-1ylmethyl)benzene (5) with metal [Ag(l), Cu(ll), Zn(ll), Nj(ll)] salts lead to the formation of novel two-dimensional (2D) metal-organic frameworks [Ag2(4)2][p-C6H4(COO)2]-H20 (6), [Ag(4)]C104 (7), [Cu(4)2(H20)2](CHsCOO)2-2H20 (8), [Zn(4)2(H20)2](N03)2 (9), [Ni(4)2(Ns)2]-2H20 (10), and [Ag(5)]C104 (11). All the structures were established by single-crystal X-ray diffraction analysis. Crystal data for 6: monoclinic, C2/c, a = 23.766(3) A, b = 12.0475(10) A, c = 13.5160(13) A, (beta) = 117.827(3)", Z= 4. For compound 7: orthorhombic, i, a - 7.2495(4) A, b = 12.0763(7) A, c = 19.2196(13) A, Z= 4. For compound 8: monoclinic, P2n,/ a = 8.2969(5) A, b = 12.2834(5) A, c = 17.4667(12) A, (beta) = 96.5740(10)°, Z= 2. For compound 9: monoclinic, P2/n, a =10.5699(3) A, b = 11.5037(3) A, c = 13.5194(4) A, (beta) = 110.2779(10)°, Z= 2. For compound 10: monoclinic, P2/n, a = 9.8033(3) A, b = 12.1369(5) A, c = 13.5215(5) A, (beta) = 107.3280(10)°, Z= 2. For compound 11: monoclinic C2/c, a = 18.947(2) A, b = 9.7593(10) A, c = 19.761(2) A, (beta) = 97.967(2)°, Z = 8. Both complexes 6 and 7 are noninterpenetrating frameworks based on the (6, 3) nets, and 8, 9 and 10 are based on the (4, 4) nets while complex 11 has a twofold parallel interpenetrated network with 4.8 topology. It is interesting that, in complexes 6, 7, and 11 with three-coordinated planar silver(l) atoms, each ligand 4 or 5 connects three metal atoms, while in the case of complexes 8, 9, and 10 with six-coordinated octahedral metal atoms, each ligand 4 only links two metal atoms, and another imidazole nitrogen atom of 4 did not participate in the coordination with the metal atoms in these complexes. The results show that the nature of organic ligand and geometric needs of metal atoms have great influence on the structure of metal-organic frameworks.