Syntheses and crystal structures of two cobalt carboxylate-phosphonates with 4,4′-bipyridine as a secondary metal linker

The hydrothermal syntheses and crystal structures of two novel cobalt carboxylate-phosphonates with 4,4'-bipyridine (4,4'-bipy) as the secondary metal linker are reported. Compound 1, [Co-3(H2L)(2)(H2O)(4)(4,4'-bipy)], where H5L = 4HO(2)CC(6)H(4)CH(2)N(CH2PO3H2)(2), crystallizes in the monoclinic space group C2/c with a = 25.9281(5), b = 9.76310(10), c = 17.3671(5) Angstrom, beta = 103.290(2)degrees, V = 4278.6(2) Angstrom(3), and Z = 4. Its structure contains a pillar-layered architecture in which Co-II octahedra are linked by carboxylate-phosphonate ligands to form a 2D layer and these layers are crosslinked further by 4,4'-bipy ligands to form a porous 3D network. Compound 2, [Co-2(PMIDA)(H2O)(5)(4,4'-bipy)]-4H(2)O, where H(4)PMIDA = H2O3PCH2N(CH2CO2H)(2), crystallizes in the triclinic space group P1 with a = 7.8009(7), b = 13.4560(12), c = 13.5453(12) Angstrom, alpha = 65.207(2), beta = 88.035(2), gamma = 77.135(2)degrees, V = 1255.57(19) Angstrom(3), and Z = 2. The crystal structure of compound 2 contains 1D zigzag chains in which two cobalt(n) ions are bridged by PMIDA ligand to form dimeric units, and these dimeric units are connected further by bridging 4,4'-bipy ligands. ((C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004).