Hydrothermal syntheses, crystal structures and photoluminescent properties of three metal-cluster based coordination polymers containing mixed organic ligands

Three novel metal-cluster based coordination polymers (MCCPs) with formulae [Zn-4(mu(3)-OH)(2)(H2O)(2)(sip)(2)(4,4'-bpy)(2)](.)3H(2)O (MCCP-4), [Cd-4(mu(3)-OH)(2)(H2O)(2)(sip)(2)(4,4'-bpy)(4)](H2O)-H-. (MCCP-5) and [Cd-6(mu(3)-OH)(4)(mu(2)-OH2)(2)(OH2)(2) nip)(4)(4,4'-bpy)(3)](.)3H(2)O (MCCP-6) [H(2)sip = 5-sulfoisophthalic acid, H(2)nip = 5-nitroisophthalic acid and 4,4'-bpy = 4,4'-bipyridyl] were hydrothermally synthesized and characterized by single-crystal X-ray diffraction studies. MCCP-4 crystallizes in the triclinic space group P (1) over bar with a = 10.106(2), b = 10.851(2), c = 11.125(2) Angstrom, alpha = 105.66(3), beta = 112.63(3), gamma = 98.18(3)degrees, V = 1041.8(4) Angstrom(3), and Z = 2. MCCP-5 crystallizes in the monoclinic space group C2/c with a = 25.602(1), b = 16.571(1), c = 13.322(1) Angstrom, beta = 92.524(1)degrees, V = 5646.4(2) Angstrom(3), and Z = 4. MCCP-4 and -5 consist of similar {M-4(mu(3)-OH)(2)](6+) tetranuclear building units that are joined through sip and 4,4'-bpy ligands to generate a two-dimensional structure (MCCP-4) and a three-dimensional structure (MCCP-5), respectively. MCCP-6 crystallizes in the triclinic space group P (1) over bar with a 14.295(2), b = 14.472(2), c = 20.204(3) Angstrom, alpha = 73.362(3), beta = 82.200(3), gamma = 62.769(2)degrees, V = 3560.9(10) Angstrom(3), and Z = 2. MCCP-6 contains unprecedented [Cd-6(mu(3)-OH)(4)(mu(2)-OH2)(2)](8+) hexanuclear building units which are linked through nip and 4,4'-bpy ligands to afford a two-dimensional structure. The infrared spectroscopy, thermal stability and photoluminescence of the three complexes were studied.