Syntheses, Crystal Structures and Photoluminescence Property of Zinc(II) and Nickel(II) Complexes with 2,6-Bis(2-benzimidazolyl)pyridine

Two new supermolecular complexes, [Zn(BBPY)(DPA)]center dot H2O (1) and [Ni(BBPY]SO4 (2) were synthesized by the hydrothermal reaction of o-phenylenediamine, 2,6-dipicolinic acid (DPA) with Zn(O2CCH3)(2)center dot H2O or NiSO4 center dot 6H(2)O in 10% H3PO4 solution. Their structures were characterized by elemental analysis, IR spectral analysis and thermogravimetric analysis. The single crystal structures were determined by the X-ray single crystal diffraction. Complex (1) belongs to monoclinic system and the space group is Cc, the parameters of the crystal cell for the compound are a=1.694 5(12) nm, b=1.272 1(9) nm, c=1.065 8(7) nm, beta=92.506(12)degrees. The zinc (II) is coordinated with three nitrogen atoms of one 2,6-bis(2-benzimidazolyl)pyridine (BBPY) molecule, one nitrogen atom and two oxygen atoms of one DPA molecule, generating a distorted octahedral coordination geometry. Complex (2) belongs to monoclinic system and the space group is P2(1)/c, the parameters of the crystal cell for the compound are a=1.373 5(8) nm, b=1.383 8(8) nm, c=2.027 0(1 1) nm, beta=106.133(10)degrees. The nickel (II) is coordinated with six nitrogen atoms of two BBPY molecule, forming a distorted octahedral coordination geometry, too. Complex (1) shows a strong fluorescence-emission (lambda(max)=428.9 nm) at solid state. CCDC: 787387, 1; 787388, 2.