3D hydrogen bonded heteronuclear CoII, NiII, CuII and ZnII aqua complexes derived from dipicolinic acid

The heteronuclear water-soluble and air-stable compounds [M(H2O)(5)M'(dipic)(2)] - mH(2)O (M/M' = Cu-II/Co-II (1), Cu-II/Ni-II (2), Cu-II/Zn-II (3), Zn-II/Co-II (4), Ni-II/Co-II (5), m = 2-3; H(2)dipic = dipicolinic acid) have been prepared by self-assembly synthesis in aqueous solution at room temperature, and characterized by IR, LTV-Vis and atomic absorption spectroscopies, elemental and X-ray diffraction single crystal (for 1 and 2) analyses. 1-5 represent the first examples of heteronuclear dipicolinate compounds with 3d metals. Extensive H-bonding interactions involving all aqua ligands, dipicolinate oxygens and lattice water molecules further stabilize the dimetallic units by linking them to form three-dimensional polymeric networks. (c) 2006 Elsevier B.V. All rights reserved.