Coordination polymers of Cu(II) and Cd(II) with bifunctional chelates of the type dipicolylamino-alkylcarboxylate, (NC5H4CH2)(2)N(CH2)(n)CO2H (n=1, 2, 3 and 4)

摘要

A series of bifunctional chelates of the type dipicolylamino-alkylcarboxylate (NC5H4CH2)(2)N(CH2)(n)CO2H (n = 1-4; HL1-HL4, respectively) has been prepared. Reactions of the ligands in aqueous methanol/N,N-dimethylformamide with the appropriate Cu(II) salts yielded the compounds [CuL1](NO3)center dot H2O (1 center dot H2O), [CuL2(H2O)]BF4 center dot H2O (2 center dot H2O), [Cu(HL3)(SO4)](2) (3) and [CuL4(NO3)]center dot MeOH (4 center dot MeOH). While compounds 1, 2 and 4 are one-dimensional, the detailed connectivities within the chains are quite distinct, depending on factors such as alkyl chain length and ligation of aqua ligands or anionic components. In contrast to 1, 2 and 4, the structure of 3 is molecular, a binuclear assembly of edge-sharing Cu(II) '4+2' distorted octahedra The Cd(II) species, [{CdL2}(2)(SO4)]center dot 4H(2)O (5 center dot 4H(2)O), prepared from HL2 and CdSO4 center dot nH(2)O in aqueous methanol/N,N-dimethylformamide, is two-dimensional, with a network constructed from binuclear units of seven coordinate Cd(II), {CdL2}(2)(2+), linked through bridging SO42+ groups to produce an assembly of linked hexagonal rings [{CdL2}(2)(SO4)](6).