Distinct Hydrogen-bonded MII(H2O)8 Clusters as Second Building Units for 1-D, 2-D and 3-D Supramolecular Architectures (M = Cobalt and Nickel)

摘要

Two mononuclear metal-organic complexes, [Co(Hmpdc)2(H2O)4]·4H2O 1 and [Ni(Hfmpdc)2(H2O)4]·6H2O 2, were prepared from 2,6-dimethylpyridine-3,5-dicarboxylic acid (H2mpdc) and 4-furyl-2,6-dimethylpyridine-3,5-dicarboxylic acid (H2fmpdc) with M(NO3)2 salts, respectively, and characterized by single-crystal X-ray diffraction, elemental analyses, IR spectroscopy, and photoluminescent measurement. Complex 1 crystallizes in triclinic, space group P with a = 7.634(5), b = 8.695(5), c = 10.757(6)(A), α = 69.647(7), β = 69.957(8), γ = 83.733(7)°, V = 628.9(7)(A)3, Dc = 1. 561 g/cm3, μ(MoKα) = 0.763 mm-1, F(000) = 309, Z = 1, the final R = 0.0553 and wR = 0.1469 for 1909 observed reflections (I > 2σ(I)). Complex 2 crystallizes in monoclinic, space group P21 with a = 9.5934(16), b = 12.422(2), c = 14.826(3)(A), β = 105.201(2)°, V = 1705.0(5)(A)3, Dc = 1. 479 g/cm3, μ(MoKα) = 0.655 mm-1, F(000) = 796, Z = 2, the final R = 0.0351 and wR = 0.0889 for 2387 observed reflections (I > 2σ(I)). In the crystal structures of 1 and 2, diverse supramolecular motifs from 1-D chains/ladders to 3-D networks are constructed from corresponding distinct [MⅡ(H2O)8] ion clusters as the second building units, respectively. The solid state compounds of 1 and 2 show similar photoluminescent spectra with emission maximum at ca. 466 nm at room temperature.