Inorganic Chemistry, Vol.53, No.8, 4130-4143, 2014
Tuning of Valence States, Bonding Types, Hierarchical Structures, and Physical Properties in Copper/Halide/lsonicotinate System
Seven cupric halide coordination polymers, namely [Cu-5(OH)(3)Br-3(ina)(4)] (1), [Cu-5(OH)(3)Cl-3(ina)(4)] (2,), [Cu-2(OH)Cl(ina)(2)] (3), [Cu-3(OH)(2)Cl-2(ina)(2)]center dot 2H(2)O (4), [Cu-3(OH)(2)Br-2(ina)(2)]center dot 2H(2)O (5), [Cu2Cl2(ina)(2)(H2O)(2)] (6), [Cu2Cl(ina)(2)(gca)(H2O)] (7), cupric complex templated cuprous halide [Cu-II(Me-ina)(2)(H2O)]-[Cu(5)(1)Br7] (8), and organic templated cuprous halide Me-2-ina[Cu2Br3] (9) (Hina = isonicotinic acid),were prepared from the starting materials of cupric halide and Hina via fine-tuning solvotherrnal reactions. According to valence states of copper, 1-7 are copper(II) complexes, 8 is a mixed-valent Cu(I,II) complex, while 9 is a Cu(I) compound. According to bonding types of halides, nine complexes can be classified as three types: complexes 1-3 include only normal X- Cu bond (X = halide); complexes 4-7 include normal X-Cu bond and X Cu weak bond; complexes 8 and 9 include normal X-Cu bond and X center dot center dot center dot H-C halogen hydrogen bonds. Complexes 1 and 2 are isomorphic three-dimensional (3D) pcu topological metal organic frameworks (MOFs) with butterfly-like Cu-4(mu(3)-OH)(2)X-2 and steplike Cu-6(mu(3)-OH)(4) cores as nodes, showing strong ferromagnetic couplings. Complex 3 also is a pcu topological MOF with only butterfly-like Cu-4(mu(3)-OH)(2)Cl-2 clusters as nodes, presenting spin canting antiferromagnetic behavior. Isostructural 4 and 5 are Cu-3(OH)(2) clusters based two-dimensional (2D) (4,4) layers, which are extended into 3D eight-connected networks via weak Cu center dot center dot center dot X bonds, showing ferromagnetic coupling. Antiferromagnetic 6 is a simple one-dimensional coordination polymer, which is extended via weak Cu center dot center dot center dot Cl bonds into 3D (3,4)-connected networks. Paramagnetic 7 is a ladderlike polymer, which is extended into 2D (3,4)-connected layer via weak Cu center dot center dot center dot Cl bonds. The syntheses of polymeric cupric complexes 1-7 mainly result from differences in reactant ratio and pH value. Utilization of reducing methanol generated novel cubane-containing [Cu5Br7](2-) chain templated by paddlewheel-like [Cu-II(Me-ina)(2)](2+) 8 and face-shared dimer-containing [Cu2Br3](-) chain templated by N-methylated and O-esterificated Me-2-ina 9. Complex 9 exhibits a strong red emission and a weaker green emission upon excitation.