Tuning the formation of cadmium(II) urocanate frameworks by control of reaction conditions: crystal structure, properties, and theoretical investigation.
The reaction of cadmium(II) perchlorate with urocanic acid under different conditions created three novel coordination compounds: [Cd2(L2)2-(L3)2(H2O)8] (1), {[Cd(L)(L2)](H2O)(1/2)}n (2), and {[Cd(L3)2](H2O)(3/2)(EtOH)}n (3), in which L, L2, and L3 are three urocanate tautomers. Complex 1 consists of two separate mononuclear units with different urocanate tautomers, which self-assemble into a 3D hydrogen-bonding network constructed by alternating 2D layers, whereas complexes 2 and 3 self-assemble into 3D alpha-polonium and four-fold interpenetrated diamondoid networks, respectively. The tautomerism of the urocanate ligands and the enormous structural diversity of their complexes are present in this system, which illustrates that the reaction temperature, pressure, and the metal ions themselves act cooperatively to tune the tautomerism of the ligands and the frameworks of their metal coordination compounds. The fluorescence-emission and nitrogen-adsorption properties of these complexes are also investigated.
Zou
Ru-Qiang
RQ
National Institute of Advanced Industrial Science and Technology, Ikeda, Osaka 563-8577, Japan.
Zhong
Rui-Qin
RQ
Jiang
Ling
L
Yamada
Yusuke
Y
Kuriyama
Nobuhiro
N
Xu
Qiang
Q