Yun-xia Che

X-ray crystal structure, spectral and magnetic properties of end-to-end di-μ-thiocyanatobis(imidazole)M(II) polymeric complexes (M=Co, Mn): supramolecular network structure based on N–H ··· S hydrogen bonding and π ··· π stacking

Two isomorphous one-dimensional chain complexes Co(NCS)2(Him)2 (1) and Mn(NCS)2(Him)2 (2) (Himu2009=u2009imidazole) have been prepared and characterized structurally. Both 1 and 2 crystallize in the monoclinic system, space group P21/n, and the structures consist of one-dimensional polymeric chains in which metal ions are bridged by two thiocyanate groups bonding in end-to-end fashion. Both 1 and 2 exhibit two-dimensional sheet structures with N–Hu2009···u2009S hydrogen bonds and three-dimensional supramolecular network structure with πu2009···u2009π stacking interactions. IR spectra indicate the presence of bridging thiocyanate groups in both 1 and 2, confirmed by their structures. The variable temperature magnetic susceptibility, measured in the 2–300u2009K range, indicates weak antiferromagnetic exchange interactions in complex 2.

Syntheses and crystal structures of two Cd(II) coordination polymers: one-dimensional chain [Cd(C4H6N2)2(C4H2O4)(H2O)2] n and two-dimensional sheet [Cd(C4H6N2)(H2O)(C4H4O4)] n · n H2O

Two new Cd(II) coordination polymers, [Cd(C4H6N2)2(C4H2O4)(H2O)2] n (1) (where C4H6N2u2009=u20092-methylimidazole, C4H2O4u2009=u2009fumarate), and [Cd(C4H6N2)(H2O)(C4H4O4)] n u2009·u2009nH2O (2), (where C4H4O4u2009=u2009succinates), have been prepared and structurally characterized by single crystal X-ray diffraction. Complex 1 crystallizes in the triclinic space group P 1 in a one-dimensional chain structure, in which carboxy is monodentate; a three-dimensional supermolecular network structure was formed through hydrogen bonding. In complex 2, the coordination geometry of the Cd atoms is a pentagonal bipyramid, and a two-dimensional sheet is formed though carboxyl group bridging. In 1 and 2, IR spectra indicate the presence of bridging carboxyl groups, confirmed by structure analyses.

Synthesis and structure of a hybrid-metallic complex [Cu4(obpy)4(Mo2O7)] containing CuI/CuII unit

An organic–inorganic hybrid mixed-valence CuI/CuII tetranuclear polymer [Cu4(obpy)4(Mo2O7)] 1 (Hobpyu2009=u20096-hydroxy-2,2′-bipyridine) has been prepared and structurally determined. [Cu4(obpy)4(Mo2O7)] 1 crystallizes in the triclinic space group P- 1, with au2009=u20099.995(5), bu2009=u200910.678(6), cu2009=u200910.838(6)u2009Å, αu2009=u200990.698(6), βu2009=u2009113.891(6), γu2009=u2009106.018(6) °, Zu2009=u20091. Two [Cu2(obpy)2]+ building units linked with one μ2-bridging molybdate dimer result in a dumbbell-like tetranuclear complex, which extends to a one-dimensional chain by π–π stacking interaction between adjacent 2,2′-bipy ligands.