Zhang Bing-Yu, Nie Jing-Jing, Xu Duan-Jun
Department of Chemistry, Zhejiang University, Hangzhou 310027, People's Republic of China.
Acta Crystallogr Sect E Struct Rep Online. 2009 Jul 22;65(Pt 8):m977. doi: 10.1107/S1600536809028347.
In the crystal structure of the title Ni(II) complex, [Ni(C(6)H(4)NO(3))(2)(C(3)H(4)N(2))(2)], the Ni(II) atom is located on a twofold rotation axis and is chelated by two oxidopyridiniumcarboxyl-ate anions and further cis-coordinated by two imidazole ligands in a distorted cis-N(2)O(4) octa-hedral geometry. The C-O bond distance of 1.2573 (19) Å found for the non-coordinating O atom of the carboxyl-ate group indicates significant delocalization of π-electron density over this residue. Similarly, the C-O bond distance of 1.260 (2) Å in the heteroaromatic ring indicates delocalization between the deprotonated hydr-oxy group and the pyridinium ring. The uncoordinated carboxyl-ate O atom links with the imidazole and pyridinium rings of adjacent mol-ecules via N-H⋯O and C-H⋯O hydrogen bonding, leading to a two-dimensional array parallel to (100).
在标题镍（II）配合物[Ni(C₆H₄NO₃)₂(C₃H₄N₂)₂]的晶体结构中，镍（II）原子位于一个二次旋转轴上，被两个氧化吡啶羧酸根阴离子螯合，并在扭曲的顺式-N₂O₄八面体几何构型中进一步与两个咪唑配体顺式配位。羧酸根基团的非配位O原子的C - O键长为1.2573（19）Å，表明该残基上π电子密度有显著离域。同样，杂芳环中C - O键长为1.260（2）Å，表明去质子化的羟基与吡啶环之间存在离域。未配位的羧酸根O原子通过N - H⋯O和C - H⋯O氢键与相邻分子的咪唑和吡啶环相连，形成平行于（100）的二维阵列。
