Soleimannejad Janet, Aghabozorg Hossein, Hooshmand Shabnam
Acta Crystallogr Sect E Struct Rep Online. 2008 Mar 20;64(Pt 4):m564-5. doi: 10.1107/S1600536808006594.
The title compound, (C(10)H(9)N(2))[Cr(C(7)H(3)NO(4))(2)]·4H(2)O or (4,4'-bipyH)[Cr(pydc)(2)]·4H(2)O (where 4,4'-bipy is 4,4'-bipyridine and pydcH(2) is pyridine-2,6-dicarboxylic acid), was synthesized by the reaction of chromium(III) chloride hexa-hydrate with pyridine-2,6-dicarboxylic acid and 4,4'-bipyridine in a 1:2:4 molar ratio in aqueous solution. This compound is composed of an anionic complex, Cr(pydc)(2), protonated 4,4'-bipyridine as a counter-ion, (4,4'-bipyH)(+), and four uncoordinated water mol-ecules. The anion is a six-coordinate complex with a distorted octa-hedral geometry around the Cr(III) atom, formed by two tridentate pyridine-2,6-dicarboxyl-ate, pydc(2-), groups. Inter-molecular O-H⋯O, N-H⋯O and C-H⋯O hydrogen bonds, and C-O⋯π stacking inter-actions (with distances of 3.3390 (13) and 3.4575 (13) Å) connect the various components into a supra-molecular structure.
标题化合物（C₁₀H₉N₂）[Cr（C₇H₃NO₄）₂]·4H₂O 或（4,4'-联吡啶鎓）[Cr（吡啶-2,6-二羧酸根）₂]·4H₂O（其中 4,4'-联吡啶为 4,4'-bipyridine，吡啶-2,6-二羧酸为 pydcH₂）通过六水合氯化铬（III）与吡啶-2,6-二羧酸和 4,4'-联吡啶以 1:2:4 的摩尔比在水溶液中反应合成。该化合物由一个阴离子配合物[Cr（pydc）₂]⁻、作为抗衡离子的质子化 4,4'-联吡啶（4,4'-bipyH⁺）和四个未配位的水分子组成。阴离子是一个六配位配合物，围绕 Cr（III）原子具有扭曲的八面体几何构型，由两个三齿的吡啶-2,6-二羧酸根（pydc²⁻）基团形成。分子间的 O—H⋯O、N—H⋯O 和 C—H⋯O 氢键以及 C—O⋯π 堆积相互作用（距离为 3.3390（13）和 3.4575（13）Å）将各个组分连接成一个超分子结构。
