Yang E, Li Zhao-Ji, Zhang Jian, Chen Yu-Biao, Yao Yuan-Gen
State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002, People's Republic of China.
Acta Crystallogr C. 2004 Sep;60(Pt 9):m457-9. doi: 10.1107/S0108270104017378. Epub 2004 Aug 21.
The reaction of cadmium chloride with pyridine-2,6-dicarboxylic acid (PDA) and 98% H2SO4 in ethanol led to the formation of the title compound, bis[mu-6-(ethoxycarbonyl)pyridine-2-carboxylato]-1:2kappa4O6,N,O2:O2;1:2kappa4O2:O2,N,O6-bis[diaquachlorocadmium(II)] dihydrate, [Cd2(C9H8NO4)2Cl2(H2O)4].2H2O. PDA is esterified to monoethyl pyridine-2,6-dicarboxylate (MEPD) by the catalysis of H2SO4 during the reaction. The dinuclear Cd(II) complex lies about an inversion centre and the unique Cd atom has a pentagonal-bipyramidal geometry. The two Cd atoms are bridged by two carboxylate O atoms, forming a planar Cd2O2 unit. Stair-like chains are formed via O-H.Cl hydrogen bonds and these are further arranged into two-dimensional layers via hydrogen bonds involving solvate water molecules.
氯化镉与吡啶 - 2,6 - 二羧酸（PDA）以及98%的硫酸在乙醇中反应，生成了标题化合物二水合双[μ - 6 -（乙氧羰基）吡啶 - 2 - 羧基] - 1:2κ⁴O⁶,N,O²:O²;1:2κ⁴O²:O²,N,O⁶ - 双[二水氯镉（II）]，[Cd₂(C₉H₈NO₄)₂Cl₂(H₂O)₄]·2H₂O。反应过程中，PDA在硫酸催化下被酯化为单乙基吡啶 - 2,6 - 二羧酸酯（MEPD）。双核Cd（II）配合物位于一个反演中心周围，独特的Cd原子具有五角双锥几何构型。两个Cd原子通过两个羧酸根O原子桥连，形成一个平面Cd₂O₂单元。通过O - H…Cl氢键形成阶梯状链，并且这些链通过涉及溶剂化水分子的氢键进一步排列成二维层。
