【摘要】 以5-硝基间苯二甲酸与硝酸钬在水溶液中反应制备了配合物Ho2(5-nip)2-(5-Hnip)2(H2O)8·4H2O(5-H2nip为5-硝基间苯二甲酸),并对其进行了元素分析、红外、热重和X-射线单晶衍射表征.结构分析表明,配合物中5-Hnip?以?2-?1:?1双齿桥连模式将两个相邻Ho3+离子连接成二聚体形式,分子间的O–H···O氢键和三种不同的?-?堆积作用使相邻的二聚体单元与游离水分子形成三维超分子结构.运用RD496-2000型微热量计在298.15 K下测定了该化合物在水溶液中生成反应的焓变.设计合理的热化学循环,辅助文献的热化学数据,以Hess定律计算得到了该化合物在298.15 K下的标准摩尔生成焓θf m?H为?(3371.5±16.9)kJ/mol.更多还原

【Abstract】 A lanthanide coordination compound, Ho2(5-nip)2(5-Hnip)2(H2O)8·4H2O(5-H2nip = 5-nitroisophthalic acid), has been synthesized and characterized by elemental analysis, IR, TG-DSC, and single-crystal X-ray diffraction. Structural analysis reveals that the adjacent Ho3+ centers are bridged by the 5-Hnip? ligands with ? 2-? 1:? 1 bidentate mode into dimmers, which are further interconnected by abundant hydrogen bonds and three different kinds of ?-? packing interactions to generate a 3D supramolecular architecture. The molar enthalpy of dissolution in water for Ho(NO3)3·5H2O, the enthalpy change of reaction of formation in water, are determined to be at(298.15 ± 0.01) K by microcalorimetry. Based on a designed reasonable thermochemical cycle and Hess’ s law, the standard molar enthalpy of formation at(298.15 ± 0.01) K for the title compound,θmf?H, is calculated to be ?(3371.5 ± 16.9) kJ/mol.更多还原