【摘要】 用半经验量子化学AM1方法分析了化合物3-溴咔唑-9-乙酸的分子构象.结果表明,化合物3-溴咔唑-9-乙酸晶体存在分子间非对称分叉型氢键;该非对称分叉型氢键支配化合物的堆积结构.与此同时,同咔唑环氮原子相连的羧甲基易在一定范围内摆动,分叉型氢键是晶体状态下和真空中羧甲基位置变化的原因之一;非对称分叉型氢键使分子体系得到4.97kJ/mol的额外稳定作用能.更多还原

【Abstract】 Semiempirical quantum chemistry AM1 method was adopted to analyze the molecular conformation of 3-Br-carbazole-9-yl-acetic acid.Results indicate that there exist asymmetrical bifurcated hydrogen bonds in 3-Br-carbazole-9-yl-acetic acid crystal,and the stacking structure of the crystal is dominated by the asymmetrical bifurcated hydrogen bonds.In the meantime,the caboxymethyl group connected with the carbazole nitrogen atom readily flaps within a certain range,and the varying locations of the caboxymethyl groups in the solid state and structure in vacuo of the compound can be partly attributed to the bifurcated hydrogen-bond.Besides,the asymmetric bifurcated hydrogen bond adds 4.97 kJ/mol of additional stabilization energy to the molecular system.更多还原