缩氨基(硫)脲席夫碱化合物的自发对称性破缺研究

Abstract

[中文文摘]制备了4-苯基-1-(吡啶-2-亚甲基)氨基脲(PPMSC)和4-苯基-1-(吡啶-2-亚甲基)氨基硫脲(PPMTC).用元素分析、MS、1HNMR、UV吸收光谱、X射线单晶衍射和固体CD光谱等对其进行了表征.晶体结构数据显示PPMSC属于Sohncke P212121空间群,单个分子之间通过氢键形成一个一维螺旋链状结构,沿a轴形成左手螺旋结构.固体CD光谱和重结晶实验证明,PPMSC手性晶体的形成是结晶诱导的绝对不对称合成.PPMTC的固体CD光谱和重结晶实验具有与PPMSC类似现象.[英文文摘]Two (thio)semicarbazide compounds, 4-phenyl-1-(pyrid-2-ylmethylene)semicarbazide (PPMSC) and 4-phenyl-1-(pyrid-2-ylmethylene)thiosemicarbazide (PPMTC), were prepared and characterized by elemental analysis, MS, IR, 1H NMR, UV absorption spectra, solid-state circular dichroism (CD) spectra, and X-ray single-crystal diffraction. The X-ray crystallographic data indicated that PPMSC crystallized in a space group of Sohncke P212121, PPMSC molecules formed the left-handed helix running along the crystallographic axis a via the intermolecular hydrogen bondings. The solid-state CD spectra and repeated recrystallization revealed that the formation of chiral PPMSC crystals could be regarded as crystallizationinduced asymmetric synthesis. Although the crystal structure of PPMTC has not been obtained, PPMTC has the similar properties with PPMSC.