Chiroptical Properties and the Racemization of Pyrene and Tetrathiafulvalene-Substituted Allene: Substitution and Solvent Effects on Racemization in Tetrathiafulvalenylallene
作者:Masashi Hasegawa、Seiya Iwata、Yasuto Sone、Junta Endo、Hideyo Matsuzawa、Yasuhiro Mazaki
DOI:10.3390/molecules19032829
日期:——
in various solvents and compared with that of 1,3-bis(tetrathiafulvalenyl)allene (bis-TTF-allene) derivative 2. The first-order rate plot of the intensity of the ECD spectra at a given time interval gave the rate of racemization. Mild racemization was observed in polar solvents, whereas a relatively fast rate was obtained in less polar solvents. In addition, the TTF groups of the allene also accelerate
不对称的 1,3-二苯基丙二烯衍生物 3 与 4,5-双(甲硫基)四硫富瓦烯基和 1-芘基取代基相连并被制备和表征。通过X-射线晶体学分析确定分子结构。使用循环手性 HPLC 完成光学拆分,并通过旋光度和电子圆二色性 (ECD) 光谱检查其手性。标题化合物在日光下进行光消旋化。在各种溶剂中研究了这种行为,并与 1,3-双(四硫富瓦烯基)丙二烯(双-TTF-丙二烯)衍生物 2 的行为进行了比较。 ECD 光谱在给定时间间隔内的强度的一级速率图给出了外消旋化率。在极性溶剂中观察到轻度外消旋化,而在极性较小的溶剂中获得相对较快的速率。此外,丙二烯的TTF基团也加快了外消旋化速度。这些结果表明外消旋化机制通过非极性双自由基结构发生。