Department of Chemistry, University of Toronto , 80 St. George Street, Toronto, Ontario, M5S 3H6, Canada.
Inorg Chem. 2013 Dec 2;52(23):13779-90. doi: 10.1021/ic402485d. Epub 2013 Nov 19.
This study introduces small molecule tellurophenes that can undergo photoreductive elimination. A tellurophene compound with strong light absorption properties and extended π-conjugation, 2,5-bis[5-(N,N'-dihexylisoindigo)]tellurophene (1), has been synthesized. Halogen oxidative addition to the tellurium center from various halogen sources gives the dibromo- (1Br2) and dichloro- (1Cl2) adducts, leading to a red-shift in the optical absorption properties. In the presence of excess opposing halogen, 1Br2 and 1Cl2 can interconvert, with equilibrium favoring the dichlorotellurophene adduct. Reductive elimination reactions were studied using optical absorption spectroscopy, NMR spectroscopy, thermogravimetric analysis, and matrix-assisted laser desorption/ionization (MALDI) analysis. Thermal reductive elimination from 1Br2 and 1Cl2 occurs in the solid-state to restore 1. Photoreductive elimination occurs under irradiation with green (505 nm) light in solution in the presence of a halogen trap with some decomposition. This is the first example of photoreductive elimination from a mononuclear tellurophene complex.
本研究介绍了可经历光还原消除的小分子碲吩。已合成了具有强光吸收性质和扩展π共轭的碲吩化合物 2,5-双[5-(N,N'-二己基茚满)]碲吩（1）。来自各种卤源的卤原子对碲原子中心的氧化加成，得到了二溴化物（1Br2）和二氯化物（1Cl2）加合物，导致光吸收性质的红移。在过量相反卤素的存在下，1Br2 和 1Cl2 可以相互转化，平衡有利于二氯代碲吩加合物。使用光学吸收光谱、NMR 光谱、热重分析和基质辅助激光解吸/电离（MALDI）分析研究了还原消除反应。1Br2 和 1Cl2 的热还原消除在固态中发生，以恢复 1。在存在卤素捕获剂的情况下，在溶液中用绿光（505nm）照射发生光还原消除，伴有一些分解。这是首例单核碲吩配合物的光还原消除实例。
