Helicene Aromaticity Deviates from the Clar Rule—On the Electronic Dissimilarity of Large Isomeric Fibonacenes
作者:Ludmilla Sturm、Albert Artigas、Yoann Coquerel、Ivan H. Bechtold、Fabien Durola、Harald Bock
DOI:10.1002/anie.202403170
日期:——
Long isomeric fibonacenes—a phenacene, a helicene and a croissant-shaped isomer—are found to show strikingly different absorption and emission spectra, despite their equivalent Kekulé structures. Complementary computations based either on magnetic or electronic criteria for aromaticity indicate that in long helicenes, the Clar and Kekulé rules of preferred sextet localization do not hold.
长异构体斐波那苯——非并苯、螺旋烯和羊角面包形异构体——被发现表现出截然不同的吸收和发射光谱,尽管它们具有相同的凯库勒结构。基于芳香性的磁性或电子标准的互补计算表明,在长螺旋烯中,首选六重奏定位的克拉和凯库勒规则不成立。