2-(3,5-Dinitrophenyl)-1,3-dithiane Carbanion: A Benzylic Anion with a Low Energy Triplet State
作者:Raffaele R. Perrotta、Arthur H. Winter、William H. Coldren、Daniel E. Falvey
DOI:10.1021/ja204711a
日期:2011.10.5
π-electron-withdrawing groups in the meta position(s) have low energy diradical or triplet electronic states. Specifically, the 2-(3,5-dinitrophenyl)-1,3-dithiane carbanion is predicted to have nearly degenerate singlet and triplet states at the (U)B3LYP level as a free anion. Its lithium ion pair is predicted to be a ground-state triplet with a substantial (26 kcal/mol) singlet-triplet energy gap. Experiments
DFT 水平的计算预测,在间位具有强 π 吸电子基团的苄基阴离子具有低能双自由基或三重电子态。具体而言,预计 2-(3,5-二硝基苯基)-1,3-二噻烷碳负离子在 (U)B3LYP 水平上作为游离阴离子具有几乎简并的单线态和三线态。预计它的锂离子对是基态三重态,具有相当大的(26 kcal/mol)单重态-三重态能隙。使用化学捕获、NMR 和 Evans 方法对该阴离子进行的实验强烈表明,该阴离子要么是三重态,要么是具有非常低能量三重态的基态单重态。