Air stable high-spin blatter diradicals: non-Kekulé <i>versus</i> Kekulé structures
作者:Xiaoguang Hu、Lei Zhao、Hanjiao Chen、Yousong Ding、Yan-Zhen Zheng、Mao-sheng Miao、Yonghao Zheng
DOI:10.1039/c8tc05150j
日期:——
Air stable high-spin diradicals under ambient conditions are relatively rare. We report two 1,2,4-benzotriazinyl based diradicals, non-Kekulé o-DBT and Kekulé p-DBT, with a highly twisted bridge. The studies of magnetic susceptibilities reveal that both diradicals possess singlet ground states and small singlet–triplet energy gaps (ΔEs–t = −0.21 and −0.18 kcal mol−1 for o-DBT and p-DBT, respectively)
在环境条件下,空气稳定的高旋转双自由基相对较少。我们提出两个基于1,2,4-苯并三双自由基,非凯库勒Ö - DBT和凯库勒p - DBT,具有高度扭曲的桥梁。磁化率的研究揭示,这两个二价基团具有单重基态和单重小-三重态能隙(Δ Ë S-T = -0.21 -0.18和千卡摩尔-1为ø - DBT和p - DBT,分别导致热可及的三重态激发态。此外,可变温度电子自旋共振公开了o - DBT和p - DBT的两个自旋中心之间的平均距离随温度升高而增加。最后,两个双自由基分子在高功率辐照和热处理下均显示出很高的稳定性。特别地,o - DBT粉末在高达270°C的温度下表现出出色的热稳定性,而没有明显的分解。