中山大学谭庚文团队报道了一种三联体亚硝基化合物的分离与表征。相关研究成果发表在2024年11月19日出版的国际学术期刊《自然—化学》。

硝基自由基化合物是各种含氮转化中的短寿命中间体。根据取代基的电子性质，它们具有单重态或三重态基态。三重态氮具有高度反应性，在环境条件下在冷凝相中分离它们具有挑战性。

该文中，研究人员报告了一种由大体积醇二烯配体支撑的三重芳基硝胺的合成和分离。芳基硝基芳烃通过各种光谱和结构技术进行了充分表征，包括电子顺磁共振光谱和单晶X射线衍射。其高稳定性在很大程度上归因于，支持配体提供的空间位阻和有效的电子离域。

电子顺磁共振光谱结合高度相关的基于波函数的从头计算，为轴向零场分裂D=0.92cm^-1和消失菱形E/D=0.002的三重态基态硝烯提供了支持。

附：英文原文

Title: Isolation and characterization of a triplet nitrene

Author: Wang, Dongmin, Chen, Wang, Chen, Haonan, Chen, Yizhen, Ye, Shengfa, Tan, Gengwen

Issue&Volume: 2024-11-19

Abstract: Nitrene radical compounds are short-lived intermediates in a variety of nitrogen-involved transformations. They feature either a singlet or a triplet ground state, depending on the electronic properties of the substituents. Triplet nitrenes are highly reactive and their isolation in the condensed phase under ambient conditions is challenging. Here we report the synthesis and isolation of a triplet arylnitrene supported by a bulky hydrindacene ligand. The arylnitrene is fully characterized by various spectroscopic and structural techniques including electron paramagnetic resonance spectroscopy and single-crystal X-ray diffraction. Its high stability is largely attributed to the steric hindrance and effective electron delocalization provided by the supporting ligand. Electron paramagnetic resonance spectroscopy in conjunction with highly correlated wavefunction-based ab initio calculations provides support for a triplet ground state nitrene with axial zero-field splitting D=0.92cm–1 and vanishing rhombicity E/D=0.002.

DOI: 10.1038/s41557-024-01669-9

Source: https://www.nature.com/articles/s41557-024-01669-9