SOMO-HOMO level conversion in triarylmethyl-cored N-heterocyclic carbene-Au(I)complexes triggered by selecting coordination halogens  

作　　者：Le Zhang Hui-Yu Xie Xin Li Li-Ying Sun Ying-Feng Han 

机构地区：[1]Key Laboratory of Synthetic and Natural Functional Molecule of the Ministry of Education,Xi'an Key Laboratory of Functional Supramolecular Structure and Materials,College of Chemistry and Materials Science,Northwest University,Xi'an 710127,China

出　　处：《Chinese Chemical Letters》2024年第11期512-516,共5页中国化学快报（英文版）

基　　金：support from the National Natural Science Fund for Distinguished Young Scholars of China(No.22025107);Shaanxi Fundamental Science Research Project for Chemistry&Biology(No.22JHZ003);the National Youth Top-notch Talent Support Program of China,Xi’an Key Laboratory of Functional Supramolecular Structure and Materials,and the FM&EM International Joint Laboratory of Northwest University。

摘　　要：Conventionally,organic radicals adhere to the Aufbau principle,the energy level of the singly occupied molecular orbital(SOMO)is not below the highest occupied molecular orbital(HOMO),but somewhat abnormal phenomena have appeared recently.In this study,we introduce a novel strategy by incorporating unique NHC-Au-X units into a tris(2,4,6-trichlorophenyl)methyl(TTM)system to create metal-involved open-shell complexes,denoted as TTM-NHC-Au-X(X=I,Br,or Cl).Density-functional theory calculations were used to predict an inversion in the energy of the SOMO and highest doubly occupied molecular orbital(HOMO)of TTM-NHC-Au-I,which is supported by experimental results.Organometallic radicals TTM-NHC-Au-X demonstrated distinct properties with different coordinated halides.The radical behaviors have been investigated by EPR,UV-vis spectroscopy and cyclic voltammetry,additional structural information provided by structurally comparing related the precursor complexes given by X-ray crystallography.TTM-NHC-Au-I with SOMO-HOMO conversion(SHC)features a highly thermal decomposition temperature up to 305℃.Furthermore,the photostability of TTM-NHC-Au-I was found to be 75and 23 times greater than that of TTM-NHC-Au-Br and TTM-NHC-Au-Cl,respectively.These findings provide valuable insights into the structural and electronic design principles governing the occurrence of SOMO-HOMO conversion in open-shell systems.

关 键 词：SOMO-HOMO conversion N-heterocyclic carbenes Aufbau and non-Aufbau Electronic structure Halogen atoms Radical 

分 类 号：O641.4[理学—物理化学]