Photoluminescent nickel(Ⅱ)carbene complexes with ligand-to-ligand charge-transfer excited states  

作　　者：Chun-Liang Hou Jia-Xi Song Xiaoyong Chang Yong Chen 

机构地区：[1]Key Laboratory of Photochemical Conversion and Optoelectronic Materials&CAS-HKU Joint Laboratory on New Materials,Technical Institute of Physics and Chemistry,Chinese Academy of Sciences,Beijing 100190,China [2]University of Chinese Academy of Sciences,Beijing 100049,China [3]Department of Chemistry,Southern University of Science and Technology,Shenzhen 518055,China

出　　处：《Chinese Chemical Letters》2024年第1期357-360,共4页中国化学快报（英文版）

基　　金：the Natural Science Foundation of China(No.22175191);Y.C.thanks the financial support from CAS-Croucher Funding Scheme for Joint Laboratories and Beijing Municipal Science&Technology Commission(No.Z211100007921020).

摘　　要：While nickel(II)complexes have been widely used as catalysts for carbon-carbon coupling reactions,the exploration of their photophysical and photochemical properties is still in the infancy.Here,a series of square-planar Ni(II)complexes[(diNHC)NiX2]bearing chelating benzimidazole-based bis(N-heterocyclic carbene)ligands and varying anionic coligands(1,X=Cl;2,X=Br;3,X=I)are synthesized and structurally characterized.In solid state,both 1 and 2 exhibit orange-red photoluminescence under ambient conditions.The photophysical and electrochemical measurements along with density functional theory(DFT)calculations reveal that the low-energy emissions can be attributed to singlet excited states with ligand-to-ligand charge-transfer(LLCT)character.This work suggests that strong-field N-heterocyclic carbene ligands play a crucial role to achieve the luminescence of Ni(II)complexes.

关 键 词：Nickel(II)complexes N-Heterocyclic carbene Luminescence Ligand-to-ligand charge-transfer character Low-lying d-d excited states 

分 类 号：O641.4[理学—物理化学]