Abstract
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 struc-turally 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 car-bene ligands play a crucial role to achieve the luminescence of Ni(Ⅱ)complexes.
基金项目
国家自然科学基金(22175191)
CAS-Croucher Funding Scheme for Joint Laboratories()
北京市科委项目(Z211100007921020)
NETL
NSTL
万方数据