title: Theoretical Studies of Photodeactivation Pathways of NHC-Chelate Pt(II) Compounds with Different Numbers of Triarylboron Units: Radiative and Nonradiative Decay Processes.
abstract: The radiative and nonradiative decay processes of four platinum(II) complexes chelated with triarylboron (TAB)-functionalized N-heterocyclic carbenes (NHC) are investigated by using density functional theory (DFT) and time-dependent DFT (TD-DFT) calculation, for probing into the influence of different numbers of TAB on the phosphorescent emission properties. For the radiative decay processes, zero-field splitting energies, radiative rates, and lifetimes are explored, and corresponding factors including transition dipole moments, singlet-triplet splitting energies as well as spin-orbit coupling matrix elements are also analyzed in detail. Additionally, energy-gap law is considered in the temperature-independent nonradiative decay processes; meanwhile, potential energy profiles are obtained to elaborate the temperature-dependent nonradiative decay processes. As a result, radiative rates declined slightly with the increased numbers of TAB. The minimum temperature-independent nonradiative decay may occur in BC-3 due to its smallest structural distortion between S0and T1states. According to the potential energy profiles of the deactivation pathways, four investigated phosphors have the similar temperature-dependent nonradiative decay processes because of the incredibly analogous energy barriers. We speculate that it does not mean greater phosphorescent emission and higher phosphorescent quantum yield with more TAB units, which would provide extraordinary assistance for further research in potential phosphors of organic light-emitting diodes.
authors.affiliation: Key Laboratory of Luminescence and Real-Time Analytical Chemistry, Ministry of Education, College of Chemistry and Chemical Engineering, Southwest University , Chongqing 400715, China.
authors.forename: Fengying
authors.initials: F
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Luminescence and Real-Time Analytical Chemistry, Ministry of Education, College of Chemistry and Chemical Engineering, Southwest University , Chongqing 400715, China.
authors.forename: Yanyan
authors.initials: Y
authors.lastname: Xu
authors.affiliation: Key Laboratory of Luminescence and Real-Time Analytical Chemistry, Ministry of Education, College of Chemistry and Chemical Engineering, Southwest University , Chongqing 400715, China.
authors.forename: Wenting
authors.initials: W
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Luminescence and Real-Time Analytical Chemistry, Ministry of Education, College of Chemistry and Chemical Engineering, Southwest University , Chongqing 400715, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Shen
authors.affiliation: Key Laboratory of Luminescence and Real-Time Analytical Chemistry, Ministry of Education, College of Chemistry and Chemical Engineering, Southwest University , Chongqing 400715, China.
authors.forename: Ming
authors.initials: M
authors.lastname: Li
authors.affiliation: Key Laboratory of Luminescence and Real-Time Analytical Chemistry, Ministry of Education, College of Chemistry and Chemical Engineering, Southwest University , Chongqing 400715, China.
authors.forename: Rongxing
authors.identifier: http://orcid.org/0000-0003-3100-2722
authors.initials: R
authors.lastname: He