Theoretical Study and Design of Phosphorescent Cyclometalated (C∧C*)PtII(acac) Complexes: The Substituent Effect Controls the Radiative and Nonradiative Decay Processes

摘要: Density functional theory (DFT) and time-dependent DFT calculations were performed to evaluate the influence of substituent effect (1) R = 4-Me, (2) 4-OMe, (3) 2,3-OC6H4 on phenyl ring (C∧C*)PtII(acac) (C∧C* phenylimidazole, acac acetylacetone), respectively, absorption phosphorescent spectra properties, as well radiative nonradiative processes. We found that emissions complexes 2 3 originate from Kasha-like T1 state, whereas complex 1 originates non-Kasha T2 state. Compared with emission 1, peaks are red-shifted, which is attributed p−π π–π conjugation effects resulting electron-donating groups −OCH3 −OC6H4 ligand C∧C*, respectively. The rate constants (κr) larger than namely, κr(1) < κr(2) κr(3), indicating κr can be efficiently increased by enlarging π-conjugation at main (C∧C*)PtII(acac), cause increas...