Theoretical investigations of the substituent effect on the absorption and emission properties for a series of platinum (II) complexes supported by tetradentate N2O2 chelates |
| |
Authors: | Li Yang Ji-Kang Feng Ai-Min Ren |
| |
Institution: | aState Key Laboratory of Theoretical and Computational Chemistry, Institute of Theoretical Chemistry, Jilin University, 119 Jie Fang Road, Changchun 130023, People's Republic of China bThe College of Chemistry, Jilin University, Changchun 130023, People's Republic of China |
| |
Abstract: | The photophysical properties, which vary as R is varied, of a series of Pt(N2O2)] complexes bearing bis(phenoxy)bipyridine auxiliaries with different substituents R=H (Pt-H) (1), 4,4′-2NH2 (Pt-NH2) (2), 4,4′-2tBu (Pt-tBu) (3), 4,4′-2CN (Pt-CN) (4), and 4,4′-2NO2 (Pt-NO2) (5) are investigated using density functional theory (DFT) and time-dependent density functional theory (TDDFT). The solvent effects are discussed in CH2Cl2, CH3CN and CH3OH solutions, respectively, by polarizable continuum model (PCM). It is anticipated that compared with σ-donor substituents, π-acceptors have more dramatic effects on the electronic and optical properties in this series of complexes. Introduction of π-electron withdrawing substituents on bipyridine ligand will benefit the LLCT (or MLCT) and prohibit the non-radiative pathways via d–d transitions by increasing the energy gap between the HOMO–LUMO and d–d transitions. The results also reveal that the lowest-energy excitations of all complexes show blue-shifts in the polarized solution and when the polarity of the solvent increases from CH2Cl2, CH3CN and CH3OH, the low-energy broad absorption band exhibit blue-shifts. The lowest-energy excitations and photoluminescence of all complexes are dominated by π(phenoxy)→π*(bpy/NO2) (LLCT) excited state mixed with some energetically dπ (Pt)→π*(bpy/NO2) (MLCT) transition. |
| |
Keywords: | Pt Photophysical property DFT PCM |
本文献已被 ScienceDirect 等数据库收录! |
|