Tuning electronic structure and photophysical properties of [Ir(ppy)₂(py)₂]+ by substituents binding in pyridyl ligand: a computational study.
Iridium (III) 2-phenylpyridine (ppy) complexes with two suitable monodentate L ligands [Ir(ppy)₂(L)₂]⁺ (ppy = 2-phenylpyridine, py = pyridine, L = 4-pyCN 1, 4-pyCHO 2, 4-pyCl 3, py 4, 4-pyNH₂ 5) were studied by density functional theory (DFT) and time-dependent DFT methods. The influences of ligands L on the electronic structure and photophysical properties were investigated in detail. The compositions and energy levels of the lowest unoccupied molecular orbital (LUMO) are changed more significantly than those of the highest occupied molecular (HOMO) by tuning L ligands. With the electronegativity decrease of L ligands 4-pyCN > 4-pyCHO > 4-pyCl > py > 4-pyNH₂, the LUMO distributing changes from py to ppy, and the absorptions have an obvious red shift. The calculated results showed that the transition character of the absorption and emission can be changed by adjusting the electronegativity of the L ligands. In addition, no solvent effect was observed in the absorptions and emissions.
School of Chemistry and Materials Science, Shanxi Normal University, Linfen 041004, China.
Ting-Ting
TT
Zhang
Xiao-Xia
XX
Qi
Jianfeng
J
Jia
Hai-Shun
HS
Wu
D000042:Absorption; D003198:Computer Simulation; D004583:Electrons; D007495:Iridium / Q000737:chemistry*; D008024:Ligands; D008027:Light; D049449:Luminescence; D008958:Models, Molecular; D008968:Molecular Conformation; D011725:Pyridines / Q000737:chemistry*; D011789:Quantum Theory; D012997:Solvents / Q000737:chemistry; D013057:Spectrum Analysis; D013816:Thermodynamics
D008024:Ligands; D011725:Pyridines; D012997:Solvents; C058324:2-phenylpyridine; D007495:Iridium