Efficient Blue-Emitting Ir(III) Complexes with Phosphine Carbanion-Based Ancillary Ligand: A DFT Study

• Published in: The journal of physical chemistry. A, Molecules, spectroscopy, kinetics, environment, & general theory Molecules, spectroscopy, kinetics, environment, & general theory, 2011-10, Vol.115 (42), p.11689-11695
• Main Authors: Wang, Jian, Bai, Fu-Quan, Xia, Bao-Hui, Zhang, Hong-Xing
• Format: Article
• Language: English
• Subjects: A: Molecular Structure, Quantum Chemistry, General Theory; Color; Density functional theory; Electronic structure; Emission; Emission analysis; Grounds; Ligands; Phosphines
• ISSN: 1089-5639; 1520-5215
• DOI: 10.1021/jp200878y

We report a theoretical study on a series of heteroleptic cyclometalated Ir(III) complexes for OLED application. The geometries, electronic structures, and the lowest-lying singlet absorptions and triplet emissions of [(fppy)2Ir(III)(PPh2Np)] (1), and theoretically designed models [(fppy)2Ir(III)(PH2Np)] (2) and [(fppy)2Ir(III)Np]−(3) were investigated with density functional theory (DFT)-based approaches, where, fppyH = 4-fluorophenyl-pyridine and NpH = naphthalene. The ground and excited states were, respectively, optimized at the M062X/LanL2DZ;6-31G* and CIS/LanL2DZ:6-31G* level of theory within CH2Cl2 solution provided by PCM. The lowest absorptions and emissions were evaluated at M062X/Stuttgart;cc-pVTZ;cc-pVDZ level of theory. Though the lowest absorptions and emissions were all attributed as the ligand-based charge–transfer transition with slight metal-to-ligand charge–transfer transition character, the subtle differences in geometries and electronic structures result in the different quantum yields and versatile emission color. The newly designed molecular 3 is expected to be highly emissive in deep blue region.