title: Authentic-blue phosphorescent iridium(III) complexes bearing both hydride and benzyl diphenylphosphine; control of the emission efficiency by ligand coordination geometry.
abstract: Sequential treatment of IrCl(3) x nH(2)O with 2 equiv of benzyl diphenylphosphine (bdpH) and then 1 equiv of 3-trifluoromethyl-5-(2-pyridyl) pyrazole (fppzH) in 2-methoxyethanol gave formation to three isomeric complexes with formula [Ir(bdp)(fppz)(bdpH)H] (1-3). Their molecular structures were established by single crystal X-ray diffraction studies, showing existence of one monodentate phosphine bdpH, one terminal hydride, a cyclometalated bdp chelate, and a fppz chelate. Variation of the metal-ligand bond distances showed good agreement with those predicted by the trans effect. Raman spectroscopic analyses and the corresponding photophysical data are also recorded and compared. Among all isomers complex 1 showed the worst emission efficiency, while complexes 2 and 3 exhibited the greatest luminescent efficiency in solid state and in degassed CH(2)Cl(2) solution at room temperature, respectively. This structural relationship could be due to the simultaneously weakened hydride and the monodentate bdpH bonding that are destabilized by the trans-pyrazolate anion and cyclometalated benzyl group, respectively.
authors: Department of Chemistry, National Tsing Hua University, Hsinchu 300, Taiwan.
authors: Yuan-Chieh
authors: YC
authors: Chiu
authors: Chen-Huey
authors: CH
authors: Lin
authors: Jui-Yi
authors: JY
authors: Hung
authors: Yun
authors: Y
authors: Chi
authors: Yi-Ming
authors: YM
authors: Cheng
authors: Kang-Wei
authors: KW
authors: Wang
authors: Min-Wen
authors: MW
authors: Chung
authors: Gene-Hsiang
authors: GH
authors: Lee
authors: Pi-Tai
authors: PT
authors: Chou
mesh_terms: D003198:Computer Simulation; D007495:Iridium / Q000737:chemistry*; D008024:Ligands; D049408:Luminescent Agents / Q000138:chemical synthesis / Q000737:chemistry*; D008956:Models, Chemical; D008958:Models, Molecular; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D010720:Phosphines / Q000737:chemistry*; D013237:Stereoisomerism; D014867:Water / Q000737:chemistry*
chemical_list: D008024:Ligands; D049408:Luminescent Agents; D009942:Organometallic Compounds; D010720:Phosphines; C544819:benzyl diphenylphosphine; D014867:Water; D007495:Iridium