Yang, Cheng-Han published the artcileHeteroleptic Cyclometalated Iridium(III) Complexes Displaying Blue Phosphorescence in Solution and Solid State at Room Temperature, SDS of cas: 219508-27-7, the publication is Inorganic Chemistry (2005), 44(22), 7770-7780, database is CAplus and MEDLINE.
A series of heteroleptic Ir(III) metal complexes 1–3 bearing two N-phenyl-substituted pyrazoles and one 2-pyridyl pyrazole (or triazole) ligands were synthesized and characterized to attain highly efficient, room-temperature blue phosphorescence. The N-phenylpyrazole ligands, dfpzH = 1-(2,4-difluorophenyl)pyrazole, fpzH = 1-(4-fluorophenyl)pyrazole, dfmpzH = 1-(2,4-difluorophenyl)-3,5-dimethylpyrazole, and fmpzH = 1-(4-fluorophenyl)-3,5-dimethylpyrazole, show a similar reaction pattern with respect to the typical cyclometalated (C-N) chelate, which utilizes its ortho-substituted Ph segment to link with the central Ir(III) atom, while the second 2-pyridylpyrazole (or triazole) ligand, namely, fppzH = 3-(trifluoromethyl)-5-(2-pyridyl)pyrazole, fptzH = 3-(trifluoromethyl)-5-(2-pyridyl)triazole, and hptzH = 3-(heptafluoropropyl)-5-(2-pyridyl)triazole, undergoes typical anionic (N-N) chelation to complete the octahedral framework. X-ray structural analyses on complexes [(dfpz)2Ir(fppz)] (1a) and [(fmpz)2Ir(hptz)] (3d) were established to confirm their mol. structures. Increases of the ππ* energy gaps of the Ir(III) metal complexes were systematically achieved with two tuning strategies. One involves the substitution for one or two fluorine atoms at the N-Ph segment or the introduction of two electron-releasing Me substituents at the pyrazole segment of the H(C-N) ligands. Alternatively, we have applied the more electron-accepting triazolate in place of the pyrazolate segment for the third (N-N)H ligand. Our results, on the basis of steady-state, relaxation dynamics, and theor. approaches, lead to a conclusion that, for complexes 1–3, the weakening of iridium metal-ligand bonding strength in the T1 state plays a crucial role for the fast radiationless deactivation. For the case of [(fmpz)2Ir(hptz)] (3d), a thermal deactivation barrier of 4.8 kcal/mol was further deduced via temperature-dependent studies. The results provide a theor. basis for future design and synthesis of the corresponding analogs suited to blue phosphorescent emitters.
Inorganic Chemistry published new progress about 219508-27-7. 219508-27-7 belongs to triazoles, auxiliary class Trifluoromethylated Building Blocks, name is 2-[5-(Trifluoromethyl)-1H-1,2,4-triazol-3-yl]pyridine, and the molecular formula is C8H6ClNO, SDS of cas: 219508-27-7.
Referemce:
https://en.wikipedia.org/wiki/1,2,3-Triazole,
Triazoles – an overview | ScienceDirect Topics