Tuning the photophysical and electrochemical properties of iridium(III) 2-aryl-1-phenylbenzimidazole complexes

Iridium(III) 2‐Phenylbenzimidazole Complexes: Synthesis, Structure, Optical Properties, and Applications in Dye‐Sensitized Solar Cells

“…As Ir d orbitals link the π-systems of the C N and N N ligands, their contribution to the occupied MOs of 1-3 immediately affects the intensity of LLCT. [16] The greater contribution of the Ir d orbitals, the more intensive LLCT and, clearly, MLCT bands. For example, ε max of G1 is much lower than those of G2-G4, especially for complex 3, where the contribution of the Ir d orbitals in HOMO-1 is 13 % (Table S3).…”

“…In our previous paper, [16] Ir III 2-arylbenzimidazole complexes, particularly 3, were shown to be promising candidates for applications in DSSC as dyes owing to their suitable redox potentials of the ground and excited states and good optical characteristics. Unfortunately, 1 and 2 demonstrated irreversible redox behavior and poor solubility in most organic solvents (except DMSO).…”

“…All the complexes were synthesized by a two-stage method including a modified version of Nonoyama's synthesis [18] for the preparation of the cyclometalated μ-chlorobridged iridium(III) dimers [(C N) 2 Ir(μ-Cl) 2 Ir(C N) 2 ] followed by their reaction with H 2 dcbpy, and finally with NH 4 PF 6 to produce the desired complexes. [16] After washing the intermediate iridium(III) dimers with water, ethanol, and ether (to eliminate unreacted starting material), they were used in the second step without characterization or further purification. [16] .…”

“…[16] After washing the intermediate iridium(III) dimers with water, ethanol, and ether (to eliminate unreacted starting material), they were used in the second step without characterization or further purification. [16] .…”

“…[14,15] Recently, we have studied two series of Ir III complexes with 2-aryl-1-phenylbenzimidazoles in which the aryl unit was modified by electron-donating/withdrawing groups. [16,17] The probability of electronic transitions from donor to acceptor ligands was shown to depend dramatically on the contribution of the Ir d orbitals to the occupied MOs of the complexes. The incorporation of different substituents into the benzimidazole unit of similar C N ligands is very likely to be useful for further vary- (3), where LH = 1-H-2-phenylbenzimidazole, LMe = 1-methyl-2-phenylbenzimidazole, LPh = 1,2-diphenylbenzimidazole, and H 2 dcbpy = 2,2′-bipyridine-4,4′-dicarboxylic acid.…”