1609033-44-4Relevant articles and documents
Tuning the photophysical and electrochemical properties of iridium(III) 2-aryl-1-phenylbenzimidazole complexes
Bezzubov, Stanislav I.,Doljenko, Vladimir D.,Troyanov, Sergey I.,Kiselev, Yuri M.
, p. 22 - 30 (2014)
A series of heteroleptic bis-cyclometalated iridium(III) complexes, [Ir(cpbi)2(H2dcbpy)][PF6] (1), [Ir(pbi) 2(H2dcbpy)][PF6] (2), and [Ir(mpbi) 2(H2dcbpy)][PF6] (3), where pbi = 1,2-diphenylbenzimidazole, cpbi = 2-(4-chlorophenyl)-1-phenylbenzimidazole, mpbi = 2-(3,4-dimethoxyphenyl)-1-phenylbenzimidazole, and H2dcbpy = 2,2′-bipyridine-4,4′-dicarboxylic acid has been synthesized and characterized by elemental analysis, 1H, 31P NMR, and high resolution mass-spectra. Molecular structure of complex 3 has been determined from single-crystal X-ray analysis. The complexes exhibit absorption up to 550 nm with molar absorptivities of 2500 M-1 cm-1. They have strong luminescence in broad yellow-to-red region in solutions at room temperature. While chloro-substituent (complex 1) causes a little hypsochromic shift of the absorption maxima compared to unsubstituted 2, introduction of two methoxy-groups (complex 3) gives rise to a bathochromic shift of about 100 nm. Alternating current voltammetry studies of the complexes indicates reversible oxidation and reduction potentials. Calculated excited state oxidation potentials for 1-3 are negative enough to efficiently inject electrons into the conduction band of TiO2 (EF). 2014 Elsevier B.V. All rights reserved.
