Effect of the donor–acceptor properties of ligands on the spectroscopic and electrochemical properties of mixed-ligand complexes of Pt(II) and Ir(III) with cyclometalated 2-phenylbenzothiazole

• Published in: Optics and spectroscopy Vol. 122; no. 3; pp. 426 - 434
• Main Authors: Katlenok, E. A., Smirnov, S. N., Ivanov, A. Yu, Makarenko, S. V., Balashev, K. P.
• Format: Journal Article
• Language: English
• Published: Moscow Pleiades Publishing 01.03.2017; Springer Nature B.V
• Subjects: Charge transfer; Condensed-Matter Spectroscopy; Lasers; Ligands; Optical Devices; Optics; Photonics; Physics; Physics and Astronomy; Voltammetry
• ISSN: 0030-400X; 1562-6911
• DOI: 10.1134/S0030400X17030110

The results of the spectroscopic NMR ( 1 H, 13 C, and 195 Pt), infrared, optical, and voltammetric characteristics of the mixed-ligand complexes of Pt(II) and Ir(III) with metalated 2-phenylbenzothiazole and tert -butylisocyanide ( t BuNC), acetonitrile (AN), ethylenediamine (En), O -ethyldithiocarbamate (Exn – ), and diethyldithiocarbamate (Dtc–) ions are presented. It is demonstrated that the change in donor–acceptor interaction of ligands t BuNC, AN, En, Exn – , and Dtc – with metal leads to an increase in the energy of the highest occupied molecular orbital of the complexes and is accompanied by a shift of the cathode potential of the metal-centered oxidation, a bathochromic shift of the spin-allowed and spin-forbidden metal-tocyclometalated ligand optical charge transfer transitions, and an increase the degree of mixing of the 1 MLCT and triplet intraligand states, responsible for the phosphorescence of the complexes.