A new phosphorescent heteroleptic cuprous complex with a neutral 2-methylquinolin-8-ol ligand: synthesis, structure characterization, properties and TD-DFT calculations

• Published in: Acta crystallographica. Section C, Crystal structure communications Vol. 73; no. Pt 6; p. 486
• Main Authors: Shou, Rong Er, Song, Li, Chai, Wen Xiang, Qin, Lai Shun, Wang, Tian Gen
• Format: Journal Article
• Language: English
• Published: England Wiley Subscription Services, Inc 01.06.2017
• Subjects: Absorption; Abundance; Asymmetry; Atomic properties; Cations; Charge transfer; Chelation; Chemical synthesis; Copper; Density; Density functional theory; Emission analysis; Emitters; Ligands; Low cost; Mathematical analysis; Metals; Phosphorescence; Photoluminescence; Purity; Structural analysis; Time dependence; X-ray diffraction; X-rays; xanthene; phosphorescent emitter; luminescence; 2-methylquinolin-8-ol; crystal structure; OLED technology; diphenylphosphanyl; TD-DFT; heteroleptic cuprous complex
• ISSN: 0108-2701; 2053-2296; 1600-5759
• DOI: 10.1107/S2053229617007549

Luminescent Cu complexes have emerged as promising substitutes for phosphorescent emitters based on Ir, Pt and Os due to their abundance and low cost. The title heteroleptic cuprous complex, [9,9-dimethyl-4,5-bis(diphenylphosphanyl)-9H-xanthene-κ P,P](2-methylquinolin-8-ol-κ N,O)copper(I) hexafluorophosphate, [Cu(C H NO)(C H OP )]PF , conventionally abbreviated as [Cu(Xantphos)(8-HOXQ)]PF , where Xantphos is the chelating diphosphine ligand 9,9-dimethyl-4,5-bis(diphenylphosphanyl)-9H-xanthene and 8-HOXQ is the N,O-chelating ligand 2-methylquinolin-8-ol that remains protonated at the hydroxy O atom, is described. In this complex, the asymmetric unit consists of a hexafluorophosphate anion and a whole mononuclear cation, where the Cu atom is coordinated by two P atoms from the Xantphos ligand and by the N and O atoms from the 8-HOXQ ligand, giving rise to a tetrahedral CuP NO coordination geometry. The electronic absorption and photoluminescence properties of this complex have been studied on as-synthesized samples, whose purity had been determined by powder X-ray diffraction. In the detailed TD-DFT (time-dependent density functional theory) studies, the yellow emission appears to be derived from the inter-ligand charge transfer and metal-to-ligand charge transfer (M+L')→LCT excited state (LCT is ligand charge transfer).