Water-soluble dinuclear iridium(iii) and ruthenium(ii) bis-terdentate complexes: photophysics and electrochemiluminescence. Issue 36 (30th August 2022)

• Record Type: Journal Article
• Authors: Liu, Bingqing; Yang, Xin; Jabed, Mohammed; Kilina, Svetlana; Yang, Zhengchun; Sun, Wenfang
• Is Part Of: Dalton transactions. Volume 51:Issue 36(2022)
• Page Start: 13858
• Page End: 13866
• Publication Date: 2022-08-30
• Subjects: Chemistry, Inorganic -- Periodicals; Chemistry, Physical and theoretical -- Periodicals; Chemistry, Inorganic -- Periodicals; 546.05
• DOI: 10.1039/d2dt02104h
• Languages: English
• ISSNs: 1477-9226

Abstract

Abstract : The photophysics and electrochemiluminescence properties of four water-soluble dinuclear Ir(iii ) and Ru(ii ) complexes are impacted by the terminal-capping 4′-phenyl-2, 2′:6′, 2"-terpyridine or 1, 3-di(pyrid-2-yl)-4, 6-dimethylbenzene ligands and by the metal centers. Abstract : The synthesis, photophysics, and electrochemiluminescence (ECL) of four water-soluble dinuclear Ir(iii ) and Ru(ii ) complexes (1–4 ) terminally-capped by 4′-phenyl-2, 2′:6′, 2′′-terpyridine (tpy) or 1, 3-di(pyrid-2-yl)-4, 6-dimethylbenzene (N^C^N) ligands and linked by a 2, 7-bis(2, 2′:6′, 2′′-terpyridyl)fluorene with oligoether chains on C9 are reported. The impact of the tpy or N^C^N ligands and metal centers on the photophysical properties of 1–4 was assessed by spectroscopic methods including UV-vis absorption, emission, and transient absorption, and by time-dependent density functional theory (TDDFT) calculations. These complexes exhibited distinct singlet and triplet excited-state properties upon variation of the terminal-capping terdentate ligands and the metal centers. The ECL properties of complexes 1–3 with better water solubility were investigated in neutral phosphate buffer solutions (PBS) by adding tripropylamine (TPA) as a co-reactant, and the observed ECL intensity followed the descending order of 3 > 1 > 2 . Complex 3 bearing the [Ru(tpy)2 ] 2+ units displayed more pronounced ECL signals, giving its analogues great potential for further ECL study.