6318-00-9Relevant academic research and scientific papers
Iridium(III) Sensitisers and Energy Upconversion: The Influence of Ligand Structure upon TTA-UC Performance
Elgar, Christopher E.,Otaif, Haleema Y.,Zhang, Xue,Zhao, Jianzhang,Horton, Peter N.,Coles, Simon J.,Beames, Joseph M.,Pope, Simon J. A.
supporting information, p. 3427 - 3439 (2021/02/05)
Six substituted ligands based upon 2-(naphthalen-1-yl)quinoline-4-carboxylate and 2-(naphthalen-2-yl)quinoline-4-carboxylate have been synthesised in two steps from a range of commercially available isatin derivatives. These species are shown to be effective cyclometallating ligands for IrIII, yielding complexes of the form [Ir(C^N)2(bipy)]PF6 (where C^N=cyclometallating ligand; bipy=2,2′-bipyridine). X-ray crystallographic studies on three examples demonstrate that the complexes adopt a distorted octahedral geometry wherein a cis-C,C and trans-N,N coordination mode is observed. Intraligand torsional distortions are evident in all cases. The IrIII complexes display photoluminescence in the red part of the visible region (668–693 nm), which is modestly tuneable through the ligand structure. The triplet lifetimes of the complexes are clearly influenced by the precise structure of the ligand in each case. Supporting computational (DFT) studies suggest that the differences in observed triplet lifetime are likely due to differing admixtures of ligand-centred versus MLCT character instilled by the facets of the ligand structure. Triplet–triplet annihilation upconversion (TTA-UC) measurements demonstrate that the complexes based upon the 1-naphthyl derived ligands are viable photosensitisers with upconversion quantum efficiencies of 1.6–6.7 %.
Triple zirconocene/br?nsted acid/CuO cooperative and relay catalysis system for tandem Mannich addition/C-C formative cyclization/oxidation
Luo, Yanlong,Sun, Huaming,Zhang, Weiqiang,Wang, Xiu,Xu, Shan,Zhang, Guofang,Jian, Yajun,Gao, Ziwei
, p. 28616 - 28625 (2017/07/10)
A new triple cooperative and relay catalysis system featuring the Mannich addition followed by C-C construction and oxydehydrogenation is described. The zirconocene dichloride and trimellitic acid synergic catalysis triggered the Mannich addition and C-C bond construction reactions, while CuO allowed relay catalysis for oxydehydrogenation. This novel strategy demonstrated superior activity for the synthesis of substituted quinolines from commercially available anilines, aldehydes and ketones. The corresponding substituted quinolines were synthesized with 32 examples in 90-96% yields under mild reaction conditions. A novel zirconocene-Br?nsted acid complex, generated in situ and acting as an active catalyst, was validated from the mechanistic studies.
