Hydrogen‐Generating Ru/Pt Bimetallic Photocatalysts Based on Phenyl‐Phenanthroline Peripheral Ligands. Issue 22 (9th October 2018)

• Record Type: Journal Article
• Authors: O'Reilly, Laura; Pan, Qing; Das, Nivedita; Wenderich, Kasper; Korterik, Jeroen P.; Vos, Johannes G.; Pryce, Mary T.; Huijser, Annemarie
• Is Part Of: Chemphyschem. Volume 19:Issue 22(2018)
• Page Start: 3084
• Page End: 3091
• Publication Date: 2018-10-09
• Subjects: electron storage -- excited-state equilibrium -- inter-ligand internal conversion -- Ru/Pt photocatalysts -- ultrafast photodynamics; Chemistry, Physical and theoretical -- Periodicals; 541.05
• DOI: 10.1002/cphc.201800658
• Languages: English
• ISSNs: 1439-4235

Abstract

Abstract: Recent studies on hydrogen‐generating supramolecular bimetallic photocatalysts indicate a more important role of the peripheral ligands than expected, motivating us to design a Ru/Pt complex with 4, 7‐diphenyl‐1, 10‐phenanthroline peripheral ligands. Photoinduced intra‐ and inter‐ligand internal conversion processes have been investigated using transient absorption spectroscopy, spanning the femto‐ to nanosecond timescale. After photoexcitation and ultrafast intersystem crossing, triplet states localised on either the peripheral ligands or on the bridging ligand/catalytic unit are populated in a non‐equilibrated way. Time‐resolved photoluminescence demonstrates that the lifetime for the Ru/Pt dinuclear species (795±8 ns) is significantly less than that of the mononuclear analogue (1375±20 ns). The photocatalytic studies show modest hydrogen turnover numbers, which is possibly caused by the absence of an excited state equilibrium. Finally, we identify challenges that must be overcome to further develop this class of photocatalysts and propose directions for future research. Abstract : Reaching an excited‐state equilibrium is a key to increasing the hydrogen‐generation activity of supramolecular bimetallic photocatalysts based on phenyl‐phenanthroline peripheral ligands.