Photocatalytic Generation of Hydrogen from Water Using a Platinum(II) Terpyridyl Acetylide Chromophore

• Published in: Journal of the American Chemical Society Vol. 128; no. 24; pp. 7726 - 7727
• Main Authors: Du, Pingwu, Schneider, Jacob, Jarosz, Paul, Eisenberg, Richard
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 21-06-2006
• Subjects: Chemistry; Exact sciences and technology; General and physical chemistry; Photochemistry; Physical chemistry of induced reactions (with radiations, particles and ultrasonics); Water; Platinum Complexes; Catalytic reaction; Nitrogen heterocycle; Organic ligand; Transition metal Complexes; Photochemical reaction; Complex catalyst; Experimental study; Complexes Mixed; Visible radiation; Reaction mechanism; Chemical decomposition; Catalyst activity; Ultraviolet visible spectrometry
• ISSN: 0002-7863; 1520-5126
• DOI: 10.1021/ja0610683

The cationic complex [Pt(tolylterpyridine)(phenylacetylide)]+ has been used as a photosensitizer for the reduction of aqueous protons in the presence of a sacrificial electron donor to make H2. In this system, triethanolamine (TEOA) acts as the sacrificial reducing agent, methyl viologen (MV2+) serves as an electron transfer agent, and colloidal Pt stabilized by polyacrylate functions as the catalyst for H2 generation. The Pt(II) chromophore undergoes both oxidative and reductive quenching, but H2 is only seen when both TEOA and MV2+ are present. Irradiation of the reaction solution for 10 h with λ > 410 nm leads to 85 turnovers and an overall yield of 34% based on TEOA. While H2 evolution is maximized for the system at pH 7, it is also seen at pH 5 and 9, in contrast with earlier reports using Ru(bpy)3 2+ as the photosensitizer. This is the first time that a Pt diimine or terpyridyl complex has been used as the photosensitizer for H2 generation from aqueous protons.