Activating a [FeFe] Hydrogenase Mimic for Hydrogen Evolution under Visible Light**
Philipp Buday, Chizuru Kasahara, Elisabeth Hofmeister, Daniel Kowalczyk, Micheal K. Farh, Saskia Riediger, Martin Schulz, Maria Wächtler, Shunsuke Furukawa, Masaichi Saito, Dirk Ziegenbalg, Stefanie Gräfe, Peter Bäuerle, Stephan Kupfer, Benjamin Dietzek‐Ivanšić, Wolfgang Weigand
Abstract
Abstract Inspired by the active center of the natural [FeFe] hydrogenases, we designed a compact and precious metal‐free photosensitizer‐catalyst dyad ( PS‐CAT ) for photocatalytic hydrogen evolution under visible light irradiation. PS‐CAT represents a prototype dyad comprising π‐conjugated oligothiophenes as light absorbers. PS‐CAT and its interaction with the sacrificial donor 1,3‐dimethyl‐2‐phenylbenzimidazoline were studied by steady‐state and time‐resolved spectroscopy coupled with electrochemical techniques and visible light‐driven photocatalytic investigations. Operando EPR spectroscopy revealed the formation of an active [Fe I Fe 0 ] species—in accordance with theoretical calculations—presumably driving photocatalysis effectively (TON≈210).