Giereth, RobinObermeier, MartinForschner, LukasKarnahl, MichaelSchwalbe, MatthiasTschierlei, Stefanie2024-10-102024-10-1020212367-09321905373155http://nbn-resolving.de/urn:nbn:de:bsz:93-opus-ds-150345http://elib.uni-stuttgart.de/handle/11682/15034http://dx.doi.org/10.18419/opus-15015Photosensitizing units have already been applied to enable light‐driven catalytic reduction of CO2 with mononuclear rhenium complexes. However, dinuclear catalytic systems that are able to activate CO2 in a cooperative bimetallic fashion have only rarely been combined with photosensitizers. We here present detailed studies on the influence of additional photosensitizers on the catalytic performance of a dirhenium complex (Re2Cl2) and present correlations with spectroscopic measurements, which shed light on the reaction mechanism. The use of [Ir(dFppy)3] (Ir, dFppy=2‐(4,6‐difluorophenyl)pyridine)) resulted in considerably faster CO2 to CO transformation than [Cu(xant)(bcp)]PF6 (Cu, xant=xantphos, bcp=bathocuproine). Emission quenching studies, transient absorption as well as IR spectroscopy provide information about the electron transfer paths of the intermolecular systems. It turned out that formation of double reduced species [Re2Cl2]2- along with an intermediate with a Re-Re bond ([ReRe]) can be taken as an indication of multi‐electron storage capacity. Furthermore, under catalytic conditions a CO2‐bridged intermediate was identified.eninfo:eu-repo/semantics/openAccesshttps://creativecommons.org/licenses/by-nc-nd/4.0/540article2023-11-14