Steering photoinduced electron transfer in intramolecular photocatalysts by peripheral ligand control

11 December 2023, Version 1
This content is a preprint and has not undergone peer review at the time of posting.


Bridged photosensitizer-catalyst systems are promising models to study photocatalytic hydrogen evolution. However, the systems in literature are structurally diverse and therefore hard to compare. Many systems show highly complex photophysics including several accepting orbitals for the excited state, as a result catalytic activity is hard to predict. Here we present a bimetallic Ru-Pt photocatalyst bearing peripheral spectator ligands at the ruthenium(II) photocenter as a member of the Ru-tpphz-Pt family. Consequently, it features a single acceptor tpphz ligand and socalled unidirectional electron transfer, i.e., electron transfer without co-occurring transfer to peripheral ligands, from the excited state. Thus – and in contrast to recently used peripheral ligands – the new spectator ligands do not disrupt electron transfer towards the catalytic center. By comparison to known systems, this facilitates unprecedented insight into the importance of electron transfer from the bridge to the catalytic center moving towards more rational design of oligonuclear photocatalysts.


Hydrogen Evolution Reaction
Spectator Ligand
Unidirectional Electron Transfer

Supplementary materials

Supporting Information to 'Steering photoinduced electron transfer in intramolecular photocatalysts by peripheral ligand control'
Supporting Information to the manuscript with detailed experimental, synthetic, spectroscopic, crystallographic, and theoretical details.


Comments are not moderated before they are posted, but they can be removed by the site moderators if they are found to be in contravention of our Commenting Policy [opens in a new tab] - please read this policy before you post. Comments should be used for scholarly discussion of the content in question. You can find more information about how to use the commenting feature here [opens in a new tab] .
This site is protected by reCAPTCHA and the Google Privacy Policy [opens in a new tab] and Terms of Service [opens in a new tab] apply.