Organopolymer with dual chromophores and fast charge-transfer properties for sustainable photocatalysis.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 31015478.
- Also identified by DOI 10.1038/s41467-019-09316-5 and PMC identifier 6478678.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Photocatalytic polymers offer an alternative to prevailing organometallics and nanomaterials, and they may benefit from polymer-mediated catalytic and material enhancements. MPC-1, a polymer photoredox catalyst reported herein, exhibits enhanced catalytic activity arising from charge transfer states (CTSs) between its two chromophores. Oligomeric and polymeric MPC-1 preparations both promote efficient hydrodehalogenation of α-halocarbonyl compounds while exhibiting different solubility properties. The polymer is readily recovered by filtration. MPC-1-coated vessels enable batch and flow photocatalysis, even with opaque reaction mixtures, via "backside irradiation." Ultrafast transient absorption spectroscopy indicates a fast charge-transfer process within 20 ps of photoexcitation. Time-resolved photoluminescence measurements reveal an approximate 10 ns lifetime for bright valence states. Ultrafast measurements suggest a long CTS lifetime. Empirical catalytic activities of small-molecule models of MPC-1 subunits support the CTS hypothesis. Density functional theory (DFT) and time-dependent DFT calculations are in good agreement with experimental spectra, spectral peak assignment, and proposed underlying energetics.