Photochemistry
Slow photogenerated Rh–H prefers aldehydes
Open access · cc by · source: Europe PMC
Proflavine plus a Cp*Rh mediator makes dilute Rh(III)–H that reduces aldehydes while ketones wait, unlike fast formate hydride transfer.
Key findings
10 mol% of both catalysts in 1:1 DMF/H2O is optimal; a flow reactor speeds the reaction 5× without losing selectivity. Rh(III)–H appears at 612 nm. Φ = (0.14 ± 0.05)% at 455 nm. Triplet 3PFH+* (~2 μs) is reduced by TEOA to PF·– (~530 nm), which then reduces Rh. Aerated runs still give ~30% via photoionization.
Methodology
Authors optimized PF/Rh cat in DMF/water at 455 nm, screened aldehyde/ketone pairs (including a keto-aldehyde), compared formate-generated Rh–H, and used Stern–Volmer, UV-vis, headspace H2 and pump–probe spectra.
Limitations
Quantum yield is low because of fluorescence, H2 evolution and Rh(II) disproportionation; one bifunctional substrate gives a pinacol side product; imine reductions need dry DMSO/thiourea and are a separate optimisation.
How this study connects
Role on claims
Each row is a claim on a concept or method page where this paper supports, challenges, or qualifies the statement. Roles are hand-checked — not a model guess.
Not yet placed on a claim. This paper has study layers, but no concept page yet cites it as support, challenge, or qualifier.
Related papers in this topic
Same topic cluster — not a recommendation engine.