title: Light-induced proton-coupled electron transfer inside a nanocage.
abstract: Triggering proton-coupled electron-transfer (PCET) reactions with light in a nanoconfined host environment would bring about temporal control on the reactive pathways via kinetic stabilization of intermediates. Using a water-soluble octahedral Pd6L4 molecular cage as a host, we show that optical pumping of host-guest charge transfer (CT) states lead to generation of kinetically stable phenoxyl radical of the incarcerated 4-hydroxy-diphenylamine (1-OH). Femtosecond broadband transient absorption studies reveal that CT excitation initiates the proton movement from the 1-OH radical cation to a solvent water molecule in ~890 fs, faster than the time scale for bulk solvation. Our work illustrates that optical host-guest CT excitations can drive solvent-coupled ultrafast PCET reactions inside nanocages and if optimally tuned should provide a novel paradigm for visible-light photocatalysis.
authors.affiliation: Department of Chemical Sciences, Tata Institute of Fundamental Research , Mumbai 400005, India.
authors.forename: Rahul
authors.initials: R
authors.lastname: Gera
authors.forename: Ankita
authors.initials: A
authors.lastname: Das
authors.forename: Ajay
authors.initials: A
authors.lastname: Jha
authors.forename: Jyotishman
authors.initials: J
authors.lastname: Dasgupta