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Exploiting Potential Inversion for Photoinduced Multielectron Transfer and Accumulation of Redox Equivalents in a Molecular Heptad
journal contribution
posted on 2018-04-13, 17:24 authored by Julia Nomrowski, Oliver S. WengerPhotoinduced
multielectron transfer and reversible accumulation
of redox equivalents is accomplished in a fully integrated molecular
heptad composed of four donors, two photosensitizers, and one acceptor.
The second reduction of the dibenzo[1,2]dithiin acceptor occurs more
easily than the first by 1.3 V, and this potential inversion facilitates
the light-driven formation of a two-electron reduced state with a
lifetime of 66 ns in deaerated CH3CN. The quantum yield
for formation of this doubly charge-separated photoproduct is 0.5%.
In acidic oxygen-free solution, the reduction product is a stable
dithiol. Under steady-state photoirradiation, our heptad catalyzes
the two-electron reduction of an aliphatic disulfide via thiolate-disulfide
interchange. Exploitation of potential inversion for the reversible
light-driven accumulation of redox equivalents in artificial systems is
unprecedented and the use of such a charge-accumulated state for multielectron
photoredox catalysis represents an important proof-of-concept.