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Electron Transfer and Multi‐Electron Accumulation in ExBox 4+
Author(s) -
Dyar Scott M.,
Barnes Jonathan C.,
Juríček Michal,
Stoddart J. Fraser,
Co Dick T.,
Young Ryan M.,
Wasielewski Michael R.
Publication year - 2014
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.201402444
Subject(s) - viologen , electron transfer , photoexcitation , intramolecular force , chemistry , electron , femtochemistry , femtosecond , photochemistry , raman spectroscopy , xylylene , molecule , ultrafast laser spectroscopy , electron donor , spectroscopy , catalysis , atomic physics , stereochemistry , laser , organic chemistry , optics , physics , quantum mechanics , excited state
Molecules capable of accepting and storing multiple electrons are crucial components of artificial photosynthetic systems designed to drive catalysts, such as those used to reduce protons to hydrogen. ExBox 4+ , a boxlike cyclophane comprising two π‐electron‐poor extended viologen units tethered at both ends by two p ‐xylylene linkers, has been shown previously to accept an electron through space from a photoexcited guest. Herein is an investigation of an alternate, through‐bond intramolecular electron‐transfer pathway involving ExBox 4+ using a combination of transient absorption and femtosecond stimulated Raman spectroscopy (FSRS). Upon photoexcitation of ExBox 4+ , an electron is transferred from one of the p ‐xylylene linkers to one of the extended viologen units in ca. 240 ps and recombines in ca. 4 ns. A crystal structure of the doubly reduced species ExBox 2+ was obtained.