Electron Transfer and Multi‐Electron Accumulation in ExBox4+1. (11th April 2014)

• Record Type: Journal Article
• Authors: Dyar, Scott M.; Barnes, Jonathan C.; Juríček, Michal; Stoddart, J. Fraser; Co, Dick T.; Young, Ryan M.; Wasielewski, Michael R.
• Is Part Of: Angewandte Chemie. Volume 126:Number 21(2014)
• Page Start: 5475
• Page End: 5479
• Publication Date: 2014-04-11
• Subjects: Chemistry -- Periodicals; 540
• DOI: 10.1002/ange.201402444
• Languages: English
• ISSNs: 0044-8249

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>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. ExBox⁴⁺, a boxlike cyclophane comprising two π‐electron‐poor extended viologen units tethered at both ends by two <italic>p</italic>‐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 ExBox⁴⁺ using a combination of transient absorption and femtosecond stimulated Raman spectroscopy (FSRS). Upon photoexcitation of ExBox⁴⁺, an electron is transferred from one of the <italic>p</italic>‐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 ExBox²⁺ was obtained.</p> </abstract>