title: Redox-switchable squaraines with extended conjugation.
abstract: [reaction: see text] The redox chemistry of pi-extended squaraines is investigated using cyclic voltammetry, in-situ spectroelectrochemistry and quantum chemical calculations. Squaraine 1 is reversibly oxidized to the radical cation and dication whereas reduction shows limited electrochemical but fully chemical reversibility. The radical cation of 1 reveals absorption bands at 1000 nm and a "two-band feature" at 1600 nm. Their implications on the intramolecular electron transfer are discussed.
authors.affiliation: Universität Regensburg, Institut für Organische Chemie, Universitätsstr. 31, D-93040 Regensburg, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Büschel
authors.forename: Ayyappanpillai
authors.initials: A
authors.lastname: Ajayaghosh
authors.forename: Easwaran
authors.initials: E
authors.lastname: Arunkumar
authors.forename: Jörg
authors.initials: J
authors.lastname: Daub