Dual-mode electrochromism switched by proton transfer: dynamic redox properties of bis(diarylmethylenium)-type dyesElectronic supplementary information (ESI) available: spectral data for new compounds. See http://www.rsc.org/suppdata/cc/b1/b104742f/
Abstract
Upon oxidative dimerization of pale yellow
Ar2CCHPh 1 (Ar =
4-Me2NC6H4), deep blue 1,4-dication
22+ was obtained as a stable salt, which was transformed into 1
by reductive C–C bond fission; deprotonation of 22+ gave
intense yellow diene 3, which was interconvertible with violet dication
42+ by two-electron transfer, thus exhibiting two distinct modes
of electrochromism before and after proton transfer.