title: Novel Ru-dioxolene complexes as potential electrochromic materials and NIR dyes.
abstract: A series of Ru(bpy)(2)-dioxolene complexes 1-4 (bpy = 2,2'- bipyridine) and corresponding Ru(dcb)(2)-dioxolene complexes 5-8 (dcbH(2) = 2,2'-bipyridine-4,4'-dicarboxylic acid) have been prepared, and their spectroelectrochemical behavior in solution has been investigated. The complexes show reversible electrochemical behavior accompanied by a strong NIR absorption in their semiquinone forms due to a Ru(dpi) --> sq(pi) MLCT band. Complete quenching of the NIR absorption occurs both upon oxidation (to the quinone form) and upon reduction (to the catechol form) very close to 0 V. The color of the systems can be tuned by using a wide range of ligands. The complexes 5-8 can be anchored onto nanocrystalline inorganic semiconductors allowing incorporation into potential electrochromic devices. As a proof of principle, compound 8 has been adsorbed on nanocrystalline Sb-doped SnO(2) supported on FTO glass, and it displays reversibly switchable electrochromic behavior in the NIR.
authors.affiliation: Dipartimento di Chimica, Università di Ferrara, Via L Borsari, 46, Ferrara, Italy. swp@dns.unife.it
authors.forename: Peter F H
authors.initials: PF
authors.lastname: Schwab
authors.forename: Sara
authors.initials: S
authors.lastname: Diegoli
authors.forename: Matteo
authors.initials: M
authors.lastname: Biancardo
authors.forename: Carlo Alberto
authors.initials: CA
authors.lastname: Bignozzi