Light‐Sensitive Molecular Building Blocks with Electron Transfer Activity: Synthesis and Properties of a Photochemically Switchable, Dicyanovinyl‐Substituted Furan

Abstract

How does a light/current switch function at the molecular level? The title compounds could contribute to a deeper understanding. Visible light transforms 1 into 2. Both 1 as well as 2 are electron‐transfer active. Since 2 is reduced electrochemically far more readily than 1, photochemically modulated current pulses are observed (R = 5‐(2,2‐dicyanovinyl)‐2‐furyl).

Dihydroazulene: from controlling photochromism to molecular electronics devices

“…Daub and co-workers described in 1989 gating of the current flux in an electric circuit by DHA-VHF photochromism. 33 Later steps towards incorporating the DHA-VHF-system into singlemolecule molecular electronic devices were taken in 2011 by the groups of Nielsen and Kubatkin. 6a By sublimation, the DHA could be trapped in between silver electrodes in a pre-fabricated nano-gap and light-induced switching between two conduction states was observed.…”

Synthesis, Chemistry and Applications of 5‐Hydroxymethyl‐furfural and Its Derivatives

“…Daub et al 160 The reaction of FDC with trimethylene-bis-(triphenylphosphonium) bromide resulted in the formation of 1,4:16,13-diepoxy [18]annulene 58.…”

Controlling Two‐Step Multimode Switching of Dihydroazulene Photoswitches

“…Fine‐tuning of the rate of ring closure (VHF→DHA) has been accomplished by substitution with either electron‐withdrawing and/or ‐donating groups with kinetics behavior that satisfies Hammett correlations,9 and it has also been shown that having a strong electron acceptor such as a buckminsterfullerene (C 60 ) covalently attached to DHA quenches the light‐induced ring opening 10. Also, by reversible oxidation of a covalently attached ferrocene or tetrathiafulvalene unit,11 or by protonation of an aniline substituent9a,b the photochromism of the DHA/VHF couple can be controlled. Along this line, molecules with two photochromic units have attracted interest as multimode switches.…”