title: Visible-light-triggered molecular photoswitch based on reversible E/Z isomerization of a 1,2-dicyanoethene derivative.
abstract: A designed bis(dithienyl) dicyanoethene-based, strictly E/Z photoswitch (4TCE) operates through state-selective (E and Z isomer) photoactivation with visible light. The E and Z isomers of 4TCE exhibit remarkably different spectroscopic characteristics, including a large separation (70 nm) in their absorption maxima (λ(max)) and a 2.5-fold increase in molar extinction coefficient from cis to trans. The energetically stable trans form can be completely converted to the cis form within minutes when exposed to white light, whereas the reverse isomerization occurs readily upon irradiation by blue light (λ<480 nm) or completely by thermal conversion at elevated temperatures. These features together with excellent thermal stability and photostability of both isomers make this new E/Z photoswitch a promising building block for photoswitchable materials that operate without the need for UV light.
authors.affiliation: Department of Materials Science and Engineering, Johns Hopkins University, 3400 N Charles St, Baltimore, MD 21218 (USA).
authors.forename: Xin
authors.initials: X
authors.lastname: Guo
authors.forename: Jiawang
authors.initials: J
authors.lastname: Zhou
authors.forename: Maxime A
authors.initials: MA
authors.lastname: Siegler
authors.forename: Arthur E
authors.initials: AE
authors.lastname: Bragg
authors.forename: Howard E
authors.initials: HE
authors.lastname: Katz
mesh_terms: D004980:Ethane / Q000031:analogs & derivatives* / Q000737:chemistry; D005030:Ethylenes / Q000737:chemistry*; D007536:Isomerism; D008027:Light; D008968:Molecular Conformation; D009570:Nitriles / Q000737:chemistry*; D011789:Quantum Theory; D013056:Spectrophotometry, Ultraviolet; D014466:Ultraviolet Rays
chemical_list: C000603929:1,2-dicyanoethene; D005030:Ethylenes; D009570:Nitriles; C036216:ethylene; D004980:Ethane
keywords: 1,2-dicyanoethene; diarylethenes; molecular switches; photochromism; photoisomerization