title: The synthesis and spectral properties of a stimuli-responsive D-π-A charge transfer dye.
abstract: A new donor-π-acceptor (D-π-A) type isophorone dye was synthesized by the condensation reaction between 2-(3,5,5-trimethylcyclohex-2-enylidene)-malononitrile and indole-3-carboxaldehyde. The chemical structure of the dye was characterized by 1H NMR, EA and MS. A novel, chromogenic, fluorescent dye based on indol as donor unit and isophorone as acceptor unit displayed marked UV-visible absorption changes and highly selective fluorescence quenching in the presence of fluoride ion. The dye also exhibited sizeable colour changes when used as a pH-induced molecular switch and as a detector for volatile organic compounds. The absorption and fluorescent intensity of the dye can be reversibly selected by protonation/deprotonation of the amine moiety via control of intramolecular charge transfer (ICT), leading to a molecular switch with "on" and "off" states.
authors.affiliation: Department of Textile System Engineering, Kyungpook National University, Daegu 702-701, South Korea. shokim@knu.ac.kr
authors.forename: Sung-Hoon
authors.initials: SH
authors.lastname: Kim
authors.forename: Seon-Yeong
authors.initials: SY
authors.lastname: Gwon
authors.forename: Jin-Seok
authors.initials: JS
authors.lastname: Bae
authors.forename: Young-A
authors.initials: YA
authors.lastname: Son
mesh_terms: D000042:Absorption; D003116:Color; D004396:Coloring Agents / Q000138:chemical synthesis* / Q000737:chemistry*; D003512:Cyclohexanones / Q000138:chemical synthesis* / Q000737:chemistry*; D005459:Fluorides / Q000737:chemistry; D008670:Metals / Q000737:chemistry; D011522:Protons; D012996:Solutions; D013050:Spectrometry, Fluorescence; D013056:Spectrophotometry, Ultraviolet; D055672:Static Electricity; D013816:Thermodynamics; D055549:Volatile Organic Compounds / Q000737:chemistry
chemical_list: D004396:Coloring Agents; D003512:Cyclohexanones; D008670:Metals; D011522:Protons; D012996:Solutions; D055549:Volatile Organic Compounds; C005940:isophorone; D005459:Fluorides