title: Density functional theory study of the trans-trans-cis (TTC)-->trans-trans-trans (TTT) isomerization of a photochromic spiropyran merocyanine.
abstract: Density Functional Theory (DFT) calculations have been performed on the TTC-->TTT isomerization reaction of the open forms of the 1',3'-dihydro-8-bromo-6-nitro-1',3',3'-trimethylspiro[2H-1-benzopyran-2,2'-(2H)indole (8-Br-6-nitro-BIPS) system. The calculations were carried out in vacuo and in methylene chloride solution at different temperatures. Results are compared with the available experimental values of free energy difference and activation energy in solution.
authors.affiliation: Dipartimento di Scienze Fisiche ed Astronomiche, Università di Palermo, Via Archirafi 36, I-90123 Palermo, Italy. cottone@fisica.unipa.it
authors.forename: Grazia
authors.initials: G
authors.lastname: Cottone
authors.forename: Rosina
authors.initials: R
authors.lastname: Noto
authors.forename: Gianfranco
authors.initials: G
authors.lastname: La Manna
mesh_terms: D001578:Benzopyrans / Q000737:chemistry*; D005456:Fluorescent Dyes; D007211:Indoles / Q000737:chemistry*; D008752:Methylene Chloride; D008958:Models, Molecular; D008962:Models, Theoretical; D009574:Nitro Compounds / Q000737:chemistry*; D011744:Pyrimidinones / Q000737:chemistry*; D012996:Solutions; D013237:Stereoisomerism; D013816:Thermodynamics; D014618:Vacuum
chemical_list: D001578:Benzopyrans; D005456:Fluorescent Dyes; D007211:Indoles; D009574:Nitro Compounds; D011744:Pyrimidinones; D012996:Solutions; C088184:spiropyran; C003954:merocyanine dye; D008752:Methylene Chloride