title: Crucial dependence of chemiluminescence efficiency on the syn/anti conformation for intramolecular charge-transfer-induced decomposition of bicyclic dioxetanes bearing an oxidoaryl group.
abstract: Thermally stable rotamers of bicyclic dioxetanes bearing 6-hydroxynaphthalen-1-yl (anti-5a and syn-5a), 3-hydroxynaphthalen-1-yl (anti-5b and syn-5b), and 5-hydroxy-2-methylphenyl groups (anti-5c and syn-5c) were synthesized. These dioxetanes underwent TBAF (tetrabutylammonium fluoride)-induced decomposition accompanied by the emission of light in DMSO and in acetonitrile at 25 °C. For all three pairs of rotamers, the chemiluminescence efficiency Φ(CL) for anti-5 was 8-19 times higher than that for syn-5, and the rate of CTID (charge-transfer-induced decomposition) for anti-5 was faster than that for syn-5. The chemiluminescence spectra of the rotamers for 5a and 5c, respectively, were different. This discrepancy in the chemiluminescence spectra between rotamers can presumably be attributed to the difference in the structures of de novo keto imide anti-14 and syn-14 in an excited state, which inherit the structures of the corresponding intermediary anionic dioxetanes anti-13 and syn-13. The important difference in chemiluminescence efficiency between anti-5 and syn-5 is discussed from the viewpoint of a chemiexcitation mechanism for CTID of oxidophenyl-substituted dioxetane.
authors.affiliation: Department of Chemistry, Kanagawa University, Tsuchiya, Hiratsuka, Kanagawa 259-1293, Japan. matsumo-chem@kanagawa-u.ac.jp
authors.forename: Masakatsu
authors.initials: M
authors.lastname: Matsumoto
authors.forename: Haruna
authors.initials: H
authors.lastname: Suzuki
authors.forename: Nobuko
authors.initials: N
authors.lastname: Watanabe
authors.forename: Hisako K
authors.initials: HK
authors.lastname: Ijuin
authors.forename: Jiro
authors.initials: J
authors.lastname: Tanaka
authors.forename: Chizuko
authors.initials: C
authors.lastname: Tanaka
mesh_terms: D004988:Ethers, Cyclic / Q000737:chemistry*; D006574:Heterocyclic Compounds, 2-Ring / Q000737:chemistry*; D049449:Luminescence; D008958:Models, Molecular; D008968:Molecular Conformation
chemical_list: D004988:Ethers, Cyclic; D006574:Heterocyclic Compounds, 2-Ring; C005287:oxetane