title: Kinetics of hydrogen bonding between anthracene urea derivatives and anions in the excited state.
abstract: Urea compounds are useful anion sensors due to their hydrogen-bonding capabilities. We investigated the emissive properties of complexes consisting of urea-anthracene (nPUA, n = 1, 2) host compounds and acetate anions held as guests through intermolecular hydrogen bonding. The kinetics of a new emission band formed by conformational changes in the excited singlet state were revealed. The new band is thought to arise from a charge-transfer interaction between the anthracene and urea moieties after intermolecular hydrogen-bond reconfiguration in the excited state, with rate constants of 2.4 × 10(9) and 4.0 × 10(7) s(-1) for 1PUA and 2PUA, respectively.
authors.affiliation: Graduate School of Pure and Applied Sciences, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba, Ibaraki 305-8571, Japan.
authors.forename: Satomi
authors.initials: S
authors.lastname: Ikedu
authors.forename: Yoshinobu
authors.initials: Y
authors.lastname: Nishimura
authors.forename: Tatsuo
authors.initials: T
authors.lastname: Arai