title: New Phenol Benzoate Cyanine Picolinium Salt Photoacid Excited-State Proton Transfer.
abstract: Steady-state and time-resolved fluorescence techniques were employed to study the excited-state proton transfer (ESPT) to water and D2O of a new photoacid, phenol benzoate cyanine picolinium salt (BCyP). We found that the ground-state pKais about 6.5, whereas the excited-state pKa* is about -4.5. The ESPT rate constant, kPT, to water is ∼0.5 × 1012s-1(τPT≈ 2 ps) and in D2O the rate is 0.33 × 1012s-1. We determined that the BCyP photoacid belongs to the third regime of photoacids, the solvent-controlled regime.
authors.affiliation: Raymond and Beverly Sackler Faculty of Exact Sciences, School of Chemistry, Tel Aviv University , Tel Aviv 69978, Israel.
authors.forename: Ori
authors.initials: O
authors.lastname: Green
authors.affiliation: Raymond and Beverly Sackler Faculty of Exact Sciences, School of Chemistry, Tel Aviv University , Tel Aviv 69978, Israel.
authors.forename: Oren
authors.initials: O
authors.lastname: Gajst
authors.affiliation: Raymond and Beverly Sackler Faculty of Exact Sciences, School of Chemistry, Tel Aviv University , Tel Aviv 69978, Israel.
authors.forename: Ron
authors.initials: R
authors.lastname: Simkovitch
authors.affiliation: Raymond and Beverly Sackler Faculty of Exact Sciences, School of Chemistry, Tel Aviv University , Tel Aviv 69978, Israel.
authors.forename: Doron
authors.identifier: http://orcid.org/0000-0003-2502-639X
authors.initials: D
authors.lastname: Shabat
authors.affiliation: Raymond and Beverly Sackler Faculty of Exact Sciences, School of Chemistry, Tel Aviv University , Tel Aviv 69978, Israel.
authors.forename: Dan
authors.identifier: http://orcid.org/0000-0002-0292-4106
authors.initials: D
authors.lastname: Huppert