𝔖 Bobbio Scriptorium
✦   LIBER   ✦

Triplet-triplet absorption of 2-(2′-hydroxyphenyl) benzoxazole (HBO) in polar solvents

✍ Scribed by Guoqiang Yang; Fabrice Morlet-Savary; Zhaokui Peng; Shikang Wu; Jean-Pierre Fouassier

Publisher
Elsevier Science
Year
1996
Tongue
English
Weight
437 KB
Volume
256
Category
Article
ISSN
0009-2614

No coin nor oath required. For personal study only.

✦ Synopsis

The transient T-T absorption spectra of 2-(2'-hydroxyphenyl) benzoxazole (HBO) have been measured in liquid polar solvents and in polymethylmathacrylate. In non-protonic polar solvents the main T-T absorption is from the keto form of the compound (3K * ). With a triplet sensitizer the compound just gives a T-T absorption of its enol form (3E * ) after triplet energy transfer from the sensitizer to HBO. The excited state intramolecular proton transfer (ESIPT) from the enol form to keto form occurs just in the singlet state. The protonic solvent can break the intramolecular hydrogen bond of HBO and decrease the ESIPT process. In solid solution both 3E * and 3K * can be formed and the T-T absorptions were detected because of the inhibition of the rotational conformation transfer.

📜 SIMILAR VOLUMES

Dual phosphorescence from 2-(2′-hydroxyp
Dual phosphorescence from 2-(2′-hydroxyphenyl)benzoxazole due to keto-enol tautomerism in the metastable triplet state
✍ M.Flor Rodríguez Prieto; Bernhard Nickel; Karl H. Grellmann; Andrzej Mordziński 📂 Article 📅 1988 🏛 Elsevier Science 🌐 English ⚖ 567 KB

The photoexcitation of liquid solutions of 2-(2'-hydroxyphenyl)benzoxazole (HBO) in alkanes leads to a dual phosphorescence which can be assigned to the keto and enol forms of HBO. The keto-enol tautomerism in the metastable triplet state of HBO is practically independent of temperature. The keto an

Excited-state proton transfer in 2-(2'-h
Excited-state proton transfer in 2-(2'-hydroxyphenyl)benzothiazole: formation of the anion in polar solvents
✍ T. Elsaesser; B. Schmetzer 📂 Article 📅 1987 🏛 Elsevier Science 🌐 English ⚖ 630 KB

Excited-state proton transfer in 2-(2'-hydroxyphenyl)benzothiaxole (HBT) dissolved in pyridine is investigated. New absorptions and fluorescence bands are detected after addition of water or NaOH to the solution. The spectra are identical to the HBT anion absorption and fluorescence. Picosecond spec

The role of the cis-keto triplet state i
The role of the cis-keto triplet state in the proton transfer cycle of 2-(2′-hydroxyphenyl)benzothiazole
✍ Pi-Tai Chou; Marty L. Martinez; Shannon L. Studer 📂 Article 📅 1992 🏛 Elsevier Science 🌐 English ⚖ 455 KB

A two-step laser-induced fluorescence (TSLIF) study of 2-(2'-hydroxyphenyl)benzothiazole (HBT) in various solvents at < 100 K revealed an unusually high yield of tautomer emission resulting from the T; -tS', intersystem crossing (ISC, prime denotes the tautomer state) of the cis-keto form. The T-S I