Naslov
Excited State Intramolecular Proton Transfer (ESIPT) in (2-hydroxyphenyl)pyridines

Autori
Basarić, Nikola ; Wan, Peter

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
XXIst IUPAC Symposium on Photochemistry, Abstracts / Masahiro Irie - Kyoto : Međunarodna unija za čistu i primijenjenu kemiju (IUPAC), 2006

Skup
XXIst IUPAC SYMPOSIUM ON PHOTOCHEMISTRY

Mjesto i datum
Kyoto, Japan, 02.04.2006. - 07.04.2006

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
photochemistry; ESIPT; phenoles; pyridines; laser flash photolysis

Sažetak
We have recently reported several new examples of ESIPT between phenol as an acidic site and carbon atom of an adjacent carbocyclic aromatic ring as the basic site.[1-3] These ESIPT reactions require initial hydrogen bonding interaction between the phenol OH and the π -system of the adjacent ring that is possible only in twisted biaryl structures.[1] In the parent biphenyl system (1) short-range ESIPT gives rise to quinone methide (QM) 1 while long-range water-mediated ESIPT gives rise to QM 3. In continuation of our research on ESIPT we replaced the adjacent phenyl ring by a pyridine ring. Potential ESIPT photochemistry of 2- (4), 3- (5) and 4-(2’ -hydroxyphenyl)pyridine (6) was investigated by deuterium-exchange experiments (photolysis in D2O-CH3CN) and laser flash photolysis. Whereas ESIPT in 4 [4] results in exclusive protonation of the pyridine nitrogen, 5 and 6 undergo protonation of carbon atoms of the pyridine ring. Without water in the system, ESIPT leads to the protonation of 2- and 4- positions of the pyridine ring in 5 and 3(5)-positions in 6. Upon addition of water, besides short-range ESIPT, competing water-mediated long-range ESIPT results in protonation of position 6 of the pyridine ring in 5, and nitrogen in 6.

Izvorni jezik
Engleski

Znanstvena područja
Kemija

POVEZANOST RADA