Ground and excited state proton transfer in intramolecularly hydrogen bonded aromatic alfa-hydroxy azo, aldehydes and their derivatives

GABRIELA LEDESMA; GABRIELA IBAÑEZ; GRACIELA ESCANDAR; ALEJANDRO OLIVIERI

JOURNAL OF MOLECULAR STRUCTURE

Elsevier

Lugar: Asterdam; Año: 1997 vol. 415 p. 115 - 121

0022-2860

Abstract Intrarmolecular proton transfer occurring in the ground and excited states of a series of structurally related aromatic molecules displaying strong internal hydrogen bonding, a-hydroxy azo, aldehydes and their derivatives, is investigated. Applied spectroscopic techniques include electronic absorption and spectrofluorimetry, which are coupled to semiempirical ground‑state (AM1) and excited‑state (INDO/S‑CI) molecular orbital (MO) calculations. The results allow one to discern the presence of excited state intramolecular proton transfer (ESIPT) and primary fluorescence phenomena in the studied compounds. The results provided by spectroscopic techniques and semiempirical MO calculations are in agreement with the proposed structures for the studied compounds.