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A Photophysical Study of the α‐Carboline (1‐Azacarbazole) Aggregation Process
Author(s) -
GarcíaFernández Emilio,
Carmona Carmen,
Muñoz María A.,
Hidalgo José,
Balón Manuel
Publication year - 2012
Publication title -
photochemistry and photobiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.818
H-Index - 131
eISSN - 1751-1097
pISSN - 0031-8655
DOI - 10.1111/j.1751-1097.2011.01056.x
Subject(s) - monomer , chemistry , fluorescence , indole test , photochemistry , hydrogen bond , absorption (acoustics) , absorption spectroscopy , pyridine , fluorescence spectroscopy , molecule , polymer , stereochemistry , organic chemistry , materials science , physics , quantum mechanics , composite material
This paper reports a comprehensive photophysical study of the aggregation process of 1‐azacarbazole, or α‐carboline (9H‐pyrido[2,3‐b]indole), AC, in low polar aprotic solvents by using absorption, steady state and time‐resolved fluorescence spectroscopic techniques. To ascertain the characteristics of the aggregation process we have studied the changes produced by the increase of the AC concentration and the decrease of the temperature on the absorption and fluorescence spectra of the AC monomer. Previously, to aid the interpretation of these results, the hydrogen bonding interactions of the AC monomer with pyridine, PY, and indole, IND, have been also analyzed. The results obtained from these studies reveal that, under our experimental conditions, AC does not form doubly hydrogen bonded cyclic dimers, (AC) 2 , but singly hydrogen bonded open dimers, AC–AC, and open higher aggregates, (–AC–) n . The formation of these species shifts to the red the absorption spectrum of the AC monomer and quenches its fluorescence.