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Updated: Sep 20, 2026

Isolating Free Carbenes, their Mixed Dimers and Organic Radicals
Published on: April 19, 2019
Photophysical properties of methyl beta-carboline-3-carboxylate mediated by hydrogen-bonded complexes--a comparative
D Reyman1, M J Tapia, C Carcedo
1Departamento de Química Física Aplicada, Facultad de Ciencias, C-XIV, Universidad Autónoma de Madrid, Crta Colmenar Viejo Km 15, 28049 Cantoblanco, Madrid, Spain. dolores.reyman@uam.es
Abstract:
The hydrogen bonding interactions of methyl beta-carboline-3-carboxylate (BCCM) in both ground and first singlet excited electronic states have been studied in solvents with different properties in the presence of acetic acid, a hydrogen-bonding donor/acceptor. The methyl ester substituent reduces the pyridinic nitrogen basicity of this beta-carboline derivative. This fact has let us study the hydrogen bonding interactions in a higher range of acetic acid concentrations than for other beta-carboline derivatives previously studied. Steady and non-steady photophysical studies have been carried out in two non-polar solvents, benzene and p-dioxane; and in two polar solvents, acetonitrile and dichloromethane. Six different fluorescence emissions have been isolated corresponding to the uncomplexed BCCM, the protonated species and four different complexes between BCCM and acetic acid whose structures we have tried to elucidate.
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