Related Experiment Video
Updated: Aug 16, 2026

Synthesis of pH Dependent Pyrazole, Imidazole, and Isoindolone Dipyrrinone Fluorophores using a Claisen-Schmidt Condensation Approach
Published on: June 10, 2021
Study of 7-azaindole in its first four singlet states
1Departamento de Química Física Aplicada, Universidad Autónoma, Cantoblanco, Madrid, Spain. javier.catalan@uam.es
Abstract:
The molecular structure and properties of 7-azaindole in its first four singlet states were studied with a view to improving current understanding of the photophysical behavior of its C(2h) dimer. This dimer, which exhibits a double proton transfer via its two hydrogen bonds upon electronic excitation, has for 35 years been used as a model for the photophysical behavior of DNA base pairs. Electronic excitation of 7-azaindole simultaneously increases its acidity and basicity; these changes facilitate a concerted mechanism for the double proton transfer in the dimer. In this work, we found the acidity and basicity changes to occur only in its first pi,pi(*) excited singlet state.
Related Concept Videos
Deactivation Processes: Jablonski Diagram
π Electron Effects on Chemical Shift: Aromatic and Antiaromatic Compounds
UV–Vis Spectroscopy: Molecular Electronic Transitions
NMR Spectroscopy of Benzene Derivatives
Aryldiazonium Salts to Azo Dyes: Diazo Coupling
Structure of Benzene: Molecular Orbital Model
