Spectral characteristics of 2-aminodiphenylamine in different solvents and at various pH values.
The absorption and fluorescence spectra of 2-aminodiphenylamine (2ADA) have been studied as a function of solvent polarity and acid concentration. Analysis of solvatochromic and prototropic shifts of 2ADA reveals: (i) the presence of intramolecular hydrogen bonding between imino and amino groups in the ground state, (ii) dual fluorescence (360 and 430 nm) of the monocation (2ADA+) formed by the protonation of amino group; and (iii) proton-induced quenching of the monocation (2ADA+) fluorescence. In the dual fluorescence of 2ADA+, the longer wavelength emission at 430 nm is found to be from the twisted form of the monocation. The rate constants of the proton-induced quenching of 2ADA+ are determined.
Nayaki
S K
SK
Department of Chemistry, Faculty of Engineering and Technology, Annamalai University, Annamalainagar, India.
Swaminathan
M
M
D006863:Hydrogen-Ion Concentration; D009861:Onium Compounds; D010655:Phenylenediamines / Q000737:chemistry*; D012997:Solvents / Q000737:chemistry*; D013050:Spectrometry, Fluorescence
D009861:Onium Compounds; D010655:Phenylenediamines; D012997:Solvents; C027727:hydronium ion; C442848:2-aminodiphenylamine