US EPA

6853948 

Journal Article 

SOLVENT EFFECTS ON THE GROUND AND EXCITED-STATES PROTON-TRANSFER IN 4-METHYL-2,6-DIFORMYLPHENOL - APROTIC-SOLVENTS 

Roy, R; Roy, R; Mukherjee, S; Mukherjee, S 

1993 

1 

Indian Journal of Chemistry. Section A
ISSN: 0376-4710
EISSN: 0975-0975 

32 

1 

20-24 

WOS:A1993KX00500003 

The interaction of 4-methyl-2,6-diformylphenol (MFOH) with tributylamine and trioctylamine in different aprotic solvents has been studied quantitatively by means of electronic absorption and fluorescence spectroscopy with special attention to proton transfer at different temperatures. The acid-base interaction leads to different types of complexes, depending upon the dielectric constant of the solvents. In cyclohexane, dioxane or tetrahydrofuran hydrogen-bonded ion pair is formed, whereas a solvent-separated ion pair is formed in acetonitrile by the addition of amine in the ground state. The large Stokes-shifted band in the fluorescence spectrum of this compound in the 530 rim region is attributed to the tautomer generated by intramolecular proton transfer in the excited state. In the presence of an amine the sharp band at 445 run region in cyclohexane, dioxane and tetrahydrofuran has been assigned to the schiff base and the band at 520 run in acetonitrile to the hydrogen-bonded ion pair. Some thermodynamic data have been evaluated and discussed.<