Wydział Chemii

Dipanwita Guha

Abhijit Mandal

Aleksander Koll

Aleksander Filarowski

Samaresh Mukherjee

2000

Spectrochimica Acta Part A-Molecular and Biomolecular Spectroscopy

56

2669-2677

10.1016/S1386-1425(00)00303-6

Naukowa

Angielski

Artykuł

Ground and excited state inter- and intramolecular proton transfer reactions of a new o-hydroxy Schiff base, 7-ethylsalicylidenebenzylamine (ESBA) have been investigated by means of absorption, emission and nanosecond spectroscopy in different protic solvents at room temperature and 77 K. The excited state intramolecular proton transfer (ESIPT) is evidenced by a large Stokes shifted emission (∼11 000 cm⁻¹) at a selected excited energy in alcoholic solvents. Spectral characteristics obtained reveal that ESBA exists in more than one structural form in most of the protic solvents, both in the ground and excited states. From the nanosecond measurements and quantum yield of fluorescence we have estimated the decay rate constants, which are mainly represented by nonradiative decay rates. At 77 K the fluorescence spectra are found to be contaminated with phosphorescence spectra in glycerol and ethylene glycol. It is shown that the fluorescence intensity and nature of the species present are dependent upon the excitation energy.

Proton transfer, o-Hydroxy Schiff base, Protic solvents

https://doi.org/10.1016/S1386-1425(00)00303-6

http://www.elsevier.com