GREEN-SYNTHESIS, CHAREARIZATION, PHOTOSTABILITY AND POLARITY STUDIES OF NOVEL SCHIFF BASE DYES USING SPECTROSCOPIC METHODS

© 2012 Hadi M. Marwani^{1, 2}, Abdullah M. Asiri^{1, 2} and Salman A. Khan^1,#

^#Fax: +966 2 6952292; e-mail: sahmad_phd@yahoo.co.in

¹Chemistry Department, Faculty of Science, King Abdulaziz University, P.O. Box 80203, Jeddah 21589, Saudi Arabia;
²Center of Excellence for Advanced Materials Research, King Abdulaziz University, Jeddah 21589, P.O. Box 80203, Saudi Arabia

Received 18.10.2011 in final form 23.12.2011

Abstract. Preparation, characterization, photostability and polarity studies of novel Schiff base dyes using spectroscopic methods were achieved. The Schiff base dyes were prepared by the reaction of salicylaldehyde/2-Hydroxy-1-naphthaldehyde with aminophenazone under microwave irradiation. The spectroscopic (FT-IR, ¹H NMR, ¹³C-NMR, Mass) studies and elemental analyses were in good agreement with chemical structure of synthesized compounds. In addition, UV-Vis and fluorescence spectroscopic experiments showed that these dyes are good absorbent and fluorescent. Based on the photostability study of these dyes, minimal to no loss in fluorescence intensities of 4-[(2-Hydroxy-benzylidene)-amino] 1, 5-dimethyl-2-phenyl-1,2-dihydro-pyrazol-3-one (D1) (6.14%) and 4-[(2-Hydroxy-naphthalen-1-ylmethylene)-amino]-1,5-dimethyl-2-phenyl-1,2-dihydro-pyrazol-3-one (D2) (2.95%) was observed with an increase in the exposure time using time-based fluorescence steady-state experiments. These studies also inferred that these Schiff base dyes have a high photostability against photobleaching. In addition, Dye 2 is found to be more sensitive than Dye 1 to the polarity of the microenvironment provided by different solvents based on the results of fluorescence polarity studies.

Keywords: Schiff bases; Pyrazol-3-one; Florescent; Photostability

Биоорг.химия 2012, 38 (5): 604-609