Fluorescence Characteristic of 2-Chloropyrazine: Effect of Solvents and Concentration of Cu(II).

Zaharah Aiyub, and Zanariah Abdullah, and Yaakob, B.H. and Maizatul Akmam Abu Bakar, and Aiyub, Z See Zaharah Aiyub and Abdullah, Z See Zanariah Abdullah and Abu Bakar, M.A. See Maizatul Akman Abu Bakar (2007) Fluorescence Characteristic of 2-Chloropyrazine: Effect of Solvents and Concentration of Cu(II). Malaysian Journal of Analytical Sciences, 11 (1). pp. 105-109. ISSN 13942506

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Affiliations

University of Malaya, Dept. of Chemistry

Abstract

2-Chloropyrazine showed the highest fluorescence peak at 328 nm when excited at 290 nm in ethyl acetate. The intensity was reduced in chloroform, ethanol, acetone, dichloromethane, water and the lowest fluorescence intensity was observed in acetonitrile. The fluorescence characteristic of 2-chloropyrazine with different concentrations of copper (II) nitrate was studied as a function of the metal ion complex. The studies were carried out in ethanol and ethyl acetate in the same concentration and the maximum fluorescence was observed in ethyl acetate. When excited at 287 nm in ethanol, the complex emitted intense fluorescence at two wavelengths around 304-308 nm and 569-572 nm while in ethyl acetate it
fluoresced at 327-332 nm and 651-647 nm when excited at 290 nm. The pattern of increase and decrease of fluorescence intensity depends on the concentration of Cu(II) added. At a concentration of 9.93 x 10-5 M of Cu (II), fluorescence intensity decreased in both solvents.

Pendafluoran maksima 2-kloropirazina berlaku pada jarak gelombang 328 nm apabila di uja pada 290 nm dalam etil asetat. Keamatan pendafluoran berkurangan dalam kloroform, etanol, aseton, dikloromethana, air dan keamatan paling rendah dalam asetonitril. Ciri pendafluoran 2-loropirazina dengan kepekatan berbedza kuprum (II) nitrat juga di kaji. Kajian pendafluoran dilakukan terhadap pengunaan kesan pelarut etanol dan etil asetat bagi kepekatan yang sama. Kajian dapati pendafluoran maksima berlaku dalam pelarut etil asetat. Apabila di uja pada 287 nm dalam etanol, pendafluoran kompleks berlaku pada dua jarak gelombang iaitu, sekitar 304-308 nm and 569-572 nm, manakala dalam etil asetat pendafluoran berlaku pada 327-332 nm dan 651-647 nm apabila di uja pada 290 nm. Corak menaik dan menurun keamatan pendafluoran bergantung kepada kepekatan Cu(II) yang di tambah. Pada kepekatan 9.93 x 10-5 M Cu(II), keamatan pendafluoran menurun dalam kedua-dua pelarut.

Item Type:

Journal

Additional Information:

The authors acknowledge the Academy of Sciences Malaysia for financial support through SAGA funding 66-02-03-0045.

Keywords:

fluorescence, 2-chloropyrazine, copper(II) nitrate, metal effect, fluorescence intensity.

Subjects:

Q Science

ID Code:

1017