Spectral characteristics of sulphadiazine, sulphisomidine: effect of solvents, pH and [beta]-cyclodextrin

• Published in: Physics and chemistry of liquids Vol. 49; no. 1; p. 108
• Main Authors: Premakumari, J, Allan Gnana Roy, G, Antony Muthu Prabhu, A, Venkatesh, G, Subramanian, V K, Rajendiran, N
• Format: Journal Article
• Language: English
• Published: Abingdon Taylor & Francis Ltd 01.01.2011
• Subjects: Solvents
• ISSN: 0031-9104; 1029-0451
• DOI: 10.1080/00319104.2010.509724

The absorption and fluorescence spectra of sulphadiazine (SDA), sulphisomidine (SFM) and sulphanilamide (SAM) have been analysed in different solvents, pH and β-cyclodextin. The inclusion complexes of the above sulphonamides with β-CD were investigated by UV-Vis, fluorometry, DFT, FT-IR and 1H-NMR. The solvent study shows that the absorption and emission maxima of the SDA and SFM are more red-shifted than SAM molecule. In non-aqueous solvents, a single fluorescence band (340 nm) is observed, whereas in water and β-CD solutions, dual emission (at 340 and 430 nm) is noticed for SDA and SFM molecules. The dual emission is due to twisted intramolecular charge transfer band (TICT). Studies on β-CD solutions reveal that (1) sulphonamides form 1 : 1 inclusion complex with β-CD; and (2) the red-shift and the presence of TICT in the β-CD medium confirm that the heterocyclic ring is encapsulated in the hydrophobic part and aniline ring is present in the hydrophilic part of the β-CD cavity.