Spectroscopic Studies on the Molecular Complex of the Drug Atenolol with Iodine

• Published in: Journal of solution chemistry Vol. 38; no. 12; pp. 1558 - 1572
• Main Authors: Pandeeswaran, M., Elango, K. P.
• Format: Journal Article
• Language: English
• Published: Boston Springer US 01-12-2009; Springer
• Subjects: Chemistry; Chemistry and Materials Science; Condensed Matter Physics; Drugs; Electronics; Exact sciences and technology; Fluorescence; General and physical chemistry; Geochemistry; Industrial Chemistry/Chemical Engineering; Inorganic Chemistry; Iodine; Mathematical models; Oceanography; Physical Chemistry; Quenching; Solutions; Spectroscopic analysis; Spectroscopy; Solvent effect; Fluorescence; Charge transfer complex; Atenolol; Iodine; Drug; Complexation; Stoichiometry; Ions; Activation parameter; Infrared spectrometry; Thermodynamic parameter; Molecular complex; Raman spectrometry; Rate constant; Charge transfer
• ISSN: 0095-9782; 1572-8927
• DOI: 10.1007/s10953-009-9467-3

Spectroscopic and spectrofluorimetric studies were made of the interaction between the drug atenolol and iodine. The interaction was found to proceed through the initial formation of a charge transfer (CT) complex as an intermediate species. The product of this interaction has been isolated and characterized using UV-Vis, FT-IR and Raman spectroscopic techniques. Formation of the triodide
species was confirmed by its electronic and Raman spectra. Peaks appeared in Raman spectrum of the isolated product at 153, 102 and 85 cm
−1
that are assigned to
ν
as
(I-I),
ν
s
(I-I) and
respectively, which confirmed the presence of the
ion. The stoichiometry of the complex was found to be 1:2. The rate of their reaction has been measured as a function of time and solvent. Pseudo-first-order rate constants for the reaction were measured at various temperatures and the thermodynamic activation parameters (Δ
G
#
,Δ
S
#
and Δ
H
#
) were computed. Preliminary fluorescence quenching studies indicated that the interaction between atenolol and iodine is spontaneous and proceeds through a CT complex, and the quenching of fluorescence of atenolol by iodine increases as the extent of such complexation increases