title: Spectroscopic and spectrofluorimetric studies on the interaction of irbesartan with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone and iodine.
abstract: Raman, UV-vis, 1H NMR, FT-IR, mass and fluorescence spectral techniques were employed to investigate the mechanism of interaction of irbesartan (IRB) drug with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) and iodine. Interaction of IRB with iodine yields triiodide ion and its formation was confirmed by electronic and Raman spectra. The peaks appeared in Raman spectrum of the isolated product at 143, 113 and 76 cm(-1) are assigned to νas(I-I), νs(I-I) and δ(I3-) respectively, confirmed the presence of I3- ion. The interaction of DDQ with irbesartan was found to proceed through the formation of outer complex and its conversion to the CT complex. Formation constant (K), molar extinction coefficient (ɛ) and thermodynamic properties ΔH#, ΔS# and ΔG# were determined and discussed. Fluorescence quenching studies indicated that the interaction between the IRB and the acceptors are spontaneous and the IRB-DDQ interaction is found to be stronger than that the other system. Solvent variation studies indicated that the binding constant increased with an increase in polarity of the medium.
authors.affiliation: Department of Chemistry, Gandhigram Rural Institute, Deemed University, Gandhigram 624 302, India.
authors.forename: K
authors.initials: K
authors.lastname: Ganesh
authors.forename: C
authors.initials: C
authors.lastname: Balraj
authors.forename: K P
authors.initials: KP
authors.lastname: Elango
mesh_terms: D016227:Benzoquinones / Q000737:chemistry*; D001713:Biphenyl Compounds / Q000737:chemistry*; D002703:Chloranil / Q000737:chemistry*; D005030:Ethylenes / Q000737:chemistry*; D007455:Iodine / Q000737:chemistry*; D000077405:Irbesartan; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D009570:Nitriles / Q000737:chemistry*; D013050:Spectrometry, Fluorescence; D013056:Spectrophotometry, Ultraviolet; D017550:Spectroscopy, Fourier Transform Infrared; D013059:Spectrum Analysis, Raman; D013777:Tetrazoles / Q000737:chemistry*
chemical_list: D016227:Benzoquinones; D001713:Biphenyl Compounds; D005030:Ethylenes; D009570:Nitriles; D013777:Tetrazoles; D002703:Chloranil; C000928:dichlorodicyanobenzoquinone; D007455:Iodine; C003393:tetracyanoethylene; D000077405:Irbesartan