Fluorescence spectral studies of some imidazole derivatives

Jayabharathi, Jayaraman; Thanikachalam, Venugopal; Srinivasan, N.; Perumal, Marimuthu Venkatesh

doi:10.1016/j.saa.2012.01.030

Cited by 21 publications

(20 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The presence of the biphenyl and the imidazole fluorescent groups (fluorophores) allowed to collect the fluorescence spectra of both the ligands from pH 1 to 7 [49], [50]. In the pH range 1 -2 the fluorescence peak shifts towards higher energy both in 30 In Figure 3, the fluorescence intensities at fixed wavelength are superimposed to the speciation plots obtained from the potentiometric results (Fig.…”

Section: Fluorescence Resultsmentioning

confidence: 99%

Complex formation equilibria of Cu2+ and Zn2+ with Irbesartan and Losartan

Lachowicz

Nurchi

Crisponi

et al. 2017

European Journal of Pharmaceutical Sciences

View full text Add to dashboard Cite

We conducted a thorough study of Cu 2+ complex formation equilibria with Irbesartan and Losartan, the two primary drugs for the cure of cardiovascular diseases, with the aim of recognising if these drugs could exert a chelating action toward Cu 2+. We used different complementary techniques to gain a clear picture of the involved protonation and complexation equilibria. The low solubility in water of the ligands and of the formed metal complexes prevented the use of water as solvent, so we had to perform the measurements in mixed methanol-water solvents. Further, we studied the related equilibria with Zn 2+ for evaluating a potential interference of this essential metal ion, largely present in biological fluids. Our study provided a strong evaluation of the formed complexes and of the relative stability constants. The binding of both metal ions takes place through the tetrazole moiety except for the Zn 2+ -Irbesartan system. In this last case, NMR measurements gave evidence of a tautomeric equilibrium involving the imidazole ring and the aliphatic chain. The estimated complexation model, and the related stability constants, allowed a speciation study in human plasma, based on a number of simplifying assumptions, which remarked that both drugs, Losartan and Irbesartan, could exert a chelating action, scavenging non-negligible amounts of Cu 2+ from the organism.

show abstract

Section: Fluorescence Resultsmentioning

confidence: 99%

Complex formation equilibria of Cu2+ and Zn2+ with Irbesartan and Losartan

Lachowicz

Nurchi

Crisponi

et al. 2017

European Journal of Pharmaceutical Sciences

View full text Add to dashboard Cite

show abstract

“…However, the yield was also higher when the reaction was preformed with 2-methoxyl benzaldehyde with an electron-donating substituted group and furil as the starting materials. A possible reason is that the target product, XI (entry 11), showed better stabilization of the stable resonance structure XIb formed in an acidic medium (Jayabharathi et al, 2012a) (Fig. 1).…”

Section: Resultsmentioning

confidence: 99%

“…), they were red-shifted to 418 nm (II ) and 472 nm (XIII ) ( Table 6), respectively. The red-shift of an emission band might be caused by the stronger interaction between the solvent and the excited state molecules (Jayabharathi et al, 2012a). Polar solvents stabilized the excited state of II and XIII (Mi et al, 2003;Jayabharathi et al, 2012a).…”

Section: Studies Of Thermal Stability and Photoluminescence Propertiesmentioning

confidence: 99%

“…The red-shift of an emission band might be caused by the stronger interaction between the solvent and the excited state molecules (Jayabharathi et al, 2012a). Polar solvents stabilized the excited state of II and XIII (Mi et al, 2003;Jayabharathi et al, 2012a). ThereBrought to you by | New York University Bobst Library Technical Services Authenticated Download Date | 6/8/15 2:58 PM fore, the emission spectra of both compounds, II and XIII, are broad and solvent dependent (Loiseau et al, 2005;Yang et al, 2009).…”

Section: Studies Of Thermal Stability and Photoluminescence Propertiesmentioning

confidence: 99%

See 1 more Smart Citation

Microwave-assisted solvent-free synthesis and luminescence properties of 2-substituted-4,5-di(2-furyl)-1H-imidazoles

Zhang

Chen

et al. 2015

Chemical Papers

View full text Add to dashboard Cite

A solvent-free microwave-assisted method for the synthesis of 2-substituted-4,5-di(2-furyl)-1H-imidazoles was developed. Imidazoles with moderate to good yields were produced by condensation of furil with aldehydes over acidic alumina impregnated with ammonium acetate, and they were characterized by FT-IR, HRMS, 1 H NMR and 13 C NMR spectroscopy. Crystal structure of 2,4,5-tri-2-furyl-1H-imidazole (I ) in the orthorhombic space group Pbca was reported, which showed more coplanarity than the reported crystal structure of I in the monoclinic space group Cc. Moreover, their luminescent properties were investigated. It was found that the organic small molecule compounds synthesized possess higher fluorescence quantum efficiency (up to 0.508) in a 0.1 M H2SO4 aqueous solution dissolved in 0.5 mL of CH3OH; along with higher stability; also the emission of some compounds synthesized in the solution was sensitive to the polarity of the solvents.

show abstract

“…These properties may be responsible for the small number of reports in the literature regarding the synthesis of imidazoles bearing furan ring as a substituent [161]. While the biological and pharmacological potency of tetra-substituted imidazoles have been extensively investigated, their luminescence properties have been largely overlooked, except for 1-R 1 -2-R-4,5-dialkyl-1H -imidazoles [204]. A series of new tetra-substituted imidazoles 253 with furan rings were constructed by the treatment of 2-R-4,5-di(furan-2-yl) imidazoles 250 and benzyl chlorides or allyl chloride in the presence of sodium hydride [203] to yield 1-R 1 -2-R-4,5-di(furan-2-yl)-1H -imidazole derivatives 253; they were obtained in good yields.…”

Section: Synthesis Of 1245-tetra-aryl-1h-imidazolesmentioning

confidence: 99%