http://nopr.niscpr.res.in/handle/123456789/800 Mon, 12 Oct 2026 20:49:17 GMT 2026-10-12T20:49:17Z http://nopr.niscpr.res.in/handle/123456789/2173 Title: Photochemistry of 6-chloro-3-hydroxy-2-(2'-thienyl)- 4-oxo-4H-1-benzopyran Authors: Bala, Ritu; Kumar, Rupesh; Yusuf, Mohamad; Bansal, W R Abstract: On photolysis of the titled compound around its λmax (360 nm), it rearranges to 6-chloro-3-hydroxy-3-(2'-thienyl)-1,2-indandione as analysed by IR, NMR and by coupling with o-phenylenediamine. Quantitative analysis of the photolysed mixture by spectral measurements also confirms it. Quantum yield of the product is low (~0.05), which is not affected by the polarity of the solvent. Page(s): 1440-1444 Sat, 01 Sep 2007 00:00:00 GMT http://nopr.niscpr.res.in/handle/123456789/2173 2007-09-01T00:00:00Z http://nopr.niscpr.res.in/handle/123456789/2172 Title: Synthesis and anion recognition of acetate ions using pyrrole-⍺-carboxaldehyde 2,4-dinitrophenyl hydrazone Authors: Yu, Ming; Lin, Hai; Lin, Huakuan Abstract: A pyrrol-based anion receptor (1) for acetate ions has been designed and synthesized. The receptor has been characterized by various chemical methods. Anion binding studies have been carried out using ¹H NMR and UV-vis spectra. The results indicate that deprotonation takes place after receptor 1 binds CH3COO. 1 exhibits high selectivity for acetate ions for complementarity between the receptor and anion. The compound may be useful in the field of sensor materials. Page(s): 1437-1439 Sat, 01 Sep 2007 00:00:00 GMT http://nopr.niscpr.res.in/handle/123456789/2172 2007-09-01T00:00:00Z http://nopr.niscpr.res.in/handle/123456789/2171 Title: Derivative spectrophotometry for determination of zinc(II) and cadmium(II) using diphenylcarbazone in presence of Triton X-100 Authors: Kaur, Varinder; Malik, Ashok Kumar; Verma, Neelam; Rao, A L J Abstract: Diphenylcarbazone has been used for the simultaneous and in-dividual determination of zinc(II) and cadmium(II) at trace levels. The carbazone complexes of zinc(II) and cadmium(II) at pH 7–10 are pink in color, and are soluble in TX-100 micellar media. Un-der optimum conditions, calibration graphs for individual and simultaneous determination by first, second, third and fourth de-rivative spectrophotometry has been obtained. A zero crossing method using fourth derivative at 493.5 nm and 448.5 nm has been used for simultaneous determination of Zn(II) and Cd(II) respectively. To investigate the selectivity of the method, the ef-fects of diverse ions on the determination of zinc and cadmium have also been studied. The recommended procedure has been applied to synthetic binary alloys and pharmaceutical samples. Page(s): 1432-1436 Sat, 01 Sep 2007 00:00:00 GMT http://nopr.niscpr.res.in/handle/123456789/2171 2007-09-01T00:00:00Z http://nopr.niscpr.res.in/handle/123456789/2170 Title: Oxidation of aspartic acid by water soluble colloidal MnO₂ in absence and presence of ionic and nonionic surfactants Authors: Akram, Mohd.; Altaf, Mohammad; Din, Kabir-ud Abstract: The kinetics of the oxidation of aspartic acid by water-soluble form of colloidal manganese dioxide has been studied in acidic perchlorate media. Monitoring the disappearance of the colloidal MnO₂ spectrophotometrically at 390 nm has been used to follow the kinetics. The reaction is first-order in both [MnO₂] and [aspartic acid] but fractional-order in [HClO₄]. The results suggest formation of an adsorption complex between aspartic acid and MnO₂. The complex decomposes in a rate-determining step, leading to the formation of a free radical, which again reacts with the colloidal MnO₂ in a subsequent fast step to yield the product. The anionic micelles of sodium dodecyl sulfate have no effect on the oxidation rate whereas the rate constant increased with increase in [TX-100] which has been explained in terms of mathematical model proposed by Tuncay et al. A mechanism in agreement with the observed kinetic results is proposed and discussed. Freundlich isotherm is used to explain the adsorption of aspartic acid on colloidal MnO₂. Different activation parameters (Ea, ΔH#, ΔS#) have been evaluated and discussed. Page(s): 1427-1431 Sat, 01 Sep 2007 00:00:00 GMT http://nopr.niscpr.res.in/handle/123456789/2170 2007-09-01T00:00:00Z