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Item 4-(N,N-diethylamino) benzaldehyde thiosemicarbazone in the spectrophotometric determination of palladium(2007) Parameshwara, P.; Karthikeyan, J.; Nityananda Shetty, A.N.; Shetty, P.4-(N,N-diethylamino)benzaldehyde thiosemicarbazone(DEABT) is proposed as a sensitive and selective analytical reagent for the spectrophotometric determination of palladium(II). The reagent reacts with palladium (II) in a potassium hydrogen phthalate-hydrochloric acid buffer of pH 3.0, to form a yellow complex. Beer's law is obeyed in the concentration range up to 3.60 ?gmL-1. The optimum concentration range for minimum photometric error as determined by Ringbom plot method is 0.36-3.24 ?g mL-1. The yellow Pd(II)-DEABT complex shows a maximum absorbance at 408 nm, with molar absorptivity of 3.33 × 104 dm3 mol-1 cm-1 and Sandell's sensitivity of the complex from Beer's data, for D=0.001, is 0.0032 ?g cm-2. The composition of the Pd(II)-DEABT complex is found to be 1:2 (M:L). The interference of various cations and anions in the method were studied. The proposed method was successfully used for the determination of Pd(II) in alloys, catalysts, complexes and model mixtures with a fair degree of accuracy.Item Spectrophotometric determination of platinum(IV) in alloys, complexes, environmental, and pharmaceutical samples using 4-[N,N-(diethyl)amino] benzaldehyde thiosemicarbazone(2010) Naik, P.P.; Karthikeyan, J.; Nityananda Shetty, A.N.4-[N,N-(Diethyl)amino] benzaldehyde thiosemicarbazone (DEABT) is proposed as an analytical reagent for the spectrophotometric determination of platinum(IV). The DEABT forms 1:2 yellow complex with Pt(IV), which is sparingly soluble in water and completely soluble in water-ethanol-DMF medium. The Pt(IV)-DEABT complex shows maximum absorbance at 405 nm. Beer's law is valid up to 7.80 ?g cm-3, and optimum concentration range for the determination of platinum(IV) is 0.48-7.02 ?g cm-3. The molar absorptivity and Sandell's sensitivity of the method are found to be 1.755 × 104 dm3 mol-1 cm-1 and 0.0012 ?g cm-2, respectively. The relative error and coefficient of variation (n=6) for the method does not exceed ±0.43% and 0.35%, respectively. Since the method tolerates a number of metal ions commonly associated with platinum, it can be employed for the determination of platinum in environmental samples, pharmaceutical samples, alloys, catalysts, and complexes. The method is rapid as the Pt(IV)-DEABT complex is soluble in water-ethanol-DMF medium and not requiring any time consuming extraction method for the complex. © 2010 Springer Science+Business Media B.V.Item Analytical properties of p-[N,N-bis(2-chloroethyl)amino]benzaldehyde thiosemicarbazone: Spectrophotometric determination of palladium(II) in alloys, catalysts, and complexes(2011) Karthikeyan, J.; Parameshwara, P.; Nityananda Shetty, A.N.p-[N,N-bis(2-chloroethyl)amino]benzaldehyde thiosemicarbazone (CEABT) is proposed as a new, sensitive, and selective analytical reagent for the spectrophotometric determination of palladium(II). The reagent reacts with palladium(II) in the pH range 1-2 to form a yellow-colored complex. Beer's law is obeyed in the concentration range up to 2.64 ?g cm-3. The optimum concentration range for minimum photometric error as determined by Ringbom's plot method is 0.48-2.40 ?g cm-3. The yellowish Pd(II)-reagent complex shows a maximum absorbance at 395 nm, with molar absorptivity of 4.05 × 104 dm3 mol-1 cm-1 and Sandell's sensitivity of the complex from Beer's data, for D= 0.001, is 0.0026 ?g cm-2. The composition of the Pd(II)-CEABT reagent complex is found to be 1:2 (M-L). The interference of various cations and anions in the method were studied. The proposed method was successfully used for the determination of Pd(II) in alloys, catalysts, complexes, water samples, and synthetic alloy mixtures with a fair degree of accuracy. © 2010 Springer Science+Business Media B.V.Item A rapid extractive spectrophotometric determination of copper(II) in environmental samples, alloys, complexes and pharmaceutical samples using 4-N,N(dimethyl)amino]benzaldehyde thiosemicarbazone(2011) Karthikeyan, J.; Naik, P.P.; Nityananda Shetty, A.N.4-[N,N-(Dimethyl)amino]benzaldehyde thiosemicarbazone (DMABT) is proposed as an analytical reagent for the extractive spectrophotometric determination of copper(II). DMABT forms yellow colored complex with copper(II) in the pH range 4.4-5.4. Beer's law is obeyed in the concentration range up to 4.7 ?g mL -1. The optimum concentration range for minimum photometric error as determined by Ringbom plot method is 1.2-3.8 ?g mL-1. The yellowish Cu(II)-DMABT complex shows a maximum absorbance at 420 nm, with molar absorptivity of 1.72 × 104dm3 mol-1 cm-1 and Sandell's sensitivity of the complex obtained from Beer's data is 0.0036 ?g cm-2. The composition of the Cu(II)-DMABT complex is found to be 1:2 (M/L). The interference of various cations and anions in the method were studied. Thus the method can be employed for the determination of trace amount of copper(II) in water, alloys and other natural samples of significant importance. © 2010 Springer Science+Business Media B.V.Item Design and: In vitro biological evaluation of substituted chalcones synthesized from nitrogen mustards as potent microtubule targeted anticancer agents(Royal Society of Chemistry, 2017) Sabina, X.J.; Karthikeyan, J.; Velmurugan, G.; Muthu Tamizh, M.M.; Nityananda Shetty, A.N.A new series of p-[N,N-bis(2-chloroethyl)amino]benzaldehyde substituted chalcone derivatives were designed and synthesized, and their structures were characterized by spectroscopic techniques and single crystal XRD studies. Compounds 3a-f crystallized in the triclinic system with a centrosymmetric space group P1, except for crystal 3c which crystallized in the monoclinic crystal system with a centrosymmetric space group P21/c. Molecular docking studies were utilized to reveal the binding mode of the derivatives to identify new tubulin inhibitors. Density functional theory calculations were performed to understand the structural and electronic properties of these chalcones. The DFT results show that the HOMOs of all the chalcones lie in the range of -5.65 to -6.17 eV and the LUMOs in the range of -2.01 to -3.21 eV. The experimental results are well supported by the theoretical structural analysis. The biological activity of these compounds showed high potency of growth inhibitory effects with sub-micromolar IC50 values ranging from 0.089 to 0.200 ?M against A549 and HepG2 cancer cell lines. Furthermore, these compounds exhibited a strong inhibitory effect on tubulin polymerization. 3e showed the highest mean activity against both the cancer cells and in tubulin inhibition. This correlated well with the theoretical results from the pharmacophore binding model. Hence, these six compounds, particularly 3e, could be considered as potential leads in the development of new anticancer agents. © The Royal Society of Chemistry and the Centre National de la Recherche Scientifique 2017.