A rapid and sensitive extractive spectrophotometric determination of palladium(II) in synthetic mixtures and hydrogenation catalysts using pyridoxal-4-phenyl-3-thiosemicarbazone

Synthesis and spectroscopic characterization of 3,4-difluoroacetophenone-thiosemicarbazone and its palladium(II) complex: evaluation of antimicrobial and antitumour activity

A new cis-palladium(II)diaqua(3,4-difluoroacetophenonethiosemicarbazone complex (Pd(II) complex) is synthesized using 3,4-difluoroacetophenonethiosemicarbazone(L). The L and its Pd(II) complex are characterized and confirmed by elemental analyses, electrochemical analyses, FT-IR, FT-Raman, UV-Vis, HRMS and LC-MS techniques. Ligand L is further characterized by (1)H, (13)C and (19)F NMR spectroscopy. The crystal structure of L is unambiguously characterized by single X-ray crystallography. The ligand (L) belongs to monoclinic system with P2(1)/C space group and the unit cell parameters are a(Å)=9.1144(7), b(Å)=13.7928(7), c(Å)=8.4174(5), α(°)=90, β(°)=100.715, γ(°)=90 and volume V(A(3))=1039.73(11). The Raman bands observed for the L and its Pd(II) complex are in good agreement with the FT-IR spectral data. The Pd(II) complex is found to be highly efficient in inhibiting the growth of human pathogens like Salmonella typhimurium and Klebsiella pneumonia with MIC value 10.0μg/mL whose inhibition zones are almost comparable with the standard antibiotic. The synthesized compounds have shown antiproliferative activity against the human breast cancer cell lines MDA-MB231 by intermitting the regular pathway of ribonucleotidereductase.

Analytical properties of p-[N,N-bis(2-chloroethyl)amino]benzaldehyde thiosemicarbazone: spectrophotometric determination of palladium(II) in alloys, catalysts, and complexes

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 μg cm(-3). The optimum concentration range for minimum photometric error as determined by Ringbom's plot method is 0.48-2.40 μg cm(-3). The yellowish Pd(II)-reagent complex shows a maximum absorbance at 395 nm, with molar absorptivity of 4.05×10(4) dm3 mol(-1) cm(-1) and Sandell's sensitivity of the complex from Beer's data, for D=0.001, is 0.0026 μg 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.

Selective and sensitive extractive spectrophotometric determination of micro amounts of palladium(II) in spiked samples: using a new reagent N-ethyl-3-carbazolecarbaxaledehydethiosemicarbazone

N-Ethyl-3-cabazolecarboxaldehydethiosemicarbazone (ECCT) is proposed as a new, sensitive and selective complexing reagent for the separation and extractive spectrophotometric determination of palladium(II) at pH: 4.0 to form a yellowish orange colored 1:1 chelate complex, which is very well extracted in to n-butanol. The absorbance was measured at a maximum wavelength, 410 nm. This method obeys Beer's law in the concentration range 0.0-6.6 microg mL(-1) and the correlation coefficient of Pd(II)-ECCT complex is 0.998, which indicates an excellent linearity between the two variables with good molar absorptivity and Sandell's sensitivity, 1.647 x 10(4) l mol(-1)cm(-1), 6.49 x 10(-3) microg cm(-2), respectively. The instability constant of complex calculated from Edmond's method, 2.724 x 10(-5) was in good agreement with the value calculated from Asmus' method 2.624 x 10(-5), at room temperature. The precision and accuracy of the method is checked with calculation of relative standard deviation (n = 5), 0.839. Edmond's method was observed to be a more selective method in the presence of EDTA, oxalate and phosphate ions. The method was successfully applied for the determination of Pd(II) in water samples, synthetic mixtures and hydrogenation catalysts, employing an atomic absorption spectrometer for comparing these results.

4-(N,N-diethylamino) benzaldehyde thiosemicarbazone in the spectrophotometric determination of palladium

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 microgmL(-1). The optimum concentration range for minimum photometric error as determined by Ringbom plot method is 0.36 - 3.24 microg mL(-1). The yellow Pd(II)-DEABT complex shows a maximum absorbance at 408 nm, with molar absorptivity of 3.33 x 10(4) dm3 mol(-1) cm(-1) and Sandell's sensitivity of the complex from Beer's data, for D = 0.001, is 0.0032 microg 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.

Development of an extractive spectrophotometric method for the determination of copper(II) in leafy vegetable and pharmaceutical samples using pyridoxal-4-phenyl-3-thiosemicarbazone (PPT)

A highly sensitive extractive spectrophotometric method has been developed for the determination of copper(II) using pyridoxal-4-phenyl-3-thiosemicarbazone(PPT) as an analytical reagent. The PPT forms reddish brown species of copper(II) at a pH range of 3.0-5.5, and the complex was extracted into n-butanol. The Cu(II)-PPT complex shows maximum absorbance at 440 nm, with molar absorptivity and Sandell's sensitivity being 2.16 x 10(4) L mol(-1) cm(-1) and 2.94 x 10(-3) microg cm(-2), respectively. The system obeys Beer's law in the range of 0.2-5.0 mg/L. The regression coefficient of the Beer's law straight line is 0.338, and the correlation coefficient is 0.96. The detection limit of the method is 0.0065 microg mL(-1). Most of the common metal ions generally found associated with copper do not interfere. The repeatability of the method was checked by finding the relative standard deviation. The developed method has been successfully employed for the determination of copper(II) in leafy vegetable and pharmaceutical samples. The method is evaluated by analyzing samples from the Bureau of Analyzed Samples (BCS 233, 266, 216/1, 207, and 179) and by intercomparison of experimental values using AAS.