Chemical Reports

Thermal properties and spectroscopic characterization of new synthesized 1,3-propanediylbis (triphenylphosphonium) peroxydisulfate as a member of phosphonium persulfates were studied. ¹H, ¹³C, ³¹P NMR and FT-IR were used to structural characterization of the title salt. To study the thermal behavior of the salt DSC, TG and DTA methods were used. Specific heat capacity of the salt was determined by DSC method in comparison of sapphire disk. Theoretical DFT computations such as structural optimization, energy, charge distribution, HOMO-LUMO energy levels and thermochemical parameters were performed with the Gaussian 09 package software using B3LYP/6-31+G* level of theory. Oxidation of several benzylic alcohols was performed by the persulfate salt in water as a mild oxidative agent.

Two Pseudomonas aeruginosa isolates from natural biofilms (marine and freshwater environment) were investigated for exopolymer (EPS) production and chemical characterization.  Both the isolates were categorized using molecular tools as P. aeruginosa species, The EPS production was distinct with various carbon and nitrogen sources, the average EPS yield by the two Pseudomonas strains was 55 µg ml^-1.  Modelling was done to establish the relation between observed and predicted EPS yields. The chemical composition, FTIR and Raman spectroscopy analysis of the two EPS showed that carbohydrate content was more in marine strain, while protein content was relatively high in the freshwater strain. Thermo-gravimetric analysis of the two EPS showed endothermic decomposition. Biochemical study by gel permeation chromatography showed that the marine strain EPS is a highly glycosylated biomolecule, while the freshwater EPS is a weakly glycosylated biomolecule with molecular weights 140,000 and 300,000 Daltons respectively. The EPS produced by the two Pseudomonas isolates has implication in process and chemical industries.   

An EPR study of the paramagnetic centers formed by γ irradiation of polycrystalline NaVO₃ was made at 77 K and room temperature  was performed. According to their EPR parameters and thermal behavior, the centers were attributed to: VȮ₃, VȮ_3^2-, VO, VO⁺, Ȯ₂^- radicals. The spin-spin relaxation time was calculated from the derivative peak-to-peak line widths assuming Lorentzian lines. A mechanism of the paramagnetic species formation was proposed.

Light rare earth (La, Ce, Pr) oxides with 3D superstructure are a kind of particularly interesting materials because of their unique optical, electronic, magnetic, and catalytic properties arising from the confinement of the 4f electrons. Here, we report a rapid and simple electrodeposition methodology for the assembly of three-dimensional (3D) superstructures of La₂O₃, CeO₂, and Pr₂O₃ nanobelts using the nitrates based electrolytes with NH₄Ac, and KCl as additives. The removal efficiencies of Congo red solution for La₂O₃, CeO_2, and Pr₂O₃ nano superstructures can reach 68%, 76% and 71% in dark. But CeO₂ show better removal efficiency than La₂O₃ and Pr₂O₃ under light irradiation.

In this literature review, we will introduce most reported methods that have been developed for determination of certain anti-ulcer drugs such as Ranitidine hydrochloride, Famotidine, Omeprazole, Pantoprazole sodium, Tinidazole and Doxycycline hyclate in their pure form, combined form with other drugs, combined form with degradation products, and in biological samples.