Classical chemical sciences
The photochemistry of 3-azido-1H-pyrazolo[3,4-c]pyridazine ring-system has been investigated. The irradiation of 3-azido-4,5-diphenyl- 1H-pyrazolo[3,4-c]pyridazine 1 in various solvents brings to a photolytic nitrene intermediate, which involves into a ring-opening to give 3- substituted pyridazine derivatives. During the photolysis of 1 in toluene and/or anisole the photoattack reaction of nitrene with the solvents is faster than the ring opening thus the corresponding 3-(arylanilino)pyrazolo[3,4-c]pyridazine derivatives are formed. The photolysis in the presence of diethyl malonate led to a mixture of three pyridazine derivatives.
Keywords: 3-Azido-4,5-diphenyl-1H-pyrazolo[3,4-c]pyridazine, photolysis in solvents; nitrene formation
Theoretical model of laser destruction process of chemical compounds by laser radiation is proposed in the work. Models for calculation of vibration spectrum of molecule in nonregular condensed medium and for kinetic parameters of electron transfer and photo-transfer process between the particles are presented within the framework of quantum-mechanical approach. In terms of obtained analytic results it is proposed to calculate frequency spectrum for valence vibrations of atoms in molecule and to split corresponding chemical bonds by the help of laser emission. Obtained radicals may be used for formation of other chemical compounds, particularly, with application of laser emission also.
Keywords: laser radiation; destruction; valence vibrations; chemical bond splitting
Evidences seem to indicate that existence of stable mercurous nitrite, reported by P. C. Ray, is doubtful. Ray also reported a number of subnormal compounds of platinum and gold, for which he proposed astounding constitutions, which are most likely to be metal cluster compounds; the plausible structures of a few of these are proposed. Their investigations by X-ray crystallography to determine their structures and thus establish their identity would be fruitful.
Keywords: Mercurous nitrite; Gold and platinum clusters
Densities, viscosities and speeds of sound for the binary systems of butyl propionate with cyclopentanone, 3-pentanone, cyclohexanone and acetophenone have been determined as a function of composition at (303.15 and 313.15) K and atmospheric pressure. The excess volume (VE), excess Gibbs free energy of activation of viscous flow (ΔG*E), deviation in speeds of sound (Δu), isentropic compressibility (KS), deviation in isentropic compressibility (ΔKS), and intermolecular free length (Lf) were derived from the experimental data. These binary data were correlated as a function of the mole fraction by using the Redlich- Kister Polynomial equation to determine the fitting parameters and the standard deviations.
Keywords: butyl propionate; cyclohexanone; cyclopentanone; 3-pentanone; acetophenone; density; viscosity; speed of sound; binary mixture
The title compound 3,3,6,6-tetramethyl-9-(3,4-dimethylphenyl)-3,4,6,7,9,10-hexahydroacridine-1,8-dione (C25H31NO2) crystallizes in the monoclinic space group P21/c with unit cell parameters: a=18.616(3), b=9.9747(13), c=11.8093(15) Ǻ, β=91.89(13)º, Z=4. The crystal structure was solved by direct methods and refined by full-matrix least-squares procedures to a final R-value of 0.075 for 3088 observed reflections. The central ring of the acridinedione system adopts a boat conformation. The four essentially planar atoms (C10/C11/C13/C14) of this ring [maximum deviations = 0.2047(3) Ǻ] forms dihedral angles of 87.32º(13) with the benzene ring. The two outer rings of the acridinedione system adopt sofa conformations. The crystal packing is stabilized by intermolecular N-H…O interactions.
Keywords: Acridinediones, Crystal structure, Direct methods, N-H…O hydrogen bonding
The title compound 3'-[(4-fluorophenyl)carbonyl]-5'-(hydroxymethyl)-4’-phenylspiro[indole-3,2'-pyrrolidin]-2(1H)-one is synthesized by the straightforward multicomponent reaction of 1-(4-fluorophenyl)-3-phenylprop-2-en-1-one, isatin and serine, and is crystallises in monoclinic space group C2/c.The molecule is essentially planar except one of the pyrrolidin ring which adopts normal envelope conformation. The supermoleular assembly is consolidated by interactions [centroid- centroid distance= 3.7983(18)]. The crystal structure is stabilized by one C-H…O intra-hydrogen bond, two N-H…O and one O-H…N inter-hydrogen bonds, and these interactions links the molecules into chain extending along the b-axis.
Keywords: spiro[indole-3,2'-pyrrolidine], 1-(4-fluorophenyl)-3-phenylprop-2-en-1-one, isatin; crystal structure, intermolecular and intramolecular hydrogen bonds
The reaction of Cu(ClO4)2·6H2O with 2-amino-5-(trifluoromethyl)pyridine (5-TFMAP) in 1-propanol/water solution gave the product [Cu2(5-TFMAP)4(OH)2](ClO4)2·(5-TFMAP)2. The complex forms as a dihydroxide briged Cu(II) dimer with two coordinated 5-TFMAP on each copper ion and two non-coordinated 5TFMAP molecules in the asymmetric unit. Although hydroxide bridged Cu(II) dimers generally exhibit strong magnetic exchange, the compound shows only very weak antiferromagnetic interactions (~ -1.7 K) which is attributed to the Cu-O-Cu bridging angles.
Keywords: Copper(II) complexes, magnetic susceptibility, X-ray structure
A simple, sensitive and accurate spectrophotometric method is developed for the quantitative determination of aminophenol isomers, i.e. oaminophenol, m-aminophenol and p-aminophenol. The method is based on the interaction between these amines and 9-chloroacridine reagent (9-CA). The spectra of the products show maximum absorption at 436 nm. Beer’s law is obeyed in the concentration range of 0.25- 12, 0.2-10 and 0.0-10 μg mL-1 with molar absorptivity values 7.20х103, 7.67х103 and 5.93 х103 L mol-1 cm-1 for the above mentioned isomers respectively. The mean percent recoveries are ranged between 97.3 % and 101.07 % with relative standard deviation (RSD) ≤ 4.7 % for all the isomers. In addition, the stability constant has been determined and the mechanism is proposed for the 9-CA-aminophenol products.
Keywords: spectrophotometric determination; o-aminophenol; m-aminophenol; p-aminophenol; 9-chloroacrididne
Materials and environmental chemistry
The effect of cationic conventional surfactants myristyltrimethylammonium bromide (TTAB), cetyltrimethylammonium bromide (CTAB), and cetylpyridinium chloride (CPC) on the interaction of dipeptide glycyl-alanine (Gly-Ala) with ninhydrin has been studied spectrophotometrically under different conditions. The reaction rates are higher in the presence of surfactants but the reaction order remains the same in both the media (first- and fractional-order with respect to [Gly-Ala] and [ninhydrin]). Quantitative kinetic analyses of kψ[surfactant] data were performed on the basis of pseudo-phase model of the micelles (proposed by Menger and Portnoy and developed by Bunton and Romsted) and Piszkiewicz model wherein the micellar binding constants KS for Gly-Ala and KN for ninhydrin with surfactant micelles were evaluated. The catalytic efficiency in TTAB increased by added electrolytes which had been discussed in detail.
Keywords: surfactant, dipeptide (Gly-Ala), ninhydrin, catalysis, micelles, TTAB, CTAB, CPC, salts
The level concentration of metallic elements (Hg, Cd, and Fe, Mn, Zn, Cu, Pb, and Ni) in muscles and liver tissue, which have a tendency to accumulate different metals, of marine fish (Pagothenia borchgrevinki) in the Antarctic ocean is investigated. With the view that it may lead to a further investigation of the quality of the Antarctic ocean environment.
Keywords: Antarctic fish; accumulation of heavy metals; Pagothenia borchgrevinki
Starch-Phenol based polymer synthesized by the process of polycondensation which further is modified into two different branches. In one case with Linseed Oil Epoxy and PS-PMMA co-polymer by melt blending method for the preparation of biodegradable blend and in another case by transition metals Mn(II), Co(II), Ni(II), Cu(II) and Zn(II) for synthesizing coordination polymer. The type of modified starch used in the composition inherently affects the properties and also play a role in the biodegradability of the developed material. All the synthesized polymeric ligands were characterized by Fourier transform infrared spectroscopy (FT-IR), 1H NMR spectroscopy, 13C NMR spectroscopy, UV-visible spectra, magnetic moment measurements, thermogravimetric analysis (TGA), Differential Scanning Calorimetry (DSC), Scanning electron microscopy (SEM) and Biodegradation studies. Thermal data revealed that Polymer metal complexes are lesser in thermal strength than blend and that the biodegradation rates of blends and polymer metal complexes are somewhat similar.
Keywords: use the Keywords style for the list of keywords, separating with a comma each items
Spark Plasma Sintering (SPS) of thermal plasma synthesized nanosize powders were studied without removing the free carbon impurities. Instead, SiC was mixed with silicon powder to react with the free carbon during sintering with boron as sintering aids. Density of the resulted disc samples found to be increased with the applied temperature and achieved a maximal 93 % of relative density at 1950 °C after 5 minutes holding time. The obtained samples composed of β-SiC along with a few per cent of un-reacted graphite.
Keywords: Sintering, silicon carbide, SPS, porosity, plasma synthesis
Historical sand stone monuments, is subjected to degradation induced by diverse mycoflora. Fungi are among the most active microorganisms in these processes. Fungal ability in production of pigments and organic acids have crucial role in discoloration and degradation of different types of sandstone in historical monuments. This investigation focuses on myco-ecological analyses of microbial bio-film from Mama Bhanja temple of Chhattisgarh State. The seven (07) fungal organisms with specific distribution on sandstone monuments were isolated. Fungi from Ascomycotina as well as Deuteromycotina were more frequent. The most frequent isolated fungal species from these historical sandstone monuments are Aspergillus niger, Curvularia lunata, Rhizoctonia solani and Aspergillus flavus. Aspergillus niger was common in almost all the sandstone structures of this monument. The frequency and relative frequency of these fungal organisms associated with deteriorated sandstone monuments site provides valuable data for future studies.
Keywords: Degradation; deterioration; sandstone monuments; myco-ecological; biofilm
Soil samples were collected from an oil spilled polluted site in the Niger Delta, Nigeria. The polycyclic aromatic hydrocarbon content was determined using gas chromatography. Results indicated that 1,2-benzanthracene was the most abundant with concentration of 11.90 mg kg-1 for surface and 8.10 mg kg-1 for subsurface. Benzo[b]fluoranthene followed closely with concentrations of 2.15 mg kg-1 for surface and 2.02 mg kg-1 for subsurface. There was low concentration of phenanthrene in the samples (0.01 mg kg-1) which indicate that the samples suffered from mild evaporation caused by weather. Various ratios such as the Σ3-6 ringed PAHs/Σ5-alkylated PAHs of 2.77; fluoranthene/pyrene of 7.89; benz[a]anthracene/chrysene of 9.79 were far greater than unity (>1) indicating petrogenic source; phenanthrene/anthracene ratio is 0.10 depicted that the area under study was unexposed to bush burning.
Keywords: Polycyclic aromatic hydrocarbons; Petrogenic; Bodo city; oil spillage and distribution ratios
Hybrid materials containing sulfo-substituted cobalt(II) phthalocyanines and various pre-treated solid organic and inorganic matrixes (poly(methyl methacrylate), polypropylene, silicon dioxide) have been obtained. It is shown that the plasma chemical activated polypropylene matrix results 85-90 % attachment of the macrocycles. Attaching the sulphonated cobalt(II) phthalocyanines to silicon dioxide matrix, ~65 % of the macrocycles were found to be bound.
Keywords: water-soluble porphyrins and metallophthalocyanines, polymer matrix, surface modification
Biochemistry, molecular biology and biotechnology
Active substances such as Saponins (41.1 %), volatile oils (2.5 %) and Tannins (13.2 %) are isolated from Glycyrrhiza glabra plant, and some mineral elements such as sodium (203 ppm), calcium (176 ppm) and potassium (181 ppm) respectively from the Glycyrrhiza glabra seeds. The concentration of the mineral elements was measured by using Flame Spectrometer. Also a study of anti-bacterial activity of the extracts was made using two types of pathogenic bacteria viz., Escherichia Coli and aurous Staphylococcus showed the ability of inhibition for all different extracts by vary inhibition diameters for different active substances, concentrations and bacteria. One type of cancer cellular line used to study the effect of Glycyrrhiza glabra extracts were studied on the growth of Rhabdomyo sarcomas (RD) cell line in human by using in vitro system and compared with anticancer drug cisplatin (cis-pt) as a positive control. The cancer cell were treated with different concentration for each of the three treatments and cis-pt after 72 h exposure time. The cytotoxic activity was tested by inhibition rate as parameter. The results showed significant differences (p < 0.05) for each three treatments when the inhibition rates were increased. There was strong correlation between the three treatments and the different concentrations in comparison with cisplatin.
Keywords: Glycyrrhiza glabra extracts, antibacterial and anticancer activity, extraction, isolation, Rhabdomyo sarcoma
Industrial and engineering chemistry
The composition of the melt was described in which, primarily the preparation of aluminum electroplatings at low - temperatures: 95-110 0C is possible on hardware and steels such as: ST-3, Cr-18 and ST-40, as well as on screw like hardware (bolts, nuts), manufactured from steels 25CrMoFe and 35MoFe. Optimum conditions of the process of plating preparation and electrochemical parameters were also determined. The effect of various metal-modifier (Pb, Sn, Bi, Mn, Zr, Cr) on plating process and quality of the melt has also been studied.
Keywords: Low-temperature electrolysis, halide melt, aluminum electroplating
The method for gold extraction from the residues of vacuum-thermal treatment of the concentrate of gold-containing antimony ore of Zopkhito (deposit) has been established by eco-friendly electrochemical method. The effect of main technological parameters on the process of electrochemical leaching of the residues has been studied in the presence of a selective ligand, thiourea, in chloride system and optimal conditions of leaching have been established providing for the gold extraction from gold-containing residues by 82-90 % in the conditions of so-called “soft” oxidation without release of molecular chlorine at the anode and eco-contamination. Continuous technological process of electrochemical leaching of the residues of gold-containing antimony ore and electrochemical reactor for realization of this process are proposed.
Keywords: electrochemical processing, gold-containing antimony ores, gold extraction
Radiochemistry and isotopes
We became aware of the article, “Production of Calcium Monohydrogenphosphate from Sebaiya Phosphate Ore Leaching by Nitric Acid” published in Eur. Chem. Bull. 2013, 2(10), 752-757. We do not recommend using dicalcium phosphate prepared by this method as animal feed unless uranium and fluorine are first removed from solution before forming the product.
Keywords: Dicalcium phosphate; phosphate ores; uranium and fluoride removal from phosphate ores
We have been concerned with a method which is applicable in commercial scale. CaHPO4 was produced by precipitating a fraction of P2O5 using calcium carbonate (not any other calcium salt) in order to achieve the precipitation reaction in a pH below the pH of uranium and fluoride precipitation range. Finally we adjusted the pH of the final product and the ratio between Ca and P. Therefore, the final product is not contaminated with uranium.
Keywords: Production of dicalcium phosphate; uranium contamination; fluoride precipitation