Classical and Advanced Chemical Sciences
Tandem reaction of N'-(4-cyano-1-phenyl-1H-pyrazol-5-yl)-N,N-dimethylimidoformamide (6) with acylhydrazines in N,Ndimethylacetamide leads to the formation of 2-R-7-phenyl-7H-pyrazolo[4,3-e][1,2,4]triazolo[1,5-c]pyrimidines (10a-f).
Keywords: pyrazolo[4,3-e][1,2,4]triazolo[1,5-c]pyrimidines; aminopyrazole; acylhydrazines; N,N-dimethylformamide dimethylacetal; tandem reaction
The transmitted light intensity (TLI) and polarized optical microscopy (POM) measurements of [Mn(OS(CH3)2)6](ClO4)2 and [Zn(OS(CH3)2)6](ClO4)2, as a function of temperature, showed that only some of the phase transitions discovered earlier for these compounds by the differential scanning calorimetry were now observed as anomalies on the TLI curves and as different textures in POM pictures. Above-mentioned methods indicated that discovered phases of both compounds were the crystalline phases with different orientational dynamical disorder. Additionally, it was confirmed that these both compounds melt at 488 and 465 K, respectively.
Keywords: hexakis(dimethylsulphoxide)manganese(II) tetraoxochlorate(VII); hexakis(dimethylsulphoxide)zinc tetraoxochlorate(VII); phase transitions; melting points; transmitted light intensity; polarized optical microscopy
Cesium carbonate catalyzed three-component condensation reaction of an aldehyde, malononitrile and α-naphthol or β-naphthol proceeded rapidly in ethanol to afford corresponding naphthochromenes in high yield under microwave irradiation.
Keywords: Multicomponent reaction, cesium carbonate, microwave irradiation, chromenes
The aromatic rings in 2,7-dimethoxy-1,8-bis(1-naphthoyl)naphthalene in crystal accumulate non-coplanarly to each other, with the dihedral angle between the terminal naphthalene and the 2,7-dimethoxynaphthalene rings of closer to 90° than the homologous compounds, 1,8- dibenzoyl-2,7-dimethoxynaphthalene and 2,7-dimethoxy-1,8-bis(2-naphthoyl)naphthalene. Molecular packing structures of the title compound and the homologous two compounds are classified by screw-sense and orientation of molecular assembly with a two-fold screw axis. In the title compound, right(left)-handed 21 helical assemblies are oriented in a downward (an upward) direction forming a plane. The plane is alternately stacked with the counter handed version. In the homologous compounds, right (left)-handed 21 helical assemblies are oriented in an upward (a downward) direction to form a plane. In other words, the 21 helical assemblies in the molecular packing of the title compound correspond to the 180° rotated one of the homologous compounds as space geometry. In the right(left)-handed 21 helical assembly of the title compound, two types of effective C–H…O=C hydrogen bonds are observed, i.e., (sp3)C–H…O=C hydrogen bond and (sp2)C–H…O=C hydrogen bond. On the other hand, either of two types of C–H…O=C hydrogen bonds is found in a right(left)-handed 21 helical assembly of the homologous two compounds. Besides, the title compound has (sp3)C–H…O=C hydrogen bonds between the righthanded 21 helical assembly and the left-handed one, and the homologous two compounds have effective π…π stacking interactions and (sp2)C–H…O=C hydrogen bonds. Cooperative two types of C–H…O=C hydrogen bonds in right(left)-handed helical assembly induce a downward (an upward) orientation of the 21 helical assemblies, showing P21/c space group. Sole function of either (sp3)C–H…O=C hydrogen bond or (sp2)C–H…O=C one in right(left)-handed helical assembly leads the opposite oriented right(left)-handed 21 helical assemblies, showing C2/c space group.
Keywords: Non-coplanarly accumulated aromatic rings molecule, Cooperative hydrogen bonds, Orientation of 21 helical assembly
Trifluoromethanesulfonic acid efficiently catalyzes the conjugate addition of indoles to p-benzoquinones under mild conditions affording the corresponding indolylquinones in high yields with high selectivity. In particular, the poorly reactive menadione underwent reaction with indoles under similar conditions to give 3-indolylnaphthoquinones.
Keywords: p-Quinones, indoles, trifluoromethanesulfonic acid, indol-3-ylbenzoquinones
Fluoroimines have been reduced to their corresponding amines by means of NaBH4 using MeOH as a solvent at room temperature. The reaction time and yield are 1-1.5 hr and 77-90%, respectively. Reduction process is very effective, inexpensive and clean for synthesis of fluoroamines in good yield. The structures of the compounds are supported by FTIR, mass spectrometry 1H and 13C NMR spectral data.
Keywords: NaBH4 reduction; fluoroamines; fluoroimines; spectral data
Materials and Environmental Chemistry
Biogenic synthesis of silver nanoparticles has attracted researcher’s attention in recent days because of the necessity to develop new clean, cost effective and efficient techniques. In our study, we report green biogenic approach to synthesize silver nanoparticles using flower extract of Rosa damascena as reducing and stabilizing agent. The phytochemicals present in the petal extract induced the reduction of Ag+ ions which resulted in the formation of conjugated nanoparticles. The formation and stability of the as-produced nanoparticles were monitored by UV-visible spectrophotometer that demonstrated an absorbance peak at around 412 nm corresponding to the plasmon resonance of silver nanoparticles. The average crystallite size of the particles calculated from the obtained XRD spectra using Debye Scherrer’s formula was 4 nm. TEM results confirmed the formation of nano-sized polydispersed quasi-spherical shaped particles having the average diameter size of approximately 20 nm. Analysis of FTIR spectra revealed that the chemical moieties containing mainly amine, carboxyl, alcohol, esters functional groups coated the surface of the nanoparticles. Obtained nanoparticles were highly stable with no agglomeration even it is preserved for a period of 3 months and showed ‘good’ antibacterial activity.
Keywords: Rosa damascene; phytochemicals; silver nanoparticles; plasmon resonance; antimicrobial activity
Chemical and microbiological contamination of ground water has several implications for human health. The study of chemical and microbiological contamination of water is carried out in Sitnica river (Kosova). Water samples are collected at 10 sampling points and fourteen different parameters are investigated. The program, Statistica 6.0, is used for calculations of basic statistical parameters and anomalies (extremes and outliers). The chemometric approach and the results yielded useful information about water quality and can lead to better water resource management. Dendograms and box-whisker plots are drawn to evaluate the chemical variation. The level of some microbiological and phsico-chemical parameters and eco-toxic ions from surface water are compared with the results from the river source where anthropogenic effects are negative. Our results show that chemical and microbiological pollutions are the results of anthropogenic factors coming from settlements, peripheral rivers and agricultural in the region surround.
Keywords: Chemical and microbiological evalution, Sitnica water, contamination, statistical analysis
Synthesis of polyacrylonitrile (PAN)-organoclay nanocomposite was studied through grafting of PAN onto organophilic kaolinite. The organophilic kaolinite was prepared by treatment of kaolinite with different ratios of hexadecylethyldimethylammonium (HDEDMA) to kaolinite. The chemical grafting polymerization of acrylonitrile (AN) onto organophilic kaolinite was performed. The synthesized polymerorganoclay nanocomposite was studied for simultaneous adsorption of Cr(VI) and methylene blue dye (MB) from aqueous solutions. The results of Cr(VI) or the dye adsorption revealed that the adsorbed amounts increased with increasing HDETMA concentration. The removal percentage of Cr(VI) reached more than 98 % if individually studied, while 96 % was obtained when competing with dye. Also the adsorption of Cr(VI) was potentially influenced by its concentration in solution. The isothermal studies were performed using Langmuir and Freundlich models. The maximum calculated adsorption capacity was found to be 127 mg g-1 and 68 mg g-1 for Cr(VI) and methylene blue, respectively for individual adsorption, while in simultaneous adsorption their adsorption capacity was not affected by the other.
Keywords: Polymer; organoclay; composite; chromium(VI); dyes; poly(acrylonitrile); kaolinite; methylene blue; adsorption
In this paper, the liquid-solid extraction of thorium(IV) by sodium bentonite and magnetic bentonite is reported. Magnetic adsorbent can be quickly separated from a medium by a simple magnetic process. Various parameters have been studied to assess the performance of maghemite nanocomposite clay for the removal of Th(IV). The operating variables studied are initial Th(IV) concentration, pH, ionic strength, temperature and contact time. The time needed for magnetic bentonite to adsorb the maximum of Th(IV) is 45 min and 60 min for sodium bentonite. For magnetic bentonite, optimal extraction yield was achieved at an initial pH equal at 6.2 and for sodium bentonite, the variation of initial pH has no influence on the extraction yield. The sorption capacities of sodium bentonite and magnetic bentonite are 41.24 and 31.34 mg.g-1 respectively. Adsorption equilibrium data were calculated for Langmuir and Freundlich isotherms. It was found that the sorption of Th(IV) on sodium and magnetic bentonite was better suited to the Langmuir adsorption model. Thermodynamics data leads to endothermic and spontaneous process for magnetic bentonite and exothermal for sodium bentonite. The quantitative elution study of thorium can be realized with acetic acid for sodium bentonite and sulfuric acid for magnetic bentonite.
Keywords: Bentonite; nanoparticle; isotherm; thorium; magnetic process
Chemical and Biological Aspects of Life
Essential oil from flowers, leaves and fruits of Calotropis gigantea (L), was extracted by hydrodistillation method. Total 21 components in leaves, 43 components in flowers and 21 components in fruits were identified. The extracted oil was characterized by GC and GC-MS techniques. Constituents common to flower, leaves and fruit were 3-hexen-1-ol, benzaldehyde, benzyl alcohol, ± linalool, oct-3-en-2-ol, phenethyl alcohol, α- terpineol, 2,4-dimethylacetophenone, 4-vinylguaiacol and n-tetradecane.
Keywords: Calotropis gigantean; benzyl alcohol; 4-vinylguaiacol; ± linalool; α- terpineol
The aim of this study was designed to determine the effect of hypertension on the level of lipid fractions and percentage of fatty acids in serum. The study included 50 patients with hypertension, blood was taken after 10-12 h fasting. The age of patients was between 60 and 80 years. Blood samples from (50) normal subject with the same age were collected as control. The patients samples collection were from the medical word. A number of biochemical parameters were measured using enzymatic kits methods also the analysis and the measurement of percentage of fatty acids in fatty component of serum (cholesterol ester (CE), phospholipids (PL) and triglyceride (TG)) separated by thin layer chromatography(TLC) followed by transmethylation of fatty acids and measurement of fatty acids percentage using Capillary Gas Chromatography (CGC). The result of this study showed that there is a significant differences in the level of studied biochemical parameters and fatty acids percentage in hypertension patients compared with the control group. The results of this study also showed that a significant increase in level of (TG) in serum of hypertension patients. The result showed that a significant increase in percentage of (PUFA) in (PL) part.
Keywords: Hypertension, fatty acids, cholesterol ester, phospholipids, triglyceride
Polyphenolic compounds are bioactive substances widely distributed in the plant kingdom. They act as natural antioxidants and their presence contributes to the color, flavor, and aroma of food. Therefore, they are considered dietary antioxidants with interesting benefits to health. In this article the extraction of total phenolics, total flavonoids and antioxidants activity from Eryngium creticum was determined after obtaining the plant extracts by conventional and non-conventional extraction techniques. Also this study aims to determine the bioactive constituents present in E. creticum extracts by using GC-MS method. The results obtained show that microwave assisted extraction is the best technique used for the extraction of phenolic compounds and flavonoids from E. creticum giving a yield of 34.46 μg mL-1 and 21.05 μg mL-1 respectively. However, the antioxidants activity, evaluated by the DPPH assay was low in all the extraction techniques. Also the results showed the presence of 9 fatty acid derivatives, most of them have therapeutic effects on human health. These results explain the use of E. creticum in traditional medicine to treat various diseases.
Keywords: Flavonoids; phenols; antioxidant activity; microwave-assisted extraction; bioactive compounds
The polymorphisms of ACE gene is investigated using polymerase chain reaction for detection of ACE I/D genotype frequency in hypertensive cases in sector of Egyptian population. Serum ACE is significant higher in hypertensive group than normotensive one (27.5± 4.4 and 21.3± 5.4 ng mL-1, respectively. Mean SBP (systolic blood pressure), DBP (diastolic blood pressure) and urinary protein excretion in DD genotype were 181±17 mmHg, 112±19 mmHg, 3.8±0.48 mg mL-1 and 141.5± 36.8 mg day-1, respectively but in II genotype these were 142± 10 mmHg, 99± 13 mmHg, 4.35±0.4 mg mL-1 and 116.4± 36 mg day-1, respectively. In hypertensive patients, serum ACE levels in DD, ID and II genotypes were 36.2± 5.7, 22.1± 3.7 and 24.5± 4.9 unit ?, respectively. D/D ACE gene polymorphism plays a role in the development of target organ damage in severe essential hypertension and might have a prognostic value. It can be considered as one of the risk factor of hypertension.
Keywords: I/D ACE gene polymorphism, essential hypertension
Adenosine deaminase (ADA) activity increased in certain clinical conditions including tuberculosis and bacterial infections. In this study, the ADA isoenzymes patterns are assayed in ascites of different etiologies. Ninety two patients with ascites were selected and investigated to determine the cause of ascites. Total ADA and its isoenzymes are assayed spectophotometerically beside polyacrylamide gel electrophoretically. The total ADA in ascitic fluid secondary to parainfection in case of TB, abdominal cancer and liver cirrhosis is found to be 34.5±11.1, 87.6±23.6, 32.7±10.1 and 28.5±7.3 U L-1 respectivly. The ADA1m was 24.5±11.1, 4.3±1.9, 2.8±2.2 and 10.1±3.3 U L-1. ADA1c was 7.8±3, 16.5±6.2, 4.7±1.3 and 10.1± .3 U L-1 respectivly. ADA2 was 2.2±3.9, 65.9±33.5, 26.2±6.2 and 3.3±9.7 U L-1 respectively. Hence it is concluded that total ADA above 41 U L-1 and ADA2 above 32 U L-1 in ascetic fluid have high sensitivity value in TB peritonitis. The ascitic fluid ADA1m/ADA more than 50 % has high specificty value in parainfective peritonitis. Total ascitic ADA<41 U L-1 and ADA2/ADA ratio>50 % have high specificity in abdominal cancer.
Keywords: ADA; tuberculosis; liver cirrhosis
We have compared the frequency of thyroid antibodies among diabetic (DM) patients with type 1 and type 2. Diagnosed type-1 DM patients, having no previous of history were taken as subjects and divided into early adulthood (18 to 35 yrs) and later adulthood (after 35 yrs) groups. Matched subjects with DM type II are taken as controls. In all subjects, serum concentration of free T3 and free T4, TSH, Thyroid peroxidase antibody (TPO-Ab) and Thyroglobulin antibodies (TG-Ab) were determined. It has been observed that the serum FT3 levels was lower in type-1 diabetics patients as compared to type II DM. In addition there was a slightly increase in the values of anti-TPO and anti-TG antibodies in later adult hood of type I DM when compared to the values of early adult hood of type I DM. And there was significant increase in the values of anti-TPO and anti-TG antibodies in later adulthood of type I DM when compare to the values of later adulthood of type II DM. It has been suggested that estimation of thyroid antibodies should be done periodically for every diabetic patients.
Keywords: Diabetes mellitus; serum TSH; serum FT3; serum FT4; anti TPO antibodies; anti TG antibodies
Industrial and Engineering Chemistry, Biotechnology
The new heterogenized zirconium phenolate complexes containing different bulky ionic liquid type amine hydrochloride substituents in ortho-position have been synthesized and characterized. The oligomerization of the ethylene was carried out with use of these complexes activated by aluminium organic compounds in heptane, toluene and chlorobenzene. In the presence of diethyl aluminium chloride these complexes show higher activity than in the presence of ethylaluminium dichloride. The distributions and composition of the obtained oligomer products depend on the nature of aluminium organic compound used. The oligomerization products consist of C4 - C18 oligomers when diethyl aluminium chloride is used as a cocatalyst. In the presence of ethylaluminium dichloride the higher branched structured oligomers (oil fraction with boiling point > 350 °C) is obtained with >75 % yield. The products are easily separated from the catalysts by simple decantation and zirconium complexes may be repeatedly reused in successive ethylene oligomerization.
Keywords: ethylene, oliqomerization, ionic-liquid, zirconium precursor, synthetic oil
Theoretical and Computational Chemistry
Analysis of the equations of state of the hard convex body chain and hard spheres has been done for predicting the vapor liquid equilibrium (VLE) of simple fluids of n-alkanes. The repulsive part of the Boublik equation of state for the hard convex body chain has been found as an equivalent alternative either for the well known Carnahan-Starling repulsive term or the established van der Waals repulsive part of hard spheres equations of state. The attractive parts of these equations of state have the similar form as that of the van der Waals and are obeying the power-law temperature dependency. Add-on separation method of compressibility factor has been used for these equations of state. The simulated data for VLE densities from these equations of state are found to agree well with the available experimental data for n-alkane fluids.
Keywords: equations of state; vapour liquid equilibrium; critical parameters; hard convex body chain
To reduce the cost of carbon capture, transportation and eventual geologic storage at potential geologic sites future sequestration plans envisage the locating of power plants at potential geologic sites. The implication is that the injection temperature of flue gas will be typically those encountered in combustion power plants. This, obviously has a geomechanical consequence considering the fact that heat transferred from the aquifer to the low permeability cap rock will cause excessive pore pressure build up due to poor pore pressure diffusion characteristics of these rocks. While these low permeability rocks are required to provide stratigraphic trapping mechanisms such excessive pore pressure build up can result in compromising the geomechanical integrity. This paper has used heat transfer theories and geomechanical concepts to obtain steady state temperature distribution in cap rocks for temperatures ranging from 50 to 800 °C. In so doing, cap rock critical temperatures for tensile and shear failures have been established for a potential on-site gas injection into saline aquifers.
Keywords: wettability; saturation; shear failure; CO2 injection; geosequestration; diffusivity; thermophysical; steady state