Iranian Journal of Chemistry and Chemical Engineering
Volume:10 Issue: 1, May-Jun 1991

Thermal behaviour of various solid feldspars are different, namely those of bivalent cations show no change in the distribution of Al and Si atoms, whereas feldspars of univalent cations become more disordered with raising temperature. In the latter case Al atoms migrate from the sites they occupy. At low temperatures and interchange positions with the Si atoms. At high temperatures (but still below the melting point) the mixture of the two feldspars forms a solid solution, while at low temperatures two almost pure phases separate out from each. Other. The behaviour of pure feldspar (like albite) have been theoretically studied by various methods, while solid solutions of feldspars of univalent cations have not been studied (due to their complexity). In this paper statistical mechanical methods are used to study sodium and potassium feldspar solutions.

Fischer-Tropsch catalysts with high activity and selectivity for olefins were produced using mordenite type SiO2/Al2O3=12, 20, 28, 62 zeolite supported iron carbonyl compounds and were characterized by X-ray powder diffraction. The adsorption of volatile Fe(CO)5 on the support surface was carried out under vacuum at room temperature. Reduction pretreatment and the formation of active metallic iron particles were monitored by vibrating sample magnetometer (VSM). The magnetic saturation time was observed to increase with increasing the Al2O3 content of catalyst system indicating an increasing interaction between iron and alumina. The activity and selectivity of different iron deposited mordenite sample were investigated during Fischer-Tropsch synthesis of hydrocarbon with H2/CO=2 in the temperature range of 400-500°C using a microreactor system. The results correlated with the acidic properties of surface and/or with metallic state of active iron particles of the catalyst.

On the basis of 102 assigned frequencies to in plane vibrations of pyrimidine, pyrimidine-2-d2, pyrimidine-2, 5-d2, pyrimidine-4, 6-d2, pyrimidine-2, 4, 6-d3 and pyrimidine-d4, 35 valance force filed constants including 14 principals and 21 interaction force constants are calculated. New assignments are suggested for n18b and n19b normal modes in pyrimidine-2,5-d2 and n14 and n18b normal modes in pyrimidine-d4. With this new assignments the agreement between observed and calculated product rule and sum rule has improved.

Peroxyoxalate system includes an oxalate ester, peroxide and a fluorescer. The energy resulted from the reaction of oxalate ester and peroxide is transferred to fluorescer and cause it to fluoresce. The effect of reactants chemical structure, their concentration, solvent media (polarity and viscosity) and the temperature, on the intensity of the illuminated light with respect to time have been studied. The effect of chemical structure of oxalate ester, fluorescer and peroxide on the intensity of light was found to be as follows: DNPO

The virial coefficients can be obtained from statistical mechanics in connection with the intermolecular potentials. The intermolecular potential of polyatomic molecules is usually assumed to consist of a spherically symmetric component plus a contribution due to asphericity of the molecular charge distribution. In this study, the second virial coefficients have been calculated for N2, Co, and SF6 from the lennard-Jones (6-12) potential. The results are in good agreement with those obtained experimentally.

The kinetic study of the condensation reaction between phloroglucinol and acetone was investigated at 30, 35, 40 and 45±0.05 °C in 100% methanol. The hydrochloric acid concentrations used were 0.0261, 0.0364, 0.0577 and 0.0728 M. The reaction was investigated with and without a promoter, thioglycollic acid (TGA), and taking into account the functionality (h) of phloroglucionol. The reaction was found to obey a second order rate law, the rate increasing with an increase in acid catalyst concentration. The activation parameters for the overall reactions have been calculated. The raction was also carried out in solvents 1,4-di-oxane, isopropanol, ethanol and methanol. The overall rate constants were resolved into step rate constants. A mechanism consistent with the kinetic data has been suggested.

A Study was made on the interaction between histon H1 and sodium n-dodecyl sulphate (SDS) in the presence of sodium arsenate inside a phosphate buffer of pH 6.4, using spectroscopy and equilibrium dialysis at 27 °C. The binding data has been used to obtain the gibbs free energy in terms of a theoretical model based on the Wyman binding potential. The binding data hs been analysed in terms of Hill equation, to obtain Hill coefficient. The data show that sodium arsenate exhibits an unusually greater degree of denaturation for the structure of H1.

3,3'-Dicarboxy-4,4'-diaminobiphenyl was synthesized from Onitrobenzoic acid following standard procedures. Diazotization of this compound with isoamylnitrite, under approtic condition gave diphenyl-4,4'-bis-diazonium-3,3'-dicarboxylate and subsequent thermal decomposition of this diazonium compound produced 3,4,3',4'-tetradehydrobiphenyl (bisbenzyne) as a reactive intermediate. Bisbenzyne was trapped with the diene 2,3,4,5-tetraphenylcyclopentadienone via a [4]diels-Alder cycloaddition reaction yielding the previously unreported 5,6,7,8,5',6',7',8'-octaphenyl-2,2'-binaphthyl. This novel compound was fully characterized by elemental analysis IR and 1HNMR spectroscopy.

Carthamin, the natural dye of carthamus tinctorius (Golrang) was separated by soxhlet extraction and further purified in good yields. Its mordant dyeing of wool, using potassium dichromate as mordant, showed a high washing fastness (above 4). Mordanting by «sweet chrome», «sour chrome», and «reduced chrome» proved that last one to be superior.