3413

161 دكتري

كارشناسي ارشد

﴿ شيمي آلي ﴾

اصفهان: دانشگاه صنعتي اصفهان، دانشكده شيمي

1385

يازده، 167، [II] ص. : مصور، جدول، نمودار

ص. ع: به فارسي و انگليسي

مهران غياتي

امان الله امين زاده

شهرام تنگستاني نژاد، حميدرضا معماريان، كيقباد شمس، شادپور ملك پور

شيمي

ID161 دكتري

به فارسي و انگليسي : قابل رئيت در نسخه ديجيتال

Abstract ZrO2 TiO2 mixed oxides with a Ti and Zr molar ratio of 1 1 were prepared with and withoutsurfactant by the sol gel method Catalysts containing 5 35 H3PO4 were prepared using thesemixed oxides and the catalytic performance of each material for vapor phase Fries rearrangementof phenyl acetate PA to 2 hydroxyacetophenone 2 HAP was determined At optimizedconditions the conversion of PA over 15 wt H3PO4 TiO2 ZrO2 surf and 15 wt H3PO4 TiO2 ZrO2 varied between 91 and 85 2 and selectivity to 2 HAP was between 81 9 and 48 3 respectively In all cases the formation of 2 HAP was clearly favored in comparison to that of paraisomer The 4 HAP in the improved conditions was about 1 1 In comparison with othercatalysts the percentage of phenol in the optimized condition was lower than 16 The solventeffect on Fries rearrangement was investigated and dichloromethane showed better results TheFries rearrangement was carried out in the temperature range of 473 to 673 K ZrO2 TiO2 mixed oxides with a Ti and Zr molar ratio of 1 1 were prepared with and withoutsurfactant by the sol gel method Catalysts containing 5 35 H3PO4 were prepared using thesemixed oxides and the catalytic performance of each material for vapor phase acylation of phenol to2 hydroxy acetophenone 2 HAP was determined During the reaction of phenol with ethylacetate 2 HAP was found to be the major product when 4 hydroxy acetophenone was not detectedin the product stream phenylacetate PA and alkylated products were the minor products In thebest experimental conditions the alkylated products were less than 0 5 This reaction mayrepresent an environmentally friendly alternative to use the ethyl acetate as the acylating reagent The adsorption behaviour of hexadecylpyridinium bromide CPB onto bentonite was studiedas a function of temperature Thermodynamic parameters such as H and S were calculatedfrom the slope and intercept of the linear plot of logKd against 1 T Based on the calculation of thethermodynamics of adsorption it is evident that the principal contribution to the G of negativevalue is the large positive value of S whereas H is positive Analysis of adsorption resultsobtained at temperatures 288 297 303 307 313 K showed that the adsorption pattern onbentonite followed the modified Langmuir isotherm The intercalation of surfactant in theinterlamellar space was followed by X ray measurements Non ionic surfactants have been adsorbed on bentonite Iran as a relatively good adsorbent invarious temperatures 297 to 323 K The experimental data obtained from non ionic surfactants onbentonite have been fitted into the adsorption isotherm equations such as Langmuir Freundlich Langmuir freundlich Modified Langmuir Hill Redlich Peterson BET Halsey Harkins Jura Smith Henderson Chaung Pfost Oswin and some modified forms of these isotherms and theirgoodness of fit have been compared The thermodynamic data of Gibbs free energy G0 enthalpy H0 and entropy S0 terms have been determined for the non ionic surfactantadsorption the negative values of G0 obtained indicates that the non ionic surfactant adsorptionprocess is a spontaneous one Finally the intercalation of surfactant in the interlamellar space wasfollowed by X ray measurements The use of potassium dichromate as a synthetically useful oxidizing agent is reported for theoxidation of an industrially important lipophilic alcohol employing modified clay as the phase transfer catalyst The phase transfer catalysis results in nearly complete oxidation of the 2 ethylhexanol in 40 min at room temperature with high selectivity to the 2 ethylhexanal comparedto 48 h in its absence Kinetic studies show the reaction occurs via transfer of Cr2O7 2 into theorganic phase The emphasis will be on simplicity of the condition as a preparative organic method selectivity with regard to overoxidation efficiency and mildness of conditions

مهران غياتي

امان الله امين زاده

شهرام تنگستاني نژاد، حميدرضا معماريان، كيقباد شمس، شادپور ملك پور