Chemistry Commons^™

The Activity Of Alloy Cu-Ni Electrode In Electroreduction Of Aromatic Nitro-Compounds, Chunan Ma, Shaoping Tong, Xiaojun Cheng, Hui Wang

Journal of Electrochemistry

Cu-Ni alloy on the basis of copper at different ratio Cu/Ni are prepared by codepostion. The cathode activtiy of film are studied by steady-state polarization for electroreduction nitro-benzene (NB) and 1,5-dinitroanthraquinone (1,5-DNA) to p-aminophenol and 1,5-diamino-4,8-dihydroanthraquinone respectly. The results show that the alloy cathodes at different ratio Cu/Ni have different exchange current density (i^o) and apparent activition energy (E_A). The alloy (CN-30) has maximal i^o and minimal E_A by codeposition at the following conditions: electrolyte: 0.05 mol/L CuSO₄·5H₂O+0.6 mol/L NiSO₄·6H₂O+0.25 mol/L Na₃Cit·2H₂O; …

A Quantum-Chemical Investigation On 5,5'-Bi(1h-1.2,4-Triazole)), A. A. İki̇zler, R. Abbasoğlu, N. Saltek, M. Şeri̇fova

Turkish Journal of Chemistry

The conformational analysis of flexible 5,5'-bi(1H-1,2,4-triazole) molecule containing various reaction centers has been performed by the semiempirical methods MNDO,AM1 and PM3, and the internal rotation barrier calculated. The most stable conformation of the molecule has been determined to be the planar trans conformation. According to the three methods, 5,5'-bi(1H-1,2,4-triazole) molecule (C) has been found to be relatively more stable than its tautomer 3,3'-bi(1H-1,2,4-triazole)(B) and to be less stable than its other tautomer 3,3'-bi(4H-1,2,4-triazole)(A). Moreover, the electronic properties of 5,5'-bi(1H-1,2,4-triazole) molecule and the effect of conformational changing on electronic and geometric properties have also been investigated. To determine the protonation sites …

One-Pot Preparation Of 1,3-Dihydro-1- (Trifluoromethyl)Isobenzofuran-1-Ol Derivatives From 1,2-Dibromobenzene, Daniel Becker, Hui Li, Daniel L. Flynn

Chemistry: Faculty Publications and Other Works

A one-pot method for the preparation of 1,3-dihydro-1-(trifluoromethyl)isobenzofuran-1-ol derivatives 5from 1,2-dibromobenzene is described

Coadsorption Of Para-Toluene Sulfamide And 1.4-Butynediol At Mercury Electrode, Shukun Huang, Naixian Xie, De Gao, Qiang Liu

Journal of Electrochemistry

The coadsorption characteristics of para-toluene sulfamide and 1,4-butynediol atmercury electrode have been studied by means of electrocapillary curve, differential capacity curve, Stuart model and the SCFMO method (CNDO/2). The coadsorption is a physical adsorption occuringnaturally. Lateral and flat orientations in the two adsorbates close to their maximum adsorptionpotential were considered respectively. Unlike attractive interactions of their own, there was arepulsive interaction at their coadsorption layer. A preferred adsorption of 1,4-butynediol occurred when they were at the same volume concentration.

Dehydrobromination Of Some 1,3-Dibromo-1,1- Difluoro Compounds Som (4+2) Cycloaddition Reactions Of 1,1-Difluoro-1,3-Dienes, Christopher Foti

Retrospective Theses and Dissertations

The title 1,3-dibromo- l, l-difluoro compounds are dehydrobrominated in the presence of l,8-diazabicyclo[5.4.0]undec-7-ene (DBU). Reaction of simple saturated dibromides with DBU at 25 °C affords moderate yields of monoelimination products in which the reaction is 100% stereoselective and regioselective. Highly conjugated dienes are synthesized at mild reaction conditions in contrast to simple alkyl or pentafluorophenyl dienes which are inaccessible via a double dehydrobromination reaction due to the unexpected formation of trifluoromethyl compounds. Aromatic gem-difluorodienes react with 4-phenyl-1,2,4-triazoline-3,5-dione and a mechanistic experiment demonstrates the relative reactivities of the isomers of 1, l-difluoro-4-phenyl-1,3-butadiene in a Diels-Alder reaction. The unfluorinated analogue of 1, …

I. Evaluation Of Iron Whiskers And Stainless Steel Microwaves As Catalysts For Ammonia Synthesis Ii. Hydrodechlorination Of Chloralkanes On Iron Whisker Catalysts, Diane Kaefer-Northcott

Retrospective Theses and Dissertations

This report consists of two parts. Part I concerns the evaluation of stainless steel microwires and iron whiskers, as catalysts for ammonia synthesis. Several comparison catalysts were also evaluated for their catalytic ability for ammonia synthesis. The effect of potassium promotion on filament and comparison catalysts was determined.

Part II concerns the evaluation of iron whisker catalysts with regard to their catalytic ability for their hydroechlorination fo chloroalkanes. The chloroalkanes that were used in the hydroechlorination reactions were carbon tetrachlorida, chloroform, methylene chloride, and 1, 1, 1-trichloroethane. The hydroechlorination reactions were conducted in the gas phase, either in the prsence …

Preparation Of Geminal Diflourodienes, Antonio Landavazo

Retrospective Theses and Dissertations

This report discusses research involving the preparation of germinal difluorodienes. Free radical addition of dibromodifluoromethane to 1-hexene and cyclohexene was performed, followed by a double dehydrohalogenation to yield 1,1-difluoro-1,3-heptadiene and 3-(difluoromethylene)cyclohexene, respectively. NMR, IR, and mass spectral data were obtained and presented as groundwork for further research. A study comparing the free radical initiators, benzoyl peroxide and 2,2’-azobis-(2-methyl)proprionitrile (AIBN) was included, showing neither as ideal initiators for the free radical additions performed. The relative stabilities of the bromodifluoromethyl and the difluoroiodomethyl radicals were approximated. A Diels-Alder reaction of 1,1-difluoro-1,3-heptadiene with 4-phenyl-1,2,4-triazoline-3,5-dione produced the expected [4 + 2] cycloadduct in good …

Part I: The Synthesis Of Potential Agrochemicals. Part Ii: The Use Of Gold's Reagent As A Lynch Pin In The Formation Of Five And Six Membered Heterocycles, Keith F. Correia

Retrospective Theses and Dissertations

This research report focuses on two topics: the synthesis of potential agrochemicals and the use of Gold's reagent as a lynch pin to form five- and six-membered heterocycles. A diacyl hydrazide and two oxadiazoles are prepared for use as possible insecticides. Gold's reagent behaves as a one-atom and two-atom lynch pin when reacted with 1, 4- and 1, 5-dinucleophiles, respectively. Reaction conditions, interpretation of spectral data, and recommendations for further research are provided.

Method For Direct Preparation For 1,2,4-Triazole From Hydrazine And Formamide, Harris E. Petree, Joseph R. Pociask, John T. Gupton

Chemistry Faculty Publications

Process for the preparation of 1,2,4-triazole comprises contacting hydrazine or its aqueous solutions with at least about 2.5 moles of formamide at a temperature of 140° to 210° C. and then recovering the resultant 1,2,4- triazole in yields of 92-98% with 94-98% purity. The formamide is maintained in an excess over about the 2.5 molar amount consumed in the reaction with the hydrazine. Recovery steps for isolating the 1,2,4-triazole are disclosed.

Cyclodimerization Of 1,3-Pentadiene With Homogeneous Nickel Catalyst, Morteza Soltani

Retrospective Theses and Dissertations

Piperylene concentrate is a complex mixture of 5-carbon unsaturated hydrocarbons obtained as by-products when naptha or gas oils are cracked. The major component in this mixture is 1,3-pentadiene. The cyclodimerization of 1,3-pentadience in piperylene concentrate by using a nickel catalyst was studied. Various types of ligands were used in the preparation of the nickel catalyst. The effect of each ligand on activity of the catalyst in dimerization of diene, on conversion, and on yield of reaction were investigated. The effect of reaction conditions, such as temperature, pressure, and reaction time, on conversion of monomer, yield of dimer, and selectivity of …

Separation Of 1,3-Pentadiene From A Five-Carbon Olefin Mixture By Use Of 13x Molecular Sieves, Samuel G. Maller

Retrospective Theses and Dissertations

Piperylene concentrate is a complex mixture of 5-carbon unsaturates. The major components are trans-1,3-pentadiene and cyclopentene. The object of this work is to form a product high in cyclopentene and a product high in the pentadienes, through the use of 13X zeolite molecular sives. Separation by molecular sieves is difficult because of the tendency of trans and cis pentadience to polymerize o the sieve and to thus decrease the adsorptive capacity of the sieve. Nitrogenous bases (dimethylamine, pyridine, and piperidine) were used in an attempt to neutralize any acid sites on the sieve. Dealumination by EDTA was used to decrease …

Isomerization And Dehydrocyclization Of 1,3-Pentadiene, Thomas E. Marcinkowski

Retrospective Theses and Dissertations

Piperylene concentrate is a complex mixture of 5-carbon unsaturated hydrocarbons obtained as a by-product when naphtha or gas oils are cracked. The major component in this mixture is 1,3-pentadiene. During the course of this study, a number of trials, utilizing liquid phase reaction conditions, were made to investigate the geometric isomerization of 1,3-pentadiene and its separation from the piperylene concentrate. Isomerization was accomplished employing catalytic amounts of iodine at temperatures ranging from 0°C to reflux. Using this method, the maximum amount of trans-1,3-pentadiene obtained was 70% as compared to 51% in the piperylene concentrate. Recovery of the product was 90%, …

Separation Of 1,3-Pentadiene With Molecular Sieves, Steven R. Schwinn

Retrospective Theses and Dissertations

The feasibility of separating piperylene (1,3-pentadiene) from a mixture of five-carbon olefins and diolefins with Linde 5A Molecular Sieves was investigated. Olefins and especially diolefins are very reactive and tend to polymerize on the highly polar adsorptive surface thereby clogging the pores of themolecular sieve. It is believed that the acid sites within the zeolite cages catalyze this polymerization reaction and that poisoning of these sites by adsorption of a nitrogenous base (ethylenediamine, dimethylamine or ammonia) or hydrogen sulfide inhibits the formation of polymers. Two criteria were used in the evaluation of the polymerization inhibitors tested. First, a series of …

The Vapor Phase Oxidation Of 1, 3-Pentadiene, David E. Sasser

Retrospective Theses and Dissertations

The vapor phase oxidation of 1.3-pentadiene, over heterogeneous catalysts, was investigated with the objective of producing 2,4-pentadienal and 2,4-pentadienoic acid. Copper and cobalt-molybdenum catalysts, both supported and unsupported, were utilized at various reaction temperatures, residence times and feed ratios. The matter of 1,3-pentadiene vaporization and introduction into the reactor system proved to be critical. Low temperature vaporization of the hydrocarbon and dilution with the oxidant, air, was found to be necessary to avoid polymerization of the feed. Alumina-supported catalysts were found to be very active, leading to severe cracking of the hydrocarbon feed and subsequent carbonization of the catalysts. Silica-supported …

The Liquid Phase Oxidation Of 1,3-Pentadiene, Carl B. Reaves

Retrospective Theses and Dissertations

The liquid phase autoxidation of 1,3-pentadiene to 2,4-pentadienoic acid utilizing gaseous oxygen at atmospheric pressure was investigated as a possible route for direct utilization of piperylene obtained during the cracking of naptha to ethylene. Catalyst system consisting of cobalt, manganese, and iron salts promoted by sodium, potassium and hydrogen bromides, were used under a variety of condition of catalyst concentration, temperature, oxygen flow and piperylene purity. Under all conditions studied, a large number of oxidation products were formed. Maximum yields of 2,4-pentadienoic acid were obtained using a cobalt acetate bromide catalyst at 85°C.