Catalytic hydrogenation of 2-butyne-1,4-diol to 2-butene-1,4-diol at atmospheric pressure in the liquid phase

Selective hydrogenation of 2-butyne-1,4-diol to 2-butene-1,4-diol on suspended palladium and Raney nickel catalysts at atmospheric pressure was studied. The optimal parameters of this reaction were determined. Samples containing 90% 2-butene-1,4-diol were prepared.     

Preparation and Study of Some Copolyesters

Terephthalate unsaturated copolyesters with ethylene glycol and 2-butene-1,4-diol, with ethylene glycol and 2-butyne-1,4-diol, with ethylene glycol and diethylene glycol, and with 2-butyne-1,4-diol were synthesized by trans-esterification reactions. Proton nuclear magnetic resonance spectroscopy was used to elucidate the structures of the copolyesters. The intrinsic viscosities of the copolyesters were measured in o-chlorophenol at 30°C. The number-average molecular weights of these copolyesters were determined by using a vapor pressure osmometer. The thermal behaviors of the copolyesters were studied by differential thermal analysis and are discussed in terms of structural differences.     

一种简便合成2-丁炔-1,4-二醇衍生物的新方法

由2-丁炔-1,4-二醇可以很方便地得到2-丁炔-1,4-二氯,这一试剂在有机合成中有着广泛的应用。而在其它条件相同的情况下,制备2-丁炔-1,4-二溴并未得到相应较好的结果。我们用无水苯为反应溶剂,以温和的 (PPh3)PBr2作为卤代试剂(冰浴下液溴逐滴滴入PPh3苯溶剂中当场生成)卤化2-丁炔-1,4-二醇,选择性合成得到2-丁炔-1,4-二溴衍生物。同时也实现了2-丁炔-1,4-二醋酸酯的合成。     

Effect of Chloride Ions on the Behavior of Saccharin, N-Methylsaccharin, and 2-Butyne-1,4-diol during Electrodeposition of Nickel from Acid Electrolytes

Rates of transformation of organic additives (saccharin, N-methylsaccharin, 2-butyne-1,4-diol) and accumulation of products of their cathodic reactions are studied during nickel electrodeposition from the chloride and Watts electrolytes. A large concentration of chloride ions accelerates the saccharine and N-methylsaccharin consumption due accelerated synthesis of o-toluenesulfamide, N-methyl-o-toluenesulfamide, and N-methylbenzylsultam, thus facilitating adsorption of additives on the nickel cathode via the carbonyl group. An inhibition of adsorption via the sulfonyl group is accompanied by a decrease in the accumulation of corresponding benzamides. An increase in the concentration of chloride ions in electrolytes containing 2-butyne-1,4-diol promotes accumulation of 2-buten-1,4-diol and inhibits hydrogenation of the double bond to a saturated bond. Differences in the behavior of the additives are due to (i) competition of chloride ions with the additives in the electrolyte or with their electroreduction products during adsorption on the nickel cathode, (ii) a change in the deposit potential, and (iii) a change in the concentration of inclusions in the deposits, which determine the catalytic activity of the cathode.     

Analysis of products from hydrogenation of 2-butyne-1,4-diol

Conclusions A qualitative and quantitative method has been developed for analysis of a mixture of butane-1,4-diol, cis-2-butene-1,4-diol, trans-2-butene-1,4-diol, and 2-butyne-1,4-diol in the form of their diacetates by gas chromatography.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 4, pp. 942–944, April, 1970.     

Voltammetry of Formaldehyde at Mechanically Renewable Solid Electrodes

The electrochemical behavior of formaldehyde (CH₂O) at solid electrodes made of platinum, gold, silver, cobalt, nickel, copper, and graphite was studied. The working surface of the electrodes was renewed by cutting a thin layer (0.5 m) immediately in the test solution. It was found that, in alkaline solutions, CH₂O was oxidized at all electrodes other than cobalt and graphite ones while scanning the potential to the anode and cathode regions. The peaks of CH₂O oxidation at platinum and gold electrodes using potential scanning in the anode and cathode directions, as well as at nickel, copper, and silver electrodes using potential scanning in the anodic direction, are suitable for analytical purposes.     

Investigation of Electrosorption of Organic Molecules onto Gold and Nickel Electrodes Using an Electrochemical Quartz Crystal Microbalance

The adsorption behaviors of two organic molecules, benzoic acid (BA) and 2-butyne-1,4-diol (BD), on metal electrodes have been studied using an electrochemical quartz crystal microbalance (EQCM) combined with the cyclic voltammetry technique. In the range of potentials studied, BA molecules were adsorbed onto an electrodeposited gold electrode with a saturation concentration of 5.0 × 10¹⁴ molecules/cm². It was found that the Frumkin isotherm model was most suitable to depict the electrosorption behavior. The isotherm parameters by nonlinear fitting, which agreed with the literature values, implied BA was chemisorbed on the gold surface. For BD on an electrodeposited nickel electrode, the equivalent molar mass of the reaction species was calculated on the basis of the voltammetry curve and mass curve, which were obtained simultaneously during the potential scan. The analysis of EQCM data for the electrosorption of BD on gold and nickel electrodes showed an irreversible characteristic; the latter effectively inhibited the hydrogen evolution reaction.     

Procedures for recovery of crystalline 2-butyne-1,4-diol from industrial aqueous solutions and for its purification

Four procedures for recovery of crystalline 2-butyne-1,4-diol from aqueous solutions and for its purification were examined. Samples of crystalline 2-butyne-1,4-diol containing 98.5 to 99.9 wt % target product were obtained.     

Electrolytic reduction of 2-butyne-1,4-diol as a route to trans-2-butene-1,4-diol

The effect of the cathode material on the electrochemical transformations of 2-butyne-1,4-diol at atmospheric pressure was studied by chromatographic analysis. The optimal parameters of the selective synthesis of trans-2-butene-1,4-diol were determined.     

A chemical study of 2-butyne-1,4-diol

Commercial grade 2-butyne-1,4-diol has been used in electroplating for several years. In laboratory experiments, its presence in the electrolyte increases the current efficiency of zinc electro-winning. Its chemical behaviour in solution is not well known. The present paper indicates that the brownish technical grade 2-butyne-1,4-diol contains the monomer, the dimer and some trimer. Pure monomeric 2-butyne-1,4-diol is a white solid obtained by evaporation of the technical grade product. The monomer is slowly transformed into dimer and possibly into a trimer when dissolved in water. Various analytical techniques were used in the study of this system. Factor analysis with column cross-validation was applied to chromatographic data to help in the resolution of the system.     

Reductive cleavage of C-OH bonds in allyl position-formation of gaseous products in the course of the cathodic reduction of some simple unsaturated alcohols

The problem of the reductive cleavage of C?OH bonds in allyl position has been considered starting from the literature data concerning the behaviour of allyl alcohol. The formation of hydrocarbons has been shown in the case of the electroreduction of crotyl alcohol, 2-butene-1,4-diol, propargyl alcohol, 2-butyne-1,4-diol and 1-butyne-3-ol. The composition of the gaseous products was analyzed, current efficiency values with respect to the hydrocarbon formation were calculated. Schemes for the reduction path were given.     

Liquid-phase catalytic hydrogenation of 2-butyne-1,4-diol to 1,4-butanediol at atmospheric pressure on suspended catalysts

The optimum parameters of hydrogenation of 2-butyne-1,4-diol to 1,4-butanediol on the suspended palladium and Ni-Raney catalysts at atmospheric pressure were found. In selected conditions a yield up to 90% of 1,4-butanediol was reached.     

Influence of pulse plating conditions on the structure and properties of pure and composite nickel nanocrystalline coatings

An additive-free Watts type bath containing micron- and nano-SiC particles (1 μm and 20 nm respectively), as well as ultrafine-WC particles (200 nm), was used for the production of pure Ni and nickel matrix composite electrocoatings under both direct and pulse current conditions. Moreover, nickel nanocrystalline deposits were obtained from a Watts type bath containing small amounts of 2-butyne-1,4-diol, in order to investigate the combined advantages of additives and pulse technique on the properties of the deposits. The influence of the variable electrolysis parameters, the particle size and the organic additive concentration on the surface morphology, the structure and properties of the deposits were discussed. It has been proved that the application of pulse electrodeposition affects drastically the structural characteristics and properties of the deposits and under well-defined conditions could lead to the preparation of nanostructured materials with improved mechanical properties. Published in Russian in Elektrokhimiya, 2008, Vol. 44, No. 6, pp. 802–811. The text was submitted by the authors in English.     

Raman-spectrum investigation of 2-butyne-1,4-diol 2-butyne-1,4-diol diacetate,and 1,4-dichloro-2-butyne

Summary 2-Butyne-1,4-diol, 2-butyne-1,4-diol diacetate, and 1,4-dichloro-2-butyne exist in cisoid and transoid forms because of the operation of factors hindering free rotation of individual groups of atoms in these molecules around the corresponding single bonds.     

Rearrangement of 2-butyne-1,4-diol to butyrolactone catalyzed by ruthenium complexes

The isomerization of 2-butyne-1,4-diol to butyrolactone catalysed by ruthenium complexes is described.     

Functional Acetal Methacrylates: III. Electrophilic Addition of Diols to 2-(Vinyloxy)ethyl Methacrylate

Reactions of 2-(vinyloxy)ethyl methacrylate with diols [ethylene glycol, diethylene glycol, triethylene glycol, oligoethylene glycol-400, Z-2-butene-1,4-diol, 2-butyne-1,4-diol, 1,1,3,3-tetramethyl-1,3-bis(3-hydroxypropyl)disiloxane, 2,2-bis(4-hydroxyphenyl)propane] and polyols (glycerol, pentaerythritol) under electrophilic conditions (1 wt% of CF₃COOH, 20-60°C, 1-3 h) result in quantitative formation of functional acetal methacrylates.     

The flammability properties of copolyesters and copolycarbonates containing acetylenes

The flammability properties of copolyesters and copolycarbonates containing varying percentages of 2-butyne-1,4-diol and 2,4-hexadiyne-1,6-diol were studied by use of oxygen index and dynamic thermogravimetry. The char formation was found to increase with increasing polymer unsaturation. For nonconjugated acetylenes there is an increase in the oxygen index with increasing unsaturation in a polymer. In contrast, conjugated acetylenes dramatically decrease the oxygen index of a polymer system.     

Stereochemistry of additions to a triple bond

Summary In the photochemical bromination of 2-butene-1,4-diol, its diacetate, and 2,5-dimethyl-3-hexene-2,5-diol in nonpolar solvents, trans-addition products are formed, whereas their acetylenic analogs give mainly cis-dibromides. The differences in the behavior of acetylenes and the corresponding olefins are to be explained on the view that under identical conditions they may react by different mechanisms. Thus, under given conditions 2-butyne-1,4-diol diacetate is brominated by a chain mechanism, whereas the corresponding olefin is brominated by a nonchain mechanism.     

2,3-Bis(diphenylphosphynyl)-1,3-butadiene via a double [2,3]-sigmatropic rearrangement. A reinvestigation of the reaction of 2-butyne-1,4-diol with chlorodiphenylphosphine

Contrary to previous reports, the reaction of 2-butyne-1,4-diol with chlorodiphenylphosphine yields 2,3-bis(diphenylphosphinyl)-1,3-butadiene 3 instead of the 1,4-isomer. The structure of the product has been elucidated from ¹H, ¹³C and ³¹P-NMR spectroscopic data.     

Electrochemical behaviour of lanthanum fluoride in molten fluorides

The electrochemical behaviour of lanthanum fluoride dissolved in molten lithium fluoride and in eutectic mixture LiF-CaF₂ was investigated by cyclic voltammetry and laboratory electrolysis. The cyclic voltammetry experiments were carried out at 900°C and 800°C, respectively, in a graphite crucible (counter electrode). Several types of working electrodes (Mo, W, Ni and Cu) were used. Ni/Ni(II) was used as a reference electrode. Laboratory electrolysis was carried out in the system LiF-CaF₂-LaF₃ at 800°C in galvanostatic (j _c = −0.21 A cm⁻²) and potentiostatic (E = 0.87 V) regimes. In both cases, nickel served as the cathode and graphite as the anode. It was found that no new separate reduction peak occurred on the molybdenum or tungsten electrodes in the investigated systems. When copper or nickel electrodes were used, new peaks corresponding to the reduction of lanthanum(III) to lanthanum metal appeared. This can be explained by the formation of alloys or intermetallic compounds of lanthanum with copper or nickel. X-ray microanalysis showed that lanthanum was electrodeposited together with calcium under formation of intermetallic compounds with the electrode materials in the galvanostatic regime. In the potentiostatic regime, mainly lanthanum was deposited, which enabled its separation.