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Showing papers on "Acetonitrile published in 1973"


Journal ArticleDOI

215 citations


Journal ArticleDOI
TL;DR: In this article, it was shown that in the presence of catalyst poisons such as acetonitrile or mercury, the currents for formic acid oxidation, measured in the potential range +0.4 to + 0.8V E(H) at Pt can be substantially increased.
Abstract: : In the presence of catalyst poisons such as acetonitrile or mercury, it is shown that the currents for formic acid oxidation, measured in the potential range +0.4 to +0.8V E(H) at Pt can be substantially increased. The effect is shown to originate from blocking of the surface at less positive potentials mainly in the H adsorption/desorption region where an inhibitor for the main formic acid oxidation reaction is normally formed in the absence of additive. Under the latter conditions, steady-state oxidation currents are normally small and decrease with time due to build-up of an inhibiting species from the HCOOH or intermediates involved in its oxidation. The competitive effects of Hg and CH3CN are different insofar as a given extent of surface blocking causes different effects on the formic acid oxidation current. Comparative experiments on the effect of CH3CN on methanol oxidation are described. (Modified author abstract)

136 citations


Journal ArticleDOI
TL;DR: In this article, the authors employed specular reflectance spectroscopy to identify reaction intermediates and study the kinetics of their decay reactions, and found that solution-free anion radical CO[graphic omitted] was the intermediate in the reduction of CO2 in aqueous solution and in a number of aprotic solvents.
Abstract: Modulated specular reflectance spectroscopy was employed to identify reaction intermediates and to study the kinetics of their decay reactions. The solution-free anion radical CO[graphic omitted] was found to be the intermediate in the reduction of CO2 in aqueous solution and in a number of aprotic solvents. In the former case, the rate constant for protonation was found to be 5.5 1. mol–1 s–1. In aprotic systems, the mechanism for formation of oxalate involved coupling of CO[graphic omitted] with CO2 and not a dimerisation of the former, the rate constant being 7.5 × 103 l. mol–1 s–1. The decay reaction of the thianthrene cation radical generated anodically in acetonitrile containing controlled concentrations of water was found to be pseudo first order; possible mechanisms are discussed.

108 citations


Journal ArticleDOI
TL;DR: The base hydrolysis of acetonitrile to acetamide is catalyzed by a factor of 2 X l0(6) on coordination to CO(NH3)5 8+.
Abstract: The base hydrolysis of acetonitrile to acetamide is catalyzed by a factor of 2 X l0(6) on coordination to CO(NH3)5 8+. Hydroxide appears to attack the carbon atom of the nitrile group, while in a separate and concurrent process the methyl protons exchange. On addition of acid to the acetamido complex produced, protonation occurs on the carbonyl oxygen (pKa = 3.02; μ = 1.0 M, NaC104; T = 25°) rather than on the amide nitrogen atom.

75 citations


Journal ArticleDOI
TL;DR: In this article, the electrochemical oxidation of Ph 3 P at a platinum electrode in CH 3 CN solvent has been studied using cyclic voltammetry and controlled potential electrolysis.

64 citations


Journal ArticleDOI
TL;DR: In the presence of small amounts of added acid in acetonitrile, the only observable product by rapid electrochemical techniques is monoprotonated benzoquinone as mentioned in this paper.

61 citations


Journal ArticleDOI
TL;DR: In this article, it was shown that ΔS°t(M++ X−) is relatively independent of M+ and of X− if M+ is Na+, K+, Rb+ and Cs+ and if X− is Cl−, Br−, I−, and ClO−4.
Abstract: Heats of solution of 1:1 electrolytes in acetonitrile have been determined, and enthalpies of transfer of the electrolytes from water to acetonitrile thus calculated. Free energies of transfer of a number of electrolytes from water to nonaqueous solvents have also been determined. Together with previous data, these measurements yield entropies of transfer of electrolytes from water to N-methylformamide (NMF), methanol, ethanol, dimethyl sulphoxide (DMSO), acetonitrile, NN-dimethylformamide (DMF) and acetone; single-ion entropies of transfer from water to these solvents are tabulated for up to 11 cations and 5 anions. It is shown that ΔS°t(M++ X–) is relatively independent of M+ and of X– if M+ is Na+, K+, Rb+, and Cs+ and if X– is Cl–, Br–, I–, and ClO–4. For transfers to or from water and methanol, this constancy of ΔS°t(M++ X–) is not maintained if M+ is R4N+, Ph4As+, and Ph4P+ and if X– is Ph4B–.“Absolute” single-ion entropies of transfer have been obtained, and a treatment is given that enables these single-ion values to be reproduced accurately, and further single-ion values to be predicted, for transfers from water to NMF, methanol, ethanol, DMSO, acetonitrile, DMF, acetone, formamide and liquid ammonia. For these solvents (other than water and methanol) only one adjustable parameter per solvent is required. It is also shown that the so-called “iceberg effect” for solution of organic ions is very large in water, small in methanol, and non-existent in NMF, ethanol, acetonitrile, DMF, acetone and (possibly) DMSO.

55 citations


Journal ArticleDOI
TL;DR: In this paper, a quasi-reversible electrochemical reaction with a coupled dimerization is reported. But the reaction is irreversible and the kinetic constant is 2×10 5 mol −1 1 s −1.

39 citations


Journal ArticleDOI
TL;DR: In this paper, the cobalt carbonyl-catalyzed hydromethoxy carbonylation of butadiene is studied and the reaction proceeds in the presence of a pyridine base to give methyl 3-pentenoate.
Abstract: The cobalt carbonyl-catalyzed hydromethoxycarbonylation of butadiene is studied The reaction proceeds in the presence of a pyridine base to give methyl 3-pentenoate Isoquinoline is found to be a better solvent for the production of methyl 3-pentenoate than pyridine, not only because the yield of the ester is somewhat higher in the presence of isoquinoline than in the presence of pyridine, but also because it is far less volatile than pyridine, so that the product can be easily separated from the solvent and the catalyst by distillation Also, the hydromethoxycarbonylation of methyl 3-pentenoate under somewhat different conditions is found to give a good yield of dimethyl adipate The hydroformylation of methyl 3-pentenoate is studied as well The effect of such a solvent as THF, benzene, and acetonitrile in increasing the selectivity to methyl 5-formylpentanoate is found to increase in this order: acetonitrile

39 citations


Journal ArticleDOI
TL;DR: In this paper, it was shown that perfluoroalkyl derivatives of silver may be produced by reacting fluoroolefins with silver salts in the presence of alkali metal fluorides in dimethylformamide, 1,2-dimethoxyethane or acetonitrile as a solvent.

38 citations


Journal ArticleDOI
TL;DR: In this paper, the double layer capacity at the mercury/acetonitrile interface in the presence of alkali metal and tetraalkylammonium perchlorates is investigated.
Abstract: : The results of a study of double layer capacity at the mercury/acetonitrile interface in the presence of alkali metal and tetraalkylammonium perchlorates are presented. It is shown that the Li(+), Na(+), tetraethylammonium, and perchlorate ions are not significantly adsorbed over most of the polarizable range of the electrode, whereas the K(+) and Cs(+) ions are adsorbed at more cathodic potentials. Inner layer capacity data are presented and discussed in terms of the specific effects of ions on interfacial structure. (Author)

Journal ArticleDOI
TL;DR: In this article, the voltammetric behavior of the bromide ion at a platinum electrode in acetonitrile solvent has been investigated and the occurrence of three subsequent anodic processes has been established.

Journal ArticleDOI
TL;DR: In this article, the electrochemical behavior of di-(1,2-bisdiphenyl-phosphinoethane)M(I) chloride (M=Rh, Ir) has been investigated on the mercury electrode in acetonitrile.



Journal ArticleDOI
TL;DR: In this article, a variety of methods were described for deoximation of isopropyl tri-O-acetyl-2-oximino-α-D-arabino-hexopyranoside (1) to isoprocess poly(1) poly(2)-poly(1)-hexophyranosuloside (2) using acetaldehyde in acetonitrile and hydrochloric acid.
Abstract: A variety of methods are described for the deoximation of isopropyl tri-O-acetyl-2-oximino-α-D-arabino-hexopyranoside (1) to isopropyl tri-O-acetyl-α-D-arabino-hexopyranosuloside (3). Using acetaldehyde in acetonitrile and hydrochloric acid, both 3 and its lyxo-isomer (4), from the corresponding oxime (2), were obtained in crystalline form. Comparisons of the chemical shifts of the anomeric hydrogens of the ulosides with those of the corresponding oximes require the oximes to possess the C-1/OH syn- or Z-configuration.

Journal ArticleDOI
TL;DR: In this article, the electrochemical oxidation of phenyldisulfide at a platinum electrode has been studied in acetonitrile with NaClO 4 and fluoroborate salts as supporting electrolytes.

Journal ArticleDOI
TL;DR: In this article, the comparative uptake of dioxygen by these compounds to form diooxygen complexes has been studied and the sulphinate, Ir(P-toluenesulphinate)-(CO)(PPh3)2 is O-bound but upon further co-ordination of CO or O2, sulphinate changes to S-bound although addition of methyl iodide produces an O -bound iridum(III) compound.
Abstract: Acetonitrile is displaced from [Ir(CO)(CH3CN)(PPh3)2]+ by the co-ordinating anions, F–, OH–, NCO–, NCS–, O2CH–, O2CCF3–, SH–, CCPh–,P-toluenesulphinate, and CN– to yield four-co-ordinate analogues of IrCl(CO)-(PPh3)2 except for the cyanide which is five-co-ordinate, IrCN (CO)(PPh3)3. The comparative uptake of dioxygen by these compounds to form dioxygen complexes has been studied. The sulphinate, Ir(P-toluenesulphinate)-(CO)(PPh3)2is O-bound but upon further co-ordination of CO or O2 the sulphinate changes to S-bound although addition of methyl iodide produces an O-bound iridum(III) compound.



Journal ArticleDOI
TL;DR: In this article, a quasi-reversible electron transfer from the lone-pair electrons on the 4-dimethylamino-nitrogen atom to form the cation radical was investigated.
Abstract: The anodic oxidation of 4-dimethylamino-, 4-methylamino-, 4-amino-, and unsubstituted antipyrines has been investigated in acetonitrile at a glassy-carbon electrode. The first step in the anodic oxidation of 4-dimethyl-aminoantipyrine is a quasi-reversible electron transfer from the lone-pair electrons on the 4-dimethylamino-nitrogen atom to form the cation radical. The blue-violet cation radical decays in a second-order manner with a rate constant of 12·0 ± 0·4 l mol–1 s–1 at 25 °C as determined by reversal coulometry. The second-order rate constant determined by spectrophotometry increases with increase in concentration of 4-dimethylaminoantipyrine. A well resolved e.s.r. spectrum of the cation radical was obtained and interpreted on the basis of HMO calculation. A mechanism for the first wave of the anodic oxidation of 4-dimethylaminoantipyrine is suggested.

Journal ArticleDOI
TL;DR: Ru(PPh3)2Cl2 and [Ru(AsPh3]2CL2]2 have been reacted with aniline, o-chloroniline and o-toluidine, quinoline, 2-methylpyridine, N,N′-bipyridyl, diethylamine and triethylamine.

Journal ArticleDOI
TL;DR: By treatment of erythromycin A with compounds containing a mobile halogen atom, an anhydrocompound C37H65NO12 was obtained in up to 95% yield.
Abstract: By treatment of erythromycin A with compounds containing a mobile halogen atom (tetraacetylglucosyl bromide, t-butyl bromide, triphenylmethyl chloride) in aprotic solvents of high dielectric constant (nitromethane, acetonitrile) and in the presence of pyridine, an anhydrocompound C37H65NO12 was obtained in up to 95% yield. Analytical, spectral, and chemical data indicated that the compound was erythromycin A 8, 9-anhydro-69-hemiketal (2).

Journal ArticleDOI
TL;DR: The acid catalysed reaction of acetonitrile or benzonitrile with N-alkoxycarbonylaziridines, 1a and 1b yields the corresponding 1alkoxy carbonyl-2-imidazolines, 2ax, 2ay, and 2bx as mentioned in this paper.


Journal ArticleDOI
TL;DR: In this paper, the reaction of IrCl (CO)(PPh3)2 with silver perchlorate in various solvents gives [Ir(CO)(solvent) 2]ClO4.
Abstract: Reaction of IrCl (CO)(PPh3)2 with silver perchlorate in various solvents gives [Ir(CO)(solvent)(PPh3)2]ClO4. Crystalline salts have been isolated where solvent = acetonitrile, benzonitrile, and dimethyl sulphoxide. [Ir(CO)(CH3CN)(PPh3)2]+ redily undergoes substitution reactions with carbon monoxide, phosphines, and isocyanides and, the following cations hsve been characterised: [Ir(CO)3(PPh3)2]+, [Ir(CO)(PPh3)3]+, [Ir(CO)(PPh2Me3)]+, [Ir(CO)(PPh2Et)3]+, [Ir(PPh2Me)4]+, [Ir(CO)(Ph2PCHCHPPh2)2]+, [Ir(CO)(p-Tolylisocyanide)(PPh3)2]+ and [Ir(p-tolylisocyanide)3(PPh3)2]+

Journal ArticleDOI
TL;DR: In this article, the electrochemical behavior of dibenzothiophene at a platinum electrode in acetonitrile solvent has been studied by cyclic and a.c. voltammetry.

Journal ArticleDOI
TL;DR: In this paper, the analysis of the infrared spectra of ternary mixtures LiClO4-S1-S2 shows a preferential solvation of the Li+ ion by ammonia and methylamines (S2) in acetonitrile or tetrahydrofuran (S1) and by acetitrile (S 2) in nitromethane (S 1).
Abstract: The analysis of the infrared spectra of ternary mixtures LiClO4–S1–S2 shows a preferential solvation of the Li+ ion by ammonia and methylamines (S2) in acetonitrile or tetrahydrofuran (S1) and by acetonitrile (S2) in nitromethane (S1). The appearance of wide bands in the "ion-cage" vibration region is related to the formation of different species [Li(S1)n − i(S2)i]+. The variation of their relative concentration when ρ = [S2]/[LiClO4] increases explains the frequency shift of the bands. The interaction energy Li+ ion – solvent molecule decreases when the number of S2 molecules in the first solvation shell increases and does not seem to depend on the dielectric constant of the surrounding medium. The mean composition of the first solvation shell is obtained from intensity measurements of absorption bands of the S2 molecules not bonded to the ions; in favorable cases (S2 = ND3, CH3CN) solvation number of the Li+ ion in the pure solvent could be estimated. The solvating power of the different bases used is s...