摘要:

The diethylamine catalyzed hydrolysis of trimethylfluorosilane in acetonitrile solution has been studied by the nuclear magnetic resonance technique. The concentration and temperature dependence of the preexchange lifetime of a fluorine in the exchange reaction was determined from the collapse of the trimethylfluorosilane doublet. The order with respect to trimethylfluorosilane, water, and diethylamine was experimentally determined. Approximate values of the equilibrium constant for the hydrolysis reaction were obtained at several temperatures.

ISSN:0008-4042    

DOI:10.1139/v72-494

出版商:NRC Research Press    

年代:1972

数据来源: NRC

摘要:

Several ammine complexes of osmium(II) containing one or two π-acceptor ligands have been prepared. They have been characterized by analytical techniques and their infrared and electronic spectra have been recorded and assignments proposed. Comparison with similar ruthenium(II) complexes has been made when possible.

ISSN:0008-4042    

DOI:10.1139/v72-495

出版商:NRC Research Press    

年代:1972

数据来源: NRC

摘要:

The thermal transformation in anhydrous acetates of Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, and Y has been studied by thermal analysis. The enthalpy change, ΔH, and the entropy change, ΔS, accompanying the transformation process are reported and related to ionic radius of the rare earth element.The acetates of the rare earth elements, La, Pr, and Nd did not exhibit the thermal transformation property.

ISSN:0008-4042    

DOI:10.1139/v72-496

出版商:NRC Research Press    

年代:1972

数据来源: NRC

摘要:

It was found by McElwain and Pritchard (1c), as a result of numerical experiments on the transport matrix for the dissociation of H2, that an apparent correspondence existed between the eigenvalues λiand the pairs of transition probabilities (Ai,i−1;Ai−1,i). In the present work, a qualitative understanding of this result is attempted, using an unusual form of solution of the master equation.

ISSN:0008-4042    

DOI:10.1139/v72-497

出版商:NRC Research Press    

年代:1972

数据来源: NRC

摘要:

The reaction of alkanes with a mixture of bromine and mercuric oxide gives alkyl bromides in preparatively useful yields. The reagent is significantly more reactive than elemental bromine, and it is believed that bromine monoxide, formedinsituby the interaction of bromine and mercury oxide, is the reactive intermediate. Bromination by bromine monoxide is a free radical chain process in which hydrogen abstraction is carried out predominantly by bromoxy (BrO•) radicals, and to a lesser extent by bromine atoms.

ISSN:0008-4042    

DOI:10.1139/v72-498

出版商:NRC Research Press    

年代:1972

数据来源: NRC

摘要:

The kinetics of the formation and dissociation of Cu(II) complexes of adenosine have been determined in acidic and basic medium. In acidic medium, the complex is formed between the Cu(II) and the adenine base and the kinetic parameters have been obtained in this case using a temperature jump method. In basic medium, only the dissociation of the complexes could be studied by a stopped-flow method, by addition of EDTA or strong acid solutions. In these complexes, Cu(II) is bridged with ribose hydroxyls. Finally,D-ribose has also been studied for comparison in the same conditions. The mechanism of these reactions is discussed.

ISSN:0008-4042    

DOI:10.1139/v72-499

出版商:NRC Research Press    

年代:1972

数据来源: NRC

摘要:

The solubility of mercury in aqueous 6.10 mNaCl has been determined between 5 and 70 °C. Solubility equations and thermodynamic functions are derived and compared with those for mercury in water. Salting-out constants are given.

ISSN:0008-4042    

DOI:10.1139/v72-500

出版商:NRC Research Press    

年代:1972

数据来源: NRC

摘要:

The kinetics of the oxidation of tetrahydrofuran by ruthenium tetroxide in aqueous perchloric acid solutions have been investigated. The rate of reaction is found to be directly dependent on the concentrations of oxidant and reductant, but inversely dependent on the acidity of the medium. A mechanism involving hydride abstraction in the rate determining step was found to be consistent with the evidence obtained from isotopic labeling and an analysis of the activation parameters (ΔH≠ = 14.0 kcal/mol, ΔS≠ = −18.4 e.u.) of the reaction. This conclusion is further substantiated by noting the similarity between the reactions of ruthenium tetroxide with alcohols and ethers.

ISSN:0008-4042    

DOI:10.1139/v72-501

出版商:NRC Research Press    

年代:1972

数据来源: NRC

摘要:

An approximate expression for the direct correlation function of a real fluid in terms of its intermolecular potential and hard-sphere distribution functions is examined. Calculations for argon using the Percus–Yevick hard-sphere distribution functions are compared with molecular correlation functions from X-ray scattering data and the macroscopic integral of the correlation function related to the isothermal compressibility. The results are not satisfactory for any pair potential unless the parameters are made state dependent. However, since partial compensation occurs on integration, fairly good correlation of the isothermal compressibility can be obtained up to twice the critical density (except near the critical point itself) using Lennard–Jones (6–12) potential parameters obtained from second virial coefficient data and the Barker–Henderson hard-sphere diameter.

ISSN:0008-4042    

DOI:10.1139/v72-502

出版商:NRC Research Press    

年代:1972

数据来源: NRC

摘要:

The rate of exchange of deuterium between hydrogen gas and water catalyzed by pentacyanocobaltate(II) has been measured as a function of pressure and temperature at a constant total cobalt concentration, 0.05 M, and ionic strength, 1 M. The rates of evolution of hydrogen from solutions of hydridopentacyanocobaltate(III) have been determined under identical conditions. These data have been employed to test the validity of a mechanism for the-catalyzed isotope exchange reaction, and to clarify the controversy over the magnitude of the specific rate for the deuterium transfer stepCalculations show that kinetic isotope and ion pairing effects are significant.

ISSN:0008-4042    

DOI:10.1139/v72-503

出版商:NRC Research Press    

年代:1972

数据来源: NRC