摘要:

At this point in time several major problems must be solved before the results of acid-base reactions can be predicted, even moderately well in given solvent. Theoretically, it would be desireable to be able to estimate, on the basis of energy, the intrinsic acidity of acids as well as the basicity of substances with which acids react under practical circumstances, whether the latter is a solvent or a reference base. The available data suggest that hydrogen-containing substances exhibit characteristic protonic acidities which can be manifested, more or less, in different solvents. The ionization of a substance to form protons in the gas phase is a suggested unambiguous measure of its inherent acid strength, but sufficient thermochemical data are not available to estimate the extents of such processes for a series of related compounds. The gas phase ionization can be related to the ionization process in solution by considering the solvation of the molecular form of the acid, its conjugate base, the proton. In general, little is known of the fundamental nature of the solvation process for molecular acids and their conjugate ions, although estimates of the energy of solvation of the proton in a series of solvents, or the energy required to transfer a proton between two solvents, have been made. Perhaps the most difficult of the theoretical areas that need to be addressed is a detailed consideration of the nature of electrostatic solute-solvent interactions, as well as the more specific hydrogen-bonded interactions. Such interactions must be better understood from a theoretical standpoint before a priori decisions can be made concerning which factors, if any, will determine the course of an acid-base reaction.

ISSN:0007-8980    

DOI:10.1080/10408347108542763

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor

ISSN:0007-8980    

DOI:10.1080/10408347108542764

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor

摘要:

To the reader who is only casually familiar with electrochemical measurements based on periodic perturbations, perhaps one of the most surprising aspects of this review is its illustration of the level and scope of influence of the methodology considered. Hopefully, it has been made evident that the literature gives witness to notable growth in the three areas of importance to any experimental method:theory, instrumentation, and application. One finds successful application to chemical systems whose types encompass the entire range of solution chemistry, from the molecule of life (DNA) to the simplest elemental ions. Having never bothered to actually keep a quantitative record of the output, even this writer was rather surprised upon first realizing that a yield in the neighborhood of 100 publications per year has characterized this field in the last 3½ years. Even in the present era of the "information explosion" this must be considered a nontrivial level of activity. Because many scientists, even among electrochemists, view ac polarography and related techniques as a special peripheral area, it was considered worthwhile to attempt to convey in this review the point that such an outlook is inconsistent with the level and scope of activity one finds in the literature. Consequently, a subject-oriented review was attempted, rather than one oriented toward specific outstanding papers. The latter would have been the easier choice as a shorter, more conveniently organized review could have been generated. Hopefully, the disadvantages with the approach adopted are offset by the fact that this review makes the reader aware of the role being played by the ac polarographic method in widely diversified areas of scientific endeavor. Even more important, it is hoped that an appreciation for the future potentialities of the method and its possible evolutionary pathways has been generated.

ISSN:0007-8980    

DOI:10.1080/10408347108542765

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor