Electrostatic effects on ionization equilibria. 3-Substituted bicyclo[2,2,2]octane-1-carboxylic acids

1979 ◽  
Vol 44 (10) ◽  
pp. 2928-2945 ◽  
Author(s):  
Zdeněk Friedl ◽  
Jaroslav Hapala ◽  
Otto Exner
Keyword(s):  
Carboxylic Acids ◽  
Substituent Effects ◽  
Molecular Size ◽  
Geometrical Parameters ◽  
Electrostatic Effects ◽  
Ellipsoidal Cavity ◽  
Theoretical Predictions ◽  
Ionization Equilibria ◽  
The One

Nine 3-substituted (I-IX) and one 2-substituted (XI) bicyclo[2,2,2]octane-1-carboxylic acids were prepared as model compounds for verification of the electrostatic theory of substituent effects. On the one hand they are regular-shaped and suitable for calculations, on the other hand they allow to evaluate the role of the angle θ of the substituent dipole. The apparent pK values in 50% ethanol and 80% methyl cellosolve were correlated with σI constants (ρI 1.18 and 1.42, respectively) and compared with theoretical predictions based on the spherical and ellipsoidal cavity models. The agreement is very good with the new Ehrenson model but still satisfactory with some others not matching exactly the actual molecule shape. The substituent effects are resonably correlated with the substituent dipoles and with the geometrical parameters but exceptions are notable. Comparison with the previous results implies that the theory reproduces fairly the substituent effects in carboxylic acids of a given molecular size and not too unsymmetrical shape; the cavity model is, however, sufficiently flexible to compensate partly even for some non-electrostatic effects neglected by the basic theory.

Electrostatic effects on ionization equilibria: Solvent dependence

1984 ◽  
Vol 49 (1) ◽  
pp. 179-189 ◽  
Author(s):  
Karel Kalfus ◽  
Zdeněk Friedl ◽  
Otto Exner
Keyword(s):  
Gas Phase ◽  
Carboxylic Acids ◽  
Dissociation Constants ◽  
Aprotic Solvents ◽  
Benzoic Acids ◽  
Cavity Model ◽  
Electrostatic Effects ◽  
Solvent Dependence ◽  
Ionization Equilibria ◽  
Substituted Benzoic Acids

Apparent dissociation constants of 3-substituted bicyclo[2,2,2]-octane-1-carboxylic acids I-III and of several substituted benzoic acids were measured in four pure solvents. The results - together with numerous literature data concerning dissociation in other solvents and in the gas phase - were compared with the prediction of the electrostatic theory. The theory fails to reproduce the essential features of the solvent dependence as it predicts generally too small effects and does not differentiate between protic and aprotic solvents. The mentioned goal cannot be achieved by any more sophisticated cavity model or by any other theory as far as it characterizes the solvent only through its bulk permittivity.

Electrostatic effects on ionization equilibria: MNDO study of proton and hydrogen transfer reactions of 5-fluoropentanoic acid

1985 ◽  
Vol 63 (5) ◽  
pp. 1068-1072 ◽  
Author(s):  
Zdenek Friedl
Keyword(s):  
Proton Transfer ◽  
Gas Phase ◽  
Carboxylic Acids ◽  
Hydrogen Transfer ◽  
Opposite Sign ◽  
Substituent Effects ◽  
Transfer Reactions ◽  
Small Contribution ◽  
Bond Strengths ◽  
Ionization Equilibria

Relative proton transfer enthalpies δΔH0 and homolytic bond strengths δΔH0 (A—H) of sp and ap conformers of 5-fluoropentanoic acid, as well as some related aliphatic and 4-X-bicyclo[2.2.2]octane-1-carboxylic halogenoacids, have been calculated by the MNDO method. The results, together with literature data concerning the gas phase acidities, were compared with the prediction of the electrostatic theory. It is shown that the substituent effects on acidities of carboxylic acids are largely due to substituent interactions in the anions and only to a smaller extent to interactions in the neutral acids. A small contribution (about one-eighth to one-fourth as large in magnitude but of opposite sign) is possibly also made by substituent effects on homolytic bond strengths DH0 (A—H).

A Tentative Cause of Discrepancy Between FVIII:C Estimation

1979 ◽  
Author(s):  
M.J. Seghatchian
Keyword(s):  
Molecular Size ◽  
Molecular Forms ◽  
Factor X ◽  
Two Stage ◽  
One Stage ◽  
Preferential Adsorption ◽  
The One ◽  
Molecular Nature ◽  
Similar Peak

Biochemical analysis based on the molecular size and change was performed on normal, patient plasmas and clinical concentrate to differentiate various molecular forms of FVIII:C. Assay of the effluent fractions by one stage, two stage and chromogenic methods revealed two major peaks of activities, measured to differing extents by various methods. Thromboplastin generation methods (two stage clotting and chromogenic) were particularly sensitive to smaller forms, which had a faster electrophoresis mobility and eluted in the gamma globulin region. The one stage method measured mainly the aggregated forms (MW> 300.000), with the slower electrophoretic mobility.A discrepancy of about 30% between the two methods could account for the detection of the smaller form, which predominated in plasma rather than concentrate. This had a preferential adsorption on Al(OH)3 and some FVIII.C neutralising activity. A similar peak of activity was identified in haemophilia and V.Wd. plasma isolated on sepharose suggesting that the whole plasma contained an inhibitory factor acting on the clotting activity. Excess factor X and traces or thrombin-like enzymes could be identified in this region. Thus the role of these factors in accelerating the rate of FXa generation by activating FVIII can not be excluded.Regardless of the molecular nature of this form of FVIII, this activity may play an important role in controlling haemstasis via VIII activation and may explain the discrepancy between assay of plasma versus concentrate.

You Are the One I Want to Communicate With!

2013 ◽  
Vol 44 (1) ◽  
pp. 16-25 ◽  
Author(s):  
Sabrina Pierucci ◽  
Olivier Klein ◽  
Andrea Carnaghi
Keyword(s):  
Memory Bias ◽  
Shared Reality ◽  
Communication Partner ◽  
Shared Reality Theory ◽  
The One ◽  
Study Participants

This article investigates the role of relational motives in the saying-is-believing effect ( Higgins & Rholes, 1978 ). Building on shared reality theory, we expected this effect to be most likely when communicators were motivated to “get along” with the audience. In the current study, participants were asked to describe an ambiguous target to an audience who either liked or disliked the target. The audience had been previously evaluated as a desirable vs. undesirable communication partner. Only participants who communicated with a desirable audience tuned their messages to suit their audience’s attitude toward the target. In line with predictions, they also displayed an audience-congruent memory bias in later recall.

The Formation of Intermediate Product I in a Purified System The Role of Factor IX or of its Precursor and of a Hageman Factor-PTA Fraction

1961 ◽  
Vol 6 (02) ◽  
pp. 224-234 ◽  
Author(s):  
E. T Yin ◽  
F Duckert
Keyword(s):  
Intermediate Product ◽  
Factor Ix ◽  
Assay Method ◽  
Lag Phase ◽  
Factor X ◽  
Haemophilia B ◽  
Hageman Factor ◽  
One Stage ◽  
The One

Summary1. The role of two clot promoting fractions isolated from either plasma or serum is studied in a purified system for the generation of intermediate product I in which the serum is replaced by factor X and the investigated fractions.2. Optimal generation of intermediate product I is possible in the purified system utilizing fractions devoid of factor IX one-stage activity. Prothrombin and thrombin are not necessary in this system.3. The fraction containing factor IX or its precursor, no measurable activity by the one-stage assay method, controls the yield of intermediate product I. No similar fraction can be isolated from haemophilia B plasma or serum.4. The Hageman factor — PTA fraction shortens the lag phase of intermediate product I formation and has no influence on the yield. This fraction can also be prepared from haemophilia B plasma or serum.

THE ROLE OF ANTHROPONYMS IN THE SEMANTIC FIELD OF ARTISTIC WORKS

2019 ◽  
Vol 2019 (29) ◽  
pp. 66-77
Author(s):  
Lidiya Derbenyova
Keyword(s):  
Literary Work ◽  
Main Theme ◽  
Semantic Field ◽  
New Meanings ◽  
Minor Part ◽  
The One ◽  
A Minor ◽  
And Storage ◽  
Horizon Of Expectations

The article explores the role of antropoetonyms in the reader’s “horizon of expectation” formation. As a kind of “text in the text”, antropoetonyms are concentrating a large amount of information on a minor part of the text, reflecting the main theme of the work. As a “text” this class of poetonyms performs a number of functions: transmission and storage of information, generation of new meanings, the function of “cultural memory”, which explains the readers’ “horizon of expectations”. In analyzing the context of the literary work we should consider the function of antropoetonyms in vertical context (the link between artistic and other texts, and the groundwork system of culture), as well as in the context of the horizontal one (times’ connection realized in the communication chain from the word to the text; the author’s intention). In this aspect, the role of antropoetonyms in the structure of the literary text is extremely significant because antropoetonyms convey an associative nature, generating a complex mechanism of allusions. It’s an open fact that they always transmit information about the preceding text and suggest a double decoding. On the one hand, the recipient decodes this information, on the other – accepts this as a sort of hidden, “secret” sense.

Public Procurement Principles Generated by the Treaty of Rome

2020 ◽  
Vol 26 (2) ◽  
pp. 217-223
Author(s):  
Ioan-Gabriel Popa
Keyword(s):  
European Economic Community ◽  
Public Procurement ◽  
Free Movement ◽  
European Directives ◽  
Community Institutions ◽  
Treaty Of Rome ◽  
General Principles Of Law ◽  
Free Movement Of Goods ◽  
The One

AbstractIn order to understand the principles of public procurement in Romania, it is necessary to analyze, on the one hand, the European directives that regulate the actual public procurement and, on the other hand, the context in which the European directives were adopted. Even with the directives in force, the more general provisions contained in the Treaty of the European Economic Community (EEC) in Rome, hereinafter referred to as the Treaty, are applied, as well as many more general principles of law that will guide the interpretation of these directives. The Treaty was adopted in Rome, in 1957 and became applicable from January 1, 1958. It is considered that the source of the principles of public procurement is the Treaty. Even if in Treaty contained no specific provisions regarding the field of public procurement, it reflects the principles and the general framework for the functioning of the single market, a market characterized through the prism of the fundamental freedoms established by the Treaty: the free movement of goods, services, capital and persons. As the field of public procurement is closely linked to the free movement of goods, this principle is promoted and implemented in the practice of this field based on the regulations, directives and decisions of the Community institutions. The role of the free movement of goods is to harmonize the relationships involved in the process of purchasing goods, but also to ensure the homogeneity, coherence and balance of this process.

Adiabatic large polarons in anisotropic molecular crystals

2011 ◽  
Vol 35 (1) ◽  
pp. 15-27
Author(s):  
Zoran Ivić ◽  
Željko Pržulj
Keyword(s):  
Energy Transfer ◽  
Effective Mass ◽  
Molecular Crystals ◽  
Single Chain ◽  
Proper Understanding ◽  
One Dimensional ◽  
Interchain Coupling ◽  
Large Polaron ◽  
The One

Adiabatic large polarons in anisotropic molecular crystals We study the large polaron whose motion is confined to a single chain in a system composed of the collection of parallel molecular chains embedded in threedimensional lattice. It is found that the interchain coupling has a significant impact on the large polaron characteristics. In particular, its radius is quite larger while its effective mass is considerably lighter than that estimated within the one-dimensional models. We believe that our findings should be taken into account for the proper understanding of the possible role of large polarons in the charge and energy transfer in quasi-one-dimensional substances.

NURTURING OF CHILDREN THROUGH DRAMA AND THEATRE: THE CASE OF INTWASA KOBULAWAYO PERFORMANCES

2016 ◽  
Vol 13 (2) ◽  
pp. 86-99
Author(s):  
Vimbai Moreblessing Matiza
Keyword(s):  
Political Development ◽  
Children And Youth ◽  
Main Task ◽  
Growing Up ◽  
Theatrical Performances ◽  
History Of ◽  
The One

Dramatic and theatrical performances have a long history of being used as tools to enhance development in children and youth. In pre-colonial times there were some forms of drama and theatre used by different communities in the socialisation of children. It is in the same vein that this article, through the Intwasa koBulawayo performances, seeks to evaluate how drama and theatre are used to nurture children and youth into different developmental facets of their lives. The only difference which this article will take into cognisance is that the performances are done in a different environment, which is not the one used in the pre-colonial times. Although these performances were like this, the most important factor is the idea that children and youth are socialised through these performances. It is also against this backdrop that children and youth are growing up in a globalised environment, hence the performances should accommodate people from all walks of life and teach them relevant issues pertaining to life as they live it now. Thus the main task of the article is to spell out the role of drama and theatre in the nurturing of children and youth through socio economic and political development in Intwasa koBulawayo festivals.

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