Bond Refractions Research Articles

Temperature and baric changes in the refractive indices of LiKSO4 crystals

The effect of uniaxial pressures (up to 200 bar) along the main crystallophysical axes on the spectral (300–750 nm) and temperature (77–300 K) dependences of the refractive indices ni(λ, T) of LiKSO4 crystals has been investigated. A baric increase in ni(λ, T) is revealed, which is caused by the increase in the electronic polarizability αi, bond refraction, and the change in the oscillator parameters due to the variation in the band gap Eg. It is shown that uniaxial pressure shifts phase-transition points both to high and low temperatures by affecting the crystal structure. A ternary point is found in which the incommensurate phase disappears and a paraelectric-to-commensurate phase transition occurs under pressure.

Bond density and physicochemical properties of a hydrogenated silicon nitride film

Hydrogenated silicon nitride films of 100–300 nm in thickness were prepared on GaAs and Si wafers by plasma enhanced chemical vapor deposition. The number of Si and N atoms in the film was measured by Rutherford backscattering. The number of H atoms was determined by an energy recoil detection (ERD) technique. A zero dose extrapolation method was employed to eliminate the effect of undesirable decrease in ERD count during ion-beam irradiation. The atomic density was determined by dividing the number of atoms by the film thickness obtained from ellipsometry. Infrared absorption cross sections of the SiH and NH bonds were obtained by using a correlation curve between IR band areas and the number of hydrogen atoms from ERD. The density of chemical bonds such as SiSi, SiN SiH and NH was obtained by equating the atomic density with the absorption cross-section of the bonds. Investigation of the refractive index of films with different chemical structures suggests that a concept of the bond refraction can explain a relatively high refractive index (1.8–2.3) and low density (2.1–2.7g/cm −3) of the Si-rich silicon nitride films, as compared with a stoichiometric compound Si 3N 4. The etch rate of the silicon nitride film in buffered oxide etchant solution showed a linear relation against the density of silicon atoms that were not bonded to hydrogen.

Hyperconjugation in phenyl and benzyl derivatives of the main group IV elements

The σ p and σ p + constants for 63 ER 3- n X n and CR 3- n- m X n [E(CH 3) 3] m substituents in C 6H 5ER 3- n X n (I) (E = Si, Ge, Sn, Pb, Hg, B, P, As, Sb; R = H, Alk; X = τ-donor group or groups having lone electron pairs) have been analyzed, and for C 6H 5CR 3- n- m X n [E(CH 3) 3] m (II), (E = Si, Ge, Sn, Pb). The σ p + - σ p difference characterizes the strengthening of donor (or weakening of acceptor) properties of substituents towards C 6H 5 group (i.e. hyperconjugation strengthening when the positive charge appears on the aromatic ring). It has been shown that hyperconjugation increases with increase in chemical bond polarizability, i.e. with bond refraction, R D. Linear relationships of σ p + - σ p with ΣR D for compounds I and II were found. It was found that the two resonance effects by the ER 3- n X n (E = Si, Ge, Sn, Pb) substituents towards the aromatic ring are opposite directions. These substituents are donors at hyperconjugation and acceptors at ( p-d) τ-interaction.

Correlation between molar refraction and gas chromatographic retention data

A study was made of the correlation between the measured molar refractions of 22 heterocyclic nitrogen-containing compounds with related structures, the molar refractions calculated from the bond refractions and the molar refractions predicted from gas chromatographic data. It was found that the time- and material-consuming experimental measurement of the molar refractions can be adequately substituted by calculation of the data, but in certain cases it is preferable to supplement the calculation with molar refraction values predicted via other experimentally obtained parameters such as I apol and I pol.

A simple method of obtaining σ values of alkyl substituents

The Taft's σ value of any given alkyl substituent can be calculated from the equation σ = −0.255 σ b + 0.461 since the value of σ b, an alkyl substituent constant, of any alkyl group can be obtained from the CC and CH bond refractions.

A further extension of the linear relationship between molecular rotation and bond refraction in open-chain monosubstituted alkanes

It has been shown that, in the correlations of molecular rotations with bond refractions for open-chain mono-substituted alkanes, H(CH2)b(CH3)C*H(CH2)nX (b > 1, n ≥ 0), the compounds with different n and X for a given b can now be grouped into a single series.

Linear relationship between molecular rotation and bond refraction in organophosphorus compounds

The molecular rotations, [M]D of eight series of organophosphorus compounds have been satisfactorily correlated with the sum of their bond refractions, ΣRD, by using the empirical equation [M]D = mΣRD+I where m and I are constants for a given series of compounds and D denotes the sodium D line.

Linear relationship between molecular rotation and bond refraction in the α- d-mannopyranose, α- d-talopyranose, α- d-lyxopyranose, and α- d-rhamnopyranose series

Linear relationship between molecular rotation and bond refraction in the α- d-mannopyranose, α- d-talopyranose, α- d-lyxopyranose, and α- d-rhamnopyranose series

Linear relationship between molecular rotation and bond refraction in carbohydrates

The molecular rotations ([M] d ) of derivatives of α- d-glucopyranose, α- d-galactopyranose, and α- d-xylopyranose having different substituents at the anomeric carbon atom are shown to be linearly related to the bond refractions ΣR d in the form of the empirical equation [M] d = mΣR d + I, where m and I are constants.

δ +-substituent constants for (organometal)methyl groups: a bond polarizability model for hyperconjunction

Internally consistent and properly scaled δ +-substituent constants for (organometal)—methyl groups are derived from several photophysical data sets. These δ +-values are well correlated by a model which considers that stabilization of an adjacent electron-deficient center is proportional to the polarizability of the carbonmetal bond as measured by bond refractions and expressed in a group polarizability function. The model also accommodates the hyperconjugative effects shown by β-deuterium substitution in solvolysis reactions and points to nonhyperconjugative effects as the basis of the Baker-Nathan order. A “best set” of δ +-values for the —CH 2MR n substituents (M = C, Si, Ge, Sn, Pb, Hg; R = Me, Ph or X) is suggested. Seventeen other δ + values for organometallic substituents are presented.

An extension of the linear relationship between molecular rotation and bond refraction

The usefulness of the empirical equation [M]D = mΣRD+I, first proposed by Davis and Jensen, in the correlations of the molecular rotations of series of structurally closely related compounds was originally limited to monovalent and linear substituents ([M]D is the molecular rotation, ΣRD is the sum of bond refractions, and m and I are constants for a given series of compounds). A different treatment of the term ΣRD extends the usefulness of the equation to all types of substituents.

Optical activity. Empirical correlation between optical rotation and bond refraction

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTOptical activity. Empirical correlation between optical rotation and bond refractionDennis Duval Davis and Frederick R. JensenCite this: J. Org. Chem. 1970, 35, 10, 3410–3416Publication Date (Print):October 1, 1970Publication History Published online1 May 2002Published inissue 1 October 1970https://doi.org/10.1021/jo00835a049RIGHTS & PERMISSIONSArticle Views113Altmetric-Citations18LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (810 KB) Get e-Alerts Get e-Alerts

The Molar Refraction of Liquid Organosilicon Compounds.

MODERN ATTEMPTS to correlate refractive index with molecular structure of liquid organosilicon compounds began with a 1946 article of Sauer (39), who used the literature data of 49 silicon compounds to devise a system which involved both group and bond refractions. Later in the same year, Warrick (62 ) , in extending the Denbigh (7) concept of bond refraction to 72 silicon compounds, calculated values for 10 species of silicon bonds, using Denbigh’s values for bonds of elements other than silicon. Results differing only slightly from Warrick’s were obtained from 139 silicon compounds by Vogel, Cresswell, and Leicester (58), who used values from Vogel’s table (57) for elements other than silicon. In all of this prior work, the classical Lorenz-Lorentz equation

THE ELECTRIC MOMENTS OF SUPPOSEDLY SYMMETRICAL CYCLIC SUBSTANCES

The distortion polarizations of polysubstituted benzenes and cyclobutanes which have been examined by the randomly oriented solid pellet technique seem to be lower but never higher than the electronic polarization values derived from bond refractions, and are considered to be more reliable than the latter. In almost all of the supposedly symmetrical substances which have been examined the total solute polarization always exceeds the measured distortion polarization and usually exceeds the calculated MRD. These substances must then be polarized, although the moments which have been determined are not numerically reliable because of solvent effects. Whenever possible the temperature coefficients of these apparent moments have been determined and are usually but not always positive. From these temperature coefficients it is presumed that some substances, like naphthalene, are rigidly dipolar whereas others, like hexachlorobenzene, have activation states which are unsymmetrical and therefore contributory to the moment which actually is measured.

Some physical properties of n‐alkyl trifluoroacetates

AbstractMeasurements have been made of the physical properties of a series of pure n‐alkyl trifluoroacetates. The values of the bond parachors, bond refractions and bond refractivities for the (C‐F) link are compared with those derived previously for the n‐alkyl fluorides.

ELECTRON GROUP POLARIZABILITY AND MOLECULAR PROPERTIES OF ORGANOPHOSPHORUS COMPOUNDS*

Annals of the New York Academy of SciencesVolume 79, Issue 7 p. 189-232 ELECTRON GROUP POLARIZABILITY AND MOLECULAR PROPERTIES OF ORGANOPHOSPHORUS COMPOUNDS* Henry Tolkmith, Henry Tolkmith Edgar C. Britton Research Laboratory, The Dow Chemical Company Midland, Mich.Search for more papers by this author Henry Tolkmith, Henry Tolkmith Edgar C. Britton Research Laboratory, The Dow Chemical Company Midland, Mich.Search for more papers by this author First published: October 1959 https://doi.org/10.1111/j.1749-6632.1959.tb42781.xCitations: 13 * A major part of this work. entitled Bond Refraction. Bond Nature, AND Structure of Organophosphorus Compounds, was accorded an A. Cressy Morrison Award in Natural Science by The New York Academy of Sciences, on December 4. 1958. AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Citing Literature Volume79, Issue7Electron Group Polarizability and Molecular Properties of Organophosphorus CompoundsOctober 1959Pages 189-232 RelatedInformation

The Bond Refraction Values for Ti-O in Organic Titanates

The Bond Refraction Values for Ti-O in Organic Titanates

Bond Refractions for Tin, Silicon, Lead, Germanium and Mercury Compounds

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTBond Refractions for Tin, Silicon, Lead, Germanium and Mercury CompoundsArthur I. Vogel, William T. Cresswell, and James LeicesterCite this: J. Phys. Chem. 1954, 58, 2, 174–177Publication Date (Print):February 1, 1954Publication History Published online1 May 2002Published inissue 1 February 1954https://doi.org/10.1021/j150512a015RIGHTS & PERMISSIONSArticle Views110Altmetric-Citations67LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (442 KB) Get e-Alerts

A System of Bond Refractions for Tin Compounds

A System of Bond Refractions for Tin Compounds

Group and Bond Refractions in Organosilicon Liquids

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTGroup and Bond Refractions in Organosilicon LiquidsRobert O. SauerCite this: J. Am. Chem. Soc. 1946, 68, 6, 954–962Publication Date (Print):June 1, 1946Publication History Published online1 May 2002Published inissue 1 June 1946https://doi.org/10.1021/ja01210a013RIGHTS & PERMISSIONSArticle Views85Altmetric-Citations22LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (876 KB) Get e-Alerts Get e-Alerts