JCP Nameplate
  • Volume/Page
  • Keyword
  • DOI
  • Citation
  • Advanced
   
 
 
 

You Tube Flickr Twitter iResearch App Facebook

SECTION LISTING

BROWSE VOLUMES

Year Range: 
Search Issue | RSS Feeds RSS
Previous Issue

1 Dec 1945

Volume 13, Issue 12, pp. 539-586


The Isotope Effect and the Ratio Rule

Walter F. Edgell

J. Chem. Phys. 13, 539 (1945); http://dx.doi.org/10.1063/1.1723991 (8 pages) | Cited 4 times

Online Publication Date: 22 December 2004

Full Text: | Download PDF

Show Abstract
A perturbation treatment of the isotope effect has been developed which gives the change in the normal coordinates as well as the frequencies of vibration. The ratio rule is obtained from this treatment, and the conditions which are prerequisite to its application are clearly indicated. At present the lack of required experimental data limits the utility of this rule somewhat, and a more useful but generally less accurate form of it has been derived, which depends for its validity upon the ability to construct symmetry coordinates which approximate the corresponding normal coordinates. The application of these equations to experimental data has been illustrated. In particular the modified ratio rule has been tested on the molecules CD4, CH3D, CHD3, CDCl3, CD3Cl, ND3, B10F3, C2D4, and C2D6 and found to give generally good results.

Thermodynamic Properties of Ethylbenzene Vapor from 300° to 1500°K

F. G. Brickwedde, M. Moskow, and R. B. Scott

J. Chem. Phys. 13, 547 (1945); http://dx.doi.org/10.1063/1.1723992 (7 pages) | Cited 5 times

Online Publication Date: 22 December 2004

Full Text: | Download PDF

Show Abstract
In this paper are presented tables of the more important thermodynamic functions of ethylbenzene in the ideal gas state from 300° to 1500°K. These functions were calculated using spectroscopic, structural, and calorimetric data. Six investigations of the Raman spectrum of ethylbenzene and three of the infra‐red absorption spectrum were available for an assignment of frequencies to the intramolecular vibrations. Included in the paper is a calculation from calorimetric data of the enthalpy and entropy of saturated vapor at 294°K relative to the solid at 0°K. This paper completes a report on a determination of the thermodynamic properties of ethylbenzene covering the solid, liquid, and vapor phases, extending from 0° to 1500°K. All the experimental results are presented in detail in preceding papers.

The Reaction of Hydrogen Atoms with Acetone

G. M. Harris and E. W. R. Steacie

J. Chem. Phys. 13, 554 (1945); http://dx.doi.org/10.1063/1.1723993 (6 pages) | Cited 7 times

Online Publication Date: 22 December 2004

Full Text: | Download PDF

Show Abstract
The reaction of hydrogen atoms with acetone vapor has been investigated by means of the Wood‐Bonhoeffer technique at room temperature. The sole reaction products under these conditions are methane and carbon monoxide. A deuterium exchange experiment showed that the methane product is almost completely deuterized, while undecomposed acetone is exchanged to the extent of 4.1 atom percent. A reaction series has been devised which satisfactorily explains the experimental facts. The activation energy of 9 kcal. found for the over‐all process has been assigned to the proposed initiatory step:
math

The Reaction of Hydrogen Atoms with Dimethyl Mercury

G. M. Harris and E. W. R. Steacie

J. Chem. Phys. 13, 559 (1945); http://dx.doi.org/10.1063/1.1723994 (4 pages) | Cited 1 time

Online Publication Date: 22 December 2004

Full Text: | Download PDF

Show Abstract
The Wood‐Bonhoeffer method has been applied to a study of the reaction of hydrogen atoms with dimethyl mercury. The organometallic undergoes rapid decomposition at room temperature, giving as products methane, ethane, and metallic mercury. The variation of the ratio of methane to ethane formation with change in the relative concentrations of reactants has been satisfactorily explained on the basis of a postulated reaction mechanism, all steps in which are assumed to have an activation energy ≤6 kcal.

The Mercury Photosensitized Reactions of Propane at Low Pressures

B. deB. Darwent and E. W. R. Steacie

J. Chem. Phys. 13, 563 (1945); http://dx.doi.org/10.1063/1.1723995 (9 pages) | Cited 10 times

Online Publication Date: 22 December 2004

Full Text: | Download PDF

Show Abstract
The mercury photosensitized reactions of propane have been investigated at room temperature between 0.7 and 84.5 mm Hg. At high pressures the products consisted almost entirely of hexane and hydrogen but at low pressures methane and C2 and C4 hydrocarbons were produced in increasing amounts. The production of methane was much less than in the similar reactions of ethane. The effect of pressure on the nature of the reaction can be accounted for by a C☒H split followed by atomic cracking and recombination reactions as proposed by Steacie and Dewar, but the difference in the products from propane and ethane make it likely that the reaction proceeds, at least in part, by the formation of an active molecule. At low pressures the rate of propane disappearance is retarded and the extent of C☒C split increased by the addition of hydrogen. The effect of added hydrogen is explained by an increase in the rates of recombination of hydrogen atoms and of atomic cracking reactions.

Molecular Constants and Chemical Theories V. Some Remarks on Physical Constants and Theories of Higher Valence States

R. Samuel

J. Chem. Phys. 13, 572 (1945); http://dx.doi.org/10.1063/1.1723996 (13 pages) | Cited 2 times

Online Publication Date: 22 December 2004

Full Text: | Download PDF

Show Abstract
In answer to a recent article of Dr. Wheland, criticizing the previous papers of this series, some points of theoretical and experimental evidence are discussed. The criticism of the above paper is rejected in full (with the exception of a minor point on the calculation of ionic percentage contributions from bond moments). This article goes slightly beyond the previous ones in a number of points. Attention may be drawn to two of them. The question why different values of molecular constants are produced by the process of sharing or by a change of valency is discussed in greater detail. Furthermore, while maintaining that individual constants cannot distinguish between different structures or theories, it is shown that they can do so in conjunction. Indeed in conjunction they offer definite experimental evidence which supports the classical concepts but is not compatible with the semipolar double bond and its translation into resonance structures.

Chain Initiation in Catalyzed Polymerization

Max S. Matheson

J. Chem. Phys. 13, 584 (1945); http://dx.doi.org/10.1063/1.1723997 (2 pages) | Cited 15 times

Online Publication Date: 22 December 2004

Full Text: | Download PDF

Abstract Unavailable
back to top
RSS Feeds

High Velocity Fragments in Secondary Photochemical Processes

Richard A. Ogg and Russell R. Williams

J. Chem. Phys. 13, 586 (1945); http://dx.doi.org/10.1063/1.1723998 (1 page) | Cited 12 times

Online Publication Date: 22 December 2004

Full Text: | Download PDF

Abstract Unavailable
Close

Google Calendar

ADVERTISEMENT

Go to AIP Home   © AIP Publishing LLC
close