CaltechTHESIS
  A Caltech Library Service

Electron Diffraction Investigation of the Structure of Gas Molecules

Citation

Palmer, Kenneth James (1938) Electron Diffraction Investigation of the Structure of Gas Molecules. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/1ggw-5611. https://resolver.caltech.edu/CaltechTHESIS:01312025-033006515

Abstract

In the year 1931 Wierl published a paper in which he gave the results of an investigation of the molecular structures of some twenty compounds in which high velocity electrons were diffracted by the respective compounds in the gaseous state. Since that time electron diffraction by gas molecules has come to be recognized as a powerful tool for the study of molecular structure, and today the structures of approximately two hundred compounds have been determined by this method.

Since the molecules of most compounds which have a fairly high vapor pressure at a temperature in the neighborhood of 300° C possess covalent bonds, the electron diffraction method is an excellent way of determining the covalent radii of atoms, and of studying the variations in interatomic distances due to differences in bond type and to differences in environment. The results of such studies have demonstrated the usefulness of assigning radii to atoms and have also led to empirical relations, for example that connecting bond distance and bond type, which enable one to predict with considerable accuracy the interatomic distances in many compounds. The reliability of these predictions has been adequately confirmed for compounds containing first row elements, in particular organic compounds. This is due to the comparative simplicity of the carbon atom as compared with atoms lying outside the first row of the periodic table. However, further study will no doubt lead to the discovery of more embracing relations, which will enable one to predict, not only distances, but also angles for all simple molecules. It is hoped that the results of the investigation reported in the first part of this thesis will prove to be a step in this direction.

The second part gives the results of an investigation of the structures of the dimeric molecules aluminum chloride, bromide, and iodide. In the third part the structure of selenium dioxide is reported. The fourth part is concerned with the effect of the benzene ring on the C-Cl distance in seven of the chlorobenzenes, end in the fifth and last part of this thesis the structure of nitrosyl chloride and nitrosyl bromide e.re discussed.

Item Type:Thesis (Dissertation (Ph.D.))
Subject Keywords:(Chemistry)
Degree Grantor:California Institute of Technology
Division:Chemistry and Chemical Engineering
Major Option:Chemistry
Thesis Availability:Public (worldwide access)
Research Advisor(s):
  • Unknown, Unknown
Thesis Committee:
  • Unknown, Unknown
Defense Date:1938
Record Number:CaltechTHESIS:01312025-033006515
Persistent URL:https://resolver.caltech.edu/CaltechTHESIS:01312025-033006515
DOI:10.7907/1ggw-5611
Default Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:16976
Collection:CaltechTHESIS
Deposited By: Ben Maggio
Deposited On:04 Feb 2025 22:25
Last Modified:04 Feb 2025 22:26

Thesis Files

[img] PDF - Final Version
See Usage Policy.

41MB

Repository Staff Only: item control page