Structural Studies of Some Molecules by X-Ray-, Electron-, and Neutron-Diffraction Methods

McAdam, Alexander (1969) Structural Studies of Some Molecules by X-Ray-, Electron-, and Neutron-Diffraction Methods. PhD thesis, University of Glasgow.

Abstract

This thesis is divided into three parts, and describes the results of structural studies carried out by X-ray, neutron, and electron diffraction techniques. In Part I are the results of two gas-phase electron diffraction studies. Part II is concerned with hydrogen bonding in the crystalline acid salts of dicarboxylic acids, while Part III contains the results of least-squares refinements carried out on crystalline polyphosphate compounds. In the introductory chapters of Part I the techniques of gas-phase electron diffraction are briefly discussed. Thereafter are given the results of studies of the molecular structures of tetramethyldiphosphine and unsym-dimethylhydrazine, compounds containing, respectively, P-P and N-N single bonds. Values of 2.192A and 1.455A have been determined for the lengths of these bonds. Apart from a chapter reviewing hydrogen bonding with special reference to acid salts, Part II contains the results of X-ray structure analyses of the acid salts caesium hydrogen succinate monohydrate and potassium hydrogen succinate, together with a neutron diffraction study of the latter. Both compounds have been shown to possess 'very short' hydrogen bonds lying across crystallographic elements of symmetry. Part III describes least-squares refinements of the crystal structures of two polyphosphate compounds which had previously been refined only by electron-density difference syntheses (Jost, 1961 and 1965). Some apparent anomalies in the lengths of P-O bridge bonds in one of these structures, Kurrol's sodium salt, Type A, have been removed. Three appendices are also included. Appendix I contains a procedure for calculating the molecular geometry and interatomic distances in tetramethyldiphosphine. The second appendix contains a program for refining the unit cell dimensions of a crystal, given the h, k, l, and sintheta values of a number of high-order reflexions. Appendix III consists of a paper on the refinement of Kurrol's sodium salt, Type A, described in Part III.

• Item Type: Thesis (PhD)
• Qualification Level: Doctoral
• Keywords: Molecular chemistry, Physical chemistry, Analytical chemistry
• Date of Award: 1969
• Depositing User: Enlighten Team
• Unique ID: glathesis:1969-78478
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 30 Jan 2020 15:16
• Last Modified: 30 Jan 2020 15:16
• URI: https://theses.gla.ac.uk/id/eprint/78478