CaltechTHESIS
  A Caltech Library Service

The Gas-Phase Ion Chemistry of Substituted Silanes

Citation

Murthy, Srihari (1993) The Gas-Phase Ion Chemistry of Substituted Silanes. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/8gv5-xy57. https://resolver.caltech.edu/CaltechTHESIS:01042013-113332582

Abstract

Ion-molecule reactions in the chlorosilanes, SiHnCl4-n (n = 0-3), and in phenylsilane have been studied by the technique of Fourier transform ion cyclotron resonance spectrometry.

In Chapter 1, the motivations for studying the gas-phase ion chemistry of substituted silanes as well as brief descriptions of the gas phase ion chemistry of the chlorosilanes and of phenylsilane are presented.

Chapter 2 deals with the gas-phase ion chemistry of the chlorosilanes, SiHnCl4-n (n = 0-2). Reactions of the chlorosilyl ions with neutral chlorosilanes and with silane as well as the reactions of the silyl ion with neutral chlorosilanes are presented. The chlorosilyl ions participate in Hˉ, Clˉ transfer reactions and disproportionation reactions. The mechanisms of these reactions are discussed. The Clˉ affinities of the chlorosilyl ions, SiHnCl3-n+ (n = 0-2), lie within a range of 1.2 kcal mol-1 and decrease in the order SiH2Cl+ > SiHCl2+ ≈ SiCl3+. The heats of formation of the chlorosilyl ions are determined.

Chapter 3 deals with the gas-phase ion chemistry of monochlorosilane. The difference in the Hˉ affinities of the ions SiH2Cl+ and SiHCl2+ is determined to be 1.5 ± 0.3 kcal mo-1. The Hˉ affinities of the chlorosilyl ions, SiHnCl3-n+ (n = 0-2), lie within a range of 1.8 kcal mol-1 and decrease in the order SiHCl2+ ≈ SiCl3+ > SiHCl2+. Protonated SiH3Cl is generated by proton transfer from CH5c and is observed to react with SiH3Cl to yield (SiH3)2Cl+.

Chapter 4 deals with the gas-phase ion chemistry of phenylsilane. In analogy with toluene, two (parent – H)+ cations are produced by the electron impact ionization of phenylsilane. These cations are identified to be the phenylsilyl and the silacycloheptatrienyl cations.

Chapter 5 explores the gas-phase ion chemistry of phenylsilane in great detail. Reactions of the parent and fragment ions (created by electron impact ionization) with neutral phenylsilane and with C6D6 are presented. Two structural isomers are identified for the C6H8Si+ cation and three structural isomers are identified for the C6H6Si+ cation. The Hˉ affinity of the phenylsilyl cation is also presented.

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):
  • Beauchamp, Jesse L.
Thesis Committee:
  • Unknown, Unknown
Defense Date:24 May 1993
Record Number:CaltechTHESIS:01042013-113332582
Persistent URL:https://resolver.caltech.edu/CaltechTHESIS:01042013-113332582
DOI:10.7907/8gv5-xy57
Default Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:7369
Collection:CaltechTHESIS
Deposited By: John Wade
Deposited On:04 Jan 2013 22:51
Last Modified:16 Apr 2021 23:07

Thesis Files

[img]
Preview
PDF - Final Version
See Usage Policy.

21MB

Repository Staff Only: item control page