The Production, Reactions and Spectra of Low-Valent, Highly Reactive Chemical Species - with Special Emphasis on the Phosphorus-Fluorine System

摘要

The dissertation concerns research into the production and synthetic use of low-valent, high temperature species. The radicals produced and the products they formed were identified, and their structure and bonding illucidated. Reactions were carried out by means of cocondensation reactions. In this method, high energy species are cocondensed with molecules of a reactant on a 77K surface. Reactions proceed in the 'liquid-like, intermediate, transitory' ('LLIT') state of matter formed while condensation is proceeding. Radicals investigated in this work include GeH2, SiF2, GeF2, PF2, PF and CS. New compounds formed include GeH3SiF2H, GeH3SiF3, GeH3Si2F4H, GeH3Si3F6H, P3F5, and P4F6. The fluorogermylsilanes were made by cocondensation of SiF2 and GeH4. P3F5 and P4F6 were made by the cracking of P2F4 at 900C followed by the immediate condensation of the products of this cracking at 77K. P4F6 has been characterized through mass spectra, fluorine and phosphorus nmr spectra, infrared absorption spectra and elemental analysis. P2F4 was shown to undergo heterolytic and homolytic fission, when pyrolyzed at 700C, to form PF and PF2 radicals. Photolysis of P2F4 in the matrix environment produces PF3 and P3F5 in an unusual 'excitation photolysis,' wherein the reaction takes place, in the matrix environment, between excited chemical species. Some or all of the fundamental modes of vibration in the matrix environment have been determined for each of the following species using infrared absorption spectroscopy: PF, PF2, PF3, P2F4, P3F5 and P4F6. (Author)