Year

1974

Degree Name

Bachelor of Science (Hons.)

Abstract

Some Group Vili metals, prepared by prereduction of their salts with sodium borohydride, were examined for catalytic activity with deuterium oxide and halogenated aromatic compounds in heterogeneous systems. Substantial exchange of the halobenzenes examined occurred on platinum and iridium, involving incorporation of up to three deuterium atoms per molecule. The other metals examined showed only a low level of deuterium incorporation for exchange of the halobenzenes. Extensive exchange of all ring protons, however, occurred with fluorobenzene on palladium* For exchange of ring halogenated toluenes, platinum was again generally active. Nickel favoured exchange of the methyl protons of these systems. Extensive exchange of ring and methyl protons of the fluorotoluenes occurred on palladium. The results of the exchange of the chlorine and bromine substitued aromatics examined are consistent with "severe" ortho deactivation of ring protons adjacent to these groups. With fluorine the effect, whilst present, was much less pronounced. The exchange patterns observed are generally consistent with the theory of JT-complex adsorption The existing Quadnova operating system was adapted to perform quantitative isotope ratio determinations. Each of the three methods developed showed an improvement in quantitative analyses compared with the orginal system. The method involving calculation of intensities by a peak area routine proved to be the most successful.

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