
TY  - JOUR
A1  - Davis, KP 
A1  - Garnett, JL 
T1  - A comparison of homogeneous and heterogeneous platinum as catalysts for the deuteration of polyphenyl aromatic hydrocarbons
JF  - Australian Journal of Chemistry
JO  - Aust. J. Chem.
Y1  - 1975
VL  - 28
IS  - 8
SP  - 1713
EP  - 1723
KW  - 
UR  - https://doi.org/10.1071/CH9751713 
N2  - Polyphenyl aromatic compounds exchange with heavy water in the presence of both homogeneous and heterogeneous platinum with high M values. Diphenyl, m- and p-terphenyls exhibit similar isotope orientations during initial rates in both catalytic systems whereas o-terphenyl does not. The first three compounds show ortho steric effects and appear to exchange by n-dissociative processes. In m- and p-terphenyls, the deactivated ortho protons exchange heterogeneously at rates which may be directly related to their degrees of steric hindrance. With o- terphenyl, all ortho hydrogens are deactivated in homogeneous exchange whereas heterogeneously, all centre ring ortho hydrogens exchange readily. A novel catalytic intermediate has been proposed to explain this orientation. These results show that o-terphenyl is a unique compound for differentiating between homogeneous and heterogeneous metal catalysed exchange processes. The data from the polyphenyls and the condensed polycyclics support the &#960;-complex theory of catalysis. 
ER  -

