Publication Details (including relevant citation information):
Novakovic, K.; Grosjean, C.; Scott, S. K.; Whiting, A.; Willis, M. J.; Wright A. R. Phys. Chem. Chem. Phys., 2008, 10, 749‐753
This paper reports on the influence of oscillations on product selectivity as well as the dynamics
of product formation during the palladium-catalysed phenylacetylene oxidative carbonylation
reaction in a catalytic system (PdI2, KI, Air, NaOAc in methanol). The occurrence of the pH
oscillations is related to PdI2 granularity and the initial pH drop after phenylacetylene addition.
To achieve pH and reaction exotherm oscillations regulation of the amount of PdI2 is required,
ensuring that the initial pH does not fall significantly below 1 after phenylacetylene addition.
Experiments in both oscillatory and non-oscillatory pH regimes were performed in an HEL
SIMULARt reaction calorimeter with the concentration–time profiles measured using a
GC-MS. It is demonstrated that when operating in an oscillatory pH regime product formation
may be suppressed until oscillations occur after which there is a steep increase in the formation of
Z-2-phenyl-but-2-enedioic acid dimethyl ester. When operating in non-oscillatory pH mode the
products are formed steadily over time with the main products being Z-2-phenyl-but-2-enedioic
acid dimethyl ester, 2-phenyl-acrylic acid methyl ester and E-3-phenyl-acrylic acid methyl ester.