M. Robert Willcott

A kinetic study of the reaction of rhodium(II) acetate with trifluoroacetic acid

Abstract The reaction of rhodium(II) acetate with excess trifluoroacetic acid was followed by 1H NMR. Identification of the intermediate compounds in the exchange process was accomplished by use of mass spectrometry. The reaction was found to be a stepwise exchange of trifluoroacetate for the acetate cage. Rate constants measured have a ratio of approximately 1:2:0·1:0·025 for k1:k2:k3:k4. The first substitution has a labilizing effect on the system causing the second substitution to occur twice as fast as the first. After the formation of Rh2(OOCCH3)2(OOCCF3)2, the reaction proceeds at a much slower rate until the completely exchanged rhodium(II) trifluoroacetate is formed.

Regularities in the 13C-NMR Chemical Shifts of the Methylene Groups in Isoprene Derived Structural Fragments

Abstract An assignment correlation is described for the 13C-nmr chemical shifts of the methylene carbons flanking transoid (E) were in part provided by Grant No. CA 11055 and Contract No. CM-87209 which were awarded by the National Cancer Institute, DHEW. The support of the National Science Foundation, Grant No. CHE-7506162, which provided funds for the acquisition of the XL-100 spectrometer system utilized in the conduct of this research is also gratefully acknowledged.