Construction of a rapid-scanning stopped-flow instrument and applications in the area of mercury porphyrins
The first part of the research presented in this thesis describes the construction of a Rapid-Scanning Stopped-Flow spectrometer from available instrumentation. Very extensive descriptions and comments on the construction and use of the instrument are presented in order to allow an uninitiated person to use the instrumentation with some degree of success. Two applications of the instrument are then presented. The first involves a kinetic study of the demetalation reaction of (5,10,15,20-tetraphenylporphinato)mercury(II) in the presence of imidazole. The reaction is found to be first order in both imidazole and the mono-imidazole mercury-porphyrin complex and, based on analysis of the data, a mechanism involving the transient formation of a cis bis-ligated mercury porphyrin is postulated. A second study in this thesis involves demetalation of the same mercury porphyrin in the presence of acidic impurities. In this qualitative study, a mechanism is postulated which involves the instantaneous formation of a porphyrin dication and its slow deprotonation into the free base porphyrin.