The 15N NMR spectra of meso-tetraphenylporphyrin, its dication, and zinc tetraphenylporphyrin have been investigated both at the natural-abundance level and with isotopic enrichment. The resonances of tetraphenylporphyrin at ambient temperatures are broadened by chemical exchange of the central hydrogen atoms. At lower temperatures, the 15N spectra provide structural information concerning the bonding of these hydrogens. The variable-temperature 15N spectra of mixtures of tetraphenylporphyrin and its dication also reveal chemical-exchange phenomena. Spectra for tetraphenylporphyrin dication and zinc tetraphenylporphyrin at the natural-abundance level are reported. Spin-lattice relaxation times and nuclear Overhauser effect data have been determined for 15N enriched samples of these two compounds.
ASJC Scopus subject areas
- Colloid and Surface Chemistry