Abstract
Reports on a magnetically split Mossbauer hyperfine spectrum of haemin in tetraphenylporphyrin host crystals and a magnetically split spectrum of haemin in tetrahydrofuran that is virtually free of the centrally superimposed quadrupole doublet due to aggregation. In the same work, magnetically split spectra of dilute solutions of haemin in dimethyl sulphoxide are reported. The effective magnetic field at the 57Fe nucleus and the quadrupole splitting were found to depend on the side chains, the solvent or host crystals, and the concentration used. Also, the effective field was found to lie in the range 477+or-3 kG to 499+or-3 kG.