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We have measured the nitrogen Is binding energies and some metal binding energies of porphyrin and phthalocyanine compounds by X-ray photoelectron spectroscopy. We find that this technique yields interesting new data. In particular, we find two kinds of nitrogen in tetraphenylporphine free base, differing in charge by about 0.2 e. We find the nitrogens of most metalloporphyrins to be similar to those of porphine base which lack protons. We find the two kinds of nitrogen in metal phthalocyanines to be identical with photoelectron spectroscopy. Finally, we find that the iron in the oxidized and reduced forms of iron porphyrin differ in charge by some 0.44 electron charges. On the whole, our results compare well with the theoretical predictions of Gouterman and coworkers.

The hyperfine tensors to the various nuclei of the ion [bis(maleonitriledithioleato)nickel]- have been calculated. Calculations have been performed with various theoretical models and have used various basis sets. The hybrid density functional (B3) methods gave the best results, when used with a triple-ζ basis set (6-311G). On the whole, the results are satisfactory, but the 61Ni hyperfine tensor is not calculated especially well.

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Electron spin resonance (ESR) can be used to determine the thermal history of charred organic material. Maize seeds were heated under controlled conditions in order to produce calibration curves relating g-values (the rate of electron splitting) and spin intensities (the number of spin centres) to heating temperatures, times and conditions. These experiments reproduced results that had been previously obtained by other laboratories, with some minor exceptions. The calibration curves were then used to reconstruct the thermal histories of charred maize kernels from several prehistoric sites in eastern North America. At these sites, the differing thermal histories of maize kernels are correlated with depositional contexts.