Molecular structures of 12 porphyrin analogues, FeIII(EtioP)X(1a-1d), FeIII(EtioCn)X(2a-2d), and FeIII(Etio-Pc)X(3a-3d), where X = F (a), Cl (b), Br (c), and I (d), are determined on the basis of X-ray crystallography. Combined analyses using Mössbauer, 1H NMR, and EPR spectroscopy as well as SQUID magnetometry have revealed that 3d exhibits a quite pure S = 3/2 spin state with a small amount of an S = 5/2 spin admixture. In contrast, all the other complexes show the S = 5/2 spin state with a small amount of the S = 3/2 spin admixture. The structural and spectroscopic data indicate a strong correlation between the spin states of the complexes and the core geometries such as Fe-N bond lengths, cavity areas, and ΔFe values.
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Inorganic Chemistry