Mössbauer spectra of tetracoordinate (phthalocyaninato)iron(II) complexes with electron-releasing substituents were measured. Two kinds of bonding parameters, Σ and ∏, that had been introduced by the authors were calculated for substituted phthalocyanines to interpret Mössbauer parameters in connection with the bonding characteristics of the macrocyclic ligands. The bonding parameters, Σ and ∏, represent σ- and π-bonding properties, respectively, and are defined to be larger when more electron density is placed on the iron. Calculated orders of Σ and ∏ are again in good correlations with the sum of the Hammett σ constants, Σσ, of the substituents: the correlations previously found for electron-withdrawing substituents are revealed to be extended to electron-releasing substituents. The correlations account with reasonable success for a set of Mössbauer data that are difficult to interpret in the usual way.
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Inorganic Chemistry