SUBSTITUENT EFFECTS ON THE ZERO-FIELD SPLITTING PARAMETERS OF LOCALIZED TRIPLET 1,3-CYCLOPENTANEDIYL BIRADICALS

Information about the reactivity of the corresponding monoradicals is provided by the D parameters of the biradicals 1. The zero-field split ting parameter D, which can be obtained from the EPR spectrum of a loc alized triplet biradical, increases with the inverse cube of the avera ge distance between the unpaired spins. For para-substituted, bisbenzy lic triplet 1,3-cyclopentanediyls 1, the D parameter varies measurably depending on the substituents X.