Exchange coupling parameters and energy levels for cyclic metal-radical complexes of bis(hexafluoroacetylacetonato)manganese(II) with 5-tert-butyl-1,3-phenylenebis(N-tert-butalaminoxyl) and (4-N-tert-butyl-N-oxyamino)pyridine

Temperature-dependent paramagnetic susceptibility data for two cyclic dimer complexes of bis (hexafluoroacetylacetonato)manganese(II) with 5-tert-buty l-1,3-phenylenebis(N-tert-butylaminoxyl) and 4-(N-tert-butyl-N-oxyamino) py ridine have been analyzed to obtain two sets of two intramolecular exchange coupling parameters J(1) and J(2). A previous model, based on one of these interactions being much weaker than the other, could not be explicitly cor related to these actual exchange-coupling parameters. However, the energy l evels of the low-lying spin states were found to be reproduced reasonably w ell by the approximate method.