ESR study of sublevel structure of anionic bis(phthalocyaninato)gadolinium(III)

Sublevel structure of the 8S7/2 electronic ground state of anionic bis(phthalocyaninato)gadolinium(III) has been determined by simulation analysis of an ESR spectrum in frozen solution. The simplex multidimensional minimization algorithm was employed to find the zero-field-splitting parameter set giving the minimum RMS error from the observed spectrum. The parameter set {B20,B40,B60} for the potential of D4d symmetry has been determined to be ±{(1.54 ± 0.01)× 10−2 cm−1, (0.9 ± 0.1)× 10−4 cm−1, (−0.6 ± 0.9)× 10−6 cm−1}. The energy difference between the lowest and highest sublevels has been found to be about 0.5 cm−1.