ELECTRON-STRUCTURE OF ORGANOMETALLIC COMPLEXES OF THE F-ELEMENTS .27. INTERPRETATION OF THE OPTICAL MAGNETOCHEMICAL, ESR AND NMR PROPERTIES OF NEUTRAL BASE ADDUCTS OF TRIS(ETA-5-CYCLOPENTADIENYL)NEODYMIUM(III)

The absorption spectrum of (Cp-d5)3Nd.THF-d8 in hydrocarbon glasses and run as pellets was measured at room and low temperatures. The bands were assigned based on calculations assuming the crystal field parameters of the Nd complex were the same as for the previously analyzed Cp3Pr.MeTHF. The parameters of an empirical Hamiltonian were fitted to the energies of 96 levels to give an r.m.s. deviation of 26 cm-1. On the basis of the wave functions of the crystal field ground state obtained from these calculations, the observed EPR spectrum of Cp3Nd0.06La0.94.THF could be explained. Making use of the calculated wave functions and eigenvalues the experimentally determined temperature dependence of mu-eff2 of powdered Cp3Nd.THF and of an oriented signel crystal of Cp3Nd.NCCH3 could be simulated. Assuming that the methyl protons of the gamma-picoline ligand of Cp3Nd.gamma-pic and (MeCp)3Nd.gamma-pic, respectively, experience only an NMR shift of dipolar type, the paramagnetic anisotropy chi parallel-to - chi perpendicular-to was estimated.