Behavior of the In-Plane g Tensor in Low-Symmetry d1 and d9 Systems with Application to Copper and Vanadyl Chelates

Abstract

A general expression is developed for the orientations and magnitudes of the principal in-plane g values of low-symmetry d1 and d9 complexes considered as highly perturbed axial systems. The low-symmetry components of the ligand field cause participation of | 3z2 − r2〉 in the ground state and reorientation of the | xz〉, | yz〉 orbital set. The way in which these effects show up in the in-plane g ellipse is investigated for a number of possible bonding situations. A critical evaluation is made of the information which can be (and that which cannot be) obtained from the in-plane g values, and the observed g parameters from electron paramagnetic resonance of several copper and vanadyl chelates of Schiff's bases and ketoenolates are discussed in terms of the theory.