Spin–orbit coupling in “tetrahedral” nickel(II) complexes; An anomaly

Abstract

Studies of the paramagnetism of tetrahedral or near-tetrahedral nickel(II) transition metal complexes within the ligand-field framework have been repeatedly characterized by abnormally small spin–orbit coupling coefficients. The same is not so for complexes with other geometries or central metal. This anomaly is not associated with a similarly reduced orbital reduction factor in the magnetic moment operator. A qualitative explanation that does not simultaneously cast doubt on the overall ligand-field approach is presented here for the first time.