Electron spin resonance studies of the pentacyanocobaltate(II) ion in various host lattices

Abstract

The e.s.r. parameters for the pentacyanocobaltate(II) ion in a range of alkali-metal halides and in potassium hexacyanocobaltate(III) are shown to be in accord with a (3d_{xz, yz})⁴(3d_xy)²(3d_z²)¹ ground-state in which there is considerable mixing of the 4s atomic orbital into the orbital of the unpaired electron. Comparison of the data with previous results shows that the extent of 4s participation decreases on changing from four- to six-fold co-ordination. A possible reason for this trend is outlined.