Electron spin resonance spectra of low-symmetry high-spin cobalt(II) complexes. 4. Tetragonal-octahedral dichlorotetrakis(pyridine)- and dichlorotetrakis(pyrazole)cobalt(II)

The ESR spectra of tetragonal-octahedral dichlorotetrakis(pyridine)- and dichlorotetrakis(pyrazole)cobalt(II) have been recorded. The former yields 811 = 3.33 and g, = 4.46, and the latter yields gl = 2.14, gz = 4.55, and g3 = 5.83. The g values of tetragonal-octahedral complexes are related to the bonding abilities of axial and equatorial ligands. Quantitative angular overlap calculations allowed us to reproduce the g values and the energies of the electronic transitions. The e, values are discussed