The v2c XES are highly sensitive to metal-ligand coordination strength and geometry, thus indicating that the ligand system in 3 and 4 enables emission at these energies from Co-based MOs that are not present in the tetrahedrally coordinated complexes 1 and 2. Detailed analysis and assignment of transitions to the observed Co K-pre-edge and Kβ v2c spectra will be discussed in section 2.4.