Single crystal electronic spectra and ligand field parameters of some nickel(II) amine-isothiocyanato and amine-nitrito complexes

The single crystal linearly polarized electronic spectra of tetragonal Ni(en)z(NCS)z and Ni(en)z(NOz)z over the 8000-30000 cm-1 range have been reported and assigned. Ligand field parameters, Dq, Ds, and Dt, and angular overlap parameters, e,’ and en’ were derived from the assigned d-d spectra. These parameters have been compared with those of the respective tetragonal amine nickel complexes with known structure whose spectra were reliably assigned. The strong dependence of Dq on the metal-donor distance has been found for en and amine nickel complexes. The possibility of transferring the eo’ and err parameters of the donor atoms, corrected for the appropriate distance, is also discussed.