Spectral properties and ligand field analysis of cis-dinitrito(1,4,8,11-tetraazacyclotetradecane)chromium(III) nitrate Original Research Article

The 77 K emission and excitation spectra, and 298 K infrared and absorption spectra of cis-[Cr(cyclam)(ONO)2]NO3 (cyclam=1,4,8,11-tetraazacyclotetradecane) have been measured. The vibrational intervals of the electronic ground state are extracted from the far-infrared and emission spectra. The 10 electronic bands due to spin-allowed and spin-forbidden transitions are assigned. Using the observed electronic transitions, a ligand field analysis was performed in the framework of the angular overlap model. It is confirmed that nitrogen atoms of the cyclam ligand have a strong σ-donor character, but nitrito ligand has weak σ- and π-donor properties toward chromium(III) ion.