A new series of nine nitronyl nitroxide Cr(III) complexes with various β-diketonates, [Cr(β-diketonato)₂(NIT2py)]PF₆, have been synthesized where NIT2py is 2-(2′-(pyridyl)-4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazolyl-3-oxide-1-oxyl, and their structures, magnetic and optical properties have been examined. X-Ray analysis of [Cr(dpm)₂(NIT2py)]PF₆ (monoclinic, space group P2₁/a, a = 13.960(4), b = 31.19(1), c = 13.940(4), Z = 4) demonstrated that NIT2py coordinated to Cr(III) as a bidentate six-membered chelate. Variable-temperature magnetic susceptibility measurements indicated the antiferromagnetic interaction between Cr(III) and NIT2py with a variety of the magnetic coupling constant J values for these complexes. From the variable temperature or solvent dependent UV–vis spectra and MCD, and/or the resonance Raman spectra of the bis(β-diketonato)(NIT2py) Cr(III) complexes, the absorption components centered around 13.3 × 10³ cm⁻¹ were assigned to the formally spin-forbidden d–d transition within the t_2g subshell associated with the intensity enhancement and the newly appeared vibronic bands around (16.0–18.0) × 10³ cm⁻¹ were due to the metal–ligand charge transfer [t_2g–SOMO(π*) MLCT] transitions. The change of their spectroscopic characteristics with varying the β-diketonato ligands is discussed in connection with the antiferromagnetic coupling constant J values on the basis of the exchange mechanism along with the coligand effect. The luminescence spectra which show a large Stokes shift suggest the antiferromagnetic interaction in the lowest excited states originates from the ²E or ²T₁ level of the Cr(III) moiety.