Polarized Crystal Spectra of Ni(NH3)4(NCS)2 and Ni(NH3)4(NO2)2

Abstract

The polarized crystal spectra of isostructural trans-Ni(NH3)4(NCS)2 and trans-Ni(NH3)4(NO2)2 have been determined at room temperature. In accordance with the spectrochemical series, the tetragonal splitting of the octahedral levels is virtually zero for the isothiocyanate and large for the nitrite. A vibronic intensity mechanism is invoked since the intensity is distributed in the polarization directions in the centro-symmetric crystals.