Luminescence and photochemistry of transition metal complexes. I. Studies of temperature dependence of tervalent chromium complexes with oxygen-, nitrogen-, and carbon-coordinated ligands

Abstract

Experimental investigations of the luminescence exhibited by a range of tervalent chromium complexes are reported. The effects of the coordinated ligand on the temperature dependence of phosphorescence are examined and rationalized in terms of the ⁴T₂-²E energy interval. In the case of hexaureachromium complexes which emit both phosphorescence and fluorescence the varying emission intensities observed for compounds with a variety of anions are interpreted in terms of competition between the non-radiative thermal repopulation process ²E ~~→ ⁴T₂ and the radiative processes ²E → ⁴A₂, ⁴T₂ → ⁴A₂.