Emission spectra transition metal complexes

The emission spectrum of Eu(4-MePy0)g(C104)3(H20)2 has been reported by Harrison and Watson (160). This spectrum was found to be identical to that reported byMelby etal. (146) for the complex Eu(4-MePy0)8(C104)3. On this basis, the water molecules in the hydrated complex are suggested to be noncoordinated. The transitions could be explained in terms of a )4d symmetry around the metal ion. The magnetically allowed SD0 - 1Fl transition occurs as the most intense band at 5915 A. 

X-ray line spectra are also produced by electronic transitions. In this case, however, the electrons involved are those in the innermost orbitals. Thus, in contrast to ultraviolet and visible emissions, the X-ray spectrum for an element is independent of its environment. For example, the emission spectrum for molybdenum is the same regardless of whether the sample being excited is molybdenum metal, solid molybdenum sulfide, gaseous molybdenum hexafluoride, or an aqueous solution of an anionic complex of the metal. 

---