RARE EARTH METAL COMPLEXES THAT EXCITE IN THE LONG UV WAVELENGTH RANGE

摘要

There is provided rare earth metal complexes of formula (I): wherein M is a cation, RE is a rare earth metal; X is a counter anion; and R1 , R2 , R3 , and R4 are each independently selected from hydrogen, alkyl of 1 - 8 carbon atoms, aryl, halo, and alkoxy. Also provided is a composition of europium bis(2,2"-bipyridine- N.N")-trinitrate with a diketonate dopant. The disclosure also provides processes for preparing the rare earth metal complexes. A mark comprising the rare earth metal complexes, and a method of applying the mark, are disclosed. The rare earth metal complexes may be used in printing systems, and for security applications.