turning short wave light into long wave visible light or for doubling or tripling the frequency of laser light in non linear optics l for tracer purposes e g in biochemistry medicine technology and natural science where the novel colorants can be linked covalently to the substrates or via secondary valences such as hydrogen bonds or hydrophobic interactions adsorption and m in highly sensitive detection processes see z analyt chem 1985 320 361 in particular as fluorescent colourants in scintillators for example the compounds of the present invention are used as high fluorescent colorants for coatings plastics and inks application especially in plastics and security printing inks other uses are in the biomedical area particularly medical imaging the fluorescent colorants of the present invention are either soluble or readily and evenly dispersed in a wide variety of solvents and polymers providing evenly colored systems which retain their color under aging or weathering conditions longer than commonly encountered dyes the fluorescence of these colored systems is much higher than systems colored by known pigments comprising similar chromophores and this fluorescence is likewise retained under aging or weathering conditions longer than commonly encountered fluorescent dyes the use of the fluorescent colorants of the present invention is not limited by the manner in which they are incorporated into the final application in any composition comprising the present fluorescent colorants one would naturally expect to find other commonly encountered components including stabilizers for example antioxidants uv absorbers hindered amine or other light stabilizers phosphites or phosphonites benzofuran 2 ones thiosynergists polyamide stabilizers metal stearates also other fluorescent materials processing aids solvents etc nucleating agents fillers reinforcing agents lubricants emulsifiers dyes.