Differently coloured crystalline modifications of organic autocomplexes ofthe nitroaromatic type

The improved methods for preparation of the differently coloured crystallin e modifications of the organic intramolecular charge transfer complexes ( a utocomplexes), having electron acceptor fragments of the nitroaromatic type , have been developed. The preparation of the coloured modifications - yell ow, orange and red for N-( p-tolyl) -2,4,6-trinitroaniline - potential nonl inear optical material are carried out under carefully controlled condition s in different organic solvents or their mixtures. The crystalline modifica tions have been characterized by means IR-spectroscopic date; fluorescence properties of these are described.