SYNTHESIS AND 2ND-HARMONIC GENERATION PROPERTIES OF 2-(4-NITROANILINO)-1,3,5-TRIAZINE DERIVATIVES

The synthesis and non-linear optical properties of a series of 2-(4-ni troanilino)-1,3,5-triazine compounds are described. The triazines show various activities in powder second-harmonic generation (SHG) dependi ng on the structures and have absorption maxima at less-than-or-equal- to 350 nm, shorter by 30-50 nm than those of the parent nitroanilines. 2-(4-Nitroanilino)-4,6-diphenyl-1,3,5-triazine affords different crys talline materials depending on the recrystallization solvent. A crysta l formed by recrystallization from toluene reveals a high powder SHG a ctivity comparable with that of 2-methyl-4-nitroaniline, while recryst allization from N,N-dimethylformamide gives an SHG-inactive crystal in which solvent molecules are incorporated in a 1 : 1 ratio by hydrogen bonding. The crystal structure of the latter was determined.