PHOTO- AND THERMOCHROMIC MANNICH BASES. 1. MANNICH BASES FROM 3,5-DI-tert-BUTYL-4-HYDROXYBENZALDEHYDE AND 2-NAPHTHOLS

Article abstract of DOI:10.1007/BF00863826

Mannich bases exhibiting photo- and thermochromic properties in solutions were synthesized from 3,5-di-tert-butyl-4-hydroxybenzaldehyde and 2-naphthols.An investigation of an acetyl derivative of methylenequinone, modeling a product of photo- and thermochromic transformations, proved that the color change of solutions of the Mannich bases is due to reversible dissociation into colored methylenequinones and morpholine.On the basis of data of x-ray diffraction analysis of one of the Mannich bases, characteristics of their molecular structure were determined, and reasons were stated for their effect on the dissociation mechanism.Keywords: synthesis, crystal structure, UV spectrum, 2,6-di-tert-butyl-4-<α-(2-hydroxy-1-naphthyl)methyl>phenol, 2,6-di-tert-butyl-4-<α-morpholino-α-(2-hydroxy-6-bromo-1-naphthyl)methyl>phenol, 2,6-di-tert-butyl-4-α-(2-hydroxy-1-naphthyl)-1,4-methylenequinone, 2,6-di-tert-butyl-4-α-(2-acetyloxy-1-naphthyl)-1,4-methylenequinone.