The final limiting stage of structural simplification of photochromic Schiff base was reached by the following statement: two molecules, sa1icyli-dene methylamine and its butyl analogue, show transient absorption bands (at room temperature) peaking at 22000 cm 1 . These bands are characteristic of the phenomenon of photochromism. They are similar to the corresponding spectra detected earlier for several larger, symmetric systems belonging to tłe same family. Experimentał characterizatioii of both molecules was compared with the theoretical calculations: geometry optimizatioii and transition energies, performed for enol, keto, and the photochromic form of salicylidene methylamine.