The behavior of 1,3,3-trimethylspiro[indoline-2,3`-2H-naphtho[2,1-b][1,4]oxazine under plastic deformation was studied on high-pressure Bridgman anvil-type apparatus at 0.53 4 GPa and room temperature.High pressures strongly modify various solids, e.g., cause an insulator3conductor transition, unusual chemical processes, changes in phase diagrams, etc. Substances subjected to high pressures are often exposed to shear stresses responsible for plastic deformations substantially affecting their behavior. A combined effect of high pressures and shear deformations on substances is strongly manifested in the case of high-pressure Bridgman anvil-type apparatus. In particular, various chemical reactions were revealed in the absence of initiators and catalysts for many classes of organic compounds. This suggests an electronic excitation of substances under such impacts. The rate of chemical processes under plastic deformations at high pressures is very weakly dependent on temperature, which supports the athermal mechanism of excitation of chemical transformations.In the context of studying the excitation mechanisms of the electronic subsystem of solids under mechanical impacts, of much interest are organic reactions that can be photochemically initiated under ordinary conditions. For such systems, the positions of the ground and excited levels of the reacting molecules, the transition energies, and transformation pathways of the excited states are well understood. We have applied such an approach to a study of the behavior of linear annelated aromatic compounds [1]. It was shown that, under plastic deformation at high pressures, only 20% of the energy required for a chemical reaction to occur in the substances under study is due to high pressures, and the remainder comes from plastic deformation. In [2], we analyzed the baric dependences of a purely mechanical characteristic of solids (flow stress) for a wide variety of organic compounds and found that such dependences can be correlated with the processes occurring in the electronic subsystem of organic substances.Another class of organic compounds whose photochemical transformations in solutions and polymer films are well understood are photochromes and, in particular, spiropyrans and spirooxazines [3 3 6]. Under photoirradiation in solution, they acquire a predominantly dark blue color (l max~6 00 nm and over) owing to a transition of the molecule from a colorless initial state A with opening of the spiro bond into a colored merocyanine form B: