Abstract
The transient species involved in photocoloration and photobleaching of indoline
6-nitrosubstituted spiropyran solutions at room temperature were studied by
picosecond flash photolysis. Transient absorption spectrum of spiropyran colorless
form consists of two bands peaked at 440 and 585 nm and is assigned to the photoinduced
intermediate non-planar cis configuration with the breaked C—O bond of the
pyran ring. This transient is found to have the buildup time shorter than 10 ps and
initial decay times of about 10 ns in benzene and 5 ns in ethanol. The colored form
exhibits the transient absorption peaked at 460 nm with the lifetime of about 200 ps
in ethanol which is assigned to