Kinetic modelling of the photochromism and metal complexation of a spiropyran dye: Application to the Co(II) – Spiroindoline-diphenyloxazolebenzopyran system

New stable colored complex of Al3+ with 1',3',3'‐trimethylspiro[2H‐1‐benzopyran‐2,2'‐indoline] (BIPS)

“…The direct measurements attest to the fast reaction of the complex formation between metal ions and MC forms of spirocompounds in solutions . The onset time of the equilibrium () being equal to 1/( k 1 + k −1 ) is rather short (approximately ≤5 s).…”

Metal complexes of the merocyanine form of nitrobenzospyran: Structure, optical spectra, stability

“…and the spectra of the complexes were determined taking advantage that the relaxation times of the coupled reactions (2) and (3) of spyropyrans are widely different: the equilibrium state of (3) -the metal binding of merocyanines -is achieved instantaneously on the timescale of (2) -the interconversion of the SP and MC isomers [27,47]. The samples in these experiments were solutions of SP-1, which were UV irradiated, their spectra were monitored and at the moment when their MC concentration decayed to 10 À5 M, the salt solution was added in various total concentrations.…”

Symmetric Bis-Azospiropyrans: Synthesis, Characterization and Colorimetric Study

“…Close proximity of two CH 3 of indoline moieties (C(3)-(CH 3 ) 2 ) to the olefinic proton or oxygen moiety of the pyranyl group were made them magnetically non-equivalent. 7 A singlet signal appeared at 2.80-2.92 ppm (6H) for two N-CH 3 protons of 4a-e, which were chemically and magnetically equivalent. The olefinic protons of 4a-e revealed two doublets, one at 4.20-4.29 ppm for two H-C(3) with large coupling constants (J = 10.2-10.3 Hz), and the other for olefinic protons 2 H-C(4) at the aromatic regions.…”