摘要
A new spirooxazine,1,3,3,2′-tetramethy1-9′-methoxyspiro [-2H-indole-2,3′-[-3H] naphth[2,1-b] [-1,4′] oxazine] (Ⅰ) was synthesized.Its photochromic process was studied using nanosecond time-resolved absorption spectroscopy techniques.After irradiation of I with 248 nm laser pulse,a short-lived col-ored species with two absorption bands was observed.In cyclohexane the two bands appear at 470 nm and640 nm,while in acetonitrile at 460 nm and 670 nm.The kinetics for the decay of the colored species is first-order,and its lifetimes are 0.5 μs in cyclohexane and 1.3 μs in acetonitrile.From these results,this short-lived species is assumed to be an intramolecular charge-transfer (CT) intermediate instead of photomero-cyanines (PMC).No absorption band of PMC has been found.The phenomenoncan be interpreted by theproposed potential energy curve.
A new spirooxazine,1,3,3,2′-tetramethy1-9′-methoxyspiro [-2H-indole-2,3′-[-3H] naphth [2,1-b] [-1,4′] oxazine] (Ⅰ) was synthesized.Its photochromic process was studied using nanosecond time- resolved absorption spectroscopy techniques.After irradiation of I with 248 nm laser pulse,a short-lived col- ored species with two absorption bands was observed.In cyclohexane the two bands appear at 470 nm and 640 nm,while in acetonitrile at 460 nm and 670 nm.The kinetics for the decay of the colored species is first- order,and its lifetimes are 0.5 μs in cyclohexane and 1.3 μs in acetonitrile.From these results,this short- lived species is assumed to be an intramolecular charge-transfer (CT) intermediate instead of photomero- cyanines (PMC).No absorption band of PMC has been found.The phenomenoncan be interpreted by the proposed potential energy curve.
基金
the National Natural Science Foundation of China
partially supported by the Laboratory of Radiation Chemistry,Shanghai Institute of Nuclear Research.
