Abstract: Photoreaction and thermal stability of the electron transfer photochromism system composed of N,N,N’,N’-tetramethyl-p-phenylenediamine (TMPD)/electron acceptor were studied in solutions and polymer films. Experimental results showed that this kind of photochromism system has high sensitivity of photoresponse. In the arylamine/onium salt (DPIOC) systems, it could be observed that rate of electron transfer increases with the decrease of oxidation potential of the arylamines, i.e., TMPD>DMA>TPA>DPA. The relationships between photoreac-tion rates and concentrations of reactants were obtained with exponents 0.66 (TMPD) and 0.16 (DPIOC) respectively. In TMPD/halogenated alkane systems, it could be found that halogena-ted alkanes having weaker C-X bonds exhibit higher rates of photochromism reaction, due to the decrease of back electron transfer reactions resulted from further decomposition of the reaction intermediate (RX^-). Efficiencies of photoinduced coloration in PMMA films are much higher than those in solutions. The thermal stability data indicated that the color stability is dependent significantly on the temperature, and coloration ability of the system reduces about a half via a circle of alternate photocoloration and thermal decoloration.

Key words: N,N’,N’-tetramethyl-p-phenylenediamine/acceptor, Photochromism, electron transfer