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淡黄色的(E)-2,5-二甲基-3-呋喃乙叉(异丙叉)-丁二酸酐,1,在紫外光作用下同旋闭环生成深红色的闭环体,7,7,a-二氢苯骈呋喃-5,6-二羧酸酐,2,在Ar~+激光(515nm)作用下,2同旋开环成1,由于在2的分子中无1-位氢,因此不发生与光消色反应相竞争的1,5氢迁移反应。用Fischer的方法测定了光化学反应1→2的光化学转化率,发现转化率是100％,证明光发色反应是定量的。对于用Ar~+激光引起的光消色反应进行稳态的光化学分析处理,结果揭示在2的激发态和1的基态之间的某一个能级处有一个过渡态X,X分别以22.43ms~(-1)和1.11ms~(-1)的速率常数转变成化合物2和1,提出一个一般性的反应能量座标以解释俘精酸酐的光致色变过程,化合物1的光发色和光消色反应遵循两条不同的反应路线。
(E) -2,5-dimethyl-3-furan ethylidene (isopropylidene) - succinic anhydride, a dark red ring formed by the same ring with UV light, 7,7 , a-dihydrobenzofuran-5,6-dicarboxylic anhydride, 2, under the action of Ar ~ + laser (515nm), 2 is the same as the open ring to form a ring. Since there is no 1-position hydrogen in the molecule of 2, As a result, a 1,5 hydrogen migration reaction that competes with the optical decoloration does not occur. The photochemical conversion of photochemical reaction 1 → 2 was measured by Fischer’s method and the conversion was found to be 100%, demonstrating that the photochromic reaction was quantitative. The steady-state photochemical analysis of the photochromic reaction caused by the Ar ~ + laser revealed that there was a transitional state X at one of the energy levels between the excited state of 2 and the ground state of 1, with the values of 22.43 ms ~ (-1) and 1.11ms ~ (-1) were transformed into compounds 2 and 1, a general reaction energy coordinate was proposed to explain the photochromic process of fulgide. The photochromic behavior of compound 1 And light achromatic reactions follow two different reaction routes.