物理化学学报 >> 1989, Vol. 5 >> Issue (03): 340-347.doi: 10.3866/PKU.WHXB19890317

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光加成生成亚硝基甲醇机理的ab initio、CI和IRC研究

于建国; 刘若庄   

  1. 北京师范大学化学系量子化学研究室
  • 收稿日期:1988-03-30 修回日期:1989-01-17 发布日期:1989-06-15
  • 通讯作者:

Ab initio AND CI STUDIES ON MECHANISM AND REACTION PATH OF THE PHOTOCHEMICAL REACTION FOR THE FORMATION OF NITROSOMETHANOL

Yu Jianguo; Liu Ruozhuang   

  1. Quantum Chemistry Group; Department of Chemistry; Beijing Normal University; Beijing
  • Received:1988-03-30 Revised:1989-01-17 Published:1989-06-15
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摘要： HNO和CH_2O可在λ_(EXC)≥645 nm和λ_(EXC)=345 nm的光照射下, 生成顺式和反式亚硝基甲醇。对于这个光反应,实验工作者提出了两种机理。本文用ab initio方法(STO-3G基组), 通过求得反应的S_0、S_1和T_1态的过渡态及反应途径(IRC), 并用GUGA CI方法(基于图形酉群理论的CI方法)计算能量, 支持了实验提出的两种机理之一, 即在两种入射光照射下, 第一步都生成反式亚硝基甲醇, 在λ_(EXC)≥645 nm的入射光继续照射下, 第一步生成的反应产物光异构化为顺式的机理。

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Abstract: Two different mechanisms have been put experimently forward for the photoreaction, in which HNO and CH_2O under both irradiation conditions at λ_(EXC)≥645 nm or λ_(EXC)=345 nm can produce cis and trans nitrosomethanol. In present paper, we located the S_0, S_1 and T_1 transition state and traced the IRC's of the reaction based on the ab initio method with STO-3G basis set. Using the GUGA CI method, we also calculated reactive and exciting energies of the reaction system. Our theoretical results support one of the two possible mechanisms suggested by experimentalists. We showed that whether the reactants are irradiated by light of λ≥645 nm or by light of λ=345 nm, in the first step of the reaction, the product formed will be trans nitrosomethanol.