Abstract
Sultine is also regarded as the precursor for producing diradical molecule, o-xylene(4). Recently W.-S. Chung synthesize a series of sultine(14) which may be the derivative of 3,4-dimethylenethiophene(8), and then discuss the thermo-reaction related to them. According the result, the isomeric reaction between sultine and sulfolene(15) is discovered accompanied with thermo-reaction of sultine and Nucleophile. This thesis first focuses on the molecular properties and substituent effect of 3,4-dimethylenethiophene(8) by using of the Density Fuctinoal Theory(DFT) . Then the study for the process of isomeric reaction described above is followed. From the calculation(B3LYP/6-31++G**) results, we found that molecule 8 is a little more stable within its triplet than singlet configuration. About the substituent effect, the more powerful electron-withdrawing group is, the more possibility is to appear energy inversion among electronic configurations. As for the reaction, we can acquire three sketches involving interaction paths for photolysis reaction of 14 and 15, including triplet potential surface only(via intersystem crossing(ISC) to exchange different configurations, this path support the Prof. Chung’s idea), singlet potential surface only, and mixing different configuration potential surface. Finally it’ll be elucidated that the tautomerism of sultne(because of S=O position, see 14-axi and 14-equ).