order to study the chemiluminescent reaction mechanism of Cypridina luciferin, a series of 6-ar yl-2-methyllimidazo[ 1,2-a]pyrazin-3-(7H)-ketone rings based derivetives( named MlPa-MlPd) was chosen as studied objectives in this work. We employed the DFT//B3LYP/6-31G* method to calculate the activation energy and the fluorescence lifetime ( ι ) of the products in the reaction from the dioxetanones to amidopy-razines in the gas phase, dimethyl sulfoxide(DMSO) , and diglyme(DG). The calculated results indicate that Cypridina luciferin analogues possessing the electron-donating aryl group have lower activation energy ( △Ea ) and the solvent has significant effect on activation energy( △Ea) , which is lowest in DMSO. The fluorescence-quantum-yield of path Ⅱ is higher in DMSO than that in path I, but it reverses in DG.%选取海萤类似物6-芳基-2-甲基咪唑[1,2-α]吡嗪-3(7H)酮环的C6位取代物(命名为MIPa ～ MIPd)进行理论研究.采用密度泛涵理论B3LYP方法在气相和二甲亚砜(DMSO)及二甘醇二甲醚(DG)两种溶剂中,对这些类似物在脱去二氧化碳反应过程中所涉及的2个反应路径的反应活化能和产物激发态的荧光寿命进行了计算,结果表明,取代吡嗪酮的过氧化四元环在DMSO溶剂中的反应活化能较低,给电子基团作为取代基时反应更快.在DMSO溶剂中,路径Ⅱ的荧光量子效率比路径Ⅰ的高,但在DG溶剂中,路径Ⅰ的荧光效率高于路径Ⅱ的荧光效率.
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