反式肉桂酸负离子模式质谱裂解脱羧机理的计算研究  

Study on the Mechanism of Decarboxylation for Trans-cinnamic Acid by Mass Spectrometry with Negative Mode

作　　者：方舟[1] 孙长海[2] 方芳[1] FANG Zhou;SUN Changhai;FANG Fang(The First Affiliated Hospital of Jiamusi University,Jiamusi 154003,China;College of Pharmacy,Jiamusi University,Jiamusi 154007,China)

机构地区：[1]佳木斯大学附属第一医院,黑龙江佳木斯154003 [2]佳木斯大学药学院,黑龙江佳木斯154007

出　　处：《海南师范大学学报（自然科学版）》2023年第2期217-222,236,共7页Journal of Hainan Normal University（Natural Science）

基　　金：黑龙江省卫生健康委科研项目(2020-326)。

摘　　要：采用密度泛函理论方法 RB3LYP/++6-311G(d,p)对反式肉桂酸负离子模式下质谱裂解脱羧机理进行了理论研究。计算结果表明,当外加能量得以满足时,反式肉桂酸可实现羧基化合物质谱不同的脱羧机制。反式肉桂酸质谱消除CO_(2)途径按去质子分子结构中的氢所经的状态可归为4类,即:氢均保持在原位碳上脱羧,侧链上β氢迁移到苯环后脱羧,β氢迁移至α碳上重排后脱羧,β氢与羧基氧结合经重排后脱羧。反式肉桂酸质谱裂解脱羧共计有5种可能途径,产生4种脱羧产物。脱羧的途径中,以去质子分子的氢保持在原位碳上并经1个过渡态的脱羧最具优势。脱羧产物中,以苯乙烯负离子能量最低、最为稳定。The mechanism of decarboxylation by mass spectrometry with negative mode for trans-cinnamic acid was studied by density functional theory method RB3LYP/++6-311g(d,p).The results showed that different decarboxylation mechanisms of carboxyl compounds can be achieved for trans-cinnamic acid when the applied energy is satisfied.According to the state of hydrogen in the deprotonated molecule structure,the elimination of CO2 by trans-cinnamic acid mass spectrometry can be classified into four categories:the decarboxylation was carried out with the hydrogen remaining on in-situ carbon;the decarboxylation was carried out afterβ-hydrogen on the side chain migrated to the benzene ring;the decarboxylation was carried out afterβ-hydrogen migrated toα-carbon and rearranged;the decarboxylation was carried out afterβ-hydrogen combined with carboxyl oxygen and rearranged.There were 5 possible ways of decarboxylation and 4 kinds of decarboxylation products produced for trans-cinnamic acid by mass spectrometry with negative mode.In the different decarboxylation pathways,the most advantageous pathway is the decarboxylation through one transition state with hydrogen remaining on in-situ carbon.Among the decarboxylation products,the styrene anion has the lowest energy and is the most stable.

关 键 词：反式肉桂酸 质谱裂解 脱羧 量化计算 

分 类 号：O657.63[理学—分析化学]