方 舟1
,孙长海2
,方 芳1*.反式肉桂酸负离子模式质谱裂解脱羧机理的
计算研究[J].海南师范大学学报自科版,2023,36(2):217-222 |
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 |
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DOI:10.12051/j.issn.1674-4942.2023.02.016 |
中文关键词: 反式肉桂酸 质谱裂解 脱羧 量化计算 |
英文关键词: trans-cinnamic acid mass spectrum fragmentation decarboxylation quantum chemical calculation |
基金项目:黑龙江省卫生健康委科研项目(2020-326) |
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中文摘要: |
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CO2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。 |
英文摘要: |
The mechanism of decarboxylation by mass spectrometry with negative mode for trans-cinnamic acid was stud‑
ied by density functional theory method RB3LYP/++6-311g (d, p). The results showed that different decarboxylation mecha‑
nisms 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 after β-hydrogen on the side chain migrated to the benzene ring; the decarboxylation was car‑
ried out after β-hydrogen migrated to α-carbon and rearranged; the decarboxylation was carried out after β-hydrogen com‑
bined 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 path‑
ways, 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. |
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