Study of Nucleophilicity in the Gas Phase

气相亲核性的研究

• 批准号: 05640672
• 负责人: MISHIMA Masaaki
• 金额: $ 1.54万
• 依托单位: KYUSHU UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1993
• 资助国家: 日本
• 起止时间: 1993 至 1994
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-05640672/
• 关键词: Gas-phase Basicity; Lewis Acid Adduct Ion; Substituent Effect; FT-ICR; Silyl Cation; Electron Affinity; Anilines; Electron-transfer Equilibrium; ラジカルアニオン; 共鳴要求度

(1) Gas phase basicities of substituted anilines toward trimethylsilyl cation have been determined by measuring trimethylsilyl cation transfer equilibria using a FT-ICR-The substituent effect on trimethylsilyl cation basicity of aniline is found to be similar to the corresponding substituent effect on proton basicity, suggesting that the Si-N bond has high covalent character. This result is consistent with that observed for acetophenone series. On the other hand, the substituent effect for Me_3Si^+basicities of stirenes was characterized by a small rho value with reduced resonance demand, suggesting that the structure of Me_3Si^+ adduct ion of stirenes with is not a open structure but a non-classical bridged one.Relative electron affinities have been determined for a series of benzene derivatives (benzaldehydes, acetophenones, methyl benzoates, and some nitrobenzenes) by measurement of electron-transfer equilibrium in the gas phase. Substituent effects on electron affinities of these systems have successfully been described in terms of the LArSR equation. It has been shown that resonance demand parameter (r) varies significantly with the system from 0.62 for nitrobenzene, via 1.11 for benzaldehyde, to 1.29 for methyl benzoate series. The stability of a parent radical anion (ring-substituent=H) decreases in the opposite order. This trend of resonance demand is consistent with that for acidities of phenols, nilines, and toluenes, suggesting that the added electron in the SOMO of radical anions is delocalized into the aromatic ring in the same manner as that of pi-electron in the HOMO of an even-electron anion system.

(1)用FT-ICR测定了三甲基硅基阳离子的转移平衡，测定了取代苯胺对三甲基硅基阳离子的气相碱性。取代基对苯胺三甲基硅基阳离子碱性的影响与相应的取代基对质子碱性的影响相似，表明苯胺的Si-N键具有高的共价性。该结果与苯乙酮系列的观察结果一致。取代基效应对苯乙烯Me_3Si^+碱性的影响表现为Rho值较小，共振需量降低，表明苯乙烯Me_3Si^+加合离子的结构不是开放结构，而是非经典桥联结构（苯甲醛、苯乙酮、苯甲酸甲酯和一些硝基苯）的测定。取代基对这些系统的电子亲合势的影响已成功地描述在LArSR方程。结果表明，共振需求参数（r）随体系的变化很大，硝基苯为0.62，苯甲醛为1.11，苯甲酸甲酯为1.29。母体自由基阴离子（环取代基=H）的稳定性以相反的顺序降低。这种共振需求的趋势是一致的，为酸性的苯酚，苯胺，和甲苯，这表明在SOMO自由基阴离子的电子离域到芳环中的方式相同的π电子在HOMO的偶电子阴离子系统。

项目成果

M.Fujio: "The Importance of Resonance Stabilization in the Benzylic Solvolysis.Substituent Effects on the Solvolysis alpha,alpha-Diipropylbenzyl Chlorides" Tetrahedron Lett.34. 8309-8312 (1993)

M.Fujio：“苯甲基溶剂分解中共振稳定性的重要性。取代基对溶剂分解 α,α-二丙基苄基氯的影响”四面体 Lett.34。

M.Sawada,Y.Okumura,Y.Takai,S.Takahashi,M.Mishima,and Y.Tsuno: "Trimethylsilyl Cation Affinities to Permethylated Monosaccharids and Simple Crown Ethers in the Gas Phase Using ICR Mass Spectrometry.An Interconnection with FAB Ionization Mechanism" J.Mass S

M.Sawada、Y.Okumura、Y.Takai、S.Takahashi、M.Mishima 和 Y.Tsuno：“使用 ICR 质谱法在气相中对全甲基化单糖和简单冠醚的三甲基甲硅烷基阳离子亲和力。与 FAB 电离的互连

J.P.Richard, V.Jagannadham, T.L.Amyes, M.Mishima, and Y.Tsuno: ""A Comparison of Substituent Effects on the Stability of alpha, alpha-Dimethylbenzyl Carbocations in Aqueous Solution and in the Gas Phase : How Significant Is Nucleophilic Solvation? "" J.Am

J.P.Richard、V.Jagannadham、T.L.Amyes、M.Mishima 和 Y.Tsuno：“取代基对水溶液和气相中 α, α-二甲基苄基碳阳离子稳定性的影响的比较：亲核溶剂化有多重要

J.P.Richard,V.Jagannadham,T.L.Amyes,M.Mishima,Y.Tsuno: "A Comparison of SubstituentEffects on the Stability of α,α-Dimethybenzyl carbocations in Aqueous Solution and in the Gas Phase:How Significant Is Nucleophilic Solvation?" J.Am.Chem.Soc.,. 116. 6706-6

J.P.Richard、V.Jagannadham、T.L.Amyes、M.Mishima、Y.Tsuno：“取代基对水溶液和气相中 α,α-二甲基苄基碳阳离子稳定性的影响：亲核溶剂化有多重要？” .美国化学学会，116。6706-6

S.Kobayashi: "Gas Phase Basicities of 1-Phenylpropynes Thermodynamic Stabilities of 1-Phenylpropenyl Cations and Resonance Demand" Tetrahedron Lett.34. 5903-5906 (1993)

S.Kobayashi：“1-苯基丙炔的气相碱基、1-苯基丙烯基阳离子的热力学稳定性和共振需求”Tetrahedron Lett.34。