Mapping of N-C Bond Formation from a Series of Crystalline Peri-Substituted Naphthalenes by Charge Density and Solid-State NMR Methodologies
Mapping of N-C Bond Formation from a Series of Crystalline Peri-Substituted Naphthalenes by Charge Density and Solid-State NMR Methodologies
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通过电荷密度和固态 NMR 方法绘制一系列结晶邻位取代萘的 N-C 键形成图
DOI：
10.1002/ange.202111100
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发表时间：
2021
影响因子：
--
通讯作者：
Rees G
中科院分区：
文献类型：
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作者：
Rees G
电荷密度研究和固态核磁共振（NMR）耦合测量相结合，由周期密度泛函理论（DFT）计算支持，用于表征一系列晶体邻取代萘中亲核氮原子和亲电碳原子之间从n -π *相互作用到键形成的转变。随着N·⋅⋅C距离的减小，在N·⋅⋅C = 1.8 Å处，两基团之间电荷密度的增加导致了拉普拉斯量的急剧下降，周期DFT计算预测了这一点，异核自旋回波NMR测量证实了这一点，长C - N键的1jncoupling为≈3-6 Hz （1.60-1.65 Å），而N·⋅⋅C >2.1 Å的1jncoupling为<1 Hz。
A combination of charge density studies and solid state nuclear magnetic resonance (NMR)1JNCcoupling measurements supported by periodic density functional theory (DFT) calculations is used to characterise the transition from an n–π* interaction to bond formation between a nucleophilic nitrogen atom and an electrophilicsp2carbon atom in a series of crystalline peri‐substituted naphthalenes. As the N⋅⋅⋅C distance reduces there is a sharp decrease in the Laplacian derived from increasing charge density between the two groups at ca. N⋅⋅⋅C = 1.8 Å, with the periodic DFT calculations predicting, and heteronuclear spin‐echo NMR measurements confirming, the1JNCcouplings of ≈3–6 Hz for long C−N bonds (1.60–1.65 Å), and1JNCcouplings of <1 Hz for N⋅⋅⋅C >2.1 Å.