Conformational diversity of 1-phenylpiperidin-4-one in the gas phase
Conformational diversity of 1-phenylpiperidin-4-one in the gas phase
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DOI：
10.1016/j.cplett.2022.139851
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发表时间：
2022-07-12
影响因子：
2.8
通讯作者：
Shlykov, Sergey A.
中科院分区：
文献类型：
--
作者：
Eroshin, Alexey V.;Phien, Tran Dinh;Shlykov, Sergey A.
取代的，饱和的环状酮（哌啶酮和环己酮）的构象偏好可能会偏离其无氧类似物。发现1-苯基哌啶-4-酮以几种形式存在，不仅芳基取代基的位置（轴向或赤道）不同，而且哌啶环本身的构型也不同：椅子-Eq，椅子-Ax和扭曲（Tw）。通过各种量子化学计算预测的气相中共存物种贡献的比率通过在337 K下对蒸气进行的同步气相电子衍射和质谱实验证实，证明与B3 LYP-D3/cc-pVTZ组合的最佳拟合：Eq：Ax：Tw = 55（13）：22（9）：23（10）vs. 40：35：25。
Conformational preferences of substituted, saturated cyclic ketones (piperidones and cyclohexanones) may deviate from those of their oxygenless analogues. 1-Phenylpiperidin-4-one was found to exist in several forms differing by not only position (axial or equatorial) of the aryl-substituent but also by a configuration of the piperidine cycle itself: chair-Eq, chair-Ax and twist (Tw). The ratios of the co-existing species contributions in gas phase predicted by various quantum chemical calculations were confirmed by synchronous gas-phase electron diffraction and mass spectrometric experiments carried out for the vapor at 337 K demonstrating a best fit with the B3LYP-D3/cc-pVTZ combination: Eq:Ax:Tw = 55(13):22(9):23(10) vs. 40:35:25.