Department of Chemistry, King's College London, London SE1 1DB, United Kingdom.
J Phys Chem A. 2022 Sep 15;126(36):6185-6193. doi: 10.1021/acs.jpca.2c04855. Epub 2022 Aug 23.
The conformational landscape of the medium-size cyclic ketone cycloundecanone has been investigated using chirped-pulse Fourier transform microwave spectroscopy and computational calculations. Nine conformations were observed in the rotational spectrum and identified from the comparison of experimental and theoretical rotational constants as well as the observed and predicted types of rotational transitions. All singly substituted C isotopologues were observed for the most abundant conformer, which allowed the determination of partial substitution and effective structures. The most abundant conformer dominates the rotational spectrum and is almost 40 times more abundant than the least abundant conformer. Conformational preferences are governed by the combination of transannular H···H and eclipsed HCCH interactions.
采用啁啾脉冲傅里叶变换微波光谱学和计算计算研究了中尺度环状酮环十一酮的构象景观。在旋转光谱中观察到了九个构象，并通过实验和理论旋转常数的比较以及观察到和预测的旋转跃迁类型将其识别出来。最丰富的构象体观察到了所有单取代的 C 同素异形体，这允许确定部分取代和有效结构。最丰富的构象体主导着旋转光谱，其丰度几乎是最不丰富构象体的 40 倍。构象偏好受跨环 H···H 和重叠 HCCH 相互作用的组合控制。
