Aromatic amides bearing 2-azulenyl group on the amide nitrogen were synthesized and their structures were investigated. The π-electron density of the N-aryl group was found to influence the cis-trans conformational preferences of these compounds in solution. X-ray crystallography revealed that the plane of the 2-azulenyl ring has a strong tendency to lie coplanar with the amide plane when the azulene group is located on the same side as the amide oxygen atom.

中文翻译：

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N-芳基-N-（2-氮烯基）乙酰胺的构象分析

合成了在酰胺氮上带有2-氮杂烯基的芳族酰胺，并对其结构进行了研究。发现N-芳基的π电子密度影响溶液中这些化合物的顺-反构象偏好。X射线晶体学表明，当氮杂基团与酰胺氧原子位于同一侧时，2-氮杂烯基环的平面具有很强的与酰胺平面共面的倾向。