The crystal structure of l‐valyl‐l‐leucine acetonitrile solvate presented here adds to 24 previously reported structures of dipeptides constructed from the five nonpolar amino acids l‐alanine, l‐valine, l‐isoleucine, l‐leucine and l‐phenylalanine. It thus constitutes the final piece in the 5 × 5 puzzle of hydrophobic dipeptide structures. This opportunity is taken to review the crystal packing arrangements and hydrogen‐bonding preferences of a rather unique group of substances, with updated information on the various hydrogen‐bonding patterns and the associated peptide conformations.

中文翻译：

---

疏水二肽：难题的最后一部分。

此处介绍的l-缬氨酸-l-亮氨酸乙腈溶剂化物的晶体结构增加了先前报道的由5种非极性氨基酸l-丙氨酸，l-缬氨酸，l-异亮氨酸，l-亮氨酸和l-苯丙氨酸构成的二肽结构。因此，它构成了疏水性二肽结构的5×5难题中的最后一块。借此机会回顾了一组相当独特的物质的晶体堆积安排和氢键偏好，并提供了有关各种氢键模式和相关肽构象的最新信息。