Structural and thermodynamic characterization of temperature-dependent changes in the folding pattern of a synthetic triamide
作者:Gregory P. Dado、Samuel H. Gellman
DOI:10.1021/ja00063a046
日期:1993.5
1 H NMR and IR studies of triamide 1 and related compounds indicate that 1 undergoes dramatic temperature-dependent conformational changes in relatively nonpolar solvents (methylene chloride and chloroform). The foldingpattern favored at low temperatures in these chlorocarbons (1c) contains a single C=O---H-N hydrogen bond in a nine-membered ring, while a foldingpattern containing only a six-membered-ring
三酰胺 1 和相关化合物的变温 1 H NMR 和 IR 研究表明,1 在相对非极性的溶剂(二氯甲烷和氯仿)中会发生显着的温度依赖性构象变化。这些氯烃 (1c) 在低温下的折叠模式在九元环中包含单个 C=O---HN 氢键,而折叠模式仅包含一个六元环 C=O--- NH 相互作用(1a)在较高温度下是有利的。二甲基亚砜是一种非常强的氢键接受溶剂,会破坏 1 中的所有内部氢键。乙腈似乎可以选择性地破坏六元环氢键,并在室温下促进九元环相互作用,相对于氯烃而言溶剂