Structural and Thermodynamic Characterization of Temperature-Dependent Changes in the Folding Pattern of a Synthetic Triamide
Structural and Thermodynamic Characterization of Temperature-Dependent Changes in the Folding Pattern of a Synthetic Triamide
复制标题
合成三酰胺折叠模式随温度变化的结构和热力学表征
DOI：
10.1002/chin.199340054
复制
发表时间：
1993
期刊：
影响因子：
--
通讯作者：
S. Gellman
中科院分区：
文献类型：
--
作者：
G. Dado;S. Gellman
变温1 H NMR和IR研究表明，三酰胺1和相关化合物1经历了显着的温度依赖性的构象变化，在相对非极性溶剂（二氯甲烷和氯仿）。这些氯代烃在低温下的折叠模式（1c）包含一个九元环中的C=O-H-N氢键，而在较高温度下的折叠模式（1a）只包含一个六元环C=O-N-H相互作用。二甲基亚砜是一种非常强的氢键接受溶剂，它破坏了1中所有的内部氢键。相对于氯代烃溶剂，乙腈似乎在室温下选择性地破坏六元环氢键并促进九元环相互作用
Variable-temperature 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 folding pattern favored at low temperatures in these chlorocarbons (1c) contains a single C=O---H-N hydrogen bond in a nine-membered ring, while a folding pattern containing only a six-membered-ring C=O---N-H interaction (1a) is favored at higher temperatures. Dimethyl sulfoxide, a very strong hydrogen-bond-accepting solvent, disrupts all internal hydrogen bonding in 1. Acetonitrile appears to disrupt the six-membered-ring hydrogen bond selectively and to promote nine-membered-ring interaction at room temperature, relative to chlorocarbon solvents