Title
Single-handed supramolecular double helix of homochiral bis(N-amidothiourea) supported by double crossed C−I···S halogen bonds
Author
Xiaosheng Yan, Kunshan Zou, Jinlian Cao, Xiaorui Li, Zhixing Zhao, Zhao Li, Anan Wu, Wanzhen Liang, Yirong Mo, Yunbao Jiang
Year
2019
Journal
Nature Communications
Abstract
The natural DNA double helix consists of two strands of nucleotides that are held together by multiple hydrogen bonds. Here we propose to build an artificial double helix from fragments of two strands connected by covalent linkages therein, but with halogen bonding as the driving force for self-assembling the fragments to the double helix. We succeed in building such a double helix in both solution and solid state, by using a bilateral N-(p-iodobenzoyl)alanine based amidothiourea which in its folded cis-form allows double and crossed C−I···S halogen bonds that lead to right- or left-handed double helix when the two alanine residues are of the same L,L- or D,D-configuration. The double helix forms in dilute CH3CN solution of the micromolar concentration level, e.g., 5.6 μM from 2D NOESY experiments and exhibits a high thermal stability in solution up to 75 °C, suggesting cooperative and thereby strong intermolecular double crossed halogen bonding that makes the double helix stable. This is supported by the observed homochiral self-sorting in solution.
Full Article
Instrument
J-810
Keywords
Circular dichroism, Stereochemistry, Solid state, Biochemistry