Is the Smallest Molecular Trefoil Knot Actually the Tightest One?
Abstract
Abstract Tightness engineering has evolved as an efficient strategy for the design of knotted, woven, and entangled molecules and materials with desired properties and functions since tightness is a primary parameter that determines the property of a knotted strand. However, as an attractive topic that inspires mathematicians, physicists, chemists, and biologists, whether the smallest knot is exactly the tightest one remains unaddressed experimentally. To tackle this challenge, a series of organic trefoil knots with the backbone‐atom as short as 70 have been successfully synthesized by developing a new modular self‐assembly approach in this study. To our great surprise, with the help of gradient tandem mass spectrometry, the quantitative tightness evaluation suggested that the molecular trefoil knot with a backbone crossing ratio (BCR) of 24.0 is even tighter than the one with a BCR of 23.3 (i.e., the smallest organic trefoil knot with the shortest ropelength synthesized so far), thus demonstrating an unexpected yet interesting odd‐even effect to enhance the understanding of the tightness regulation of molecular knots.
Article Details
Authors (12)
Wei‐Tao Xu
School of Chemistry and Molecular Engineering East China Normal University Shanghai China
Chenxing Guo
College of Chemistry and Environmental Engineering Shenzhen University Shenzhen Guangdong 518060 China
Yefei Jiang
Shanghai Key Laboratory of Green Chemistry and Chemical Processes State Key Laboratory of Petroleum Molecular and Process Engineering School of Chemistry and Molecular Engineering East China Normal University Shanghai 200062 China
Wei‐Jian Li
Shanghai Key Laboratory of Green Chemistry and Chemical Processes State Key Laboratory of Petroleum Molecular and Process Engineering School of Chemistry and Molecular Engineering East China Normal University Shanghai 200062 China
Xiao‐Qin Xu
School of Chemistry and Molecular Engineering East China Normal University Shanghai China
Xue Li
Siqi Luo
Lianrui Hu
Shanghai Engineering Research Center of Molecular Therapeutics and New Drug Development, Shanghai Frontiers Science Center of Molecule Intelligent Syntheses, School of Chemistry and Molecular Engineering
Xiujun Yu
State Key Laboratory of Radio Frequency Heterogeneous Integration, College of Chemistry and Environmental Engineering
Xiaopeng Li
State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Lingling Road, Shanghai 200032, China
Hai‐Bo Yang
School of Chemistry and Molecular Engineering East China Normal University Shanghai China
Wei Wang