Introduction of clutch function into a molecular gear system by silane-silicate interconversion

Area of Science:

• Molecular Chemistry
• Supramolecular Chemistry
• Materials Science

Background:

• Development of molecular machines and gear systems is crucial for nanotechnology.
• Previous molecular gears faced challenges in controlled rotation and separation of isomers.

Purpose of the Study:

• To introduce a clutch-declutch mechanism into a molecular gear system.
• To investigate the properties and behavior of a novel bis(4-methyl-9-triptycyl)difluorosilane based system.

Main Methods:

• Synthesis of bis(4-methyl-9-triptycyl)difluorosilane and its fluorosilicate derivative.
• Analysis of gear slippage process using thermodynamic parameters (enthalpy and entropy of activation).
• Investigation of structural properties in solid-state and solution using techniques like NMR spectroscopy (implied).

Main Results:

• The molecular gear system (1) functions in solution at room temperature despite inseparable phase isomers.
• Reversible attachment of fluoride ion forms a fluorosilicate (2) with an unusual trigonal bipyramidal structure.
• Rotation of triptycyl groups in silicate 2 is facile and independent in solution.
• Silicate 2 can be reverted to silane 1 by treatment with water.

Conclusions:

• The developed system successfully implements a reversible clutch-declutch mechanism for molecular gears.
• The unique structure and dynamic behavior of the fluorosilicate intermediate are highlighted.
• This work provides insights into the design and control of molecular mechanical systems.