6533b824fe1ef96bd12814ac

RESEARCH PRODUCT

Autonomous artificial nanomotor powered by sunlight

Margherita VenturiAmar H. FloodAlberto CrediVincenzo BalzaniMiguel Clemente-leónMiguel Clemente-leónJ. Fraser StoddartBelén FerrerBelén Ferrer

subject

Models MolecularLuminescenceMagnetic Resonance SpectroscopyTime FactorsRotaxaneLightRotaxanesUltraviolet RaysPhotochemistryMovementMolecular ConformationElectronsPhotochemistryAbsorptionQUIMICA ORGANICAPhenothiazinesRotaxaneElectrochemistryNanotechnologyNanomotorAbsorption (electromagnetic radiation)Molecular machinePhotolysisMultidisciplinaryChemistrybusiness.industryMolecular Motor ProteinsPhotodissociationTemperatureLinear motorKineticsNanoscienceFluid solutionSpectrophotometryPhysical SciencesSunlightOptoelectronicsQuantum efficiencyElectronicsLuminescencebusinessSupramolecular chemistry

description

Light excitation powers the reversible shuttling movement of the ring component of a rotaxane between two stations located at a 1.3-nm distance on its dumbbell-shaped component. The photoinduced shuttling movement, which occurs in solution, is based on a “four-stroke” synchronized sequence of electronic and nuclear processes. At room temperature the deactivation time of the high-energy charge-transfer state obtained by light excitation is ≈10 μs, and the time period required for the ring-displacement process is on the order of 100 μs. The rotaxane behaves as an autonomous linear motor and operates with a quantum efficiency up to ≈12%. The investigated system is a unique example of an artificial linear nanomotor because it gathers together the following features: ( i ) it is powered by visible light (e.g., sunlight); ( ii ) it exhibits autonomous behavior, like motor proteins; ( iii ) it does not generate waste products; ( iv ) its operation can rely only on intramolecular processes, allowing in principle operation at the single-molecule level; ( v ) it can be driven at a frequency of 1 kHz; ( vi ) it works in mild environmental conditions (i.e., fluid solution at ambient temperature); and ( vii ) it is stable for at least 10 3 cycles.

10.1073/pnas.0509011103https://dx.doi.org/10.1073/pnas.0509011103