Direct Observation of a Dark State in the Photocycle of a Light-Driven Molecular Motor
| Autor: | Arjen Cnossen, Sander Woutersen, Wybren Jan Buma, Saeed Amirjalayer, Ben L. Feringa, Wesley R. Browne |
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| Přispěvatelé: | Molecular Spectroscopy (HIMS, FNWI), HIMS Other Research (FNWI), Faculty of Science, Time-resolved vibrational spectroscopy, Synthetic Organic Chemistry, Molecular Inorganic Chemistry, Basic and Translational Research and Imaging Methodology Development in Groningen (BRIDGE) |
| Jazyk: | angličtina |
| Rok vydání: | 2016 |
| Předmět: |
ROTARY MOTOR
TRANSITION-METALS 010402 general chemistry Photochemistry 01 natural sciences VIBRATIONAL SPECTROSCOPY Article INFRARED-SPECTROSCOPY Molecular motor Physical and Theoretical Chemistry CONSISTENT BASIS-SETS DRUG-DELIVERY Spectroscopy Quantum PHOTOISOMERIZATION DYNAMICS 010405 organic chemistry Chemistry WORKING MECHANISM REAL-TIME CONICAL INTERSECTIONS Molecular machine 0104 chemical sciences Dark state Chemical physics Absorption band Excited state Transient (oscillation) |
| Zdroj: | The Journal of Physical Chemistry. A, 120(43), 8606-8612. American Chemical Society The Journal of Physical Chemistry. a The Journal of Physical Chemistry. A: Molecules, Spectroscopy, Kinetics, Environment, & General Theory, 120(43), 8606-8612. AMER CHEMICAL SOC |
| ISSN: | 1089-5639 |
| Popis: | Controlling the excited-state properties of light driven molecular machines is crucial to achieving high efficiency and directed functionality. A key challenge in achieving control lies in unravelling the complex photodynamics and especially in identifying the role played by dark states. Here we use the structure sensitivity and high time resolution of UV-pump/IR-probe spectroscopy to build a detailed and comprehensive model of the structural evolution of light driven molecular rotors. The photodynamics of these chiral overcrowded alkene derivatives are determined by two close-lying excited electronic states. The potential energy landscape of these "bright" and "dark" states gives rise to a broad excited-state electronic absorption band over the entire mid-IR range that is probed for the first time and modeled by quantum mechanical calculations. The transient IR vibrational fingerprints observed in our studies allow for an unambiguous identification of the identity of the "dark" electronic excited state from which the photon's energy is converted into motion, and thereby pave the way for tuning the quantum yield of future molecular rotors based on this structural motif. |
| Databáze: | OpenAIRE |
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