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Gourab Chatterjee Ajay Jha Alejandro Blanco-Gonzalez Vandana Tiwari Madushanka Manathunga Hong-Guang Duan Friedjof Tellkamp Valentyn I. Prokhorenko Nicolas Ferr Jyotishman Dasgupta Massimo Olivucci R. J. Dwayne Miller 《Chemical science》2022,13(32):9392
The concerted interplay between reactive nuclear and electronic motions in molecules actuates chemistry. Here, we demonstrate that out-of-plane torsional deformation and vibrational excitation of stretching motions in the electronic ground state modulate the charge-density distribution in a donor-bridge-acceptor molecule in solution. The vibrationally-induced change, visualised by transient absorption spectroscopy with a mid-infrared pump and a visible probe, is mechanistically resolved by ab initio molecular dynamics simulations. Mapping the potential energy landscape attributes the observed charge-coupled coherent nuclear motions to the population of the initial segment of a double-bond isomerization channel, also seen in biological molecules. Our results illustrate the pivotal role of pre-twisted molecular geometries in enhancing the transfer of vibrational energy to specific molecular modes, prior to thermal redistribution. This motivates the search for synthetic strategies towards achieving potentially new infrared-mediated chemistry.Channelling vibrational excitation energy to achieve ground-state charge-transfer (CT)-assisted isomerization in a donor-bridge-acceptor molecule in solution. 相似文献
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Talina R. Rusch Alexander Schlimm Nicolai R. Krekiehn Tobias Tellkamp imon Budzk Denis Jacquemin Felix Tuczek Rainer Herges Olaf M. Magnussen 《Angewandte Chemie (International ed. in English)》2020,59(39):17192-17196
Light‐induced transitions between the trans and cis isomer of triazatriangulenium‐based azobenzene derivatives on Au(111) surfaces were observed directly by scanning tunneling microscopy, allowing atomic‐scale studies of the photoisomerization kinetics. Although the azobenzene units in these adlayers are free‐standing and spaced at uniform distances of 1.26 nm, their photoswitching depends on the isomeric state of the surrounding molecules and, specifically, is accelerated by neighboring cis isomers. These collective effects are supported by ab initio calculations indicating that the electronic excitation preferably localizes on the n–π* state of trans isomers with neighboring cis azobenzenes. 相似文献
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Widukind Moormann Tobias Tellkamp Eduard Stadler Fynn Rhricht Christian Nther Rakesh Puttreddy Kari Rissanen Georg Gescheidt Rainer Herges 《Angewandte Chemie (International ed. in English)》2020,59(35):15081-15086
Photochromic systems have been used to achieve a number of engineering functions such as light energy conversion, molecular motors, pumps, actuators, and sensors. Key to practical applications is a high efficiency in the conversion of light to chemical energy, a rigid structure for the transmission of force to the environment, and directed motion during isomerization. We present a novel type of photochromic system (diindane diazocines) that converts visible light with an efficiency of 18 % to chemical energy. Quantum yields are exceptionally high with >70 % for the cis–trans isomerization and 90 % for the back‐reaction and thus higher than the biochemical system rhodopsin (64 %). Two diastereomers (meso and racemate) were obtained in only two steps in high yields. Both isomers are directional switches with high conversion rates (76–99 %). No fatigue was observed after several thousands of switching cycles in both systems. 相似文献
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Talina R. Rusch Alexander Schlimm Nicolai R. Krekiehn Tobias Tellkamp Dr. Šimon Budzák Prof. Denis Jacquemin Prof. Felix Tuczek Prof. Rainer Herges Prof. Olaf M. Magnussen 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(39):17345-17349
Light-induced transitions between the trans and cis isomer of triazatriangulenium-based azobenzene derivatives on Au(111) surfaces were observed directly by scanning tunneling microscopy, allowing atomic-scale studies of the photoisomerization kinetics. Although the azobenzene units in these adlayers are free-standing and spaced at uniform distances of 1.26 nm, their photoswitching depends on the isomeric state of the surrounding molecules and, specifically, is accelerated by neighboring cis isomers. These collective effects are supported by ab initio calculations indicating that the electronic excitation preferably localizes on the n–π* state of trans isomers with neighboring cis azobenzenes. 相似文献
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Teoman Gün Yury Kuzminykh Friedjof Tellkamp Klaus Petermann Günter Huber 《Applied Physics A: Materials Science & Processing》2008,93(2):387-391
In this contribution, we report on the 2-dimensional (2D) layer-by-layer growth of Yb(10%):Y3Al5O12 (YAG) and Yb3Al5O12 (YbAG) PLD-films on {100}-oriented YAG. The epitaxial growth was observed in situ by Reflection High Energy Electron Diffraction
(RHEED) as intensity oscillations of the specularly reflected electron beam. The properties of the films were investigated
ex situ by means of X-ray diffraction (XRD), atomic force microscopy (AFM), and optical spectroscopy. The optical emission
spectra of the films are similar to those of the corresponding crystalline bulk materials. 相似文献
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Alexander Schlimm Roland Lw Talina Rusch Fynn Rhricht Thomas Strunskus Tobias Tellkamp Frank Snnichsen Uwe Manthe Olaf Magnussen Felix Tuczek Rainer Herges 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(20):6646-6650
We report on a very unusual case of surface catalysis involving azobenzenes in contact with a Au(111) surface. A rate acceleration of the cis–trans isomerization on gold up to a factor of 1300 compared to solution is observed. By using carefully designed molecular frameworks, the electronic coupling to the surface can be systematically tuned. The isomerization kinetics of molecules with very weak coupling to the metal is similar to that found in solution. For their counterparts with strong coupling, the relaxation rate is shown to depend on the spin‐density distribution in the triplet states of the molecules. This suggests that an intersystem crossing is involved in the relaxation process. Aside from their impact on catalytic processes, these effects could be used to trigger reactions over long distances. 相似文献
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