Suchergebnisse

The second law of photochemistry states that, in most cases, no more than one molecule is activated for an excited-state reaction for each photon absorbed by a collection of molecules. In this Letter, we demonstrate that it is possible to trigger a many-molecule reaction using only one photon by strongly coupling the molecular ensemble to a confined light mode. The collective nature of the resulting hybrid states of the system (the so-called polaritons) leads to the formation of a polaritonic "supermolecule" involving the degrees of freedom of all molecules, opening a reaction path on which all involved molecules undergo a chemical transformation. We theoretically investigate the system conditions for this effect to take place and be enhanced. ; This work has been funded by the European Research Council under Grants No. ERC-2011-AdG-290981 and No. ERC- 2016-STG-714870, by the European Union Seventh Framework Programme under Grant No. FP7-PEOPLE- 2013-CIG-618229, and the Spanish MINECO under Contract No. MAT2014-53432-C5-5-R and the "María de Maeztu" program for Units of Excellence in R&D (MDM-2014-0377).

This document is the Accepted Manuscript version of a Published Work that appeared in final form in ACS Photonics, copyright © 2017 American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see http://doi.org/10.1021/acsphotonics.7b00680 ; We present an overview of the general concepts of polaritonic chemistry with organic molecules, i.e., the manipulation of chemical structure that can be achieved through strong coupling between confined light modes and organic molecules. Strong coupling and the associated formation of polaritons, hybrid light-matter excitations, lead to energy shifts in such systems that can amount to a large fraction of the uncoupled transition energy. This has recently been shown to significantly alter the chemical structure of the coupled molecules, which opens the possibility to manipulate and control reactions. We discuss the current state of theory for describing these changes and present several applications, with a particular focus on the collective effects observed when many molecules are involved in strong coupling ; This work has been funded by the European Research Council under grant agreements ERC-2011-AdG-290981 and ERC-2016-STG- 714870, by the European Union Seventh Frame-work Programme under grant agreement FP7-PEOPLE-2013-CIG-618229, and the Spanish MINECO under contractMAT2014-53432-C5-5-R and the"María de Maeztu"programfor Units of Excellence in R&D (MDM-2014-0377).

In most theoretical descriptions of collective strong coupling of organic molecules to a cavity mode, the molecules are modeled as simple two-level systems. This picture fails to describe the rich structure provided by their internal rovibrational (nuclear) degrees of freedom. We investigate a first-principles model that fully takes into account both electronic and nuclear degrees of freedom, allowing an exploration of the phenomenon of strong coupling from an entirely new perspective. First, we demonstrate the limitations of applicability of the Born-Oppenheimer approximation in strongly coupled molecule-cavity structures. For the case of two molecules, we also show how dark states, which within the two-level picture are effectively decoupled from the cavity, are indeed affected by the formation of collective strong coupling. Finally, we discuss ground-state modifications in the ultrastrong-coupling regime and show that some molecular observables are affected by the collective coupling strength, while others depend only on the single-molecule coupling constant ; This work has been funded by the European Research Council (ERC-2011-AdG Proposal No. 290981), by the European Union Seventh Framework Programme under Grant Agreement FP7-PEOPLE-2013-CIG-618229, and the Spanish MINECO under Contracts No. MAT2011-28581-C02-01 and No. MAT2014-53432-C5-5-R