The ground‐state deprotection of a simple alkynylsilane is studied under vibrational strong coupling to the zero‐point fluctuations, or vacuum electromagnetic field, of a resonant IR microfluidic cavity. The reaction rate decreased by a factor of up to 5.5 when the Si−C vibrational stretching modes of the reactant were strongly coupled. The relative change in the reaction rate under strong coupling depends on the Rabi splitting energy. Product analysis by GC‐MS confirmed the kinetic results. Temperature dependence shows that the activation enthalpy and entropy change significantly, suggesting that the transition state is modified from an associative to a dissociative type. These findings show that vibrational strong coupling provides a powerful approach for modifying and controlling chemical landscapes and for understanding reaction mechanisms.

Light–matter strong coupling allows for the possibility of entangling the wave functions of different molecules through the light field. We hereby present direct evidence of non‐radiative energy transfer well beyond the Förster limit for spatially separated donor and acceptor cyanine dyes strongly coupled to a cavity. The transient dynamics and the static spectra show an energy transfer efficiency approaching 37 % for donor–acceptor distances ≥100 nm. In such systems, the energy transfer process becomes independent of distance as long as the coupling strength is maintained. This is consistent with the entangled and delocalized nature of the polaritonic states.

A simple and robust route is described to the synthesis of single‐crystal Au nanospheres with diameters controlled in the range of 5 nm to 150 nm. The success of this synthesis relies on the use of single‐crystal Au spheres with different diameters as the seeds for successive growth and the use of a slow injection rate for the precursor to enable surface diffusion for the atoms added onto the surface of a seed. The diameters could be precisely controlled by varying the size and/or number of the seeds. The products exhibit excellent uniformity in terms of both size and shape and they are expected to find widespread use in a number of applications, including self‐assembly, fabrication of metallodielectric photonic crystals, plasmonics, and biomedical research.

Here we report the synthesis of Pd@Cu core-shell nanocubes via epitaxial growth, where the lattice mismatch is 7.1%. The synthesis involved the use of Pd seeds with different shapes (including cubes, cuboctahedra, and octahedra) for the epitaxial growth of Cu shells. Different from the conventional growth mode, Cu atoms initially nucleated only on a few of the many faces of a Pd seed, onto which more Cu atoms were continuously added to generate Cu blocks. Later, the Cu atoms also started to nucleate and grow on other faces of the Pd seed until the entire surface of the seed was covered by a Cu shell. As a result, the Pd seed was rarely located in the center of each core-shell structure. The final product took a cubic shape enclosed by {100} facets regardless of the type of Pd seeds used because of the selective capping of Cu(100) surface by hexadecylamine. The edge lengths of the Pd@Cu nanocubes could be tuned from 50 to 100 nm by varying the amount of Pd seeds while keeping the amount of CuCl(2) precursor.

We present direct evidence of enhanced non-radiative energy transfer between two J-aggregated cyanine dyes strongly coupled to the vacuum field of a cavity. Excitation spectroscopy and femtosecond pump-probe measurements show that the energy transfer is highly efficient when both the donor and acceptor form light-matter hybrid states with the vacuum field. The rate of energy transfer is increased by a factor of seven under those conditions as compared to the normal situation outside the cavity, with a corresponding effect on the energy transfer efficiency. The delocalized hybrid states connect the donor and acceptor molecules and clearly play the role of a bridge to enhance the rate of energy transfer. This finding has fundamental implications for coherent energy transport and light-energy harvesting.

The ground-state deprotection of as imple alkynylsilane is studied under vibrational strong coupling to the zeropoint fluctuations,orv acuum electromagnetic field, of aresonant IR microfluidic cavity.T he reaction rate decreased by af actor of up to 5.5 when the Si À Cv ibrational stretching modes of the reactant were strongly coupled. The relative change in the reaction rate under strong coupling depends on the Rabi splitting energy.P roduct analysis by GC-MS confirmed the kinetic results.T emperature dependence shows that the activation enthalpya nd entropyc hanges ignificantly, suggesting that the transition state is modified from an associative to ad issociative type.T hese findings show that vibrational strong coupling provides ap owerful approach for modifying and controlling chemical landscapes and for understanding reaction mechanisms.

We present direct evidence of enhanced non-radiative energy transfer between two J-aggregated cyanine dyes strongly coupled to the vacuum field of ac avity.E xcitation spectroscopya nd femtosecond pump-probe measurements show that the energy transfer is highly efficient when both the donor and acceptor form light-matter hybrid states with the vacuum field. The rate of energy transfer is increased by af actor of seven under those conditions as compared to the normal situation outside the cavity,w ith ac orresponding effect on the energy transfer efficiency.T he delocalized hybrid states connect the donor and acceptor molecules and clearly play the role of abridge to enhance the rate of energy transfer.T his finding has fundamental implications for coherent energy transport and light-energy harvesting.When an exciton transition and aresonant optical mode exchange energy faster than any competing dissipation process,itcan lead to light-matter strong coupling and the generation of two new hybrid (polaritonic) eigenstates,P + and PÀ,s eparated by the so-called Rabi splitting ( Figure 1a). This brings about interesting properties possessed by neither the original exciton or the optical mode, [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19] and leads to new possibilities,such as modified chemical reactivity, [5,6] and enhanced conductivity of organic semiconductors. [9] In the latter case,the enhancement stems from the delocalized nature of the hybrid states over the spatial extent of the optical mode [10,11] which is expected to affect energy transport according to recent theoretical studies. [12,13] In this context, it is interesting to consider how such hybrid states would affect energy transfer between donor and acceptor molecules.Energy transfer is anon-radiative process which has been extensively studied over the last century and typically involves either Coulombic interactions (Fçrster) or electronic exchange (Dexter). [20] Ak ey confirmation of energy transfer is of course ar eduction in the lifetime of the donor concomitant with the rise of the acceptor excited state population. Other factors that affect energy transfer include molecular aggregation, the presence of bridges between the donor and acceptor,a nd the density of optical states. [20][21][22][23][24][25] Strong coupling could provide an alternate effective path for energy transfer in analogy with chemically bridged donors and acceptors where the linker mediates the interactions by an effective overlap between the wave functions of both the donor and the acceptor.I nt he strong coupling case,i ti st he polaritonic states which are by construction either donor or acceptor-like that mediates the interactions in the system due to their delocalized nature.R ecently,e nergy transfer under strong coupling based on steady-state fluorescence excitation spectroscopy of the acceptor was studied. [17] However no Figure 1. a) Schematic representation of strong coupling successively with the donor resonant with acavity mode " hw c ,and then the a...

Supramolecular organic nanowires are ideal nanostructures for optoelectronics because they exhibit both efficient exciton generation as a result of their high absorption coefficient and remarkable light sensitivity due to the low number of grain boundaries and high surface-to-volume ratio. To harvest photocurrent directly from supramolecular nanowires it is necessary to wire them up with nanoelectrodes that possess different work functions. However, devising strategies that can connect multiple nanowires at the same time has been challenging. Here, we report a general approach to simultaneously integrate hundreds of supramolecular nanowires of N,N'-dioctyl-3,4,9,10-perylenedicarboximide (PTCDI-C8) in a hexagonal nanomesh scaffold with asymmetric nanoelectrodes. Optimized PTCDI-C8 nanowire photovoltaic devices exhibit a signal-to-noise ratio approaching 10, a photoresponse time as fast as 10 ns and an external quantum efficiency >55%. This nanomesh scaffold can also be used to investigate the fundamental mechanism of photoelectrical conversion in other low-dimensional semiconducting nanostructures.