On time scales of a nanosecond or less, radiolytically-generated excess electrons in ionic liquids undergo solvation processes and reactions that determine all subsequent chemistry and the accumulation of radiolytic damage. Using picosecond pulse radiolysis detection methods, we observed and quantified the solvation response of the electron in 1-methyl-1-butyl-pyrrolidinium bis (trifluoromethylsulfonyl)amide and used it to understand electron scavenging by a typical solute, duroquinone.
In this paper we image the highly confined long range plasmons of a nanoscale metal stripe waveguide using quantum emitters. Plasmons were excited using a highly focused 633 nm laser beam and a specially designed grating structure to provide stronger incoupling to the desired mode. A homogeneous thin layer of quantum dots was used to image the near field intensity of the propagating plasmons on the waveguide. We observed that the photoluminescence is quenched when the QD to metal surface distance is less than 10 nm. The optimised spacer layer thickness for the stripe waveguides was found to be around 20 nm. Authors believe that the findings of this paper prove beneficial for the development of plasmonic devices utilising stripe waveguides.
The reduction and subsequent reactions of the series of mixed ligand cobalt(III) complex cations, [Co(bipy)3]3+, [Co(phen)3]3+, [Co(en)3]3+, [Co(en)2(bipy)]3+, [Co(en)2(phen)]3+, [Co(en)2(5-NO2-phen)]3+, [Co(en)2(DPPZ)]3+, [Co(bipy)2(NH3)2]3+, [Co(bipy)(NH3)4]3+, [Co(phen)2(NH3)2](ClO4)3]3+ and [Co(phen)(NH3)4]3+, (where bipy is 2,2′-bipyridine, phen is 1,10-phenanthroline, en is ethylenediamine, 5-NO2-phen is 5-nitro-1,10-phenanthroline and DPPZ is dipyrido[3,2-a:2′,3′-c]phenazine) have been studied using pulse radiolysis. The crystal structures of the mixed ligand complexes [Co(bipy)2(NH3)2](ClO4)3, [Co(bipy)(NH3)4]Cl0.5(ClO4)2.5, [Co(phen)2(NH3)2](ClO4)3 and [Co(phen)(NH3)4](ClO4)3, have been determined. The mechanism of reduction of the cobalt(III) centre by e−aq has been found to vary depending upon the nature of the ligands present in the complex. When an aromatic ligand is present the formation of a coordinated ligand radical is observed. This decays via intramolecular electron transfer to produce the cobalt(II) complex. The rate constants for the intramolecular electron transfer processes are of the order of 103–104 s−1. The rates of ligand dissociation of bidentate ligands from the resulting cobalt(II) complexes have been determined. The relative rates of the dissociation of the first ligand from the complexes is found to be dependent upon the identity of the ligand and is related to the ligand structure. For the dissociation of the same ligand from related complexes, the electronic structure of the complex becomes a factor.
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Pulse radiolysis and laser flash photolysis are complementary tools for studying fast reactions in ionic liquids. Both techniques have been used to study solvation processes in quaternary ammonium ionic liquids, which extend into the nanosecond regime and influence the reactivity and energetics of radiolytically-generated excess electrons. The preparation and properties of ionic liquid families designed to further these studies is reported.
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
The waveguide modes in chemically-grown silver nanowires on silicon nitride substrates are observed using spectrally- and spatially-resolved cathodoluminescence (CL) excited by high-energy electrons in a scanning electron microscope. The presence of a long-range, travelling surface plasmon mode modulates the coupling efficiency of the incident electron energy into the nanowires, which is observed as oscillations in the measured CL with the point of excitation by the focused electron beam. The experimental data are modeled using the theory of surface plasmon polariton modes in cylindrical metal waveguides, enabling the complex mode wavenumbers and excitation strength of the long-range surface plasmon mode to be extracted. The experiments yield insight into the energy transfer mechanisms between fast electrons and coherent oscillations in surface charge density in metal nanowires and the relative amplitudes of the radiative processes excited in the wire by the electron.
The three-dimensional morphological control of the individual metallic nanocrystals in a coupled structure imposes an electric field localization and enhancement in all three dimensions. We exploit the unique morphology of chemically synthesized nanotriangle monomers to form assembled dimers with a bowtie-like morphology in two orthogonal planes, effectively minimizing the volume of the interaction space to a point. The antenna has a longitudinal mode at 893 nm (1.39 eV), a 294 nm (0.68 eV) red shift compared to a monomer of equivalent size. This is indicative of extremely strong coupling because of the three-dimensional confinement of the electric field within the nanogap. By changing the geometry of the nanotriangle dimer, the longitudinal mode is tunable within a 220 nm (0.45 eV) range. The distribution of the electric field in the interparticle space transitions from a localized point for a bowtie to a more distributed line for an inverted bowtie.
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