@article{7301,
  abstract     = {Several problems arise at the O2 (positive) electrode in the Li-air battery, including solvent/electrode decomposition and electrode passivation by insulating Li2O2. Progress partially depends on exploring the basic electrochemistry of O2 reduction. Here we describe the effect of complexing-cations on the electrochemical reduction of O2 in DMSO in the presence and absence of a Li salt. The solubility of alkaline peroxides in DMSO is enhanced by the complexing-cations, consistent with their strong interaction with reduced O2. The complexing-cations also increase the rate of the 1-electron O2 reduction to O2•– by up to six-fold (k° = 2.4 ×10–3 to 1.5 × 10–2 cm s–1) whether or not Li+ ions are present. In the absence of Li+, the complexing-cations also promote the reduction of O2•– to O22–. In the presence of Li+ and complexing-cations, and despite the interaction of the reduced O2 with the latter, SERS confirms that the product is still Li2O2.},
  author       = {Li, Chunmei and Fontaine, Olivier and Freunberger, Stefan Alexander and Johnson, Lee and Grugeon, Sylvie and Laruelle, Stéphane and Bruce, Peter G. and Armand, Michel},
  issn         = {1932-7447},
  journal      = {The Journal of Physical Chemistry C},
  number       = {7},
  pages        = {3393--3401},
  publisher    = {ACS},
  title        = {{Aprotic Li–O2 battery: Influence of complexing agents on oxygen reduction in an aprotic solvent}},
  doi          = {10.1021/jp4093805},
  volume       = {118},
  year         = {2014},
}

@article{6370,
  abstract     = {The molecular and supramolecular origins of the superior nonlinear optical (NLO) properties observed in the organic phenolic triene material, OH1 (2-(3-(4-hydroxystyryl)-5,5-dimethylcyclohex-2-enylidene)malononitrile), are presented. The molecular charge-transfer distribution is topographically mapped, demonstrating that a uniformly delocalized passive electronic medium facilitates the charge-transfer between the phenolic electron donor and the cyano electron acceptors which lie at opposite ends of the molecule. Its ability to act as a “push–pull” π-conjugated molecule is quantified, relative to similar materials, by supporting empirical calculations; these include bond-length alternation and harmonic-oscillator stabilization energy (HOSE) tests. Such tests, together with frontier molecular orbital considerations, reveal that OH1 can exist readily in its aromatic (neutral) or quinoidal (charge-separated) state, thereby overcoming the “nonlinearity-thermal stability trade-off”. The HOSE calculation also reveals a correlation between the quinoidal resonance contribution to the overall structure of OH1 and the UV–vis absorption peak wavelength in the wider family of configurationally locked polyene framework materials. Solid-state tensorial coefficients of the molecular dipole, polarizability, and the first hyperpolarizability for OH1 are derived from the first-, second-, and third-order electronic moments of the experimental charge-density distribution. The overall solid-state molecular dipole moment is compared with those from gas-phase calculations, revealing that crystal field effects are very significant in OH1. The solid-state hyperpolarizability derived from this charge-density study affords good agreement with gas-phase calculations as well as optical measurements based on hyper-Rayleigh scattering (HRS) and electric-field-induced second harmonic (EFISH) generation. This lends support to the further use of charge-density studies to calculate solid-state hyperpolarizability coefficients in other organic NLO materials. Finally, this charge-density study is also employed to provide an advanced classification of hydrogen bonds in OH1, which requires more stringent criteria than those from conventional structure analysis. As a result, only the strongest OH···NC interaction is so classified as a true hydrogen bond. Indeed, it is this electrostatic interaction that influences the molecular charge transfer: the other four, weaker, nonbonded contacts nonetheless affect the crystal packing. Overall, the establishment of these structure–property relationships lays a blueprint for designing further, more NLO efficient, materials in this industrially leading organic family of compounds.},
  author       = {Lin, Tze-Chia and Cole, Jacqueline M. and Higginbotham, Andrew P and Edwards, Alison J. and Piltz, Ross O. and Pérez-Moreno, Javier and Seo, Ji-Youn and Lee, Seung-Chul and Clays, Koen and Kwon, O-Pil},
  issn         = {1932-7447},
  journal      = {The Journal of Physical Chemistry C},
  number       = {18},
  pages        = {9416--9430},
  publisher    = {American Chemical Society (ACS)},
  title        = {{Molecular origins of the high-performance nonlinear optical susceptibility in a phenolic polyene chromophore: Electron density distributions, hydrogen bonding, and ab initio calculations}},
  doi          = {10.1021/jp400648q},
  volume       = {117},
  year         = {2013},
}