SCIENTIFIC HIGHLIGHTS

On the Operative Mechanism of Hole Assisted Negative Charge Motion in Ground States of Radical-anion Molecular Wires
21 March 2017

C. Franco, P. Mayorga Burrezo, V. Lloveras, R. Caballero, I. Alcón, S. Bromley, M. Mas-Torrent, F. Langa, J.T. López Navarrete, C. Rovira, J. Casado, J. Veciana. J. Am. Chem. Soc. 2017, 139, 686−692. DOI: 10.1021/jacs.6b08649

Operating mechanisms for unimolecular electron transfer/transport in the ground state of radical-anion mixed-valence derivatives occurring between their terminal perchlorotriphenylmethyl/ide groups through thiophene-vinylene oligomers that act as conjugated wires of increasing length up to 53 Å have been determined. The unique finding is that the net transport of the electron in the larger molecular wires is initiated by an electron-hole dissociation intermediated by hole delocalization (conformationally assisted and thermally dependent) forming mobile polaronic states in the bridge that terminate by an electron-hole recombination at the other wire extreme. On the contrary for the shorter radical-anions our results suggest that a flickering resonance mechanism which is intermediate between hopping and superexchange is the operative one. We support these mechanistic interpretations by applying the pertinent biased kinetic models of the charge/spin exchange rates determined by electron paramagnetic resonance and by molecular structural level information obtained from UV-Vis and Raman spectroscopies and by quantum chemical modelling. 

Hits: 4229
Oxides for new-generation electronics

On the Operative Mechanism of Hole Assisted Negative Charge Motion in Ground States of Radical-anion Molecular Wires



Also at ICMAB

  • Tuning the tilting of the spiral plane by Mn doping in YBaCuFeO5 multiferroic

    Information
    23 April 2021 83 hit(s) Oxides
    The layered perovskite YBaCuFeO5 (YBCFO) is considered one of the best candidates to high-temperature chiral multiferroics with strong magnetoelectric coupling. In RBaCuFeO5 perovskites (R: rare-earth or Y) A-site cations are fully ordered whereas their magnetic properties strongly depend on the preparation process. They exhibit partial cationic disorder at the B-site that generates a magnetic spiral stabilized through directionally assisted long range coupling between canted locally frustrated spins.
  • New Sensitive and Selective Chemical Sensors for Ni2+ and Cu2+ Ions: Insights into the Sensing Mechanism through DFT Methods

    Information
    09 April 2021 177 hit(s) Oxides
    We report the synthesis and theoretical study of two new colorimetric chemosensors with special selectivity and sensitivity to Ni2+ and Cu2+ ions over other metal cations in the CH3CN/H2O solution. Compounds (E)-4-((2-nitrophenyl)diazenyl)-N,N-bis(pyridin-2-ylmethyl)aniline (A) and (E)-4-((3-nitrophenyl)diazenyl)-N,N-bis(pyridin-2-ylmethyl)aniline (B) exhibited a drastic color change from yellow to colorless, which allows the detection of the mentioned metal cations through different techniques.
  • Silicon nanowires as acetone-adsorptive media for diabetes diagnosis

    Information
    06 April 2021 257 hit(s) Oxides
    Early detection of diabetes, a worldwide health issue, is key for its successful treatment. Acetone is a marker of diabetes, and efficient, non-invasive detection can be achieved with the use of nanotechnology. In this paper we investigate the effect of acetone adsorption on the electronic properties of silicon nanowires (SiNWs) by means of density functional theory.
  • Soft‐Chemistry‐Assisted On‐Chip Integration of Nanostructured α‐Quartz Microelectromechanical System

    Information
    30 March 2021 221 hit(s) Oxides
    The development of advanced piezoelectric α‐quartz microelectromechanical system (MEMS) for sensing and precise frequency control applications requires the nanostructuration and on‐chip integration of this material on silicon material.
  • Critical Effect of Bottom Electrode on Ferroelectricity of Epitaxial Hf0.5Zr0.5O2 Thin Films

    Information
    26 March 2021 258 hit(s) Oxides
    Epitaxial orthorhombic Hf0.5Zr0.5O2 (HZO) films on La0.67Sr0.33MnO3 (LSMO) electrodes show robust ferroelectricity, with high polarization, endurance and retention. However, no similar results have been achieved using other perovskite electrodes so far. Here, LSMO and other perovskite electrodes are compared.

INSTITUT DE CIÈNCIA DE MATERIALS DE BARCELONA, Copyright © 2020 ICMAB-CSIC | Privacy Policy | This email address is being protected from spambots. You need JavaScript enabled to view it.