UCL  IRIS
Institutional Research Information Service
UCL Logo
Please report any queries concerning the funding data shown on the profile page to:

http://www.ucl.ac.uk/finance/secure/research/post_award
Please report any queries concerning the student data shown on the profile page to:

Email: portico-services@ucl.ac.uk

Help Desk: http://www.ucl.ac.uk/ras/portico/helpdesk
Publication Detail
Structure of pi-pi Interactions in Aromatic Liquids
  • Publication Type:
    Journal article
  • Publication Sub Type:
    Article
  • Authors:
    Headen TF, Howard CA, Skipper NT, Wilkinson MA, Bowron DT, Soper AK
  • Publisher:
    AMER CHEMICAL SOC
  • Publication date:
    28/04/2010
  • Pagination:
    5735, 5742
  • Journal:
    J AM CHEM SOC
  • Volume:
    132
  • Issue:
    16
  • Print ISSN:
    0002-7863
  • Language:
    EN
  • Keywords:
    X-RAY-DIFFRACTION, BENZENE DIMER, NEUTRON-DIFFRACTION, MOLECULAR-DYNAMICS, TOLUENE, RECOGNITION, PROTEINS, PHASE, MODEL, STABILIZATION
  • Addresses:
    Skipper, NT
    UCL
    London Ctr Nanotechnol
    Dept Phys & Astron
    London
    WC1E 6BT
    England

    Rutherford Appleton Lab
    ISIS Facil
    Didcot
    OX11 0QX
    Oxon
    England
Abstract
High-resolution neutron diffraction has been used in conjunction with hydrogen/deuterium isotopic labeling to determine with unprecedented detail the structure of two archetypal aromatic liquids: benzene and toluene. We discover the nature of aromatic pi-pi interactions in the liquid state by constructing for the first time a full six-dimensional spatial and orientational picture of these systems. We find that in each case the nearest neighbor coordination shell contains approximately 12 molecules. Benzene is the more structured of the two liquids, showing, for example, a sharper nearest neighbor coordination peak in the radial distribution function. Superficially the first neighbor shells appear isotropic, but our multidimensional analysis shows that the local orientational order in these liquids is much more complex. At small molecular separations (<5 angstrom) there is a preference for parallel pi-pi contacts in which the molecules are offset to mimic the interlayer structure of graphite. At larger separations (>5 angstrom) the neighboring aromatic rings are predominantly perpendicular, with two H atoms per molecule directed toward the acceptor's pi orbitals. The so-called "anti-hydrogen-bond" configuration, proposed as the global minimum for the benzene dimer, occurs only as a saddle point in our data. The observed liquid structures are therefore fundamentally different than those deduced from the molecular dimer energy surfaces.
Publication data is maintained in RPS. Visit https://rps.ucl.ac.uk
 More search options
UCL Authors
Dept of Physics & Astronomy
Dept of Physics & Astronomy
University College London - Gower Street - London - WC1E 6BT Tel:+44 (0)20 7679 2000

© UCL 1999–2011

Search by