The ring current model of the pentaprismane molecule

Authors

  • Stefano Pelloni,

    1. Dipartimento di Chimica, dell'Università degli Studi di Modena, via Campi 183, 41100 Modena, Italy
    Search for more papers by this author
  • Raphaël Carion,

    Corresponding author
    1. Laboratoire de Chimie Théeorique, Unité de Chimie Physique Théorique et Structurale, Facultés Universitaires Notre-Dame de la Paix, rue de Bruxelles, 61, B-5000 Namur, Belgium
    • Laboratoire de Chimie Théeorique, Unité de Chimie Physique Théorique et Structurale, Facultés Universitaires Notre-Dame de la Paix, rue de Bruxelles, 61, B-5000 Namur, Belgium
    Search for more papers by this author
  • Vincent Liégeois,

    1. Laboratoire de Chimie Théeorique, Unité de Chimie Physique Théorique et Structurale, Facultés Universitaires Notre-Dame de la Paix, rue de Bruxelles, 61, B-5000 Namur, Belgium
    Search for more papers by this author
  • Paolo Lazzeretti

    1. Dipartimento di Chimica, dell'Università degli Studi di Modena, via Campi 183, 41100 Modena, Italy
    Search for more papers by this author

Abstract

Three-dimensional models of the quantum-mechanical current density JB, induced in the electron cloud of the C10H10 pentaprismane molecule by a magnetic field B applied along the C5 (a C2) symmetry axis, orthogonal to the pentagonal (a rectangular) face, and denoted by B (B), have been constructed. Predictions of near Hartree-Fock quality are reported for the diagonal components of magnetic tensors, magnetizability (ξ), nuclear shielding of carbon (σC) and hydrogen (σH), and virtual shielding at the center of mass (σCM). The complicated spatial features of the induced electronic current-density field have been rationalized and compactly described via stagnation graphs that elucidate the details of its topological structure. A representation of JB is obtained by three-dimensional perspective plots and by planar maps visualizing phase portraits of electron flow in a series of molecular domains. Both streamline JB/|JB| and modulus |JB| are analyzed. These graphic tools illustrate the competition between diatropic and paratropic regimes which determine the magnitude of various components of magnetizability and magnetic shielding of hydrogen and carbon nuclei. Shielding density maps show that the differential Biot-Savart law explains magnetic shielding at hydrogen and carbon nuclei, and virtual shielding at ring and cage centers. Similarities and/or contrasting ring current effects on magnetotropicity are discussed by a comparison with triprismane C6H6 and cubane C8H8. © 2011 Wiley Periodicals, Inc. J Comput Chem , 2011.

Ancillary