Physics

Research from University of Modena provide new insights into science

  2010 FEB 9 - (VerticalNews.com) -- "Three-dimensional models of the quantum-mechanical current density induced by a uniform magnetic field in the electron cloud have been obtained for closed-shell systems BeH-, BH, and CH+, characterized by induced orbital paramagnetism, and in planar unsaturated hydrocarbons C4H4 and clamped C8H8, exhibiting pi paramagnetism. It is shown that, even for these paramagnetic systems, the paramagnetic contributions to magnetic susceptibilities and nuclear magnetic shielding, customarily taken into account in perturbation theory approaches, can formally be eliminated via the procedure of continuous transformation Of the origin of the current density-paramagnetic zero," researchers in Modena, Italy report.

  "The definition of magnetic response properties can therefore be recast as a sum of two formally ''diamagnetic'' terms for any molecule, including systems showing strong induced orbital paramagnetism. It is shown that the paramagnetism in the compounds studied arises from the nodal topology of the electronic wave function," wrote S. Pelloni and colleagues, University of Modena.

  The researchers concluded: "In particular, paratropic vortices circulate about stagnation lines at the intersection of nodal Surfaces of the highest-occupied zero-order molecular orbital and corresponding first-order orbital."

  Pelloni and colleagues published their study in the Journal of Physical Chemistry a (Induced Orbital Paramagnetism and Paratropism in Closed-Shell Molecules. Journal of Physical Chemistry a, 2009;113(52):14465-14479).

  For additional information, contact P. Lazzeretti, University of Modena, Dipartimento Chim, Via Campi 183, I-41100 Modena, Italy.

  Publisher contact information for the Journal of Physical Chemistry a is: American Chemical Society, 1155 16th St., NW, Washington, DC 20036, USA.

  Keywords: Electronics, Magnetic Field, Paramagnetism, Physics, University of Modena.

  This article was prepared by VerticalNews Physics editors from staff and other reports. Copyright 2010, VerticalNews Physics via VerticalNews.com.