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John Polanyi

John Polanyi

Academic Title: University Professor

Phone: 416-978-3580 / fax 416-978-7580

Office: LM 262

Email:

Research Homepage: http://sites.utoronto.ca/jpolanyi/

Research

This laboratory's long-time interest in the molecular motions responsible for chemical reactions at surfaces has received a major impetus in recent times with the advent of Scanning Tunneling Microscopy, the principle diagnostic tool used by the group. The laboratory is unusual in having four Ultra High Vacuum Scanning Tuneling Microscopes (STM) at its disposal. With the aid of these instruments it is able to characterize the event of chemical reactions a-molecule-at-a-time at a variety of semi-conductor and metallic surfaces. A central finding is the localization of reaction close to the site at which the parent molecule (the reagent) physisorbs on the surface. This provides the basis for a method of maskless Molecular-Scale Imprinting, constituting a 'molecular printing press' in which the mobile molecular 'type' self-assembles, and subsequently permanently ‘imprints’ through localised chemical reaction with the underlying surface induced by heat, light or electrons. Novel mechanisms of self-assembly lead to such nano-structures as molecular corrals and switches. Studies of the imprinting step reveal detailed links between adsorbate geometry and reactivity. Experiment is supported in all cases by theory performed collaboratively with other research groups in Canada and the U.K.

Selected Publications

K.R. Harikumar, John C. Polanyi, Amir Zabet-Khosousi, Piotr Czekala, Haiping Lin, Werner A. Hofer, Directed Long-Range Molecular Migration, Energized by Surface Reaction, Nature Chem. 3, 400 (2011).

  • News & Views Article, Joseph W. Lyding, ‘Molecular Cart-Wheeling’, Nature Chem 3, 341 (2011).

K.R. Harikumar, Iain R. McNab, John C. Polanyi, Amir Zabet-Khosousi, and Werner Hofer, Imprinting Self-Assembled Patterns of Lines at a Semiconductor Surface, Using Heat, Light or Electrons, (PNAS Surface Chemistry Special Issue ‘Frontiers in Surface Chemistry’, Eds., John T. Yates & Charles T. Campbell), PNAS 108, 950 (2011).

Tingbin Lim, John C. Polanyi, Hong Guo, Wei Ji, Surface-Mediated Chain Reaction Through Dissociative Attachment, Nature Chem. 1, 85 (2011).

  • Article: Chris Adriaanse, ‘Dangling Bond Helps Grow Nanowires’, Chemistry & Industry 1, January 2011.
  • News Article, Canadian Chemical News, ‘Researchers Grow Nano-Scale Patterns on Silicon’, February 2011.

K.R. Harikumar, Lydie Leung, Iain R. McNab, John C. Polanyi, Haiping Lin and Werner A. Hofer, Cooperative Molecular Dynamics in Surface-Reaction. Nature Chemistry 1, 716 (2009).

Hong Guo, Wei Ji, John C. Polanyi and Jody (S.Y.) Yang, Molecular Dynamics of Localized Reaction, Experiment and Theory: Methyl Bromide on Si(111)-7x7, ACS Nano 2, 699 (2008).

K.R. Harikumar, Tingbin Lim, Iain R. McNab, John C. Polanyi, Linda Zotti, Serge Ayissi and Werner A. Hofer, Dipole-Directed Assembly of Lines of 1,5-Dichloropentane on Silicon Substrates by Displacement of Surface Charge, Nature Nanotech 3, 222 (2008). (News article: Stacey F. Bent, Silicon Falls Into Line, Nature Nanotech 3, 185 (2008)).

S. Dobrin, K.R. Harikumar, T.B. Lim, L. Leung, I.R. McNab. J.C. Polanyi, P.A. Sloan, Z. Waqar, J. (S.Y.) Yang, S. Ayissi and W.A. Hofer, Maskless Nanopatterning and Formation of Nanocorrals and Switches, for Haloalkanes at Si(111)-7×7, Nanotechnology 18, 044012 (2007).

Krishnan R. Harikumar, John C. Polanyi, Peter A. Sloan, Serge Ayissi, and Werner A. Hofer, Electronic Switching of Single Silicon Atoms by Molecular Field-Effects, J. Am. Chem. Soc. 128, 16791 (2006), (Featured in Nature Nanotech Research Highlights, Online Jan 5, 2007).

J.C. Polanyi, Some Concepts in Reaction Dynamics, Nobel Lecture Dec. 8, 1986, (Abridged Version) Science 236, 680 (1987).