STM contrast, electron-transfer chemistry, and conduction in molecules

Wenhai Han, Edgardo N. Durantini, Thomas Moore, Ana Moore, Devens Gust, Peter Rez, Gerald Leatherman, Gilbert R. Seely, Nongjian Tao, Stuart Lindsay

Research output: Contribution to journalArticle

131 Citations (Scopus)

Abstract

We have used a series of metalloporphyrin compounds to test for a relationship between the contrast of STM images and the electrochemical properties of the molecules. Molecules were tethered to a gold (111) surface by means of an isothiocyano linkage and both images and current-voltage (I-V) curves were obtained with the sample submerged in oxygen-free mesitylene. The contrast of the reducible molecules changed strongly with bias, and the corresponding I-V curves were highly asymmetric. The derivative of these curves (dI/dV) had a Gaussian-shaped peak at a voltage characteristic of the compound, although local measurements showed that there was considerable variation in this value from molecule to molecule of a given compound. These bias-dependent features were not observed in the less electroactive molecules, so the STM is capable of distinguishing electroactive molecules from non-electroactive molecules as we demonstrate with images of mixed films. We discuss one- and two-step electron-transfer mechanisms which are consistent with these observations.

Original languageEnglish (US)
Pages (from-to)10719-10725
Number of pages7
JournalJournal of Physical Chemistry B
Volume101
Issue number50
StatePublished - Dec 11 1997

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electron transfer
chemistry
conduction
Molecules
Electrons
molecules
Electric potential
electric potential
curves
Metalloporphyrins
mesitylene
Electrochemical properties
linkages
Gold
gold
Oxygen
Derivatives
oxygen

ASJC Scopus subject areas

  • Physical and Theoretical Chemistry
  • Engineering(all)

Cite this

STM contrast, electron-transfer chemistry, and conduction in molecules. / Han, Wenhai; Durantini, Edgardo N.; Moore, Thomas; Moore, Ana; Gust, Devens; Rez, Peter; Leatherman, Gerald; Seely, Gilbert R.; Tao, Nongjian; Lindsay, Stuart.

In: Journal of Physical Chemistry B, Vol. 101, No. 50, 11.12.1997, p. 10719-10725.

Research output: Contribution to journalArticle

Han, W, Durantini, EN, Moore, T, Moore, A, Gust, D, Rez, P, Leatherman, G, Seely, GR, Tao, N & Lindsay, S 1997, 'STM contrast, electron-transfer chemistry, and conduction in molecules', Journal of Physical Chemistry B, vol. 101, no. 50, pp. 10719-10725.
Han, Wenhai ; Durantini, Edgardo N. ; Moore, Thomas ; Moore, Ana ; Gust, Devens ; Rez, Peter ; Leatherman, Gerald ; Seely, Gilbert R. ; Tao, Nongjian ; Lindsay, Stuart. / STM contrast, electron-transfer chemistry, and conduction in molecules. In: Journal of Physical Chemistry B. 1997 ; Vol. 101, No. 50. pp. 10719-10725.
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AU - Rez, Peter

AU - Leatherman, Gerald

AU - Seely, Gilbert R.

AU - Tao, Nongjian

AU - Lindsay, Stuart

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