Coexistence of one- and two-dimensional supramolecular assemblies of terephthalic acid on Pd(111) due to self-limiting deprotonation

  • Autor: Canas-Ventura, M.-E. / Klappenberger, F. / Clair, S. / Pons, S. / Kern, K. / Brune, H. / Strunskus, T. / Wöll, C. / Fasel, R. / Barth, J. V. (2006)

  • Quelle:

    J. Chem. Phys. 125 (2006), 184710
  • Datum: 2006

  • Canas-Ventura, M.-E. / Klappenberger, F. / Clair, S. / Pons, S. / Kern, K. / Brune, H. / Strunskus, T. / Wöll, C. / Fasel, R. / Barth, J. V. (2006): „Coexistence of one- and two-dimensional supramolecular assemblies of terephthalic acid on Pd(111) due to self-limiting deprotonation“. In: J. Chem. Phys. 125 (2006), 184710

Abstract

The adsorption of terephthalic acid [C6H4(COOH)2, TPA] on a Pd(111) surface has been investigated by means of scanning tunneling microscopy (STM), x-ray photoelectron spectroscopy, and near-edge x-ray absorption fine structure spectroscopy under ultrahigh vacuum conditions at room temperature.

We find the coexistence of one- (1D) and two-dimensional (2D) molecular ordering. Our analysis indicates that the 1D phase consists of intact TPA chains stabilized by a dimerization of the self-complementary carboxyl groups, whereas in the 2D phase, consisting of deprotonated entities, the molecules form lateral ionic hydrogen bonds.

The supramolecular growth dynamics and the resulting structures are explained by a self-limiting deprotonation process mediated by the catalytic activity of the Pd surface. Our models for the molecular ordering are supported by molecular mechanics calculations and a simulation of high resolution STM images.

 

 

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