Your browser doesn't support javascript.
loading
Imine derivatives on Au(111): evidence for "inverted" thermal isomerization.
Mielke, Johannes; Leyssner, Felix; Koch, Matthias; Meyer, Stephan; Luo, Ying; Selvanathan, Sofia; Haag, Rainer; Tegeder, Petra; Grill, Leonhard.
Afiliação
  • Mielke J; Physics Department, Freie Universität Berlin, Arnimallee 14, Berlin, Germany.
ACS Nano ; 5(3): 2090-7, 2011 Mar 22.
Article em En | MEDLINE | ID: mdl-21332132
Molecules that undergo reversible isomerization between trans and cis states, typically upon illumination with light at appropriate wavelengths, represent an important class of molecular switches. In this combined scanning tunneling microscopy (STM) and high-resolution electron energy loss spectroscopy (HREELS) study, we report on self-assembled arrays of imine derivatives on a Au(111) surface. Most of the molecules are found in the trans state after deposition at room temperature, but many of them change their conformation upon heating, which we assign to switching to the cis state. As for many molecular switches, the trans isomer is the energetically more stable compound in solution, resulting in thermal cis to trans relaxation upon sufficient heating. On the surface, however, the number of cis isomers increases with temperature, pointing toward an "inverted" thermal isomerization behavior. The reason for this surface-mediated effect could be a stronger coupling, as compared to the trans state, of the central imine part of the molecule to the gold surface, which is sterically only possible in the cis state.
Assuntos

Texto completo: 1 Base de dados: MEDLINE Assunto principal: Nanoestruturas / Ouro / Iminas Idioma: En Ano de publicação: 2011 Tipo de documento: Article

Texto completo: 1 Base de dados: MEDLINE Assunto principal: Nanoestruturas / Ouro / Iminas Idioma: En Ano de publicação: 2011 Tipo de documento: Article