Force spectroscopy of iron tetraphenylporphyrin molecules with Cl tips

0539520 - FZÚ 2021 RIV US eng J - Journal Article
Scheil, K. - Gruber, M. - Ondráček, Martin - Berndt, R.
Force spectroscopy of iron tetraphenylporphyrin molecules with Cl tips.
Journal of Physical Chemistry C. Roč. 124, č. 49 (2020), s. 26889-26896. ISSN 1932-7447. E-ISSN 1932-7455
Institutional support: RVO:68378271
Keywords : scanning tunneling microscope * atomic force microscope * density functional theory * tetraphenylporphyrin * chlorine ion
OECD category: Atomic, molecular and chemical physics (physics of atoms and molecules including collision, interaction with radiation, magnetic resonances, Mössbauer effect)
Impact factor: 4.126, year: 2020
Method of publishing: Limited access
https://doi.org/10.1021/acs.jpcc.0c08894

At low sample voltages, Cl ions may be bidirectionally transferred between a Fe tetraphenylporphyrin (FeTPP) molecule on Au(111) and the tip of a low-temperature scanning tunneling microscope that also operates as an atomic force microscope. Cl-terminated gold tips are prepared this way. Chlorinated and pristine metal tips are used to probe the forces and conductances of contacts to Au(111), FeTPP, and chlorinated FeTPP. The interaction between the substrate and the Cl ion at the tip may be modeled by a point charge interacting with its image. The maximal attraction experienced by the tip in junctions with one Cl ion is much larger when the ion is located at the molecule. Junctions with two Cl ions exhibit two maxima of the attractive force. Imaging with Cl tips reveals intriguing contrast changes that are tentatively interpreted in terms of tip-induced distortions of the molecules. Density functional theory calculations reproduce important aspects of the experimental data.
Permanent Link: http://hdl.handle.net/11104/0317487