Related Experiment Video
Updated: Jul 3, 2026

Probing C84-embedded Si Substrate Using Scanning Probe Microscopy and Molecular Dynamics
Published on: September 28, 2016
Theoretical simulations of the tip-induced configuration changes of the 4,4(')-diacetyl-p-terphenyl molecule
M Mamatkulov1, L Stauffer, Ph Sonnet
1Laboratoire de Physique et de Spectroscopie Electronique, CNRS UMR 7014, Universite de Haute Alsace, 4 rue des Freres Lumiere, 68093 Mulhouse, France.
Abstract:
We have investigated from a theoretical point of view modifications of the 4,4(')-diacetyl-p-terphenyl molecule chemisorbed on Si(001) induced by the scanning tunneling microscope (STM). In previous experiments, these modifications were observed to occur preferentially at the end of the molecule after a +4.0 V voltage pulse and at the center after a +4.5 V voltage pulse. In the framework of ab initio simulations, we have realized a systematic energetic study of the dissociative chemisorption of one, two, or three phenyl rings of the substituted p-terphenyl molecule. Charge densities were then calculated for the investigated configurations and compared to the STM topographies. Before manipulation with the STM tip, the substituted p-terphenyl molecule is preferentially adsorbed without phenyl ring dissociation, allowing a partial rotation of the central phenyl ring. Our results show that the STM induced modifications observed at the end of the molecule might originate from the dissociation of two phenyl rings (one central and one external ring), while the modifications occurring at the central part of the molecule can be interpreted as a dissociation of the two external rings.
More Related Videos
11:00Hand Controlled Manipulation of Single Molecules via a Scanning Probe Microscope with a 3D Virtual Reality Interface
Published on: October 2, 2016
08:54Vibrational Spectra of a N719-Chromophore/Titania Interface from Empirical-Potential Molecular-Dynamics Simulation, Solvated by a Room Temperature Ionic Liquid
Published on: January 25, 2020
Related Concept Videos
Stability of Conjugated Dienes
A comparison of the enthalpies of hydrogenation of dienes reveals that conjugated dienes release less heat on hydrogenation, rendering them more stable than their nonconjugated analogs.
Chair Conformation of Cyclohexane
The hydrogen atoms linked to carbons are arranged in two different axial and equatorial orientations to achieve this staggered...
[4+2] Cycloaddition of Conjugated Dienes: Diels–Alder Reaction
Aromatic Hydrocarbon Cations: Structural Overview
Removing one hydrogen from the intervening CH2 group with both...
Conformations of Cyclohexane
The chair form is the most stable and derives its name from its resemblance to the “easy chair.” In the chair conformation, two carbon atoms are arranged out-of-plane — one above and one below, minimizing the torsional strain. In the chair form, the bond angle is very close to the ideal tetrahedral value,...
π Molecular Orbitals of 1,3-Butadiene
The simplest conjugated diene is 1,3-butadiene: a four-carbon system where each carbon is sp2-hybridized and has an unhybridized p orbital that contains an unpaired electron. According to molecular orbital theory, atomic orbitals combine to form molecular orbitals such that the number...