Adsorption of Supramolecular Building Blocks on Graphite: A Force Field and Density Functional Theory Study

Effect of dispersion on surface interactions of cobalt(ii) octaethylporphyrin monolayer on Au(111) and HOPG(0001) substrates: a comparative first principles study

Implication of dispersion interactions on geometric, adsorption and electronic properties of porphyrin monolayer on conductive surfaces using density functional theory.

Influence of the solvent on the stability of bis(terpyridine) structures on graphite

The effect of solvation on the adsorption of organic molecules on graphite at room temperature has been addressed with force-field molecular dynamics simulations. As a model system, the solvation of a bis(terpyridine) isomer in water and 1,2,4-trichlorobenzene was studied with an explicit solvation model. The inclusion of solvation has a noticeable effect on adsorption energies. Although the results of the various considered force fields differ quite significantly, they all agree that the adsorption of BTP from the TCB solvent is almost thermoneutral. The substrate simply acts as a template to allow a planar arrangement of the network, which is stabilized by the intermolecular interaction. Using an atomic thermodynamics approach, the order of the stability of various network structures as a function of the chemical potential is derived yielding a sequence in agreement with the experiment.

Structural and electronic properties of oligo- and polythiophenes modified by substituents

The electronic and structural properties of oligo- and polythiophenes that can be used as building blocks for molecular electronic devices have been studied by using periodic density functional theory calculations. We have in particular focused on the effect of substituents on the electronic structure of thiophenes. Whereas singly bonded substituents, such as methyl, amino or nitro groups, change the electronic properties of thiophene monomers and dimers, they hardly influence the band gap of polythiophene. In contrast, phenyl-substituted polythiophenes as well as vinyl-bridged polythiophene derivatives exhibit drastically modified band gaps. These effects cannot be explained by simple electron removal or addition, as calculations for charged polythiophenes demonstrate.

Peculiar adsorbed phase behaviour of binary mixtures of oligopyridines and extension to a ternary mixture in a host-guest system

Binary mixtures of bis(terpyridine)s show a U shape behaviour in concentration dependent surface coverage at constant molar ratio. The phase separation can be exploited to create ternary mixtures with exclusive adsorption of the third component in one phase.