@article{KroenerSchimkaKlamroth2014,
  author    = {Kroener, Dominik and Schimka, Selina and Klamroth, Tillmann},
  title     = {Laser control for coupled torsions in chiroptical switches: a combined quantum and classical dynamics approach},
  series = {The journal of physical chemistry : C, Nanomaterials and interfaces},
  volume    = {118},
  journal   = {The journal of physical chemistry : C, Nanomaterials and interfaces},
  number    = {2},
  publisher = {American Chemical Society},
  address   = {Washington},
  issn      = {1932-7447},
  doi       = {10.1021/jp410342a},
  pages     = {1322 -- 1331},
  year      = {2014},
  abstract  = {We present a novel laser pulse control for the chiroptical switch 1-(2-cis-fluoroethenyl)-2-fluoro-3,5-dibromobenzene mounted on adamantane, where the latter imitates a linker group or part of a solid surface. This molecular device offers three switching states: a true achiral "off"-state and two chiral "on"-states of opposite handedness. Due to the alignment of its chiral axis along the surface normal several defined orientations of the switch have to be considered for an efficient stereocontrol strategy. In addition to these different initial conditions, coupled torsional degrees of freedom around the chiral axis make the quest for highly stereoselective laser pulses a challenge. The necessary flexibility in pulse accomplished by employing the iterative stochastic pulse optimization method we presented recently. Still, the complexity of the system dictates a combined treatment by fast molecular dynamics and computationally intensive quantum dynamics. Although quantum effects are found to be of importance, the pulses optimized within the classical treatment allow us to turn on the chirality of the switch, achieving high enantioselectivity in the quantum treatment for all orientations at the same time.},
  language  = {en}
}
@article{UtechtPanKlamrothetal.2014,
  author    = {Utecht, Manuel Martin and Pan, Tianluo and Klamroth, Tillmann and Palmer, Richard E.},
  title     = {Quantum chemical cluster models for chemi- and physisorption of chlorobenzene on Si(111)-7x7},
  series = {The journal of physical chemistry : A, Molecules, spectroscopy, kinetics, environment \& general theory},
  volume    = {118},
  journal   = {The journal of physical chemistry : A, Molecules, spectroscopy, kinetics, environment \& general theory},
  number    = {33},
  publisher = {American Chemical Society},
  address   = {Washington},
  issn      = {1089-5639},
  doi       = {10.1021/jp504208d},
  pages     = {6699 -- 6704},
  year      = {2014},
  abstract  = {Motivated by recent atomic manipulation experiments, we report quantum chemical calculations for chemi- and physisorption minima of chlorobenzene on the Si(111)-7x7 surface. A density functional theory cluster approach is applied, using the B3LYP hybrid functional alongside Grimme's empirical dispersion corrections (D3). We were able to identify chemisorption sites of binding energies of 1.6 eV and physisorption energies of 0.6 eV, both in encouraging agreement with the trend of experimental data. The cluster approach opens up the possibility of a first-principles based dynamical description of STM manipulation experiments on this system, the interpretation of which involves both the chemi- and physisorbed states. However, we found that special care has to be taken regarding the choice of clusters, basis sets, and the evaluation of the dispersion corrections.},
  language  = {en}
}
@article{WinterThielZabeletal.2014,
  author    = {Winter, Alette and Thiel, Kerstin and Zabel, Andre and Klamroth, Tillmann and Poeppl, Andreas and Kelling, Alexandra and Schilde, Uwe and Taubert, Andreas and Strauch, Peter},
  title     = {Tetrahalidocuprates(II) - structure and EPR spectroscopy. Part 2: tetrachloridocuprates(II)},
  series = {New journal of chemistry},
  volume    = {38},
  journal   = {New journal of chemistry},
  number    = {3},
  publisher = {Royal Society of Chemistry},
  address   = {Cambridge},
  issn      = {1144-0546},
  doi       = {10.1039/c3nj01039b},
  pages     = {1019 -- 1030},
  year      = {2014},
  abstract  = {We present and discuss the results of crystallographic and electron paramagnetic resonance (EPR) spectroscopic analyses of five tetrachloridocuprate(II) complexes to supply a useful tool for the structural characterisation of the [CuCl4](2-) moiety in the liquid state, for example in ionic liquids, or in solution. Bis(benzyltriethylammonium)-, bis(trimethylphenylammonium)-, bis(ethyltriphenylphosphonium)-, bis(benzyltriphenylphosphonium)-, and bis(tetraphenylarsonium) tetrachloridocuprate(II) were synthesised and characterised by elemental, IR, EPR and X-ray analyses. The results of the crystallographic analyses show distorted tetrahedral coordination geometry of all [CuCl4](2-) anions in the five complexes and prove that all investigated complexes are stabilised by hydrogen bonds of different intensities. Despite the use of sterically demanding ammonium, phosphonium and arsonium cations to obtain the separation of the paramagnetic Cu(II) centres for EPR spectroscopy no hyperfine structure was observed in the EPR spectra but the principal values of the electron Zeeman tensor, g(parallel to) and g(perpendicular to), could be determined. With these EPR data and the crystallographic parameters we were able to carry out a correlation study to anticipate the structural situation of tetrachloridocuprates in different physical states. This correlation is in good agreement with DFT calculations.},
  language  = {en}
}
@article{BronnerUtechtHaaseetal.2014,
  author    = {Bronner, Christopher and Utecht, Manuel Martin and Haase, Anton and Saalfrank, Peter and Klamroth, Tillmann and Tegeder, Petra},
  title     = {Electronic structure changes during the surface-assisted formation of a graphene nanoribbon},
  series = {The journal of chemical physics : bridges a gap between journals of physics and journals of chemistr},
  volume    = {140},
  journal   = {The journal of chemical physics : bridges a gap between journals of physics and journals of chemistr},
  number    = {2},
  publisher = {American Institute of Physics},
  address   = {Melville},
  issn      = {0021-9606},
  doi       = {10.1063/1.4858855},
  pages     = {7},
  year      = {2014},
  abstract  = {High conductivity and a tunability of the band gap make quasi-one-dimensional graphene nanoribbons (GNRs) highly interesting materials for the use in field effect transistors. Especially bottom-up fabricated GNRs possess well-defined edges which is important for the electronic structure and accordingly the band gap. In this study we investigate the formation of a sub-nanometer wide armchair GNR generated on a Au(111) surface. The on-surface synthesis is thermally activated and involves an intermediate non-aromatic polymer in which the molecular precursor forms polyanthrylene chains. Employing angle-resolved two-photon photoemission in combination with density functional theory calculations we find that the polymer exhibits two dispersing states which we attribute to the valence and the conduction band, respectively. While the band gap of the non-aromatic polymer obtained in this way is relatively large, namely 5.25 +/- 0.06 eV, the gap of the corresponding aromatic GNR is strongly reduced which we attribute to the different degree of electron delocalization in the two systems.},
  language  = {en}
}