@phdthesis{Laudien2000,
  author    = {Laudien, Robert},
  title     = {Mechanismen der basischen und sauren Hydrolyse der Phenylkohlens{\"a}urederivate},
  pages     = {101 S.},
  year      = {2000},
  language  = {de}
}
@article{RiebeLaudienBrendleretal.2013,
  author    = {Riebe, Daniel and Laudien, Robert and Brendler, Christian and Beitz, Toralf and L{\"o}hmannsr{\"o}ben, Hans-Gerd},
  title     = {Laser ionization of H2S and ion-molecule reactions of H3S+ in laser-based ion mobility spectrometry and drift cell time-of-flight mass spectrometry},
  series = {Analytical \& bioanalytical chemistry},
  volume    = {405},
  journal   = {Analytical \& bioanalytical chemistry},
  number    = {22},
  publisher = {Springer},
  address   = {Heidelberg},
  issn      = {1618-2642},
  doi       = {10.1007/s00216-013-7186-5},
  pages     = {7031 -- 7039},
  year      = {2013},
  abstract  = {The detection of hydrogen sulfide (H2S) by 2 + 1 resonance-enhanced multi-photon ionization (REMPI) and the application of H2S as a laser dopant for the detection of polar compounds in laser ion mobility (IM) spectrometry at atmospheric pressure were investigated. Underlying ionization mechanisms were elucidated by additional studies employing a drift cell interfaced to a time-of-flight mass spectrometer. Depending on the pressure, the primary ions H2S+, HS+, S+, and secondary ions, such as H3S+, were observed. The 2 + 1 REMPI spectrum of H2S near lambda = 302.5 nm was recorded at atmospheric pressure. Furthermore, the limit of detection and the linear range were established. In the second part of the work, H2S was investigated as an H2O analogous laser dopant for the ionization of polar substances by proton transfer. H2S exhibits a proton affinity (PA) similar to that of H2O, but a significantly lower ionization energy facilitating laser ionization. Ion-molecule reactions (IMR) of H3S+ with a variety of polar substances with PA between 754.6 and 841.6 kJ/mol were investigated. Representatives of different compound classes, including alcohols, ketones, esters, and nitroaromatics were analyzed. The IM spectra resulting from IMR of H3S+ and H3O+ with these substances are similar in structure, i.e., protonated monomer and dimer ion peaks are found depending on the analyte concentration.},
  language  = {en}
}
@article{BeitzLaudienLoehmannsroebenetal.2006,
  author    = {Beitz, Toralf and Laudien, Robert and L{\"o}hmannsr{\"o}ben, Hans-Gerd and Kallies, Bernd},
  title     = {Ion mobility spectrometric investigation of aromatic cations in the gas phase},
  issn      = {1089-5639},
  doi       = {10.1021/Jp055335n},
  year      = {2006},
  abstract  = {In this work, ion mobility (IM) spectra of more than 50 aromatic compounds were recorded with a laser-based IM spectrometer at atmospheric pressure. IM spectra of PAH in the laser desorption experiment show a high complexity resulting from the occurrence of monomeric, dimeric, and oligomeric cluster ions. The mobilities of all compounds were determined in helium as drift gas. This allows the calculation of the diffusion cross sections (Omega(calc)) on the basis of the exact hard sphere scattering model and their comparison with the experimentally determined diffusion cross sections (Omega(exp)). Extended Omega(exp)/Omega(calc) and Omega(exp/)mass correlations were performed in order to gain insight into conformational properties of cationic alkyl benzenes and internal rotation of phenyl rings in aromatic ions. This is demonstrated with some examples, such as the evaluation of the dihedral angle of the ions of 9,10- diphenylanthracene, o- and m-terphenyl, and 1,2,3- and 1,3,5-triphenylbenzene. Furthermore, sandwich and T-structures of dimeric PAH cations are discussed. The analysis was extended to oligomeric ions with up to nine monomer units. Experimental evidence is presented suggesting the formation of pi-stacks with a transition toward modified pi-stacks with increasing cluster size. The distance between monomeric units in dimeric and oligomeric ions was obtained},
  language  = {en}
}
@article{LaudienRiebeBeitzetal.2008,
  author    = {Laudien, Robert and Riebe, Daniel and Beitz, Toralf and L{\"o}hmannsr{\"o}ben, Hans-Gerd},
  title     = {Detection of explosive related nitroaromatic compounds (ERNC) by laser-based ion mobility spectrometry},
  isbn      = {978-0-8194-7348-6},
  year      = {2008},
  language  = {en}
}