Molecular aniline clusters. I. The electronic ground state.
The aniline dimer and trimer are investigated in their electronic ground state. The potential energy surface was thoroughly searched for low lying minima by applying global optimizations on a model potential, which is recalibrated on-the-fly by ab initio calculations (spin-component-scaled LMP2) at relevant configurations. The most stable structure of the dimer corresponds to a head-to-tail arrangement with both aniline monomers being nearly equivalent. DFT-SAPT calculations reveal that the interaction energy is dominated by van der Waals dispersion, which is of comparable size as for the benzene dimer, but with a much larger total interaction energy than for the latter. The global minimum of the aniline trimer corresponds to a hydrogen bonding arrangement involving three directional NH-N hydrogen bonds, with the individual monomers being clearly distinguishable. Nonadditive three-body dispersion contributions appear to play a minor role for the trimer.
Schemmel
Dominik
D
Institute of Physical and Theoretical Chemistry, University of Regensburg, Universitätsstrasse 31, Regensburg D-93040, Germany.
Schütz
Martin
M
D000814:Aniline Compounds / Q000737:chemistry*; D019281:Dimerization; D004583:Electrons; D008958:Models, Molecular; D008968:Molecular Conformation; D011789:Quantum Theory; D013816:Thermodynamics
D000814:Aniline Compounds; C023650:aniline