title: Wetting Camphor: Multi-Isotopic Substitution Identifies the Complementary Roles of Hydrogen Bonding and Dispersive Forces.
abstract: Using broadband rotational spectroscopy, we report here on the delicate interplay between hydrogen bonds and dispersive forces when an unprecedentedly large organic molecule (camphor, C10H16O) is microsolvated with up to three molecules of water. Unambiguous assignment was achieved by performing multi H2(18)O isotopic substitution of clustered water molecules. The observation of all possible mono- and multi-H2(18)O insertions in the cluster structure yielded accurate structural information that is not otherwise achievable with single-substitution experiments. The observed clusters exhibit water chains starting with a strong hydrogen bond to the C═O group and terminated by a mainly van der Waals (dispersive) contact to one of the available sites at the monomer moiety. The effect of hydrogen bond cooperativity is noticeable, and the O···O distances between the clustered water subunits decrease with the number of attached water molecules. The results reported here will further contribute to reveal the hydrophobic and hydrophilic interactions in systems of increasing size.
authors.affiliation: Max Planck Institute for the Structure and Dynamics of Matter , D-22761 Hamburg, Germany.|The Center for Free-Electron Laser Science , D-22761 Hamburg, Germany.
authors.forename: Cristóbal
authors.initials: C
authors.lastname: Pérez
authors.affiliation: Max Planck Institute for the Structure and Dynamics of Matter , D-22761 Hamburg, Germany.|The Center for Free-Electron Laser Science , D-22761 Hamburg, Germany.
authors.forename: Anna
authors.initials: A
authors.lastname: Krin
authors.affiliation: Max Planck Institute for the Structure and Dynamics of Matter , D-22761 Hamburg, Germany.|The Center for Free-Electron Laser Science , D-22761 Hamburg, Germany.|The Hamburg Centre for Ultrafast Imaging at the University of Hamburg , D-22761 Hamburg, Germany.
authors.forename: Amanda L
authors.initials: AL
authors.lastname: Steber
authors.affiliation: Max Planck Institute for the Structure and Dynamics of Matter , D-22761 Hamburg, Germany.|Departamento de Quimica Fisica y Quimica Inorganica, Facultad de Ciencias, Universidad de Valladolid , 47011 Valladolid, Spain.
authors.forename: Juan C
authors.initials: JC
authors.lastname: López
authors.affiliation: Institute of Physics, Polish Academy of Sciences , 02-668 Warszawa, Poland.
authors.forename: Zbigniew
authors.initials: Z
authors.lastname: Kisiel
authors.affiliation: Max Planck Institute for the Structure and Dynamics of Matter , D-22761 Hamburg, Germany.|The Center for Free-Electron Laser Science , D-22761 Hamburg, Germany.|The Hamburg Centre for Ultrafast Imaging at the University of Hamburg , D-22761 Hamburg, Germany.
authors.forename: Melanie
authors.initials: M
authors.lastname: Schnell