title: Correlating Infrared and X-ray Absorption Energies for Molecular-Level Insight into Hydrogen Bond Making and Breaking in Solution.
abstract: While ubiquitous, the making and breaking of hydrogen bonds in solution is notoriously difficult to study due to the associated complex changes of nuclear and electronic structures. With the aim to reduce the according uncertainty in correlating experimental observables and hydrogen-bond configurations, we combine the information from proximate methods to study the N-H···O hydrogen bond in solution. We investigate hydrogen-bonding of the N-H group of N-methylaniline with oxygen from liquid DMSO and acetone with infrared spectra in the N-H stretching region and X-ray absorption spectra at the N K-edge. We experimentally observe blue shifts of the infrared stretching band and an X-ray absorption pre-edge peak when going from DMSO to acetone. With ab initio molecular dynamics simulations and calculated spectra, we qualitatively reproduce the experimental observables but we do not reach quantitative agreement with experiment. The infrared spectra support the notion of weakening the N-H···O hydrogen bond from DMSO to acetone. However, we fail to theoretically reproduce the measured shift of the X-ray absorption pre-edge peak. We discuss possible shortcomings of the simulation models and spectrum calculations. Common features and distinct differences with the O-H···O hydrogen bond are highlighted, and the implications for monitoring hydrogen-bond breaking in solution are discussed.
authors.affiliation: †Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie, Max-Born-Strasse 2 A, 12489 Berlin, Germany.
authors.forename: Mirabelle
authors.initials: M
authors.lastname: Prémont-Schwarz
authors.affiliation: ‡Institute for Methods and Instrumentation for Synchrotron Radiation Research, Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Albert-Einstein-Strasse 15, 12489 Berlin, Germany.|∥Institut für Physik und Astronomie, Universität Potsdam, Karl-Liebknecht-Strasse 24-25, 14476 Potsdam, Germany.
authors.forename: Simon
authors.initials: S
authors.lastname: Schreck
authors.affiliation: §Institute of Physical Chemistry, University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland.
authors.forename: Marcella
authors.initials: M
authors.lastname: Iannuzzi
authors.affiliation: †Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie, Max-Born-Strasse 2 A, 12489 Berlin, Germany.
authors.forename: Erik T J
authors.initials: ET
authors.lastname: Nibbering
authors.affiliation: ∥Institut für Physik und Astronomie, Universität Potsdam, Karl-Liebknecht-Strasse 24-25, 14476 Potsdam, Germany.|#Department of Physics, Stockholm University, AlbaNova University Center, 106 91 Stockholm, Sweden.
authors.forename: Michael
authors.initials: M
authors.lastname: Odelius
authors.affiliation: ‡Institute for Methods and Instrumentation for Synchrotron Radiation Research, Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Albert-Einstein-Strasse 15, 12489 Berlin, Germany.
authors.forename: Philippe
authors.initials: P
authors.lastname: Wernet
mesh_terms: D000096:Acetone / Q000737:chemistry*; D000814:Aniline Compounds / Q000737:chemistry*; D004121:Dimethyl Sulfoxide / Q000737:chemistry*; D006860:Hydrogen Bonding; D056004:Molecular Dynamics Simulation; D012996:Solutions; D012997:Solvents / Q000737:chemistry; D013055:Spectrophotometry, Infrared / Q000379:methods*; D056928:X-Ray Absorption Spectroscopy / Q000379:methods*
chemical_list: D000814:Aniline Compounds; D012996:Solutions; D012997:Solvents; D000096:Acetone; C021313:methylaniline; D004121:Dimethyl Sulfoxide