title: X-ray Raman scattering provides evidence for interfacial acetonitrile-water dipole interactions in aqueous solutions.
abstract: Aqueous solutions of acetonitrile (MeCN) have been studied with oxygen K-edge x-ray Raman scattering (XRS) which is found to be sensitive to the interaction between water and MeCN. The changes in the XRS spectra can be attributed to water directly interacting with MeCN and are reproduced by density functional theory calculations on small clusters of water and MeCN. The dominant structural arrangement features dipole interaction instead of H-bonds between the two species as revealed by the XRS spectra combined with spectrum calculations. Small-angle x-ray scattering shows the largest heterogeneity for a MeCN to water ratio of 0.4 in agreement with earlier small-angle neutron scattering data.
authors: Stanford Synchrotron Radiation Lightsource, P.O.B. 20450, Stanford, California 94309, USA.
authors: Ningdong
authors: N
authors: Huang
authors: Dennis
authors: D
authors: Nordlund
authors: Congcong
authors: C
authors: Huang
authors: Uwe
authors: U
authors: Bergmann
authors: Thomas M
authors: TM
authors: Weiss
authors: Lars G M
authors: LG
authors: Pettersson
authors: Anders
authors: A
authors: Nilsson
mesh_terms: D000097:Acetonitriles / Q000737:chemistry*; D006860:Hydrogen Bonding; D053838:Scattering, Small Angle; D013059:Spectrum Analysis, Raman / Q000379:methods; D014867:Water / Q000737:chemistry*; D014961:X-Ray Diffraction; D014965:X-Rays
chemical_list: D000097:Acetonitriles; D014867:Water; C032159:acetonitrile