Molecular association in deuterated liquid N-methylacetamide–water complex: Neutron diffraction and density functional theory study

Abstract

A structural investigation of fully deuterated liquid N-methylacetmide–water complexes (NMA-W) is performed at 308 K and atmospheric pressure by using neutron diffraction in combination with a density functional theory (DFT). The data are analyzed to yield the molecular form factor F 1( Q) and the distinct pair correlation function g L ( r). DFT calculations are performed to examine some possible clusters that may describe the local arrangement in the liquid state. Neutron measurements can be interpreted in term of trans-NMA-3D 2O complex. In this model there are two water molecules hydrogen bonded to the C O oxygen and one to the N–H group. The intermolecular structure factor extracted from this cluster fairly agrees with the experimental one beyond Q = 3 Å −1.