Influence of Molecular and Lattice Vibrations on the Stability of Layered Crystal Structure of Guanidinium Nitrate

Abstract

The dynamics of guanidinium nitrate studied by inelastic neutron scattering, infrared and Raman spectroscopy is reported. The experimental frequencies were assigned to the fundamental modes of nitrate and guanidinium ions on the basis of qualitative considerations. The assignment of the out-of-plane bending mode γ(N–H–O) of the hydrogen bond is proposed. The neutron experiment shows that skeletal deformation modes of guanidinium cations are coupled with large amplitude proton motions. The role of these modes in the stability of the guanidinium nitrate crystal structure and the transition mechanism is discussed.