Dynamics of water and template molecules in the interlayer space of a layered aluminophosphate. Experimental inelastic neutron scattering spectra and molecular dynamics simulated spectra

Abstract

We report an inelastic neutron scattering (INS) study of a templated layered chiral aluminophosphate: [Co(tn)₃]Al₃P₄O₁₆·2H₂O [tn is 1,3-diaminopropane, NH₂(CH₂)₃NH₂]. A detailed assignment of the experimental vibrational spectrum in the range 0–1000 cm^-1 has been made with the aid of molecular dynamics (MD) and density functional theory (DFT) calculations. We discuss the dynamics of interlayer water and template molecules (200–1000 cm^-1) and correlated phonon modes (16–150 cm^-1) of the aluminophosphate lattice and the interlayer species, and thereby infer some of the factors that stabilise this material.