title: Neutron vibrational spectroscopy gives new insights into the structure of poly(p-phenylene terephthalamide).
abstract: The vibrational spectra of benzanilide and poly(p-phenylene terephthalamide) have been measured using inelastic neutron scattering. These compounds have similar hydrogen-bond networks, which, for poly(p-phenylene terephthalamide), lead to two-dimensional hydrogen-bonded sheets in the crystal. Experimental spectra are compared with solid-state, quantum chemical calculations based on density functional theory (DFT). Such "parameter-free" calculations allow the structure-dynamics relation in this type of compound to be quantified, which is demonstrated here for benzanilide. In the case of poly(p-phenylene terephthalamide), vibrational spectroscopy and DFT calculations help resolve long-standing questions about the packing of hydrogen-bonded sheets in the solid state.
authors.affiliation: Institut Laue Langevin, BP156, 38042 Grenoble Cedex 9, France.
authors.forename: M
authors.initials: M
authors.lastname: Plazanet
authors.forename: F
authors.initials: F
authors.lastname: Fontaine-Vive
authors.forename: K H
authors.initials: KH
authors.lastname: Gardner
authors.forename: V T
authors.initials: VT
authors.lastname: Forsyth
authors.forename: A
authors.initials: A
authors.lastname: Ivanov
authors.forename: A J
authors.initials: AJ
authors.lastname: Ramirez-Cuesta
authors.forename: M R
authors.initials: MR
authors.lastname: Johnson