Anhydrous protonic conductors have been obtained by protonation of branched commercial poly(ethylene imine) (PEI) by H 2 SO 4 or H 3 PO 4 . The PEI· x H 2 SO 4 and PEI· x H 3 PO 4 mixtures ( x is the number of acid moles per PEI repeat unit) have been characterized by AC conductivity, infrared spectroscopy and differential scanning calorimetry (DSC) measurements for x values between 0 and 0.7. Two conduction regimes are evidenced below and above the degree of maximum protonation of the polymer which occurs at x ≈0.35. For partially protonated PEI ( x ≤0.35), only SO 4 2− or HPO 4 2− anions are present and conduction seems to occur by proton exchange between protonated and unprotonated amine groups. The room-temperature conductivity reaches a maximum of 4×10 −5 S cm −1 for PEI·0.2H 2 SO 4 and 5×10 −6 S cm −1 for PEI·0.2H 3 PO 4 and then decreases respectively down to ≈10 −6 and 10 −7 S cm −1 . Above x ≈0.35, HSO 4 − or H 2 PO 4 − anions appear and the conductivity, likely to occur now along the SO 4 2− /HSO 4 − or HPO 4 2− /H 2 PO 4 − anionic hydrogen-bonded chains, increases up to values of about 10 −4 S cm −1 for PEI·0.5H 2 SO 4 and ≈10 −5 S cm −1 for PEI·0.5H 3 PO 4 . In all cases, the log(δ T )= f (10 3 / T ) plots between 270 and 400 K present a marked curvature. Thin transparent films can be produced for x ≤0.5. Above this value they lose progressively their mechanical properties and become very hygroscopic because of the presence of excess acid.

Infrared and Raman spectroscopies have been applied to study rf sputtered tungsten oxide films as prepared and after the chemical modifications induced by successive coloration/bleaching cycles. As seen from UV-visible spectra and X-ray diffraction patterns, these films remain essentially amorphous, but it is shown that infrared spectroscopy used in absorbance and reflectance modes and with s and p polarized light is particularly well adapted to provide new information about their aging and variation of composition during the cycles. Aging effects are characterized by water adsorption and hydroxyl group formation. The modification of the amorphous initial film after annealing has also been investigated. The infrared spectra of the film after coloration or bleaching in a sulfuric acid solution show the important role of water content equilibration during the first coloration and then the reversible water extraction/injection during the following bleaching/coloration cycles. The structure of the colored film is also characterized by WO terminal groups which disappear in the bleached state. Some coloration/bleaching cycles have also been performed in organic electrolytes for comparison.

Mixtures of poly(ethylene oxide) (PEO) or poly(acrylic acid) (PAA) with NH4HSO4 can exhibit conductivities better than 10−5 S cm−1 at room temperature. The protonic conduction properties of NH4HSO4 itself are kept or even improved in the polymers, in a way which depends rather drastically on the preparation conditions and on the nature of the solvert. In the more favourable case, a P (EO)4·NH4HSO4 mixture gives a conductivity of 2×10−4 S cm−1 at 292 K (Ea=0.55 eV). IR spectroscopy indicates that the NH4+ cations are complexed and that the polymer is less crystalline than initially but to various degrees according to the nature of the solvent. In the P (AA)n·NH4HSO4 system, IR spectroscopy shows that the polymer keeps its associated amorphous structure in which the cations are practically not complexed. The compound with n=4 prepared by slow evaporation of an aqueous solution presents a conductivity of 2.4×10−5 S cm−1 at 300 K (Ea=0.52 eV). The anionic transport number is expected to be very small in these systems and protonic conduction is supposed to occur by a double transport process: NH4+ jumps and proton migration along HSO4− hydrogen-bonded chains.

The infrared and Raman spectra of powder samples of WO3 (monoclinic and hexagonal) and of WO3, xH2O (x = 1,2,13) have been recorded and the most characteristic vibrations are discussed with reference to the available structural data. In particular, a correlation has been established between the force constant and the length of the WO bond.

The three crystal phases of tetrachloroferrocene have been investigated by X-ray diffraction, incoherent neutron scattering and dielectric permittivity measurements. The molecular and crystal structures of the low-temperature ordered phase (III) have been determined from a single-crystal X-ray diffraction study, which reveals the two rings to be in the eclipsed configuration. The intermediate phase has hexagonal symmetry and the molecular dipoles are rotating among six equivalent orientations with an average residence time between jumps of only ca. 1.8 × 10–11 s. The high-temperature phase is body-centred cubic with the molecules undergoing three-dimensional rotational diffusion with Dr= 1.1 × 1010 rad2 s–1 and orientational potential minima too shallow to be established by the present experiments.

Amorphous films of ‘yellow arsenic’ composed of As4 molecules have been prepared by deposition from the vapour onto a substrate at 30 K in an X-ray diffractometer. X-ray diffraction measurements have been made at 30 K and at higher temperatures, and radial distribution functions determined. The local structure may be successfully modelled by staggered face-to-face packing of As4 tetrahedra, but attempts to model the longer range packing of As4 tetrahedra using quasi-crystalline models have had only limited success. The molecular film readily polymerizes on heating, even for T < 80 K, and the final structure at ambient temperature closely resembles that of amorphous β-arsenic.

The structure of the ordered low-temperature phase of ferrocene carboxaldehyde (C5H5FeC5H4CHO) has been determined from ambient-temperature single-crystal X-ray diffraction measurements. The structure is orthorhombic (space group P212121; Z= 4; a= 7.635 Å, b= 10.520 Å, c= 11.281 Å). The C5 rings are nearly eclipsed and the —CHO side group is almost coplanar with its ring.This structure is used to develop a model for the local structural correlations in the previously studied high-temperature disordered phase (f.c.c., a= 9.99 Å). It is proposed that the average cubic symmetry arises from a superposition of 24 orientations of local structure essentially that of the low-temperature phase and a few unit cells in extent.

Incoherent quasi-elastic and inelastic neutron scattering experiments have been performed on crystalline ferrocene carboxaldehyde in both its ordered (T < 317 K) and disordered (317 < T/K < 396) phases.The unsubstituted ring is found to be undergoing five-fold jump reorientations between indistinguishable positions at all temperatures within range of the experimental resolution (T > 170 K), with an energy barrier of 17 ± 4 kJ mol–1. The molecular motions in the disordered phase are found to be complex and involve internal rotation plus whole-molecule rotational and translational components, consistent with structural work. They are associated with time-scales in the range 10–10–10–12 s and a range of energy barriers up to 20 kJ mol–1.

Amorphous molecular As4S4 and non-stoichiometric “As2S3” evaporated films have been prepared by condensing onto a substrate at liquid nitrogen temperature in situ in the X-ray diffractometer. The structures of these films are shown to be similar, thus confirming the importance of As4S4 (realgar-type) molecules in amorphous films prepared by evaporation of “As2S3” glass. The local molecular packing in the as-deposited amorphous As4S4 film shows a preference for a packing arrangement similar to that found in the α-crystalline phase. Both as-deposited films contain gross structural defects such as molecular clusters and/or voids which irreversibly reduce in importance as the film structures relax on warming to ambient temperatures. Also, the As4S4 film partially devitrifies to the high-temperature β-crystalline phase on warming to ambient, but no devitrification occurs in the non-stoichiometeric film due to the presence of more than one molecular type.

High resolution X-ray and neutron correlation functions have been obtained for arsenic sulphide bulk glass and vapour-deposited films by making measurements to high momentum transfers. These data are compared with a vatiety of models and it is concluded that the structure of the films is dominated by the presence of As4S4 molecules in the vapour phase, which results in more As-As bonds than the minimum required by stoichoimetry. The extent to which these As4S4 molecules polymerise in the as-deposited film is unclear, but depends strongly on preparation conditions.

Ferrocene carboxaldehyde is unusual in that whilst its molecular shape is of low symmetry it shows a mesophase between 44°C and the m.p. (123°C). The nature of this phase has been investigated by X-ray diffraction and Mössbauer spectroscopy. It is shown to be an orientationally disordered molecular crystal, with a simple f.c.c. lattice (a= 999 ± 2 pm). The molecules are, on average, randomly oriented about their centres of mass C (rCFe= 46 pm). Short range correlations in molecular arrangement are accounted for by a Gaussian distribution of molecular centres with 〈U2x〉½= 69 pm. In contrast the r.m.s. displacement of the Fe in the room temperature phase is ∼ 20 pm as for ferrocene.

The structures of vapour-deposited amorphous films of composition AsxSe1−x′, with x between 0 and 1, have been investigated by X-ray diffraction. In all cases the structure of the freshly deposited film differs very considerably from that of the corresponding bulk glass. For the elemental amorphous films the structure is highly disordered and contains voids which for Se cannot be annealed out below the crystallization temperature of 70°C or, for As, below the temperature (⪆130°C) where the As film re-evaporated. Annealing of the arsenic selenide films at temperatures below Tg causes the structures to relax towards those of the bulk, with a distribution of activation energies around 25 kJ mol−1. The composition of the vapour has been examined by mass spectroscopy and it is concluded that even if some molecular identity is retained on condensation there must be considerable cross-linking to give the observed structural behaviour.

Influence of oxygen presence on the crystallization behavior of (GeS2)y(Sb2S3)1-y glasses (for y up to 0.3) was studied by differential scanning calorimetry, X-ray diffraction analysis and infrared microscopy - the study was performed in dependence on particle size. The oxygen was found to significantly accelerate crystallization from mechanically induced defects for the (GeS2)0.1(Sb2S3)0.9 composition and to sustain the intensity of crystal formation in case of the (GeS2)0.2(Sb2S3)0.8 and (GeS2)0.3(Sb2S3)0.7 compositions. On the other hand, presence of oxygen influenced neither the morphology of the crystallites, nor the actual crystallization model-free and model-based kinetics. Direct microscopic observation confirmed strict surface crystallization for all studied composition. Compositional evolutions of the viscosity data and microscopically determined crystal growth rate curves have shown that it is the exceptionally high crystal growth rate and crystallization tendency (compared to the minor-to-moderate contribution of viscosity itself) that are responsible for the significant influenceability of the (GeS2)0.1(Sb2S3)0.9 crystallization by the presence of oxygen.