Blends of polyaryletherketones (PAEK), such as polyetheretherketones (PEEK) and polyetherketoneketones (PEKK), with polybenzimidazole (PBI) are of commercial interest due to their improved high-temperature stability and wear properties. The changes of PBI and its PEEK- and PEKK-blends (50 : 50 wt %) after immersing them in liquid H₂O and D₂O, and exposing them to D₂O steam at elevated temperatures and pressures are investigated by multinuclear solid-state NMR and IR spectroscopy. Macroscopic morphological and chemical changes on the molecular scale, which take place upon high-temperature steam-treatment and the extent and reversibility of moisture uptake have been investigated. Interactions and reactions of water, steam, and aqueous solutions of LiCl and ZnBr₂ with the functional groups of the polymer components have been studied using D₂O in combination with IR, ¹H wideline, ²H, ⁷Li, and ⁷⁹Br MAS, as well as ¹³C and ¹⁵N CP/MAS NMR spectroscopy. Different locations and types of water and protons in the blends have been described and PBI has been proven to be mainly responsible for water and salt uptake into the blends. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41421.

Aqueous hydrogen peroxide is widely used as an oxidizing agent in industry and academia. Herein, the hydrogen peroxide adducts of phosphine oxides, [tBu₃PO⋅H₂O₂]₂ and [Ph₃PO⋅H₂O₂]₂⋅H₂O₂, are described. Additionally, the corresponding di(hydroperoxy)propane adducts R₃PO⋅(HOO)₂CMe₂ (R=Cy, Ph) were synthesized and characterized. All adducts could be obtained as large single crystals suitable for structural characterization by X-ray crystallography and solid-state NMR spectroscopy. The di(hydroperoxy)propane adducts are soluble in organic solvents which enables oxidation reactions in one phase. As the adducts are solid and molecular, they can easily be applied stoichiometrically. No loss of oxidizing power occurs upon long-term storage of the single crystals at room temperature or the powders at −20 °C.

Aqueous hydrogen peroxide is widely used as an oxidizing agent in industry and academia. Herein, the hydrogen peroxide adducts of phosphine oxides, [tBu₃PO⋅H₂O₂]₂ and [Ph₃PO⋅H₂O₂]₂⋅H₂O₂, are described. Additionally, the corresponding di(hydroperoxy)propane adducts R₃PO⋅(HOO)₂CMe₂ (R=Cy, Ph) were synthesized and characterized. All adducts could be obtained as large single crystals suitable for structural characterization by X-ray crystallography and solid-state NMR spectroscopy. The di(hydroperoxy)propane adducts are soluble in organic solvents which enables oxidation reactions in one phase. As the adducts are solid and molecular, they can easily be applied stoichiometrically. No loss of oxidizing power occurs upon long-term storage of the single crystals at room temperature or the powders at −20 °C.

The tridentate chelate nickel complexes [(CO)Ni{(PPh₂CH₂)₃CMe}] (2), [(CO)Ni{(PPh₂CH₂CH₂)₃SiMe}] (6), and [Ph₃PNi{(PPh₂CH₂CH₂)₃SiMe}] (7), as well as the bidentate complex [(CO)₂Ni{(PPh₂CH₂)₂CMeCH₂PPh₂}] (3) and the heterobimetallic complex [(CO)₂Ni{(PPh₂CH₂)₂CMeCH₂Ph₂PAuCl}] (4), have been synthesized and fully characterized in solution. All ¹H and ¹³C NMR signal assignments are based on 2D-NMR methods. Single crystal X-ray structures have been obtained for all complexes. Their ³¹P CP/MAS (cross polarization with magic angle spinning) NMR spectra have been recorded and the isotropic lines identified. The signals were assigned with the help of their chemical shift anisotropy (CSA) data. All complexes have been tested regarding their catalytic activity for the cyclotrimerization of phenylacetylene. Whereas complexes 2–4 display low catalytic activity, complex 7 leads to quantitative conversion of the substrate within four hours and is highly selective throughout the catalytic reaction.

Solid-state NMR spectroscopy of selected phosphine oxides adsorbed on silica surfaces establishes the surface mobilities, even of phosphine oxides with high melting points. Crystal structures of the adducts Ph₃PO⋅HOSiPh₃ and Cy₃PO⋅H₂O indicate that the interactions with silica involve hydrogen bonding of the PO group to adsorbed water and surface silanol groups.

Blends of polyaryletherketones (PAEK) with polybenzimidazole (PBI) are of commercial interest due to their improved upper service temperatures and wear properties when compared with the PAEK analogs examined to date. The retention of properties of the PBI component generally thought to be disadvantageous in more thermally or chemically aggressive environments is not well understood, nor are the specifics of interactions between the PBI and PAEK components in a melt or dry blend systems. In this initial investigation, focus is placed on the behavior and mechanism of polyetherketoneketone (PEKK)/PBI systems in contact with steam or condensed phase water. The goal is to understand the chemistry of the reaction, if any, upon exposure to steam as well as to examine the reversibility of moisture uptake of this material when exposed to liquid water or saturated steam. In this contribution, the pure polymer components and the PEKK-PBI (60 : 40 wt %) blend are steam-treated at 149°C (300°F) and 316°C (600°F). IR and solid-state NMR spectroscopy are used to study chemical or morphological transformations of the polymers. All changes detectable by ¹³C cross-polarization with magic angle spinning (CP/MAS) upon steam-treatment are reversible, and not of a chemical nature, indicating that under the conditions of exposure used here no detectable chemical degradation occurs during steam exposure and with moisture uptake. The temporary water uptake of the samples, as studied by ¹H wideline NMR and ¹³C T₁ time measurements, leads to a change in the ratio of rigid versus mobile domains of the materials. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013

A new class of tridentate phosphine ligands with the general formula [MeP{(CH₂)_xPPh₂}₃]⁺I⁻ (x=4, 7, 11) and [MeP(CH₂PPh₂)₃]⁺OTf⁻, has been synthesized and fully characterized. The linkers have been immobilized on silica with their phosphonium moieties via electrostatic interactions, and their mobility and leaching has been studied by solid-state HR-MAS (high-resolution magic angle spinning) NMR in various solvents. Immobilized Wilkinson-type rhodium complexes have been obtained by ligand exchange with the surface-bound linkers. The activities and lifetimes of the catalysts have been tested with respect to the hydrogenation of 1-dodecene. The rhodium catalyst precursor bound by the immobilized linker [MeP{(CH₂)₇PPh₂}₃]⁺I⁻ led to material with the highest activity and lifetime, and it could be recycled for 30 times in a batchwise manner. The other catalysts show shorter lifetimes. For all catalysts the formation of rhodium nanoparticles with a narrow size distribution around 4 nm has been proven.