Via an all‐catalytic route, long‐chain diamines were prepared by the catalytic direct amination of long‐chain diols, derived from plant oils. High conversion was achieved with good selectivity, with the amount of nitrile impurities formed suppressed to a low level. From the lignocellulose‐based 5‐hydroxymethylfurfural (5‐HMF), or from bis(hydroxymethyl)furan, 2,5‐bis(aminomethyl)furan (BAMF) was generated. 5‐HMF was converted in a one‐pot, one‐step direct amination and reductive amination using ammonia. In both cases, the reaction proceeded very efficiently. In the combined amination and reductive amination, the H2 concentration is a rate‐limiting factor. Reducing the partial pressure of H2 also shortened the reaction time required significantly. Polycondensation of the long‐chain diamines with long‐chain diacids led to higher molecular weight polyamides, illustrating the quality of the diamines obtained by this synthetic approach as monomers.
Heterogenized representatives of neutral phosphine sulfonato Pd(II) complexes for polar monomer insertion polymerization were prepared by two different approaches.[{κ 2 -(P,O)-(2-anisyl) 2 PC 6 H 4 SO 2 O}Pd(Me)L] (L = pyr, dmso, or Cl) complexes were physisorbed on inorganic substrates, namely, clay or silica. In addition, new phosphine sulfonato complexes bearing hydroxyl linker groups at the nonchelating P-aryl moiety were prepared. These complexes were covalently tethered to cross-linked polystyrene. All immobilized palladium complexes are active in ethylene polymerization and ethylene/MA copolymerization without any additional cocatalyst. In addition, separation from the polymer solution formed and reutilization for another polymerization were demonstrated for polystyrene-bound complexes.
The interplay between polymers and inorganic minerals during the formation of solids is crucial for biomineralization and bio-inspired materials, and advanced material properties can be achieved with organic-inorganic composites. By studying the reaction mechanisms, basic questions on organic-inorganic interactions and their role during material formation can be answered, enabling more target-oriented strategies in future synthetic approaches. Here, we present a comprehensive study on the hydrolysis of iron(iii) in the presence of polyaspartic acid. For the basic investigation of the formation mechanism, a titration assay was used, complemented by microscopic techniques. The polymer is shown to promote precipitation in partly hydrolyzed reaction solutions at the very early stages of the reaction by facilitating iron(iii) hydrolysis. In unhydrolyzed solutions, no significant interactions between the polymer and the inorganic solutes can be observed. We demonstrate that the hydrolysis promotion by the polymer can be understood by facilitating oxolation in olation iron(iii) pre-nucleation clusters. We propose that the adsorption of olation pre-nucleation clusters on the polymer chains and the resulting loss in dynamics and increased proximity of the reactants is the key to this effect. The resulting composite material obtained from the hydrolysis in the presence of the polymer was investigated with additional analytical techniques, namely, scanning and transmission electron microscopies, light microscopy, atomic force microscopy, zeta potential measurements, dynamic light scattering, and thermogravimetric analyses. It consists of elastic, polydisperse nanospheres, ca. 50-200 nm in diameter, and aggregates thereof, exhibiting a high polymer and water content.
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