Stereochemically inert cationic cobalt(III) complexes were shown to be one-component catalysts for the synthesis of cyclic carbonates from epoxides and carbon dioxide at 50 °C and 5 MPa carbon dioxide pressure. The optimal catalyst possessed an iodide counter anion and could be recycled. A catalytic cycle is proposed in which the ligand of the cobalt complexes acts as a hydrogen-bond donor, activating the epoxide towards ring opening by the halide anion and activating the carbon dioxide for subsequent reaction with the halo-alkoxide. No kinetic resolution was observed when terminal epoxides were used as substrates, but chalcone oxide underwent kinetic resolution.

Biomass processing to value-added chemicals and biofuels received considerable attention due to the renewable nature of the precursors. Here, we report the development of Ru-containing magnetically recoverable catalysts for cellulose hydrogenolysis to low alcohols, ethylene glycol (EG) and propylene glycol (PG). The catalysts are synthesized by incorporation of magnetite nanoparticles (NPs) in mesoporous silica pores followed by formation of 2 nm Ru NPs. The latter are obtained by thermal decomposition of ruthenium acetylacetonate in the pores. The catalysts showed excellent activities and selectivities at 100% cellulose conversion, exceeding those for the commercial Ru/C. High selectivities as well as activities are attributed to the influence of Fe3O4 on the Ru(0)/Ru(4+) NPs. A facile synthetic protocol, easy magnetic separation, and stability of the catalyst performance after magnetic recovery make these catalysts promising for industrial applications.

A new family of Ni-, Co-, and Cr-doped Zn-containing magnetic oxide nanoparticles (NPs) stabilized by polyphenylquinoxaline (PPQ) and hyperbranched pyridylphenylene polymer (PPP) has been developed. These NPs have been synthesized by thermal decomposition of Zn and doping metal acetylacetonates in the reaction solution of preformed magnetite NPs, resulting in single-crystal NPs with spinel structure. For the PPQ-capped NPs, it was demonstrated that all three types of metal species (Fe, Zn, and a doping metal) reside within the same NPs, the surface of which is enriched with Zn and a doping metal, while the deeper layers are enriched with Fe. The Cr-doped NPs at the high Cr loading are an exception due to favored deposition of Cr on magnetite located in the NP depth. The PPP-capped NPs exhibit similar morphology and crystallinity; however, the detailed study of the NP composition was barred due to the high PPP amount retained on the NP surface. The catalyst testing in syngas conversion to methanol demonstrated outstanding catalytic properties of doped Zn-containing magnetic oxides, whose activities are dependent on the doping metal content and on the stabilizing polymer. The PPP stabilization allows for better access to the catalytic species due to the open and rigid polymer architecture and most likely optimized distribution of doping species. Repeat experiments carried out after magnetic separation of catalysts from the reaction mixture showed excellent catalyst stability even after five consecutive catalytic runs.

Synthesis of polystyrene-block-polybutadiene (PS-b-PB) and polystyrene-block-polyisobutylene (PS-b-PIB) micelles filled with MoS x nanoparticles was carried out in a one-pot procedure in heptane using complexation with Mo(CO) 6 followed by interaction with H 2 S. The structure and composition of Mo carbonyl complexes and MoS x -containing micelles were studied using FTIR, static light scattering, turbidimetry, and transmission electron microscopy. By varying the reaction atmosphere (argon or CO) during interaction with Mo(CO) 6 , the location of MoS x species obtained after sulfiding was tailored. Carrying out complexation with PS-b-PB in CO, which is also a reaction product, prevents complexation in the PS micelle core, thus providing location of Mo species only in the PB corona. Antifrictional tests show that this location leads to better tribological performance: lower friction coefficient or higher critical load (at which the friction coefficient is measured). When MoS x species are located in the PS core (complexation with Mo(CO) 6 was carried out in argon atmosphere), low density of the micelles in the case of PS-b-PIB block copolymer with a short PS block provides much better antifrictional performance than those with the dense PS-b-PB micelles.