Re(V) alkylidyne-based catalytic systems for alkyne metathesis reactions capable of effecting alkyne metathesis, such as homo- and cross-metathesis of alkynes or diynes, ring closing metathesis and ring-opening metathesis, at room temperature to moderate temperatures. The catalysts are stable to air and moisture and tolerate a variety of functional groups in substrates and can be readily prepared on a large scale, and thus are practical catalytic systems of Re(V) alkylidynes.

The present disclosure features a method of making an engine aftertreatment catalyst, where the engine aftertreatment catalyst includes a metal oxide, a metal zeolite, and/or vanadium oxide when the metal oxide is different from vanadium oxide, each of which can be independently surface-modified with a surface modifier. The method includes providing a solution including an organic solvent and an organometallic compound; mixing the solution with a metal oxide, a metal zeolite, and/or a vanadium oxide to provide a mixture; drying the mixture; and calcining the mixture to provide a surface-modified metal oxide catalyst, a surface-modified metal zeolite catalyst, and/or a surface-modified vanadium oxide catalyst. The organometallic compound can be, for example, a metal alkoxide, a metal carboxylate, a metal acetylacetonate, and/or a metal organic acid ester.

The present disclosure relates to a transition metal based pro-catalyst represented by Formula I: wherein, the substituents have the meaning as defined in the specification. The present disclosure also relates to a process for preparing the transition metal based pro-catalyst represented by Formula I and the catalyst composition obtained therefrom. Further, the present disclosure relates to a process for polymerizing olefins by employing the catalyst composition comprising the transition metal based pro-catalyst represented by Formula I. ##STR00001##

A composition contains (A) a hydrosilylation reaction catalyst and (B) an aliphatically unsaturated compound having an average, per molecule, of one or more aliphatically unsaturated organic groups capable of undergoing hydrosilylation reaction. The composition is capable of reacting via hydrosilylation reaction to form a reaction product, such as a silane, a gum, a gel, a rubber, or a resin. Ingredient (A) contains a metal-ligand complex that can be prepared by a method including reacting a metal precursor and a ligand.

Materials for binding per- and polyfluoroalkyl substances (PFAS) are disclosed. A fluidic device comprising the materials for detection and quantification of PFAS in a sample is disclosed. The fluidic device may be configured for multiplexed analyses. Also disclosed are methods for sorbing and remediating PFAS in a sample. The sample may be groundwater containing, or suspected of containing, one or more PFAS.