Methods of selectively synthesizing n-tetrasilane are disclosed. N-tetrasilane is prepared by catalysis of silane (SiH.sub.4), disilane (Si.sub.2H.sub.6), trisilane (Si.sub.3H.sub.8), or mixtures thereof. More particularly, the disclosed synthesis methods tune and optimize the n-tetrasilane:i-tetrasilane isomer ratio. The isomer ratio may be optimized by selection of process parameters, such as temperature and the relative amount of starting compounds, as well as selection of proper catalyst. The disclosed synthesis methods allow facile preparation of n-tetrasilane.

Methods of selectively synthesizing n-tetrasilane are disclosed. N-tetrasilane is prepared by catalysis of silane (SiH.sub.4), disilane (Si.sub.2H.sub.6), trisilane (Si.sub.3H.sub.8), or mixtures thereof. More particularly, the disclosed synthesis methods tune and optimize the n-tetrasilane:i-tetrasilane isomer ratio. The isomer ratio may be optimized by selection of process parameters, such as temperature and the relative amount of starting compounds, as well as selection of proper catalyst. The disclosed synthesis methods allow facile preparation of n-tetrasilane.

A process to form a cyclic olefin polymerization catalyst which includes contacting a metal alkoxide with a transition metal halide to form a transition metal precatalyst, and contacting the transition metal precatalyst with a metal alkyl activator to form the activated catalyst comprising a transition metal carbene moiety. A cyclic olefin polymerization process is also disclosed.

A supported catalyst system is based on a transition metal carbene including the moiety M1=CR*).sub.2, wherein M.sup.1 is the transition metal and R* is hydrogen or a C.sub.1-C.sub.8 hydrocarbyl. The catalyst system can be supported on a metal oxide support such as silica or the catalyst can be self-supporting. Methods of making the catalyst system can involve precursors based on and/or reacted with aluminum alkyls, halides, and/or alkoxides. Methods of polymerizing cyclic olefins with the catalyst system can obtain polyalkenamers, cyclic olefin polymers, cyclic olefin copolymers, and other metathesis reaction products. The supported catalyst and/or monomer can be recovered and recycled to the polymerization reactor.

Highly quantitative methods for determining the concentration of residual phase transfer catalysts (PTCs) in radiotracer or radiopharmaceutical doses are described. The methods comprise mixing aliquots of the doses that can contain residual PTCs with a sodium and/or potassium salt; extracting a residual PTC/salt complex into an organic phase; and detecting the amount of PTC/salt complex in the organic phase. The detecting can involve visual colorimetry or measuring the absorbance or transmittance of the organic phase when the sodium and/or potassium salt comprises a chromophoric ion, or measuring the resistance of the organic phase. Also described are devices for use in performing the methods.

A carbon nitride membrane composite material modified by black phosphorus/metal organic framework (MOF) and a preparation method and application thereof to waste gas treatment are disclosed. First, taking urea as a raw material to calcine at a high temperature and prepare porous carbon nitride nanosheet; then carrying out surface carboxylation on the porous carbon nitride nanosheet, and modifying metal organic framework (MOF) on the surface of the porous carbon nitride through a layer-by-layer self-assembling method; stripping block black phosphorus materials into a two-dimensional black phosphorus slice by solvent exfoliation method; mixing the MOF-modified porous carbon nitride material with the two-dimensional black phosphorus material, carrying out suction filtration on the mixture under a vacuum pump to obtain the black phosphorus/MOF-modified carbon nitride membrane composite material.

A carbon nitride membrane composite material modified by black phosphorus/metal organic framework (MOF) and a preparation method and application thereof to waste gas treatment are disclosed. First, taking urea as a raw material to calcine at a high temperature and prepare porous carbon nitride nanosheet; then carrying out surface carboxylation on the porous carbon nitride nanosheet, and modifying metal organic framework (MOF) on the surface of the porous carbon nitride through a layer-by-layer self-assembling method; stripping block black phosphorus materials into a two-dimensional black phosphorus slice by solvent exfoliation method; mixing the MOF-modified porous carbon nitride material with the two-dimensional black phosphorus material, carrying out suction filtration on the mixture under a vacuum pump to obtain the black phosphorus/MOF-modified carbon nitride membrane composite material.

A slurry-phase catalyst composition may include a disulfide oil and a first metal complex. The first metal complex may include at least one transition metal selected from the group consisting of molybdenum, cobalt, nickel, tungsten, iron, and combinations of these. The first metal complex may also include a plurality of ligands bonded to the at least one transition metal. The plurality of ligands may include at least one first ligand selected from the group consisting of dim ethyl sulfide, dimethyldisulfide, diethyl sulfide, diethyldisulfide, methyl ethyl sulfide, methylethyldisulfide, and combinations thereof, and the transition metal may be bonded to a sulfur atom of the at least one first ligand.

The invention relates to a process for the preparation of a deuterated ethanol from ethanol, D.sub.2O, a ruthenium catalyst, and a co-solvent.

The present invention relates to ligands based on calixarenes, metal complexes including such ligands and their use as homogeneous or heterogeneous catalysts.