A compound of formula (I) wherein M is Pd(II) or Ni(II); X is a halide; R.sub.1 and R.sub.2 are independently organic groups having 1-20 carbon atoms, or R.sub.1 and R.sub.2 are linked to form a ring structure with the phosphorus atom; R.sub.3 is an organic group having 1-20 carbon atoms; provided that R.sub.1, R.sub.2, R.sub.3 are not each phenyl.

##STR00001##

Metal-organic frameworks (MOFs) may have Zn(II), Pb(II), and/or Cd(II) as a central metal ion, a 4,4′-bipyridylethylene (bpe) ligand as a first ligand; and fumaric acid (fum) and/or oxalic acid (ox) as a second ligand, wherein the 4,4′-bipyridylethylene ligands are stacked in the MOF, and wherein a distance between two consecutive 4,4′-bipyridylethylene ligands is less than 5 Å. Cycloadditions, particularly photoinduced [2+2] cycloadditions may be catalyzed by such MOFs, and/or the conversion of photoinduced [2+2] cycloadditions in inventive MOFs may be increased by mechanical force, such as by grinding.

The present invention relates to a method of degrading biofilm by contacting it with an aqueous mixture comprising a peroxide compound and a manganese complex, wherein the aqueous mixture comprises a macrocylic ligand. The invention also relates to a method of degrading a biofilm by contacting it with an aqueous mixture comprising a peroxide compound and a macrocyclic ligand.

The present disclosure relates to a titanium-organic framework photocatalyst for adsorption and decomposition of a volatile organic compound, a method for preparing the same and a method for removing a volatile organic compound using a titanium-organic framework photocatalyst. More specifically, a hierarchical pore structure can be formed and a pore size can be controlled by preparing a titanium-organic framework photocatalyst by coordination bonding a titanium precursor to a mixture of two carboxylic acid compounds having different electronegativity, as organic linkers, at an optimized ratio. The titanium-organic framework photocatalyst exhibits improved efficiency of adsorbing and decomposing a volatile organic compound (VOC) and can improve the photocatalytic degradation rate of the volatile organic compound (VOC).

The invention describes single-site metal catalysts such as Pt single-site centers on powdered oxide supports with a 1,10-phenanthroline-5,6-dione (PDO) or bis-pyrimidyltetrazine (BMTZ) ligand on powdered MgO, Al.sub.2O.sub.3, or CeO.sub.2.

Catalyst systems suitable for tetramerizing ethylene to form 1-octene may include a catalyst comprising a chromium compound coordinated with a ligand and a co-catalyst comprising an organoaluminum compound. The ligand may include have a chemical structure according to formula (I), wherein at least one of R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, R.sub.6, R.sub.7, R.sub.8, R.sub.9, R.sub.10, R.sub.11, and R.sub.12 have the structure according to formula (II) wherein R.sub.A, R.sub.B, R.sub.C, and R.sub.D and the remainder of R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, R.sub.6, R.sub.7, R.sub.8, R.sub.9, R.sub.10, R.sub.11, and R.sub.12 are independently chosen from a hydrogen or a (C.sub.1-C.sub.50) hydrocarbyl group.

The present disclosure relates to aerogels based on transition metal complexes, preparation thereof and there use as highly active atomically dispersed oxygen-reduction catalyst with ultra-high catalytic site density and metal content.

The invention describes single-site metal catalysts such as Pt single-site centers with a 3,6-di-2-pyridyl-1,2,4,5-tetrazine (DPTZ) ligand on support such as a powdered MgO, Al.sub.2O.sub.3, CeO.sub.2 or mixtures thereof.

Metal-organic frameworks (MOFs) may have Zn(II), Pb(II), and/or Cd(II) as a central metal ion; a 4,4′-bipyridylethylene (bpe) ligand as a first ligand; and fumaric acid (fum) and/or oxalic acid (ox) as a second ligand, wherein the 4,4′-bipyridylethylene ligands are stacked in the MOF, and wherein a distance between two consecutive 4,4′-bipyridylethylene ligands is less than 5 Å. Cycloadditions, particularly photoinduced [2+2] cycloadditions may be catalyzed by such MOFs, and/or the conversion of photoinduced [2+2] cycloadditions in inventive MOFs may be increased by mechanical force, such as by grinding.

The invention discloses a nitrogen-doped mesoporous carbon-coated Titanium dioxide composite photocatalyst, a preparation method and use thereof. The preparation method comprises the steps of: dissolving an organic ligand and Ti(OC.sub.3H.sub.7).sub.4 in a mixture of methanol and DMF at a certain ratio, performing a hydrothermal reaction, centrifuging and drying to obtain a Titanium-based metal organic framework (Ti-MOF); pyrolyzing the obtained Ti-MOF under an inert atmosphere, and oxidizing the same for etching to obtain a nitrogen-doped mesoporous carbon-coated Titanium dioxide composite photocatalyst. The obtained composite photocatalyst not only facilitates the adsorption, enrichment and mass transfer of low concentration VOCs, but also efficiently degrades VOCs under sunlight. It has high degradation activity and stability when performing photocatalytic removal of VOCs in the presence of visible light, is simple in synthesis, low in preparation cost, and has strong potential for the use in environmental protection.