Provided is a method for producing water-absorbent resin particles, which is capable of improving the gel strength for the purpose of achieving a good balance between the absorption under load and the rate of liquid permeation through gel. The present invention is a method for producing water-absorbent resin particles, which is characterized by comprising a step wherein a monomer composition containing a water-soluble vinyl monomer (a1) and/or a vinyl monomer (a2) that turns into a water-soluble vinyl monomer (a1) by means of hydrolysis and a crosslinking agent (b) is polymerized in the presence of at least one organic main group element compound selected from the group consisting of organic iodine compounds, organic tellurium compounds, organic antimony compounds, and organic bismuth compounds.

The present invention relates to a transition metal-based heterogeneous carbonylation reaction catalyst that has an excellent catalytic activity and selectivity in the carbonylation reaction and is easily separated from a product, by crosslinking polymerizing a transition metal-based homogeneous catalyst unit through a Friedel-Craft reaction; and a method for preparing lactone using the same. The transition metal-based heterogeneous carbonylation reaction catalyst allows to produce lactone or succinic anhydride with an epoxide compound while showing a high selectivity, and can be applied in industrial very usefully due to easy separation from the product and thus reusing thereof.

Use of transition metal complexes of the formula (I) in organic light-emitting diodes

##STR00001## where: M.sup.1 is a metal atom; carbene is a carbene ligand; L is a monoanionic or dianionic ligand; K is an uncharged monodentate or bidentate ligand selected from the group consisting of phosphines; CO; pyridines; nitriles and conjugated dienes which form a complex with M.sup.1; n is the number of carbene ligands and is at least 1; m is the number of ligands L, where m can be 0 or 1; o is the number of ligands K, where o can be 0 or 1; where the sum n+m+o is dependent on the oxidation state and coordination number of the metal atom and on the denticity of the ligands carbene, L and K and also on the charge on the ligands carbene and L, with the proviso that n is at least 1, and also

an OLED comprising these transition metal complexes, a light-emitting layer comprising these transition metal complexes, OLEDs comprising this light-emitting layer, devices comprising an OLED according to the present invention, and specific transition metal complexes comprising atb least two carbene ligands.

The present invention provides an organometal catalyst having a cationic transition metal complex and a borate-based bulky anion, a method for preparing the same, and a method for preparing an oligomer using the same.

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.

Use of transition metal complexes of the formula (I) in organic light-emitting diodes ##STR00001## where: M.sup.1 is a metal atom; carbene is a carbene ligand; L is a monoanionic or dianionic ligand; K is an uncharged monodentate or bidentate ligand selected from the group consisting of phosphines; CO; pyridines; nitriles and conjugated dienes which form a complex with M.sup.1; n is the number of carbene ligands and is at least 1; m is the number of ligands L, where m can be 0 or 1; o is the number of ligands K, where o can be 0 or 1; where the sum n+m+o is dependent on the oxidation state and coordination number of the metal atom and on the denticity of the ligands carbene, L and K and also on the charge on the ligands carbene and L, with the proviso that n is at least 1, and also
an OLED comprising these transition metal complexes, a light-emitting layer comprising these transition metal complexes, OLEDs comprising this light-emitting layer, devices comprising an OLED according to the present invention, and specific transition metal complexes comprising at least two carbene ligands.

Provided is a method for producing water-absorbent resin particles, which is capable of improving the gel strength for the purpose of achieving a good balance between the absorption under load and the rate of liquid permeation through gel. The present invention is a method for producing water-absorbent resin particles, which is characterized by comprising a step wherein a monomer composition containing a water-soluble vinyl monomer (a1) and/or a vinyl monomer (a2) that turns into a water-soluble vinyl monomer (a1) by means of hydrolysis and a crosslinking agent (b) is polymerized in the presence of at least one organic main group element compound selected from the group consisting of organic iodine compounds, organic tellurium compounds, organic antimony compounds, and organic bismuth compounds.

The present disclosure provides N-heterocyclic carbene ligands, catalyst complexes thereof, and methods using same. The present disclosure further provides synthetic methods of preparing the N-heterocyclic carbene ligands and catalyst complexes disclosed herein.

Use of transition metal complexes of the formula (I) in organic light-emitting diodes

##STR00001## where: M.sup.1 is a metal atom; carbene is a carbene ligand; L is a monoanionic or dianionic ligand; K is an uncharged monodentate or bidentate ligand selected from the group consisting of phosphines; CO; pyridines; nitriles and conjugated dienes which form a complex with M.sup.1; n is the number of carbene ligands and is at least 1; m is the number of ligands L, where m can be 0 or 1; o is the number of ligands K, where o can be 0 or 1; where the sum n+m+o is dependent on the oxidation state and coordination number of the metal atom and on the denticity of the ligands carbene, L and K and also on the charge on the ligands carbene and L, with the proviso that n is at least 1, and also
an OLED comprising these transition metal complexes, a light-emitting layer comprising these transition metal complexes, OLEDs comprising this light-emitting layer, devices comprising an OLED according to the present invention, and specific transition metal complexes comprising at least two carbene ligands.

The invention concerns an alkane metathesis catalyst, its production and use. The catalyst comprises a Group V, VI or VII metal alkyl with the metal in its highest oxidation state, preferably Ta or W, and the alkyl of C1-C4, preferably together with alkylidene and/or alkylidyne ligands, in particular -Me, CH2 and CH, on a metal oxide support, preferably silica partially dehydroxylated at 200 or 700 C. Substrates include cycloalkanes, preferably cyclooctane.