Provided are novel dinuclear indium catalysts of formula (A) that are capable of living and immortal ring opening polymerization and copolymerization of cyclic ester monomers for the preparation of biodegradable polymers and copolymers, in particular polyesters. Also disclosed are polymerization methods and polymer products. These dinuclear indium catalysts allow less costly, highly reactive living polymerization of cyclic ester monomers with possible high turn over rates and/or substantial stereo-chemical and microstructure control. ##STR00001##

Provided is a catalyst for transesterification reactions, which contains an iron salen complex. Also provided is a method for producing an ester compound, which is characterized by carrying out a transesterification reaction between a starting material ester and a starting material alcohol with use of the catalyst.

This invention relates to a supported catalyst system comprising: (i) at least one first catalyst component comprising a group 4 bis(phenolate) complex; (ii) at least one second catalyst component comprising a 2,6-bis(imino)pyridyl iron complex; (iii) activator; and (iv) support. The catalyst system may be used for preparing polyolefins, such a bimodal polyethylene, typically in a gas phase polymerization.

Disclosed herein is a class of chiral binuclear metal complexes for stereoselective glycoside hydrolysis of saccharides, and more particular chiral binuclear transition metal complex catalysts that discriminate epimeric glycosides and α- and β-glycosidic bonds of saccharides in aqueous solutions at near physiological pHs. The chiral binuclear metal complexes include a Schiff-base-type ligand derived from a chiral diamino building block, and a binuclear transition metal core, each which can be varied for selectivity. The metal core is a Lewis-acidic metal ion, such as copper, zinc, lanthanum, iron and nickel. The Schiff-base may be a reduced or non-reduced Schiff-base derived from aliphatic linear, aliphatic cyclic diamino alcohols or aromatic aldehydes. The ligand can be a penta- or heptadentate ligand derived from pyridinecarbaldehydes, benzaldehydes, linear or cyclic diamines or diamino alcohols.

The present invention provides a novel catalyst of formula (I): wherein M is selected from Zn(H), Co(II), Mn(II), Mg(II), Fe(II), Cr(III)—X or Fe(III)—X, and the use thereof in polymerising carbon dioxide and an epoxide.

A tetraanionic OCO pincer ligand metal-oxo-alkylidene complex is prepared from a trianionic pincer ligand supported metal-alkylidyne. The metal can be tungsten or other group 5-7 transition metal. The tetraanionic pincer ligand metal-oxo-alkylidene complex, a trianionic OCO pincer ligand metal complex, or a trianionic ONO pincer ligand metal complex can be used to polymerize cycloalkenes. The poly(cycloalkene)s are predominantly cis-alkene macrocyclics.

The present invention relates to methods for improving carbon capture using entrained catalytic-particles within an amine solvent. The particles are functionalized and appended with a CO.sub.2 hydration catalyst to enhance the kinetics of CO.sub.2 hydration and improve overall mass transfer of CO.sub.2 from an acid gas.

A catalyst which can catalyze ring-addition reaction of CO.sub.2 and an alkylene oxide at 0˜180° C. under 0.1˜8.0 MPa to produce a corresponding cyclic carbonate, and the preparation thereof. The catalyst is a conjugated microporous macromolecule polymer complexed with cobalt, chromium, zinc, copper or aluminium, and by using the macromolecule catalyst complexed with different metals to catalyze the reaction of CO.sub.2 and alkylene oxide at normal temperature and normal pressure, a yield of the corresponding cyclic carbonate of 35%˜90% can be obtained. The catalyst is easy to recover and the re-use of the catalyst has no influence on the yield; additionally, the yield can reach over 90% by controlling the reaction conditions.

The present disclosure provides novel methods of making aluminum complexes with utility for promoting epoxide carbonylation reactions. Methods include reacting neutral metal carbonyl compounds with alkylaluminum complexes.

A new family of mononuclear organometallic complexes of a divalent metal bound to sequential tetradentate monoanionic {ONNN}-type ligands, and polymerization of cyclic esters such as lactides utilizing same are provided. Novel tetradentate monoanionic {ONNN}-type ligands usable for forming these complexes are also provided.