The present invention relates to the field of polymerisation catalysts, and systems comprising these catalysts for polymerising carbon dioxide and an epoxide, a lactide and/or lactone, and/or an epoxide and an anhydride. The catalyst is of formula (I):

##STR00001##

wherein at least one of M.sub.1 or M.sub.2 is selected from Ni(II) and Ni(III)-X. A process for the reaction of carbon dioxide with an epoxide; an epoxide and an anhydride; and/or a lactide and/or a lactone in the presence of the catalyst is also described.

The present invention concerns a method for the preparation of a catalyst onto a solid support of a (semi-)conductive material consisting in depositing said catalyst onto said support from a near-neutral aqueous solution containing at least one nickel or cobalt organic complex and at least one basic oxoanion, by a method selected in the group consisting of reductive electrodeposition, photochemical electrodeposition and photoelectrochemical deposition. The present invention also concerns said catalyst and uses thereof.

An especially robust compound and its derivative metal complexes that are approximately one hundred-fold superior in catalytic performance to the previously invented TAML analogs is provided having the formula:

##STR00001##

wherein Y.sub.1, Y.sub.2, Y.sub.3 and Y.sub.4 are oxidation resistant groups which are the same or different and which form 5- or 6-membered rings with a metal, M, when bound to D; at least one Y incorporates a group that is significantly more stable towards nucleophilic attack than the organic amides of TAML activators; D is a metal complexing donor atom, preferably N; each X is a position for addition of a labile Lewis acidic substituent such as (i) H, deuterium, (ii) Li, Na, K, alkali metals, (iii) alkaline earth metals, transition metals, rare earth metals, which may be bound to one or more than one D, (iv) or is unoccupied with the resulting negative charge being balanced by a nonbonded countercation; at least one Y may contain a site that is labile to acid dissociation, providing a mechanism for shortening complex lifetime. The new complexes deliver catalytic performances that promise to revolutionize multiple oxidation technology spaces including water purification.

Various embodiments disclosed relate to bridged phthalocyanine- and napththalocyanine-metal complex catalysts and methods of using and purifying the same. In various embodiments, the present invention provides a method of purifying a catalyst. The method includes contacting a catalyst composition with acid, the catalyst composition including a catalyst, to provide an acidified catalyst composition with the catalyst dissolved therein. The method includes precipitating the catalyst, and removing the precipitated catalyst from solution, to provide a purified catalyst.

The present invention relates to the field of polymerisation catalysts, and systems comprising these catalysts for polymerising carbon dioxide and an epoxide, a lactide and/or lactone, and/or an epoxide and an anhydride. The catalyst is of formula (I): ##STR00001##
wherein at least one of M.sub.1 or M.sub.2 is selected from Ni(II) and Ni(III)-X. A process for the reaction of carbon dioxide with an epoxide; an epoxide and an anhydride; and/or a lactide and/or a lactone in the presence of the catalyst is also described.

The present invention relates to a method of generating chlorine dioxide from chlorite salts in the presence of an iron ion-containing complex, a method of treating a substrate with a chlorine-containing oxidant in the presence of an iron ion-containing complex and related aqueous media, kits and compositions.

The present invention provides unimolecular metal complexes having increased activity in the copolymerization of carbon dioxide and epoxides. Also provided are methods of using such metal complexes in the synthesis of polymers. According to one aspect, the present invention provides metal complexes comprising an activating species with co-catalytic activity tethered to a multidentate ligand that is coordinated to the active metal center of the complex.

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 polymerizing carbon dioxide and an epoxide.

The present invention provides unimolecular metal complexes having increased activity in the copolymerization of carbon dioxide and epoxides. Also provided are methods of using such metal complexes in the synthesis of polymers. According to one aspect, the present invention provides metal complexes comprising an activating species with co-catalytic activity tethered to a multidentate ligand that is coordinated to the active metal center of the complex.

Various embodiments disclosed relate to a method of oxidizing sulfur-containing compounds. The method involves contacting a sulfur-containing compound with a helmet phthalocyaninato-type catalyst in the presence of an oxidant. The present invention also provides a method of removing undesired sulfur-containing compounds from a fluid, such as natural gas, crude oil or an aqueous waste stream.