Biodegradable polymers with advantageous physical and chemical properties are described, as well as methods for making such polymers. In one embodiment, a new chemical synthesis route to technologically important biodegradable poly(3-hydroxybutyrate) (P3HB) with high isotacticity and molecular weight required for a practical use is described. The new route can utilize racemic eight-membered cyclic diolide (rac-DL), meso-DL, or a rac-DL and meso-DL mixture, derived from bio-sourced dimethyl succinate, and enantiomeric (R,R)-DL and (S,S)-DL, optically resolved by metal-based catalysts. With a stereoselective racemic molecular catalyst, the ROP of rac-DL under ambient conditions produces rapidly P3HB with essentially perfect isotacticity ([mm]>99%), high crystallinity and melting temperature (T.sub.m=171° C.), as well as high molecular weight and low dispersity (M.sub.n=1.54×10.sup.5 g/mol, Ð=1.01).

The present invention provides a method for preparing a cyclic carbonate, which has the advantages of high yield, mild reaction conditions, high catalytic efficiency under room temperature and 1 atm pressure conditions, and wide substrate scopes. It is not only suitable for monosubstituted epoxides, but also suitable for disubstituted epoxides. The method comprises the step of reacting epoxides of Formula (I) with carbon dioxide in the presence of a quaternary ammonium salt and a catalyst, to obtain a cyclic carbonate of Formula (II). The reaction formula is:

##STR00001##

Biodegradable polymers with advantageous physical and chemical properties are described, as well as methods for making such polymers. In one embodiment, a new chemical synthesis route to technologically important biodegradable poly(3-hydroxybutyrate) (P3HB) with high isotacticity and molecular weight required for a practical use is described. The new route can utilize racemic eight-membered cyclic diolide (rac-DL), meso-DL, or a rac-DL and meso-DL mixture, derived from bio-sourced dimethyl succinate, and enantiomeric (R,R)-DL and (S,S)-DL, optically resolved by metal-based catalysts. With a stereoselective racemic molecular catalyst, the ROP of rac-DL under ambient conditions produces rapidly P3HB with essentially perfect isotacticity ([mm]>99%), high crystallinity and melting temperature (T.sub.m=171° C.), as well as high molecular weight and low dispersity (M.sub.n=1.54×10.sup.5 g/mol, Ð=1.01).

Disclosed is a method for preparing a borate ester on the basis of a tricyclopentadienyl rare earth metal complex, the method comprising the following steps: uniformly stirring and mixing a catalyst, a borane and a carbonyl compound for reaction to prepare a borate ester, wherein the catalyst is a tricyclopentadienyl rare earth metal complex; and the molecular formula of the tricyclopentadienyl rare earth metal complex can be expressed as: Ln(Cp).sub.3, wherein Ln represents a rare metal selected from one of lanthanide elements. The preparation method has a higher catalytic activity, mild reaction conditions, a product that is easy to post-treat, a short reaction time, a low catalyst consumption amount, and a good range of applicable substrates, and can be used for industrial production.

The present invention provides a method for preparing a cyclic carbonate, which has the advantages of high yield, mild reaction conditions, high catalytic efficiency under room temperature and 1 atm pressure conditions, and wide substrate scopes. It is not only suitable for monosubstituted epoxides, but also suitable for disubstituted epoxides. The method comprises the step of reacting epoxides of Formula (I) with carbon dioxide in the presence of a quaternary ammonium salt and a catalyst, to obtain a cyclic carbonate of Formula (II). The reaction formula is: ##STR00001##

A nanofibrous catalyst for in the electrolyzer and methods of making the catalyst. The catalysts are composed of highly porous transition metal carbonitrides, metal oxides or perovskites derived from the metal-organic frameworks and integrated into a 3D porous nano-network electrode architecture. The catalysts are low-cost, highly active toward OER, with excellent conductivity yet resistant to the oxidation under high potential operable under both acidic and alkaline environments.

The present invention relates to a metal-organic framework composition, as well as constructs and methods thereof. In one particular example, the composition is employed to degrade a chemical agent in a non-aqueous environment.

A molecular building block composition can include a metal ion component; and a ligand component including a core including at least one functional group associated with the metal ion component and the core.

A nanofibrous catalyst for in the electrolyzer and methods of making the catalyst. The catalysts are composed of highly porous transition metal carbonitrides, metal oxides or perovskites derived from the metal-organic frameworks and integrated into a 3D porous nano-network electrode architecture. The catalysts are low-cost, highly active toward OER, with excellent conductivity yet resistant to the oxidation under high potential operable under both acidic and alkaline environments.

The present invention discloses new catalyst systems based on trivalent metal complexes of Formula I, which can facilitate the stereospecific ring-opening polymerization of (rac)-β-Butyrolactone (rac-BBL). Also provided is a process for the stereospecific synthesis of aliphatic polyesters using the catalysts of Formula I, including alcohols and polyols as chain-transfer agents to facilitate immortal ring-opening polymerization.