Rongmin Wang

A facile one-step synthesis to ionic liquid-based cross-linked polymeric nanoparticles and their application for CO2 fixation

Highly cross-linked polymeric nanoparticles (CLPNs) were prepared via a facile one-step synthesis, and these nanoparticles are effective catalysts for CO2 cycloaddition with epoxides. In this study, CLPNs were synthesized by radical copolymerization of 4-vinylbenzyl-tributylphosphorous chloride (PIL) and ethylene glycol dimethacrylate (EGDMA) in selective solvent, such as C1∼C5 alcohols. The results revealed that spherical nanoparticles with the mean diameter range of 10–100 nm could be prepared in these alcohols, and the size of the CLPNs could be facilely tuned by the feed ratio of EGDMA to PIL. The CLPNs were characterized using dynamic light scattering, scanning electron microscopy, transmission electron microscopy, atomic force microscopy, thermogravimetric analysis, atom absorbance spectrometry, and Fourier transform infrared spectroscopy techniques. In addition, CLPNs can be exploited as highly active and selective catalyst for the cycloaddition of CO2 to epoxides. The effects of parameters, such as reaction temperature, pressure, reaction time, and catalyst amount, on the cycloaddition reaction were investigated. As a result, excellent yield (100%) and selectivity (100%) of cyclic carbonates could be achieved under mild conditions (0.1 g CLPNs, 3.0 MPa CO2, 140 °C and 3 h) without the addition of any solvents or co-catalysts. Unexpectedly, the CLPNs could be dispersed in the products homogeneously, which resulted in the extremely high activity and selectivity. At the same time, the CLPNs could be easily separated by filtration after pouring the reaction mixture into toluene. CLPNs could be recycled six times with less than 1.5% loss of catalytic activity.

Fluorescence properties of ternary complexes of polymer-bond triphenylphosphine, triphenylarsine, triphenylstibine, and triphenylbismuthine, rare earth metal ions, and thenoyltrifluoroacetone

Rare earth metal ions containing polymer ternary complexes were synthesized and characterized. The functional polymers investigated were polymer-bond triphenylphosphine (PBDP), polymer-bond triphenylarsine (PBDAs), polymer-bond triphenylstibine (PBDSb), and polymer-bond triphenylbismuthine (PBDBi) as polymer ligands. Several substances, such as thenoyltrifluoroacetone (TTA), and 8-hydroxyquinoline (oxin), phenanthroline (phen) were used as low molecular weight ligands. The results show that TTA is the best low molecular weight ligand among them. The fluorescence properties of synthesized complexes were investigated; PBDAs is a better polymer ternary complex that possesses stronger fluorescence intensity coordinated with any low molecular weight ligand. The fluorescence lifetimes of Eu3+-containing polymer ternary complexes are between 0.350 and 0.469 MS. The reaction conditions of the formation and stability of rare earth metal ions–polymer–TTA ternary complexes are discussed.

Preparation and catalytic oxidation by polymer supported 4-(2-pyridylazo) rosorcinol–metal complexes

Abstract Polymer-supported 4-(2-pyridylazo) rosorcinol–metal complexes (PS-PAR-M, M=Cu, Co, Ni, Fe) were prepared and characterized by IR, ICP, XPS, and used in the oxidation of ethylbenzene as catalyst. In comparison with their catalytic activities, PS-PAR-Cu was a more effective catalyst for the oxidation of ethylbenzene without solvent. The influences of reaction temperature, the amount of catalyst and substrate concentration, as well as reaction time on the oxidation of ethylbenzene have been investigated. The reaction optimum conditions have been obtained.

Synthesis and fluorescence properties of the mixed complexes of Eu(III) with polymer ligand and thenoyl trifluoroacetone

The mixed ligand complexes of europium(III) with poly(chloromethyl styrene)-bound 1,4,8,11-tetraazacyclotetradecane (PTACT) and thenoyl trifluoroacetone (TTA) have been synthesized and characterized by Fourier transform infrared and elemental analysis, Inductively Coupled Plasma-Atomic Emission Spectrometry, and X-ray photoelectron spectroscopy. The fluorescence properties of PTACT-Eu-TTA were studied, and it is found that the polymer-mixed ligand complexes emit strong fluorescence at room temperature.

Synthesis and selective catalytic oxidation properties of polymer-bound melamine copper(II) complex

Polymer-bound melamine copper(I) complex was synthesized and characterized by FT IR, ICP, XPS, UV and element analysis. 2-Phenyl-propene and p-methyl-1-phenylethanol were produced by selective oxidation of cumene, catalysed by the polymer-bound melamine Cu(I) complex under 1 atm of oxygen at 110C.

Effect of temperature and additives on the reactivity and product selectivity of polymer-bound nickel(II) complex

Abstract Cyclohexene was catalytically oxidized in the presence of molecular oxygen and polymer-bound nickel(II) complex PS-bipy–Ni(II)–oxine (where PS-bipy=polystyrene, bipy=2,2′-bipyridine) in the absence of solvent at 70°C, affording 2-cyclohexen-1-ol, 2-cyclohexen-1-one and dicyclo[4.1.0]-2-oxygen-heterocycloheptane in 27.5% yield. The effect of temperature, additives and the amount of catalyst used on the catalytic activity and product selectivity were discussed.

Ternary copolymer of poly(ethylene oxide), terephthalyl chloride, and lithium 2,5-diaminobenzene sulfonate for ionic conduction

The ternary copolymers of poly( ethylene oxide) (PEO), terephthaloyl chloride(TPC), and lithium 2,5-diaminobenzene sulfonate ( LDABS ) have been synthesized by the separated copolymerization PEO, TPC, and LDABS. Three ternary copolymers, PEO 0.12 -TPC 0.50 -LDABS 0.38 , PEO 0.24 -TPC 0.50 -LDABS 0.26 and PEO 0.36 -TPC 0.51 -LDABS 0.13 , are thermally stable and mechanically strong ionic conductors. The combination of immobilized anionic groups (SO 3-) incorporated into the copolymer to increase the mobile cation concentration and of PEO introduced to enhance ionic conductivity via flexible chain motion. PEO 0.24 - TPC 0.50 -LDABS 0.26 was found to be a good polymeric material with good mechanical properties and a high ionic conductivity of 8.37 x 10 -6 S/cm at 25°C.

Effects of Polymer Supporters and Structures of Polymer-Bound-2, 2′-Bipyridine-Copper(II) Complexes on the Catalytic Oxidation Properties

Abstract Oxidation of alkylbenzenes to aryl alcohols and ketones with high selectivity and reactivity by linear polystyrene (PS)- and polystyrene-2% divinyl benzene (DVB)-bound-copper(II) complexes PS-bipy-Cu, PS-bipy-Cu-bipy, PS-bipy-Cu-phen, and PS-2%DVB-bipy-Cu (where bipy = 2, 2′-bipyridine and phen-1, 10-phenanthroline) was studied. The oxidation reaction was carried out in the presence of molecular oxygen in the absence of solvent at 110 ± 5°C. The reaction rate depends on the nature of the electric and steric effects of the substrates, the complex structure, and the polymer matrices.

A new kind of ternary copolymer for ionic conduction

Two novel ternary copolymers, MNEC-TPC-LDABS and MMEC-TPC-LDABS, were synthesized by condensation copolymerization of mannitol-containing oligomeric side chains (MNEC) or melamine-containing oligomeric side chains (MMEC) with terephthaloyl chloride (TPC) and lithium 2,5-diaminobenzene sulfonate (LDABS), respectively, to become thermally stable and mechanically strong ionic conductors. Incorporating anionic groups (SO 3 2- ) into the structure of copolymers increases mobile cation concentration and introducing MNEC and MMEC enhances ionic conductivity via flexible chain motion assistance. The conductivity (σ) of MNEC-TPC-LDABS is 7.82 X 10 -5 S/cm and of MMEC-TPC-LDABS is 9.17 x 10 -5 S/cm, both measured at 25°C. The crystallinity and T g of the copolymers were greatly decreased by the incorporation of dendritic macromolecule units of MNEC or MMEC. The temperature dependencies of the ionic conductivity for two polymers show curved Arrhenius plots, which suggest that ionic conduction is closely associated with segmental motion of the polymer hosts. The conductivity of the polymer electrolytes obeys the Williams-Landel-Ferry (WLF) and Vogel-Tammann-Fulcher (VTF) equation.