Ziqiang Lei

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.

Selective oxidation of cyclohexene catalyzed by polymer-bound ruthenium-2,2'-bipyridine complexes

Abstract Cyclohexene was oxidized to 2-cyclohexen-1-ol and 2-cyclohexen-1-one by atmospheric pressure of molecular oxygen in the presence of linear polystyrene-bound-2,2′-bipyridine–ruthenium complexes in the absence of solvent at 70±5°C selectively. The alcohol/ketone molar ratio of the products can be adjusted by employing different additives or by varying the reaction pH.

Preparation and catalytic activity of polymer-bound 1,10-phenanthroline and its complexes

Abstract Polymer-bound 1,10-phenanthroline (PS-phen) has been prepared by reaction of chloromethylated polystyrene with 5-amino-1,10-phenanthroline. The polymer-bound ligand and its complexes (PS-phenFephen) were characterized by IR spectroscopy and XPS. The polymer bound ferric complexes, which are N , N , N , N -type complexes, show high catalytic selectivity in the oxidation of substituted benzene.

Synthesis and fluorescence properties of terbium‐polybis(benzylsulfinyl) ethane complexes

A functional polymer polybis(benzylsulfinyl) ethane (PBBSE) and Tb 3+ -PBBSE-L (where L is low-molecular-weight organic ligands) ternary complexes were synthesized. The structures of the polymer complexes were investigated by elementary analysis and by comparison of infrared (IR) and fluorescence spectra between the polymer complexes and the corresponding low-molecular-weight complexes. Emission bands of f → ftransition of Tb 3+ in the polymer complexes were characterized. There are 4-7 emission peaks in the fluorescence spectra of the polymer complexes at excitation of ultraviolet light at room temperature. Of particular interest is the strong fluorescence intensity of the polymer ternary complex Tb-PBBSE-Phen. The fluorescence intensity of the complexes was increased in the following order: Tb-PBBSE (27.0) < Tb-PBBSE-TTA (82.3) < Tb-PBBSE-Phen (172.2). The maximum excitation energy and the apparent Stokes shift were increased just as this order in the Tb-PBBSE-low-molecular-weight ligand system complexes.

In situ formation of gold nanoparticles on magnetic halloysite nanotubes via polydopamine chemistry for highly effective and recyclable catalysis

In this study, we present a simple and green approach to fabricate a magnetic halloysite nanotube (MHNT) supported Au nanoparticle (NP) composite (MHNTs–PDA–Au) with a polydopamine functional coating for highly effective and recyclable catalysis. The fabrication of MHNTs–PDA–Au involves decoration of Fe3O4 NPs on HNTs via a one-step co-precipitation method, deposition of a polydopamine layer on the MHNTs and subsequent in situ reduction of Au NPs via polydopamine chemistry. All the processes are simple and eco-friendly without use of additional toxic reagents and complicated treatment. The obtained MHNTs–PDA–Au composite exhibits excellent and versatile catalytic activity toward the reduction of various nitrobenzene derivatives and methylene blue dye when only trace amounts of Au catalyst are used. In addition, the catalytic system can be easily recycled for several cycles based on its good magnetic properties. The synergistic combination of MHNTs, polydopamine coating and metal NPs offers a versatile platform for design of natural HNT based composite materials and will expand the applications of HNTs in heterogeneous catalysis, water purification and green chemistry.

The synthesis and tissue adhesiveness of temperature-sensitive hyperbranched poly(amino acid)s with functional side groups

The incorporation of L-3,4-dihydroxyphenylalanine (L-DOPA) residues in mussel-like biomimetic copolymers has drawn great attention due to their adhesive properties. In this work, a series of temperature-sensitive and hyperbranched poly(amino acid)s containing different functional side groups (catechol, guanidyl, mercapto and double bond) were designed and synthesized by the ring-opening polymerization of N-carboxy-α-amino acid anhydride (NCA), using a temperature-sensitive and multi-hydroxyl end pluronic L-31 as the initiator in this process. The tissue adhesive properties of these copolymers were evaluated by tensile strength tests on wet pork skin. We found that the topological structure, side groups of copolymers, adhesive temperature and cure time had influence on the wet adhesive strength, especially side groups. While only L-DOPA was incorporated into copolymeric chains, the wet adhesive strength was about 106 kPa. With guanidyl, mercapto and double bonds incorporated into copolymeric chains, an obvious increase in the wet adhesive strength was observed. Additionally, the wet adhesive strength improved by about 20 kPa at body temperature (37 °C) as compared to that at room temperature (25 °C). Meanwhile, we found that it has good biocompatibility and degradability through its cytotoxicity and degradation tests.

Sheet polymer and its complexes. II. Preparation and catalytic activity of polymeric tetrakisphenylporphyrin films crosslinked by 4,4'-biphenylene-bisulfoate

The polymeric meso-tetra-( 4,4-biphenylene-bisulfo)-phenylporphyrin and its complexes (PMTBPBSOPP, M = Co, Mn, Cu, and Zn) have been prepared in the presence of phase-transfer catalyst and characterized with ultraviolet-visible spectra, infrared spectra, X-ray photoelectron spectroscopy, and scanning electron microscopy. Its catalytic activity in oxidation of cumene, ethylbenzene, and cyclohexene by molecular oxygen have been studied. Cumene afforded efficiently cumenol (1), acetophenone ( 2 ), together with a small amount of 4-methyl acetophenone ( 3 ). Ethylbenzene afforded efficiently α-methylbenzyl alcohol (4) and acetophenone ( 5 ). Cyclohexene catalyzed by PCuTBPBSOPP in the presence of molecular oxygen afforded 1,2-cyclohexanediol (6) and 1,2-cyclohexanedione (7).

Monomeric molecular modified polymer-bound iron complexes for the oxidation of cyclohexene

Abstract Polymer-bound 2,2′-bipyridine–iron(II,III) complexes have been shown catalytically oxidize cyclic alkenes with atmospheric pressure of molecular oxygen or air in the absence of solvent at ∼70°C. When cyclohexene are oxidized, the double bonds are maintained and 2-cyclohexen-1-ol as well as 2-cyclohexen-1-one is produced with the selectivity to total alcohols and ketones in the range of 92.5–97.7%. The catalytic activity and selectivity are influenced by the polymer supported ligands, monomeric ligands and additives. Complexes with mixed ligands or with coordinatively unsaturated structures exhibit higher catalytic activity compared with the reference complexes.

A new simple synthesis of soluble copolymers of p-diethynylbenzene with phenylacetylene

Copolymers of p-diethynylbenzene with phenylacetylene in the presence of cobalt-tri-n-butylphosphine in diethylamine at room temperature with high molecular weight were synthesized. The copolymers, having the advantage of being highly soluble in common organic solvents, possess mainly trans π-conjugated polyene main chains and phenyl together with phenyl ethynyl side chains.

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.