Chuanfu Chen

Synthesis and thermal properties of novel star-shaped poly(l-lactide)s with starburst PAMAM–OH dendrimer macroinitiator

Abstract The starburst PAMAM–OH dendrimer (generation 3) as macroinitiator for the synthesis of star-shaped polylactides in the presence of stannous octoate was investigated. Effects of molar ratios of monomer to initiator, monomer to catalyst, monomer conversion, and reaction temperature on polymerization were studied. It is found that 16–21 polylactide arms can be attached to the surface of dendrimer initiator, and the molecular weight of polylactides can be controlled by variation of molar ratios of monomer to initiator and polymerization time. Thermal analysis indicates that the star-shaped polylactides possess lower glass transition temperature, melting point, crystallinity, and maximum decomposition temperature than those of linear polylactide.

Two-phase hydroformylation reaction catalysed by rhodium-complexed water-soluble dendrimers

Four water-soluble dendritic phosphonated ligands were first synthesized based on poly(amidoamine) (PAMAM) (generation 3 with 32 cascade end groups), with the hydrophilic amine or sulfonic acid groups on the surface of the dendrimer. Their Rh(I) complexes were used as the catalysts in the two-phase hydroformylation of styrene and 1-octene at mild reaction conditions. The results showed that these new water-soluble dendritic catalysts exhibited high catalytic activity both for 1-octene and styrene. These new catalysts also exhibited high selectivity for the iso-aromatic aldehyde, while in the long chain olefin case the selectivity was benefited for normal aldehyde.

Synthesis of optically active 1,1′-binaphthyl-phthalocyanines linked via a crown ether unit

Abstract Novel optically active metal and metal-free phthalocyanines, substituted with 1,1′-binaphthyl crown ether units, have been synthesized and characterized.

Synthesis and properties of optically active 6,6′-didodecyl-1,1′-binaphthyl-phthalocyanine linked through crown ether units

Abstract A novel optically active 6,6′-didodecyl-1,1′-binaphthyl-metallophthalocyanine linked through crown ether units (( S )- Pc ) has been synthesized. A stable monolayer of ( S )- Pc that is able to bind metal ions can be formed at the air–water interface. Nonlinear absorption and optical limiting behavior of ( S )- Pc have also been observed.

Synthesis of novel dendrimer-like star block copolymers with definite numbers of arms by combination of ROP and ATRPElectronic supplementary information (ESI) available: Complete experimental procedures; NMR spectra of CMG3-OH and CMG3-PLLA. See http://www.rsc.org/suppdata/cc/b4/b404143g/

Well-defined biodegradable dendrimer-like star block copolymers with up to 24 arms were successfully synthesized by combination of living ring-opening polymerization (ROP) and atom transfer radical polymerization (ATRP) on the basis of dendritic benzyl alcohols.

Quantitative Determination of the Contribution of Charge‐Transfer Complex in the Microemulsion Copolymerization of N‐Butyl Maleimide and Styrene

By using sodium dodecyl sulfate (SDS) and pentanol (PTL) as emulsifiers, the oil-in-water microemulsion containing N-butyl maleimide (NBMI, M 1 ) and styrene (St, M 2 ) was prepared . The microemulsion copolymerization using potassium persulfate (KPS) as an initiator was investigated. On the basis of kinetic model proposed by SHAN Guo-Rong, the reactivity ratios of free monomers and the charge-transfer complex (CTC) in the copolymerization were found to be r 12 = 0.0420, r 21 = 0.0644, r1C = 0.00576 and r 2C = 0.00785, respectively. A kinetic treatment based on this model was used to quantitatively estimate the contribution of CTC to the total copolymerization rate in the NBMI/St copolymerization It was about 17.0-20.0% for a wide range of monomer leed ratios.

Synthesis of the dendronized poly(p-phenylenevinylene) with appendent Fréchet-type dendrons

The dendronized poly(p-phenylenevinylene)s (PPVs) with appendent Frechet-type dendrons were successfully synthesized, and characterized by laser light scattering (LLS), thermogravimetric analysis (TGA), UV-Vis and fluorescence spectra.

OPTICAL LIMITING PROPERTIES OF OPTICALLY ACTIVE METAL-FREE AND METAL PHTHALOCYANINES SUBSTITUTED WITH CHIRAL BINAPHTHYL CROWN ETHER UNITS

The optical limiting properties of five optically active phthalocynines substituted with chiral binaphthyl crown ether units, (R)- and (S)-BNCE-H2Pc, (R)- and (S)-BNCE-CuPc, (S)-BNCE-PbPc, were investigated in solution at 532 nm with 10 ns pulses. The experimental results indicated that the (S)- and (R)-optical isomer exhibit similar optical limiting behavior and the central metal ions, Cu or Pb in the optically active metal phthalocyanine have not significantly enhanced the optical limiting behavior compared with that of the optically active metal-free phthalocyanine. In addition, the nonlinear absorption of the optically active metal-free and metal phthalocyanines was determined by the standard open aperture Z-scan technique.

Synthesis and highly ordered thin films of optically active 2'-methoxy- 1,1'-binaphthyl substituted phthalocyanines

Abstract The synthesis of metal-free and metal phthalocyanines modified with optically active binaphthyl is described. The structure is confirmed by 1 H NMR, UV-Vis, CD, and MALDL–TOF MS. They can form stable monolayers at the air–water interface. In these layers, the phthalocyanines planes are stacked in edge-on arrangement. The monolayers can be transferred onto solid substrates and the resulting LB films are characterized by UV-Vis and CD spectra. In addition, AFM is employed to provide detailed information on the high resolution surface of layer.