Thermally triggered frame-guided assembly.

We report a thermally triggered frame-guided assembly (FGA) strategy for the preparation of vesicles. We employ thermally responsive poly(propylene oxide) (PPO) to make the leading hydrophobic groups (LHGs) thermally responsive, so that they are hydrophilic below the low critical solution temperature (LCST) and the frame forms in a homogeneous environment. When the temperature is increased above the LCST, the LHGs become hydrophobic and the assembly process is triggered, which drives DNA-b-PPO to assemble around the LHGs, forming vesicles. This work verified that FGA is a general strategy and can be applied to polymeric systems. The thermally triggered assembly not only provides more controllability over the FGA process but also promotes an in-depth understanding of the FGA strategy and in a broad view, the formation mechanism and functions of cell membrane.

Air-stable Ir-(P-Phos) complex for highly enantioselective hydrogenation of quinolines and their immobilization in poly(ethylene glycol) dimethyl ether (DMPEG).

An air-stable catalyst system Ir-(P-Phos) catalyst was found to be highly effective in the asymmetric hydrogenation of quinoline derivatives. The catalyst immobilized in DMPEG was efficiently recovered and reused eight times, retaining reactivity and enantioselectivity.

Reversibly controlled morphology transformation of an amphiphilic DNA-dendron hybrid.

Spherical micelles and nanofibers assembled from an amphiphilic DNA-dendron hybrid can be reversibly achieved under optimum assembly conditions. The possible morphology transformation mechanism is proposed and further confirmed by X-ray diffraction, TEM and DLS experiments.

pH-induced morphology-shifting of DNA-b-poly(propylene oxide) assemblies.

The designed DNA sequences can make DNA-b-PPO undergo in situ transition between diblock and triblock upon pH changes, consequently, induce a morphology-shifting from spherical micelles to nanofibers. This process is reversible and the assembled structures have been characterized by CD, TEM and fluorescent experiments.

The synthesis and properties of iridium(III)-cored dendrimers with carbazole peripherally functionalized beta-diketonato dendrons.

A simple convergent synthetic approach has been developed for the synthesis of iridium(III)-cored dendrimers with carbazole peripherally functionalized beta-diketonato dendrons. The zeroth- to third-generation green-emitting dendrimers were synthesized by reacting the corresponding beta-diketonato dendrons with iridium(III) dimer under mild conditions with good yields, respectively. This approach proved to be modular, and could be used to prepare blue-green-emitting and red-emitting dendrimers with the same beta-diketonato dendrons only by using different cyclometallating ligands. The resulting dendritic ligands and iridium(III)-cored dendrimers were well characterized. Their photoluminescent properties both in solution and in the solid state were tested. It was found that all the dendrimers retained the photophysical properties of the corresponding small analogues with high emission quantum yields (0.06-0.30). Preliminary results indicated that these dendrimers functionalized carbazole units exhibited distinct light-harvesting potential, resulting in a strong intense emission from the iridium core of the dendrimers.

Polymer-supported chiral catalysts with positive support effects.

In this paper, we discuss the rational design of polymeric catalysts and the positive effect of polymer supports on the catalytic asymmetric reactions. The attachment of chiral catalysts to soluble polymers, particularly dendritic polymers, offered a potential combination of the advantages of homogeneous and heterogeneous asymmetric catalysis.