A new class of tunable metallacrown ether rhodium catalysts based on α,ω-(phosphine–phosphite) polyether ligands were prepared either by a template-induced method or by a nontemplate procedure. For the asymmetric hydrogenation of α-arylenamides with the addition of K⁺ cations, the ortho-diphenylphosphine-substituted metallacrown ether catalyst showed high enantioselectivities (up to 99 % ee), which are comparable to or better than the results obtained for phosphine–phosphite ligands with two or more chiral elements. Remarkable enhancements in enantioselectivity and noticeably increased catalytic activity were achieved through the supramolecular recognition between K⁺ cations and the metallacrown ether catalyst.

A new kind of podand-based dimeric salen ligand was synthesized, and its association with potassium cations was investigated by ¹H NMR spectroscopy. The corresponding Cr^III–salen dimer was assembled by a supramolecular host–guest self-assembly process and was then used as a catalyst in highly efficient and enantioselective asymmetric Henry reactions. Regulation by KBAr_F (BAr_F=[3,5-(CF₃)₂C₆H₃]₄B) led to remarkable improvements in yield (by up to 58 %) and enantioselectivity (for example, from 80 % ee to 96 % ee).

A new class of peripherally multiple aromatic ester-functionalized poly(benzyl ether) dendrons and/or dendrimers with different focal point substituents, surface groups, interior structures, as well as different generations have been synthesized and their structure–property relationships with respect to their gelation ability have been investigated systematically. Most of these dendrons are able to gel organic solvents over a wide polarity range. Evident dendritic effects were observed not only in gelation capability but also in thermotropic, morphological, and rheological characterizations. It was disclosed that subtle changes in peripheral ester functionalities and interior dendritic structures affected the gelation behavior of the dendrons significantly. Among all the dendrons studied, the second- and third-generation dendrons G₀G₂-Me and G₀G₃-Me with dimethyl isophthalates (DMIP) as peripheral groups exhibited the best capability in gelation, and stable gels were formed in more than 22 aromatic and polar organic solvents. The lowest critical gelation concentration (CGC) reached 2.0 mg mL⁻¹, indicating that approximately 1.35×10⁴ solvent molecules could be entrapped by one dendritic molecule. Further study on driving forces in gel formation was carried out by using a combination of single-crystal/powder X-ray diffraction (XRD) analysis and concentration-dependent (CD)/temperature-dependent (TD) ¹H NMR spectroscopy. The results obtained from these experiments revealed that the multiple π–π stacking of extended π-systems due to the peripheral DMIP rings, cooperatively assisted by non-conventional hydrogen-bonding, is the key contributor in the formation of the highly ordered supramolecular and fibrillar network. In addition, these dendritic organogels exhibited unexpected thixotropic-responsive properties, which make them promising candidates with potential applications in the field of intelligent soft materials.

New chiral binaphthyl-containing polyfluorene (PF) derivatives, PFOH, PFMOM, and PFP, bearing different binaphthyl units ((S)-2,2′-bis(methoxymethoxy)-1,1′-binaphthyl for PFMOM, (S)-1,1′-binaphthyl-2,2′-diol for PFOH, and (S)-2,2′-bis(diphenylphosphinyl)-1,1′-binaphthyl for PFP) in the backbone have been designed and synthesized through Pd-catalyzed Suzuki polycondensation. Their properties have been investigated in detail by ¹H NMR, ¹³C NMR, TGA, DSC, UV–vis, photoluminescence (in solutions, in thin films before and after annealing), and circular dichroism (CD) spectroscopic methods compared with poly(9,9-dihexylfluorene-2,7-diyl) (PF). The resulting copolymers possessed excellent solubility in organic solvents and emitted strong blue light. The phosphine oxide-containing copolymers PFP and PFMOM exhibited higher quantum yields and better thermal spectral stability in comparison with PF. All the copolymers exhibited obviously the linearly polarized photoluminescent properties both in solutions and in solid states. High emission polarization ratios (R_PL) of PFP were observed with no obvious decrease upon thermal annealing. In addition, investigation of the CD spectroscopic properties of these copolymers in THF solutions indicated that the chirality of the binaphthyls could be transferred to the whole PF backbone. All these results demonstrated that introduction of the chiral binaphthyls, particularly BINAPO, into the backbone could effectively improve the performances of the copolymers. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011