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N-Isopropylacrylamide (NIPAM) was polymerized using 1-pyrenyl 2-chloropropionate (PyCP) as the initiator and CuCl/tris [2-(dimethylamino)

Stereoregular poly(phenylacetylene) derivatives bearing L-leucine ethyl ester pendants, poly-1 and poly-2a, were, respectively, synthesized by the polymerization of N-(4-ethynylphenylcarbamoyl)-L-leucine ethyl ester (1) and N-(4-ethynylphenyl-carbonyl)-L-leucine ethyl ester (2) using Rh(nbd)BPh 4 as a catalyst, while stereoirregular poly-2b was synthesized by solid-state thermal polymerization of 2. Their chiral recognition abilities for nine racemates were evaluated as chiral stationary phases (CSPs) for high-performance liquid chromatography (HPLC) after coating them on silica gel. Both poly-1 and poly-2a with a helical conformation showed their characteristic recognition depending on coating solvents and the linkage groups between poly(phenylacetylene) and L-leucine ethyl ester pendants. Poly-2a with a shorter amide linkage showed higher chiral recognition than poly-1 with a longer urea linkage. Coating solvents played an important role in the chiral recognition of both poly-1 and poly-2a due to the different conformation of the polymer main chains induced by the solvents. A few racemates were effectively resolved on the poly-2a coated with a MeOH/CHCl 3 (3/7, v/v) mixture. The separation factors for these racemates were comparable to those obtained on the very popular CSPs derived from polysaccharide phenylcarbamates. Stereoirregular poly-2b exhibited much lower chiral recognition than the corresponding stereoregular, helical poly-2a, suggesting that the regular structure of poly-(phenylacetylene) main chains is essential to attain high chiral recognition.

The design and synthesis of new hydrogen storage nanomaterials with high capacity at low cost is extremely desirable but remains challenging for today's development of hydrogen economy. Because of the special honeycomb structures and excellent physical and chemical characters, fullerenes have been extensively considered as ideal materials for hydrogen storage materials. To take the most advantage of its distinctive symmetrical carbon cage structure, we have uniformly coated C60's surface with metal cobalt in nanoscale to form a core/shell structure through a simple ball-milling process in this work. The X-ray diffraction (XRD), scanning electron microscope (SEM), Raman spectra, high-solution transmission electron microscopy (HRTEM), energy-dispersive X-ray spectrometry (EDX) elemental mappings, and X-ray photoelectron spectroscopy (XPS) measurements have been conducted to evaluate the size and the composition of the composites. In addition, the blue shift of C60 pentagonal pinch mode demonstrates the formation of Co-C chemical bond, and which enhances the stability of the as-obtained nanocomposites. And their electrochemical experimental results demonstrate that the as-obtained C60/Co composites have excellent electrochemical hydrogen storage cycle reversibility and considerably high hydrogen storage capacities of 907 mAh/g (3.32 wt % hydrogen) under room temperature and ambient pressure, which is very close to the theoretical hydrogen storage capacities of individual metal Co (3.33 wt % hydrogen). Furthermore, their hydrogen storage processes and the mechanism have also been investigated, in which the quasi-reversible C60/Co↔C60/Co-Hx reaction is the dominant cycle process.

Metal template synthesis is a useful methodology to make sophisticated macromolecular architectures because of the variety of metal ion coordination. To use metal template methodology, chelating functionalities should be introduced to macromolecules before complexation. In this article, we demonstrate the click‐to‐chelate approach to install chelating functionality to polystyrene (PS) and complexation with Ru(II) ions to form 3‐arm and 4‐arm star‐branched PS Ru(II) complexes. Azide‐terminated PS (PS‐N3) was readily prepared by atom transfer radical polymerization using 1‐bromoethylbenzene as an initiator followed by substitution of bromine by an azide group. The Cu(I)‐catalyzed 1,3‐dipolar cycloaddition of PS‐N3 with 2‐ethynylpyridine or 2,6‐diethynylpyridine affords 2‐(1H‐1,2,3‐triazol‐4‐yl)pyridine (PS‐tapy) or 2,6‐bis(1H‐1,2,3‐triazol‐4‐yl)pyridine (PS‐bitapy) ligands bearing one or two PS chains at the first‐position of the triazole rings. Ru(II) complexes of PS‐tapy and PS‐bitapy were prepared by conventional procedure. The number‐averaged molecular weights (Mns) of these complexes were determined to be 6740 and 10,400, respectively, by size exclusion chromatography using PS standards. These Mn values indicated the formation of 3‐arm and 4‐arm star‐branched PS Ru(II) complexes [Ru(PS‐tapy)3](PF6)2 and [Ru(PS‐bitapy)2](PF6)2 on the basis of the Mn values of PS‐tapy (2090) and PS‐bitapy (4970). The structures of these complexes were also confirmed by UV–vis spectroscopy and X‐ray crystallography of the Ru(II) complexes [Ru(Bn‐tapy)3](PF6)2 and [Ru(Bn‐bitapy)2](PF6)2, which bear a benzyl group instead of a PS chain. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011