22663-09-8Relevant articles and documents
"click" tetradentate ligands
Hao, Erhong,Wang, Zhaoyun,Jiao, Lijuan,Wang, Shaowu
, p. 2660 - 2666 (2010)
A series of triazole-based N4 tetradenate ligands 1a-d are efficiently synthesized using CuI-catalyzed azide-alkyne "click" strategy and are readily coordinated to many metal ions (e.g. MnII, NiII, ZnII and FeII). The X-ray structures of the resultant metal-complexes (4a-d, 5a, 6a and 7a) reveal an octahedral mononuclear structure with two co-ligands bonded in cis sites and the two triazoles as nitrogen donors to the metal center. The MnII-complexes (4a-d) show efficient catalytic activities in the epoxidation of various aliphatic terminal olefins with peracetic acid, and feature with low catalyst loading, fast conversion and high yields. The Royal Society of Chemistry 2010.
Hyperbranched polyesters by polycondensation of fatty acid-based AB: N-type monomers
Testud, Blandine,Pintori, Didier,Grau, Etienne,Taton, Daniel,Cramail, Henri
, p. 259 - 269 (2017/08/16)
Widely available vegetable oils were readily derivatized into chemically pure ABn-type monomers (n = 2 or 3). Their polymerization led to unprecedented hyperbranched polyesters. Four different AB2/AB3-type monomers bearing one A-type methyl ester and two or three B-type alcohol functions were purposely synthesized via two elementary steps, i.e. epoxidation of the internal double bond of the vegetable oil precursors followed by ring-opening of the epoxy groups under acidic conditions. The polycondensation of these bio-sourced monomers was performed in bulk, in the presence of an appropriate catalyst, giving access to modular hyperbranched polyesters with tunable properties. Among the catalysts tested, zinc acetate, 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD) and sodium methoxide proved the most effective, allowing the achievement of molar masses in the range 3000-10000 g mol-1 and dispersities varying from 2 to 15, depending on the initial conditions. The degree of branching, DB, as determined by 1H NMR spectroscopy, was found to be between 0.07 and 0.45. The as-devised hyperbranched polyesters displayed either amorphous or semi-crystalline properties, as a function of the selected AB2/AB3-type initial monomers, with a glass transition temperature, Tg, ranging from -33 to 9 °C and a decomposition temperature at 5 wt% of the sample, Td5%, varying from 204 to 340 °C.
Synthesis of fully alternating polycarbonate with low Tg from carbon dioxide and bio-based fatty acid
Zhang, Ying-Ying,Zhang, Xing-Hong,Wei, Ren-Jian,Du, Bin-Yang,Fan, Zhi-Qiang,Qi, Guo-Rong
, p. 36183 - 36188 (2014/11/07)
The selective copolymerization of CO2 and an epoxide to form fully alternating polycarbonates is a great challenge via catalysis with the zinc-cobalt(iii) double metal cyanide complex [Zn-Co(iii) DMCC]. We describe the first perfectly alternating copolymerization of CO2 with a bio-based epoxide. The resultant polycarbonate had a low Tgs of -38 to -44 °C and two end hydroxyl groups, which were then used to initiate ring-opening polymerization of l-lactide via metal-free catalysis, affording a biodegradable triblock copolymer. This study provides a new platform copolymer for making various advanced polymers with biodegradable properties. This journal is the Partner Organisations 2014.
