13382-47-3Relevant articles and documents
Synthesis and characterization of α,ω-dihydroxy-telechelic oligo(p-dioxanone)
Grablowitz, Hans,Lendlein, Andreas
, p. 4050 - 4056 (2007)
The homopolymer of 1,4-dioxane-2-one (pDO) is well known as an established biomaterial, especially for degradable surgical sutures. Well-defined α,ω-dihydroxy telechelics based on pDO are introduced in this paper. pDO was synthesized via a one step reaction modified to a literature procedure with a yield of 50-60%. The monomer was polymerized in bulk to oligomeric products via ring-opening polymerization. The polymerization was performed without or with dibutyltin oxide as catalyst using low molecular weight alcohols as initiators. The oligomeric products have number average molecular weights (Mn) between 1800 g mol-1 and 4200 g mol-1. They were soluble in 1,2-dichloroethane or chloroform as common solvents for further reaction in solution. The α,ω-dihydroxy-functionality of the obtained telechelics was investigated by MALDI-TOF MS and 1H NMR spectroscopy. Polymerization in the presence of the catalyst lead to macrocyclic byproducts which have been detected by MALDI-TOF MS. The telechelics were semicrystalline with melting points Tm between 86 °C and 95 °C, increasing with increasing molecular weight. The melting enthalpies ΔHm ranged from 67.7 to 82.3 J g-1. An example of the synthetic opportunities arising from the availability of well-defined telechelic oligomers as starting materials are multiblock copolymers, which were synthesized successfully from oligo(p-dioxane)diol, poly[(rac-lactide)-ran- glycolide]diol and trimethylhexane diisocyanate with weight average molecular weights Mw between 62000 and 149000 g mol-1. The Royal Society of Chemistry.
Production of Hydroxy Acids: Selective Double Oxidation of Diols by Flavoprotein Alcohol Oxidase
Fraaije, Marco W.,Martin, Caterina,Trajkovic, Milos
supporting information, p. 4869 - 4872 (2020/02/11)
Flavoprotein oxidases can catalyze oxidations of alcohols and amines by merely using molecular oxygen as the oxidant, making this class of enzymes appealing for biocatalysis. The FAD-containing (FAD=flavin adenine dinucleotide) alcohol oxidase from P. chrysosporium facilitated double and triple oxidations for a range of aliphatic diols. Interestingly, depending on the diol substrate, these reactions result in formation of either lactones or hydroxy acids. For example, diethylene glycol could be selectively and fully converted into 2-(2-hydroxyethoxy)acetic acid. Such a facile cofactor-independent biocatalytic route towards hydroxy acids opens up new avenues for the preparation of polyester building blocks.
Templating a polymer-scaffolded dynamic combinatorial library
Mahon, Clare S.,Jackson, Alexander W.,Murray, Benjamin S.,Fulton, David A.
supporting information; experimental part, p. 7209 - 7211 (2011/09/12)
A water soluble polymer-scaffolded dynamic combinatorial library whose members can interconvert through acylhydrazone exchange was prepared and shown to re-equilibrate in the presence of macromolecular templates.
Carbohydrate rod conjugates: Ternary rod-coil molecules forming complex liquid crystal structures
Chen, Bin,Baumeister, Ute,Pelzl, Gerhard,Das, Malay Kumar,Zeng, Xiangbing,Ungar, Goran,Tschierske, Garsten
, p. 16578 - 16591 (2007/10/03)
T-shaped polyphilic triblock molecules, consisting of a rodlike p-terphenyl unit, a hydrophilic and flexible laterally attached oligo(oxyethylene) chain terminated by an 1-acylamino-1-deoxy-D-sorbitol unit, and two end-attached lipophilic alkyl chains, have been synthesized by palladium-catalyzed cross-coupling reactions as the key steps. The thermotropic liquid crystalline behavior of these compounds was investigated by polarized light microscopy, differential scanning calorimetry (DSC), and X-ray scattering. We investigated the mode of self-organization as a function of the length and position of the lateral polar chain and the length of the terminal alkyl chains. Depending on the size of the polar and lipophilic segments, a series of unusual liquid crystalline phases was detected. In three of these phases, the space is divided into three distinct periodic subspaces. In addition to a hexagonal channeled layer phase (ChLhex) consisting of layers that are penetrated by polar columns, there are also two honeycomb-like network structures formed by square (Colsqu/p4mm) or pentagonal cylinders (Colsqu/p4gm) . The cylinder walls consist of the terphenyl units fused by columns of alkyl chains, and the interior contains the polar side chains. In addition, a hexagonal columnar phase was observed in which the polar columns are organized in a continuum of terphenyls and alkyl chains with an organization of the terphenyl cores tangentially around the columns with the long axis perpendicular to the columns. For one compound, a reversal of birefringence was observed, which is explained by a reorientation of the terphenyl cores. The addition of protic solvents induces lamellar phases.
Supramolecular dendrimers: Unusual mesophases of ionic liquid crystals derived from protonation of DAB dendrimers with facial amphiphilic carboxylic acids
Cook, Andrew G.,Baumeister, Ute,Tschierske, Carsten
, p. 1708 - 1721 (2008/12/20)
Supramolecular liquid crystalline (LC) dendrimers were prepared by self-assembly of first to fifth generation amino terminated DAB dendrimers with facial amphiphilic carboxylic acids. These carboxylic acids are composed of three distinct incompatible segm
