17017-03-7Relevant articles and documents
Photohealable ion gels based on the reversible dimerisation of anthracene
Saruwatari, Aya,Tamate, Ryota,Kokubo, Hisashi,Watanabe, Masayoshi
, p. 13371 - 13374 (2018)
We report a photohealable ion gel based on the photodimerisation of anthracene as a dynamic covalent bond. A tetra-arm poly(ethylene glycol) terminally functionalised with anthracene was synthesised and combined with an ionic liquid to form an ion gel. Th
Preparation of a High-Strength Hydrogel with Slidable and Tunable Potential Functionalization Sites
Li, Zhao,Zheng, Zhen,Su, Shan,Yu, Lin,Wang, Xinling
, p. 373 - 386 (2016)
A hydrogel with tunable potential functionalization sites has been successfully prepared. As potential functionalization sites, (2-hydroxypropyl)-α-CDs (Hy-α-CDs) were introduced into the network of tetrahedron-like poly(ethylene glycol) (tetra-PEG) gel t
Control of the intermolecular photodimerization of anthracene derivatives by hydrogen bonding of urea groups in dilute solution
Matsumoto, Hisato,Nishimura, Yoshinobu,Arai, Tatsuo
, p. 1071 - 1079 (2016)
The photodimerization reaction of anthracene derivatives was performed by capitalizing on intermolecular hydrogen bonds. Anthracene derivatives that can control the dimerization reaction depending on the substitution site were designed by using two anthryl moieties and one urea group, referred to as N,N′-dianthracen-n-ylurea, nDAU (n = 1, 2 and 9), which are symmetrically substituted by 1-anthryl, 2-anthryl and 9-anthryl groups, respectively. We investigated the excimer emission and photodimerization reaction of these anthracene-urea derivatives using absorption, emission, and 1H NMR spectroscopy along with fluorescence decay measurements. All derivatives showed a concentration dependence of their fluorescence spectra and multiple fluorescence lifetime components even at 10-6 M. Significantly, 9DAU resulted in an intermolecular photodimerization reaction. These differences in photoreactivity of nDAU may depend on variations in the overlap of the intermolecularly associated anthracene rings of nDAU by hydrogen bonding between intermolecular urea moieties. Furthermore, the dimerization quantum yield of 9DAU was reduced by the addition of tetrabutylammonium acetate (TBAAc). Consequently, we revealed that the substitution site and the addition of TBAAc affected the dimerization reaction of anthracene-urea derivatives.
Postpolymerization modification of hydroxyl-functionalized polymers with isocyanates
Biedermann, Frank,Appel, Eric A.,Del Barrio, Jesus,Gruendling, Till,Barner-Kowollik, Christopher,Scherman, Oren A.
experimental part, p. 4828 - 4835 (2012/05/20)
The postpolymerization functionalization of hydroxyl-group terminated polymers (Mn in the range of 1000-6000 g mol-1) such as poly(ethylene glycol) (PEG), poly(N-isopropylacrylamide) (PNIPAM), poly(N,N-dimethylacrylamide) (PDMAM), and poly(tert-butyl acrylate) (PtBA) with a wide range of functional isocyanate derivatives such as azobenzene, viologen, and anthracene has been investigated. It was shown by 1H and 13C NMR, GPC, Fourier transform infrared spectroscopy (FTIR), and electrospray ionization mass spectrometry (ESI-MS) that a high degree of end-group conversion, typically >98%, with little or no formation of side products can be achieved at ambient temperature. PNIPAM, PDMAM, PtBA, and PHEAM polymers have been obtained by reversible addition-fragmentation chain transfer (RAFT) radical polymerization from a hydroxyl-group containing chain transfer agent (CTA). The formation of the carbamate has been shown to be compatible with the trithiocarbonate end-group of the RAFT polymers. Additionally, this approach allows for the direct functionalization of RAFT polymers without the need of additional steps such as deprotection or aminolysis of the CTA. This route was subsequently used for the preparation of a variety of side-chain functional polymers from poly(N-hydroxyethyl acrylamide) (PHEAM). Three different high yielding methods have been employed to prepare the isocyanates (R-NCO). Either amino or carboxylic acid precursors have been converted into the desired R-NCO or hydroxyl group moieties have been reacted with an excess of 1,6-hexamethylene diisocyanate (HDI) to statistically form the monofunctional product.
2-Arylureidobenzoic Acids: Selective Noncompetitive Antagonists for the Homomeric Kainate Receptor Subtype GluR5
Valgeirsson, Jon,Nielsen, Elsebet ?.,Peters, Dan,Varming, Thomas,Mathiesen, Claus,Kristensen, Anders S.,Madsen, Ulf
, p. 5834 - 5843 (2007/10/03)
A series of 2-arylureidobenzoic acids (AUBAs) was prepared by a short and effective synthesis, and the pharmacological activity at glutamate receptors was evaluated in vitro and in vivo. The compounds showed noncompetitive antagonistic activity at the kainate receptor subtype GluR5. The most potent compounds showed more than 50-fold selectivity for GluR5 compared to GluR6 and the AMPA receptor subtypes GluR1-4. The structure-activity relationships for the AUBAs showed distinct structural requirements for the substituents on the two aromatic ring systems. Only para-substituents were tolerated on the benzoic acid moiety (ring A), whereas ring B tolerated a variety of substituents, but with a preference for lipophilic substituents. The most potent compounds had a 4-chloro substituent on ring A and 3-chlorobenzene (6b), 2-naphthalene (8h), or 2-indole (8k) as ring B and had IC50 values of 1.3, 1.2, and 1.2 μM, respectively, in a functional GluR5 assay. Compound 6c (IC50 = 4.8 μM at GluR5) showed activity in the in vivo ATPA rigidity test, indicating that 6c has better pharmacokinetic properties than 8h, which was inactive in this test. The AUBAs are the first example of a series of noncompetitive GluR5-selective antagonists and may prove to be important pharmacological tools and leads in the search for therapeutic glutamatergic agents.
