20994-26-7Relevant academic research and scientific papers
Synthesis and characterization of block copolymers of polystyrene and thermotropic liquid crystalline polyesters
Chen, Cheng-Chih,Lin, Chih-Hung
, p. 125 - 133 (2018)
A series of block copolymers containing a thermotropic liquid crystalline polymer and an amorphous polystyrene have been synthesized. The block copolymers were prepared by solution polycondensation of α,ω-dicarboxylic acid-terminated polystyrene with 4,4′-dicarboxy-1,6-diphenoxy-hexane and 4,4′-bis(2-hydroxyalkyloxy)biphenyls in a mixture of triphenylphosphine, hexachloroethane, and pyridine. The obtained polymers were fractionated to isolate the pure block copolymer. The block copolymers were characterized by FTIR spectroscopy, differential scanning calorimetry, thermogravimetric analysis, optical polarizing microscopy measurement. Optical polarizing microscopy measurements verify the presence of a smectic liquid crystalline phase for the block copolymers. The block copolymers represent a microphase-separated morphology, i.e., both amorphous and liquid crystalline properties were displayed by the polystyrene and liquid crystalline polyester segments respectively.
New bis-thiazolium analogues as potential antimalarial agents: Design, synthesis, and biological evaluation
Caldarelli, Sergio A.,El Fangour, Siham,Wein, Sharon,Tran Van Ba, Christophe,Périgaud, Christian,Pellet, Alain,Vial, Henri J.,Peyrottes, Suzanne
, p. 496 - 509 (2013/04/23)
Bis-thiazolium salts are able to inhibit phosphatidylcholine biosynthesis in Plasmodium and to block parasite proliferation in the low nanomolar range. However, due to their physicochemical properties (i.e., permanent cationic charges, the flexibility, and lipophilic character of the alkyl chain), the oral bioavailability of these compounds is low. New series of bis-thiazolium-based drugs have been designed to overcome this drawback. They feature linker rigidification via the introduction of aromatic rings and/or a decrease in the overall lipophilicity through the introduction of heteroatoms. On the basis of the structure-activity relationships, a few of the promising compounds (9, 10, and 11) were found to exhibit potent antimalarial in vitro and in vivo activities (EC50 50 ip 0.7 mg/kg).
One-pot synthesis of cyclophane-type macrocycles using manganese(iii)- mediated oxidative radical cyclization
Ito, Yosuke,Tomiyasu, Yuichi,Kawanabe, Takahiro,Uemura, Keisuke,Ushimizu, Yuu,Nishino, Hiroshi
, p. 1491 - 1507 (2011/04/23)
Cyclophane-type macrocyclic compounds from 21 to 56 members having two fused dihydrofuran rings were synthesized by the manganese(iii)-mediated oxidation of terminal dienes with bis(3-oxobutanoate)s containing aromatics. The reaction detail, characterization and reaction pathways are described. The Royal Society of Chemistry 2011.
Synthesis and Properties of Liquid-Crystalline Polymers with Laterally and Terminally Linked Mesogenic Units
Roetz, U.,Lindau, J.,Weissflog, W.,Reinhold, G.,Unseld, W.,Kuschel, F.
, p. 185 - 194 (2007/10/02)
Within the class of dimesogenic liquid-crystalline polymers, series of new LC-polyesters with laterally and terminally linked mesogenic units were synthesized.The mesogenic moieties perpendicularly arranged to the main chain are endowed either with identical or with unequal wing groups.Depending on the wing group and the spacer length, the polyesters can form monotropic or enantiotropic nematic and smectic phases.These polymers were subjected to characterization studies using optical microscopy, differential scanning calorimetry and X-ray diffraction techniques.The phase behavior is compared with that of combined and cross-shaped polymeric mesogens.Keywords: structures of dimesogenic LC-polymers, combined LC-polymers, lateral fixation of mesogens, equal or unequal substituents.
Esters of 3-tert-butyl- and 3-tert-butyl-5-alkyl-4-hydroxyphenyl (alkane) carboxylic acids with oxethylates of polyhydroxyaromatics, process for their production, and their use as stabilizers
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, (2008/06/13)
Esters of 3-tert-butyl- and 3-tert-butyl-5-alkyl-4-hydroxyphenyl(alkane) carboxylic acids of Formula I STR1 with oxethylates of polyhydroxyaromatics of 2-6 hydroxy groups of general Formulae II and III, containing 1-6 oxethylate units, STR2 with X=(CH2)q OH X'=(CH2)r OH wherein q, r, s can be 0 or 1, preferably 0, X"=(CH2)s OH R,R', R"=H, alkyl, halogen, STR3 preferably 4-hydroxyphenyl, n=2 to 6 for z or z'=0, preferably 2 or 3, and n=1 to 5 for z or z'≠0, preferably 2 or 3, o+p=n 0≤a, z≤a+z≤6-n (in Formula II) 0≤b, c, z'≤4≤8-n (in Formula III). are useful for the stabilization of polymers.
