72885-31-5Relevant articles and documents
The synthesis and dielectric properties of a new phenylbenzoate-based calamitic liquid crystal
Ahlatc?o?lu ?zerol, Esma,Ocak, Hale,Bilgin Eran, Belk?z,Karavelio?lu, Selvi
, p. 225 - 232 (2020/08/10)
The dielectric investigation has a great importance in liquid crystal studies as a supportive method to DSC for a complete characterization of liquid crystals as well as in the electronic applications. In this study, the synthesis, mesomorphic characterization and dielectric properties of a new phenylbenzoate-based three-ring calamitic liquid crystal which composed of ester linking groups, (S)-3,7-dimethyloctyloxy chiral unit at one of terminals and n-octyloxy chain at the other end of the molecule, have been reported. The new calamitic liquid crystal 4-[4-((S)-3,7-dimethyloctyloxy)phenoxy)carbonyl]phenyl 4-(n-octyloxy)benzoate (DPCPB) has been characterized using 1H, 13C-NMR and MS-QTOF. The liquid crystalline behavior of the target compound has been investigated by differential scanning calorimetry and optical polarizing microscopy. DPCPB exhibits an enantiotropic non-tilted smectic mesophase in a wide temperature range. The real and imaginary dielectric constant, conductivity mechanism, impedance and dielectric relaxation mechanism of DPCPB have been investigated depending on frequency at different temperatures.
Nonsymmetrical cholesterol dimers constituting regioisomeric oxadiazole and thiadiazole cores: an investigation of the structure-property correlation
Pradhan, Balaram,Chakraborty, Nirmalangshu,Gupta, Ravindra Kumar,Shanker,Achalkumar, Ammathnadu S.
supporting information, p. 879 - 888 (2017/02/05)
Three series of chiral nonsymmetrical dimers were prepared by connecting promesogenic cholesterol to a bent structure derived from a substituted 1,3,4-oxadiazole or 1,2,4-oxadiazole or 1,3,4-thiadiazole moiety. These two mesogenic segments are interconnected through spacers of varying lengths and parity. The structures of the bent achiral unit were systematically varied with different central heterocyclic cores to understand the influence of bent angles on the thermal and gelation behavior. The bent angle of the achiral unit, which is determined by the heterocyclic core, has a major role in the stabilization of frustrated phases. Dimers based on the 1,3,4-oxadiazole unit with a more bent structure stabilized frustrated phases like blue phases and twist grain boundary phases. The bent system with a wider bent angle preferred to stabilize chiral nematic and smectic A phases. It is interesting to note that an increased bent structure reduced the mesophase stability as in the case of dimers based on the 1,3,4-oxadiazole unit, where many compounds exhibited monotropic phases. In the case of dimers with a wider bent angle, enantiotropic mesomorphism was observed. All the compounds showed blue light emission in the solution. Among these chiral dimers, only the compounds based on the 1,3,4-oxadiazole unit showed the gelation ability, which emphasizes how small structural changes like bent angle, dipole moment and the type of heteroatom in the heterocyclic unit affect the macroscopic self-assembly.
Synthesis and evaluation of cationic norbornanes as peptidomimetic antibacterial agents
Hickey, Shane M.,Ashton, Trent D.,Khosa, Simren K.,Robson, Ryan N.,White, Jonathan M.,Li, Jian,Nation, Roger L.,Yu, Heidi Y.,Elliott, Alysha G.,Butler, Mark S.,Huang, Johnny X.,Cooper, Matthew A.,Pfeffer, Frederick M.
supporting information, p. 6225 - 6241 (2015/06/08)
A series of structurally amphiphilic biscationic norbornanes have been synthesised as rigidified, low molecular weight peptidomimetics of cationic antimicrobial peptides. A variety of charged hydrophilic functionalities were attached to the norbornane scaffold including aminium, guanidinium, imidazolium and pyridinium moieties. Additionally, a range of hydrophobic groups of differing sizes were incorporated through an acetal linkage. The compounds were evaluated for antibacterial activity against both Gram-negative and Gram-positive bacteria. Activity was observed across the series; the most potent of which exhibited an MIC's ≤ 1 μg mL-1 against Streptococcus pneumoniae, Enterococcus faecalis and several strains of Staphylococcus aureus, including multi-resistant methicillin resistant (mMRSA), glycopeptide-intermediate (GISA) and vancomycin-intermediate (VISA) S. aureus.
