59748-18-4Relevant academic research and scientific papers
Synthesis and characterization of bent-rod liquid crystals
Del Rosso, Pablo,Hernandez, Sandra A.,Garay, Raul O.
, p. 383 - 385 (2000)
Two series of diesters with bend-rod shapes were synthesized and their thermal properties characterized by POM and DSC. The central group conformational mobility and polarity as well as the length of the mesogenic groups were varied in order to correlate these parameters with mesophase stability. Results indicate that series II diesters are enantiotropic and that their mesophase sensitivity to central group structural changes is limited.
Anisotropic and magnetic properties in non-metal and non-radical organic aggregates of tri-substituted phenyl derivatives
Tun Nur Iskandar, Nur Amanina Juniasari,Guan-Yeow, Yeap,Maeta, Nobuyuki,Ito, Masato M.,Nakamura, Yoshiyuki,Gas, Katarzyna,Sawicki, Maciej
, p. 210 - 217 (2019/12/25)
A new series of tri-substituted phenyl derivatives containing an aromatic imine unit and biphenyl ester possessing various numbers of carbon atoms at the terminal alkoxy chain, OCnH2n+1 (n = 7-12), along with a lateral o-ethoxy substituent have been successfully prepared and characterised by CHN microanalysis along with spectroscopic techniques (FTIR, 1H- and 13C-NMR). The texture observation under polarized light revealed that all the soft condensed materials exhibited an enantiotropic nematic (N) phase. The current studies have shown that the mesomorphic behaviour is greatly influenced by the length of the alkoxy chains wherein the thermal stability of a tri-substituted phenyl derivative will decrease if the terminal alkoxy chain is increased from n = 7 to 12. For the first time, these materials which do not possess any magnetic species in their structure, demonstrate magnetic interaction through naked eye observation as well as quantitative measurement using a SQUID magnetometer.
Photo and electrically switchable B7 mesophase exhibiting asymmetric bent-core liquid crystals
Srinivasan, Murugesan Vijay,Kannan, Palaninathan,Roy, Arun
, p. 1584 - 1590 (2013/06/04)
The first bent-core liquid crystal materials with a photo-active azo linkage exhibiting the B7 mesophase are reported. The lower homologues of the bent-core compounds display the B1 phase and higher homologues show the B7 mesophase. The mesomorphic properties were characterized using polarized optical microscopy, differential scanning calorimetry and X-ray diffraction. The B7 phase of these materials establishes ferroelectric switching characteristics with anticlinic organization (SmCAPF) of the molecules in the layers. The bent-core molecules with an azo linkage are important for photoisomerization studies, which indicate trans to cis isomerization at 30 s, whereas the reverse processes take place over 40 s in chloroform.
Total synthesis and structure-activity relationships of caspofungin-like macrocyclic antifungal lipopeptides
Yao, Jianzhong,Liu, Hongming,Zhou, Ting,Chen, Hai,Miao, Zhenyuan,Dong, Guoqiang,Wang, Shengzheng,Sheng, Chunquan,Zhang, Wannian
supporting information; experimental part, p. 3074 - 3085 (2012/06/01)
The echinocandins represent a well-known class of macrocyclic antifungal lipopeptides that can be used for treatment of invasive fungal infections. Due to their complex chemical structures and synthetic difficulties, the structure-activity relationships (SARs) of them are still limited. A total synthetic approach was developed to synthesize structurally diverse caspofungin-like antifungal cyclic lipopeptides, allowing for systemically investigating their SARs. Most of the designed cyclic lipopeptides showed potent antifungal activities with broad spectrum. In particular, several compounds (e.g., 30a, 30e-h, 31a-d, 32c, and 33a,b) were more active in vitro against Candida albicans or Aspergillus fumigatus than caspofungin. The findings in this work indicated that the 'left' tripeptide segment of cyclic lipopeptide scaffold might be suitable for a hydrophilic structural motif, whereas the 'right' lipotripeptide segment was preferred as a hydrophobic core. The alkoxy-naphthoyl was found to be optimal side chain and alkyl length could affect the SARs of alkoxy-aroyl side chains.
Synthesis and optical properties of luminescent naphthalene-based liquid crystals
Mori, Takeshi,Kijima, Masashi
experimental part, p. 246/[572]-256/[582] (2010/03/30)
Luminescent naphthalene-based liquid crystals were newly synthesized and changes of the luminescent color through the phase transitions were characterized. We prepared the compounds by combining naphthalene and known mesogenic cores, oxadiazole and fluoro
Synthesis and mesomorphic properties of low molar mass phosphorus derivatives
Tokushige,Mihara,Koide
, p. 27 - 38 (2007/10/03)
New liquid crystalline phosphorus derivatives were synthesized as a core model compound and/or a model compound of the component for semiflexible liquid crystalline polymers. Alkoxy, oligo ethylene oxide, or chiral moieties were introduced into the terminal group of rigid moiety in order to investigate the effect of the terminal group on the thermal properties of the phosphorus derivatives. A nematic phase appears for the phosphorus derivative with alkoxy moieties or oligo ethylene oxide chain, while a mesophase is observed for the phosphorus derivative with a chiral moiety. Some phosphorus derivatives were thermally stable until more than 300°C.
Cyclohexapeptidyl amine compounds
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, (2008/06/13)
Cyclohexapeptidyl amine compounds are disclosed of the formula: or its acid addition salt, wherein: R1is H or OH; R2is H or OH; R3is QCnH2nNRVRVI, QCnH2nNRVRVIRVII+Y?, or Q(CH2)1-3CRVIIIRIXNHRX. R4is H or OH; R5is H, OH or CH3; R6is H or CH3; RIis wherein Rais C1-C10alkyl; or (CH2)qNRbRcwherein Rband Rcare independently H, C1-C10alkyl or Rband Rctaken together are wherein Rdis C1-C16alkyl, phenyl or benzyl; RIIis H, C1-4alkyl or benzyl; RIIIis H, C1-4alkyl or benzyl; RIVis RIIand RIIItaken together as —(CH2)4— or —(CH2)5—; RVis H, C1-C4alkyl or benzyl; RVIis H, C1-C4alkyl or benzyl or RVand RVItogether is —(CH2)4— or —(CH2)5—; RVIIis H or C1-C4alkyl; RVIIIis H, (CH2)mH, (CH2)mOH, (CH2)mNH2or COX wherein X is NH2, OH or O(CH2)mH; RIXis H, (CH2)mH, or together with RVIIIis ═O (carbonyl); RXis H (except when RVIIIand RIXare H, C(═NH)NH2, C(═NH)CH2)0-3H, CO(CH2)0-3H, CO(CH2)mNH2, (CH2)2-4OH or (CH2)2-4NH2; Q is O or S; Y is an anion of a pharmaceutically acceptable salt each m is independently an integer from 1 to 3, inclusive; n is an integer from 2 to 4, inclusive; p is an integer from 1 to 2, inclusive and q is an integer from 2 to 4, inclusive.
Mesomorphic trigonal bipyramidal iron(0) isocyanide complexes
Coco, Silverio,Espinet, Pablo,Marcos, Eva
, p. 1297 - 1302 (2007/10/03)
The synthesis, characterization and mesomorphic properties of three series of isocyanides and their trigonal bipyramidal iron(0) complexes [Fe(CO)4(CNR)] (R= C6H4O(O)CC6H4C6H4OC(n)H2(n)+1, C6H4C(O)OC6H4C6H4OC(n)H2(n)+1, C6H4C6H4O(O)CC6H4OC(n)H2(n)+1, n = 6, 8, 10, 12) are described. The free isocyanides exhibit nematic and/or smectic A phases for shorter chains (n = 6, 8) and only smectic A phases for longer chains, except the isocyanides CNC6H4O(O)CC6H4C6H4OC(n)H2(n)+1 which melt with extensive decomposition and do not produce mesophases. Their coordination to give the iron complexes [Fe(CO)4(CNR)] produces a slight decrease of their transition temperatures. The iron isocyanide complexes prepared show only a smectic C phase. The relationship between the molecular structure of the complexes and their thermal behaviour is discussed.
Cyclohexapeptidyl propanolamine compounds
-
, (2008/06/13)
Certain propanolamine compounds are described which have a cyclohexapeptidyl nucleus and which possess antibiotic activity with physical properties suitable for direct use in therapeutic compositions. A process for their preparation is also described.
Cyclohexapeptidyl aminoalkyl ethers
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, (2008/06/13)
There are disclosed compounds of the general formula STR1 wherein all substituents are defined herein. The compounds are useful as antibiotic and antifungal agents.
