The effects of molecular structure and functional group of a rodlike Schiff base mesogen on blue phase stabilization in a chiral system

2019 ◽  
Vol 43 (4) ◽  
pp. 1743-1756
Author(s):  
Chiung-Cheng Huang ◽  
Yu-Chang Huang ◽  
Wei-Cheng Hsieh ◽  
Yen-Jung Chen ◽  
Shi-Kai Jiang ◽  
...  

A wider blue phase (BP) range can be induced easily when two difluoro substituted and racemic rodlike Schiff base mesogens are doped with the appropriate concentration of chiral dopants S811 or ISO(6OBA)2.

Author(s):  
Shabana Noor ◽  
Richard Goddard ◽  
Fehmeeda Khatoon ◽  
Sarvendra Kumar ◽  
Rüdiger W. Seidel

AbstractSynthesis and structural characterization of two heterodinuclear ZnII-LnIII complexes with the formula [ZnLn(HL)(µ-OAc)(NO3)2(H2O)x(MeOH)1-x]NO3 · n H2O · n MeOH [Ln = Pr (1), Nd (2)] and the crystal and molecular structure of [ZnNd(HL)(µ-OAc)(NO3)2(H2O)] [ZnNd(HL)(OAc)(NO3)2(H2O)](NO3)2 · n H2O · n MeOH (3) are reported. The asymmetrical compartmental ligand (E)-2-(1-(2-((2-hydroxy-3-methoxybenzylidene)amino)-ethyl)imidazolidin-2-yl)-6-methoxyphenol (H2L) is formed from N1,N3-bis(3-methoxysalicylidene)diethylenetriamine (H2valdien) through intramolecular aminal formation, resulting in a peripheral imidazoline ring. The structures of 1–3 were revealed by X-ray crystallography. The smaller ZnII ion occupies the inner N2O2 compartment of the ligand, whereas the larger and more oxophilic LnIII ions are found in the outer O2O2’ site. Graphic Abstract Synthesis and structural characterization of two heterodinuclear ZnII-LnIII complexes (Ln = Pr, Nd) bearing an asymmetrical compartmental ligand formed in situ from N1,N3-bis(3-methoxysalicylidene)diethylenetriamine (H2valdien) through intramolecular aminal formation are reported.


Soft Matter ◽  
2014 ◽  
Vol 10 (41) ◽  
pp. 8224-8228 ◽  
Author(s):  
Min-Jun Gim ◽  
Gohyun Han ◽  
Suk-Won Choi ◽  
Dong Ki Yoon

We have investigated dramatic changes in the thermal phase transition of a liquid-crystalline (LC) blue phase (BP) consisting of bent-core nematogen and chiral dopants under various boundary conditions during cooling from the isotropic phase.


2010 ◽  
Vol 2010 ◽  
pp. 1-7 ◽  
Author(s):  
Mantha Tsiouri ◽  
Konstantina Skorda ◽  
Christos Papadimitriou ◽  
Yang Li ◽  
J. Derek Woollins ◽  
...  

The novel lanthanide(III) complexes[Ln(NO3)2L](NO3)⋅3MeOH (Ln = La1, Pr2) and[Ln(NO3)3L](NO3)⋅2MeOH (Ln = Gd3, Yb4), where L = (NE,N′E)-2,2′-(ethane-1,2-diylbis(oxy))bis(N-(pyridin-2-ylmethylene)ethanamine), have been obtained by direct reaction of the Schiff base ligand and the corresponding hydrated lanthanide(III) nitrates in methanol. All complexes were characterized spectroscopically and thermogravimetrically. Complex4was also characterized with crystallographic studies: orthorhombic P212121,a=10.6683(14),b=13.4752(15),c=19.3320(26) Å. In the molecular structure of4, Yb(III) is surrounded by all donor atoms of the Schiff base (four nitrogen and two oxygen atoms) and four oxygen atoms belonging to two bidentate chelating nitrato ligands.


2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Qili Liu ◽  
Jianxin Zhang ◽  
Dong Li ◽  
Jianfeng Lang ◽  
Shasha Zai ◽  
...  

Cotton leaf spot (Alternaria macrospora) is a widespread disease that occurs in the main cotton-producing area of China. In managing this disease, a novel chitosan-based biopesticide, an amphiphilic N-alkyl-O-carboxymethyl chitosan derivative, was prepared. The product was selected from variations of chitosan with different molecular structures, which were obtained via a two-step reaction. First, carboxymethyl chitosans with varying molecular sizes were obtained by etherification with chloroacetic acid; then the carboxymethyl chitosan was alkylated with C4–C12 fatty aldehyde through a Schiff-base reaction. This procedure resulted in derivatives of amphiphilic N-alkyl-O-carboxymethyl chitosan, which showed strong antifungal activities against A. macrospora, and the efficacy was determined by its molecular structure.


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