scholarly journals Twist-Bend Nematogenic Supramolecular Dimers and Trimers Formed by Hydrogen Bonding

Crystals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 175 ◽  
Author(s):  
Rebecca Walker ◽  
Damian Pociecha ◽  
Alfonso Martinez-Felipe ◽  
John MD Storey ◽  
Ewa Gorecka ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Phase Behaviour ◽  
X Ray Diffraction ◽  
Temperature Dependent ◽  
Smectic C ◽  
Donor And Acceptor ◽  
Nematic Phases ◽  
Selection Of ◽  
Do So ◽  
Terminal Chain

A selection of novel non-symmetric supramolecular liquid crystal dimers and trimers formed by hydrogen-bonding have been prepared and their phase behaviour characterised by polarised optical microscopy, X-ray diffraction and temperature-dependent Fourier-transform infrared spectroscopy. We mix the bent twist-bend nematogen 4-[6-(4’-cyanobiphenyl-4-yl) hexyloxy]-benzoic acid (CB6OBA) with a series of small stilbazole-based compounds 4-[(E)-2-(n-alkoxyphenyl)ethenyl]pyridines (nOS) of varying terminal chain length (n) to obtain the CB6OBA:nOS complexes. Complexes with n ≤ 7 exhibit nematic and twist-bend nematic behaviour, followed on cooling by a smectic C phase for n = 4–7, and finally, a hexatic-type smectic X phase for n = 3–7. Mixtures with n = 8–10 exhibit a smectic A phase below the conventional nematic phase, and on further cooling, a biaxial smectic Ab phase and the same hexatic-type SmX phase. Supramolecular trimers, CB6OBA:CB6OS and CB6OBA:1OB6OS, formed between CB6OBA and dimeric stilbazoles [(E)-2-(4-{[6-(4’-methoxy[1,1’-biphenyl]-4-yl)hexyl]oxy}phenyl)ethenyl]pyridine (1OB6OS) or 4-[(E)-4’-(6-{4-[(E)-2-(pyridin-4-yl)ethenyl]phenoxy}hexyl)[1,1’-biphenyl]-4- carbonitrile (CB6OS), exhibit nematic and twist-bend nematic phases, and are the first hydrogen-bonded trimers consisting of unlike donor and acceptor fragments to do so.

Robust Microporous Molecular Frameworks Which Retain Structural Integrity Upon Template Loss

1998 ◽  
Vol 547 ◽  
Author(s):  
C. J. Kepert ◽  
M. J. Rosseinsky ◽  
D. Hesek ◽  
P. D. Beer
Keyword(s):  
Hydrogen Bonding ◽  
Molecular Modelling ◽  
Structural Integrity ◽  
Stacking Interactions ◽  
Void Space ◽  
X Ray Diffraction ◽  
X Ray ◽  
Donor And Acceptor ◽  
Modelling Techniques ◽  
Symmetry Change

AbstractRetention of the void space upon loss of the solvent template is directly demonstrated using single-crystal X-ray diffraction for molecular frameworks constructed using both hydrogen and co-ordinate bonds. While the co-ordination polymer remains rigid upon desolvation, the extra flexibility in the hydrogen-bonded framework, due both to the large number of redundant hydrogen-bonding donor and acceptor groups and the possibility of significant φ-φ stacking interactions within the framework, lead to a significant structural and symmetry change while retaining significant void volume. Molecular modelling techniques are used to understand and predict the guest uptake chemistry of these host frameworks.

Compound with Coexisting Mono- and Dinuclear Cu(II) Complexes Hosting a New Water Tape Cluster (H2O)22

2014 ◽  
Vol 69 (9-10) ◽  
pp. 987-994
Author(s):  
Wei Xu ◽  
Yue-Qing Zheng
Keyword(s):  
Complex Cation ◽  
Stacking Interactions ◽  
X Ray Diffraction ◽  
Temperature Dependent ◽  
Complex Molecules ◽  
X Ray ◽  
Thermoanalytical Techniques ◽  
Hydrogen Bond Interactions ◽  
Donor And Acceptor ◽  
2D Network

AbstractA new compound containing mono- and dinuclear Cu(II) complexes, [Cu2(phen)2(H2O)2(OH)2] [Cu(phen)2(CO3)]2(HCO3)2 · 22H2O] (phen=1,10-phenanthroline), has been prepared and characterized by X-ray diffraction analysis, thermoanalytical techniques and temperature-dependent magnetic susceptibility measurements. The hydroxo-bridged dinuclear [Cu2(phen)2(H2O)2(OH)2]2+ complex cations and the mononuclear [Cu(phen)2(CO3)] complex molecules are assembled via π···π stacking interactions into layers. A novel water tape containing (H2O)22 cluster units has been observed in the structure of the title complex. In hydrogen bond interactions HCO3- anions act as donor and acceptor to link the water tapes to form an infinite 2D network parallel to (010). According to the magnetic analyses, the coupling interactions in the dinuclear complex cation is ferromagnetic (J=34:5 cm-1)

Synthesis of N-Acylated 1,5-Benzodiazepines: Differentiation between Two Possible Acylation Sites via Hydrogen Bonding

2013 ◽  
Vol 68 (4) ◽  
pp. 397-402
Author(s):  
Carlos A. Escobar ◽  
Odette A. Alvarado ◽  
Judith A. K. Howard ◽  
Mauricio Fuentealba
Keyword(s):  
Hydrogen Bonding ◽  
Acetic Anhydride ◽  
Room Temperature ◽  
Molecular Structures ◽  
Hydroxyl Groups ◽  
Acylating Agent ◽  
X Ray Diffraction ◽  
Temperature Dependent ◽  
X Ray ◽  
Crotonyl Chloride

Temperature-dependent regioselectivity between amino and hydroxyl groups mediated by hydrogen bonding was observed in the reaction of acetic anhydride with 2-(2,3-dimethoxyphenyl)- 4-(2-hydroxyphenyl)-2,3-dihydro-1H-1,5-benzodiazepine (1), obtaining 1-acetyl-2-(2,3-dimethoxyphenyl)- 4-(2-hydroxyphenyl)-2,3-dihydro-1H-1,5-benzodiazepine (1a), when these were reacted at room temperature, and 4-(2-acetoxyphenyl)-1-acetyl-2-(2,3-dimethoxyphenyl)-2,3-dihydro-1H-1,5- benzodiazepine (1b), when they were refluxed (148 - 150 °C). Acylation of the less hindered analog 4-(2-hydroxyphenyl)-2-phenyl-2,3-dihydro-1H-1,5-benzodiazepine (2) via crotonyl chloride (a bulky acylating agent compared with acetic anhydride) afforded by refluxing only 1-crotonyl-4- (2-hydroxyphenyl)-2-phenyl-2,3-dihydro-1H-1,5-benzodiazepine (2a). All compounds were characterized spectroscopically, and the molecular structures of compounds 1a and 2a were determined by X-ray diffraction analysis.

scholarly journals Putative transmembrane transporter modulates higher-level aggression in Drosophila

2017 ◽  
Vol 114 (9) ◽  
pp. 2373-2378 ◽  
Author(s):  
Budhaditya Chowdhury ◽  
Yick-Bun Chan ◽  
Edward A. Kravitz
Keyword(s):  
Causal Effect ◽  
Nerve Terminals ◽  
Rna Seq ◽  
Wild Type ◽  
Temperature Dependent ◽  
Number Of Genes ◽  
Interesting Family ◽  
Solute Carrier ◽  
Transmembrane Transporter ◽  
Selection Of

By selection of winners of dyadic fights for 35 generations, we have generated a hyperaggressive Bully line of flies that almost always win fights against the parental wild-type Canton-S stock. Maintenance of the Bully phenotype is temperature dependent during development, with the phenotype lost when flies are reared at 19 °C. No similar effect is seen with the parent line. This difference allowed us to carry out RNA-seq experiments and identify a limited number of genes that are differentially expressed by twofold or greater in the Bullies; one of these was a putative transmembrane transporter, CG13646, which showed consistent and reproducible twofold down-regulation in Bullies. We examined the causal effect of this gene on the phenotype with a mutant line for CG13646, and with an RNAi approach. In all cases, reduction in expression of CG13646 by approximately half led to a hyperaggressive phenotype partially resembling that seen in the Bully flies. This gene is a member of a very interesting family of solute carrier proteins (SLCs), some of which have been suggested as being involved in glutamine/glutamate and GABA cycles of metabolism in excitatory and inhibitory nerve terminals in mammalian systems.

scholarly journals Thermochromic aggregation-induced dual phosphorescence via temperature-dependent sp3-linked donor-acceptor electronic coupling

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Tao Wang ◽  
Zhubin Hu ◽  
Xiancheng Nie ◽  
Linkun Huang ◽  
Miao Hui ◽  
...  
Keyword(s):  
Excited State ◽  
Room Temperature ◽  
Electronic Coupling ◽  
Temperature Dependent ◽  
Molecular Systems ◽  
Donor And Acceptor ◽  
Theoretical Investigations ◽  
Donor Acceptor ◽  
And Control ◽  
Two Temperature

AbstractAggregation-induced emission (AIE) has proven to be a viable strategy to achieve highly efficient room temperature phosphorescence (RTP) in bulk by restricting molecular motions. Here, we show that by utilizing triphenylamine (TPA) as an electronic donor that connects to an acceptor via an sp3 linker, six TPA-based AIE-active RTP luminophores were obtained. Distinct dual phosphorescence bands emitting from largely localized donor and acceptor triplet emitting states could be recorded at lowered temperatures; at room temperature, only a merged RTP band is present. Theoretical investigations reveal that the two temperature-dependent phosphorescence bands both originate from local/global minima from the lowest triplet excited state (T1). The reported molecular construct serves as an intermediary case between a fully conjugated donor-acceptor system and a donor/acceptor binary mix, which may provide important clues on the design and control of high-freedom molecular systems with complex excited-state dynamics.

scholarly journals One-step synthesis of nitrogen-grafted copper-gallic acid for enhanced methylene blue removal

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shella Permatasari Santoso ◽  
Vania Bundjaja ◽  
Artik Elisa Angkawijaya ◽  
Chintya Gunarto ◽  
Alchris Woo Go ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Adsorption Capacity ◽  
Gallic Acid ◽  
Synthesis Method ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
Temperature Dependent ◽  
One Step ◽  
Detailed Assessment ◽  
Higher Temperature

AbstractNitrogen-grafting through the addition of glycine (Gly) was performed on a metal- phenolic network (MPN) of copper (Cu2+) and gallic acid (GA) to increase its adsorption capacity. Herein, we reported a one-step synthesis method of MPN, which was developed according to the metal–ligand complexation principle. The nitrogen grafted CuGA (Ng-CuGA) MPN was obtained by reacting Cu2+, GA, and Gly in an aqueous solution at a molar ratio of 1:1:1 and a pH of 8. Several physicochemical measurements, such as Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), N2 sorption, X-ray diffraction (XRD), and thermal gravimetry analysis (TGA), were done on Ng-CuGA to elucidate its characteristics. The analysis revealed that the Ng-CuGA has non-uniform spherical shaped morphology with a pore volume of 0.56 cc/g, a pore size of 23.25 nm, and thermal stability up to 205 °C. The applicational potential of the Ng-CuGA was determined based on its adsorption capacity against methylene blue (MB). The Ng-CuGA was able to adsorb 190.81 mg MB per g adsorbent at a pH of 6 and temperature of 30 °C, which is 1.53 times higher than the non-grafted CuGA. Detailed assessment of Ng-CuGA adsorption properties revealed their pH- and temperature-dependent nature. The adsorption capacity and affinity were found to decrease at a higher temperature, demonstrating the exothermic adsorption behavior.

scholarly journals Hexakis(terthiophenylthio)benzene as a Mew Class Liquid Crystalline Molecule

1999 ◽  
Vol 23 (10) ◽  
pp. 596-597
Author(s):  
Shinobu Inoue ◽  
Shoji Nishiguchi ◽  
Satoshi Murakami ◽  
Yoshio Aso ◽  
Tetsuo Otsubo ◽  
...  
Keyword(s):  
Liquid Crystalline ◽  
Smectic A ◽  
Smectic C ◽  
Nematic Phases

A disk-like molecule, in which six α-linked terthiophenes are connected to a central benzene core via a thioether linkage, shows a sequence of calamitic liquid crystalline mesomorphism involving smectic C, smectic A and nematic phases.

Magnetic nanostructured lipid carrier for dual triggered curcumin delivery: Preparation, characterization and toxicity evaluation on isolated rat liver mitochondria

2021 ◽  
pp. 088532822110346
Author(s):  
Mohammad Yoozbashi ◽  
Hamid Rashidzadeh ◽  
Mehraneh Kermanian ◽  
Somayeh Sadighian ◽  
Mir-Jamal Hosseini ◽  
...  
Keyword(s):  
In Vitro Study ◽  
Liver Mitochondria ◽  
Rat Liver Mitochondria ◽  
Nanostructured Lipid Carrier ◽  
Mitochondrial Toxicity ◽  
X Ray Diffraction ◽  
Temperature Dependent ◽  
Reducing Ability ◽  
Transmission Electron

In this research, magnetic nanostructured lipid carriers (Mag-NLCs) were synthesized for curcumin (CUR) delivery. NLCs are drug-delivery systems prepared by mixing solid and liquid (oil) lipids. For preparation of NLCs, cetylpalmitate was selected as solid lipid and fish oil as liquid lipid. CUR-Mag-NLCs were prepared using high-pressure homogenization technique and were characterized by methods including X-ray diffraction (XRD), transmission electron microscopy (TEM), vibrating sample magnetometer (VSM), and dynamic light scattering (DLS). The CUR-Mag-NLCs were developed as a particle with a size of 140 ± 3.6 nm, a polydispersity index of 0.196, and a zeta potential of −22.6 mV. VSM analysis showed that the CUR-Mag-NLCs have excellent magnetic properties. Release rate of the drug was higher at 42 °C than 37 °C, indicating that release of the synthesized nanoparticles is temperature-dependent. Evaluation of mitochondrial toxicity was done using the isolated rats liver mitochondria including glutathione (GSH), malondialdehyde (MDA), and the ferric- reducing ability of plasma (FRAP) assays to study biosafety of the CUR-Mag-NLCs. Results of In vitro study on the isolated mitochondria revealed that both CUR-Mag-NLCs and curcumin have no specific mitochondrial toxicity.

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