Search results for "Side chain"

4,5-Disubstituted N -Methylimidazoles as Versatile Building Blocks for Defined Side-Chain Introduction

2017

Cadmium(ii) coordination polymers based on substituted malonic acid: synthesis, characterization and photoluminescence properties

2017

Four novel complexes of cadmium(II) with alkyl/aryl-substituted malonate ligands of formulae {[Cd(Memal)(H2O)]6·0.5H2O}n (1), [Cd(Etmal)(H2O)]n (2), [Cd(Butmal)(H2O)]n (3) and [Cd(Bzmal)(H2O)]n (4), (Memal = methylmalonate, Etmal = ethylmalonate, Butmal = butylmalonate and Bzmal = benzylmalonate) have been prepared and characterized by single crystal X-ray analysis. Their luminescence, UV-Vis absorption properties and thermal behaviour were also investigated. Complex 1 is a three-dimensional compound where each metal centre is connected to four other ones leading to a sodalite network with the point symbol {42·64}. Each cadmium(II) ion in 1 is seven-coordinate with a water molecule and six …

Helical supramolecular polymerization of C3-symmetric amides and retroamides: on the origin of cooperativity and handedness.

2016

The cooperative supramolecular polymerization of 1 and 2 yields P- or M-type helical aggregates depending on the absolute configuration (S or R) of the stereogenic centres attached to the side chains. The connectivity of the amide group does not affect the handedness of the helical aggregates, but determines a larger cooperativity for retroamides 1.

π-Stacked polymers in drug delivery applications

2016

Abstract Polybenzofulvenes are π-stacked polymers, which can be synthesized by spontaneous polymerization of the corresponding monomers without the use of catalysts or initiators. Therefore, they can be obtained completely free from byproducts, impurities, or harmful substances. The absence of any relevant toxic effects and cell viability impairments allows PEGylated polybenzofulvene brushes to be potentially functional in a wide range of biological, biomedical, and biotechnological applications. Moreover, the properties of these polymers, in terms of interaction with pharmacological active agents and the ability to self-assemble into nanoaggregates or a quite compact physical gel useful as…

Synthesis, Thermal, and Optical Properties of Tris(5‐aryl‐1,3,4‐oxadiazol‐2‐yl)‐1,3,5‐triazines, New Star‐Shaped Fluorescent Discotic Liquid Crystals

2019

Abstract The synthesis of tris(aryloxadiazolyl)triazines (TOTs), C 3‐symmetrical star‐shaped mesogenes with a 1,3,5‐triazine center, 5‐phenyl‐1,3,4‐oxadiazole arms, and various peripheral alkoxy side chains is reported. Threefold Huisgen reaction on a central triazine tricarboxylic acid and suitable aryltetrazoles yields the title compounds. Selected analogues with a benzene center are included in this study and allow for an evaluation of the impact of the central unit on the physical properties. Thermal (differential scanning calorimetry, DSC; polarization optical microscopy, POM), optical (UV/Vis, fluorescence), electric (time of flight, TOF), and structural (single crystal; wide‐angle X‐…

Synthesis and characterization of bi-functional photorefractive polymers

2001

Abstract A novel bi-functional photorefractive acrylate polymer with pendant carbazolyl groups and azo derivatives as side chains was synthesized, in which azo derivatives as electro-optic chromophores and carbazolyl as photoconductive moiety were covalently linked on the acrylate backbone. Photorefractive experiments showed that a high two-beam coupling gain coefficient of 93 cm −1 , diffraction efficiency of 12% and electro-optic coefficient of 26 pm/V were obtained. With increasing writing beam's intensity, the two-beam coupling enhanced gradually, and then reached saturation. Using the method of four-wave mixing, the photoisomerization grating was observed.

Amphotropic Ionomers by Attachment of Secondary Amines to a Reactive Ester Polymer

2004

We report on the synthesis of polyacrylamides that were prepared by the reaction of a reactive ester polymer with a mesogen-containing secondary amine and N-methyl-piperazine. As the polymers do not form hydrogen bonds near the amide groups, their mobility is significantly higher than that of poly(N-monoalkylacrylamides). The initially nonionic polymer shows no liquid-crystalline behavior in bulk and in mixture with ethylene glycol. This is due to the low polarity difference between the different side chains. The polarity difference can be increased by protonation or quarter-nization of the tertiary amino groups, and liquid-crystalline behavior is observed. The self-assembly multilayer buil…

1992

A series of liquid-crystalline copolymers 1 with a chiral azobenzene moiety as photoreactive mesogenic unit was prepared. The polymers were fractionated and the mesophase behaviour of the high- and low-molecular weight fractions was examined. The copolymers display smectic A and cholesteric phases. For the cholesteric phases the pitch of the helix was determined, which ranges from 3 to 20 μm. Stable monolayers at the air-water interface were obtained from two monomers and one of the homopolymers. Multilayer assemblies of the azobenzene-containing polymers can be used to study photo-induced order/disorder transitions.

Synthesis of 2-Prenylated Alkoxylated Benzopyrans by Horner–Wadsworth–Emmons Olefination with PPARα/γ Agonist Activity

2021

[Image: see text] We have synthesized series of 2-prenylated benzopyrans as analogues of the natural polycerasoidol, a dual PPARα/γ agonist with anti-inflammatory effects. The prenylated side chain consists of five or nine carbons with an α-alkoxy-α,β-unsaturated ester moiety. Prenylation was introduced via the Grignard reaction, followed by Johnson–Claisen rearrangement, and the α-alkoxy-α,β-unsaturated ester moiety was introduced by the Horner–Wadsworth–Emmons reaction. Synthetic derivatives showed high efficacy to activate both hPPARα and hPPARγ as dual PPARα/γ agonists. These prenylated benzopyrans emerge as lead compounds potentially useful for preventing cardiometabolic diseases.

Adsorption Structures of Amino Acids on Calcite(104)

2015

Elucidating the interaction details of proteins with the most stable cleavage plane of calcite , namely calcite(104), is of great importance for understanding the physicochemical mechanisms behind biomineralisation. In this context, amino acids are generally believed to serve as suitable model molecules, as they constitute the basic building blocks of proteins. In this work, we present a non-contact atomic force microscopy (NC-AFM) investigation of the adsorption of five proteinogenic amino acids on calcite(104) under ultra-high vacuum (UHV) conditions. For studying the structures formed from comparatively large amino acids, enantiopure tryptophan, tyrosine and aspartic acid molecules are d…