scholarly journals Advances in the Supramolecular Chemistry of Tetracoordinate Boron-Containing Organic Molecules into Organogels and Mesogens

2021 ◽  
Vol 9 ◽  
Author(s):  
Sanchita Shah ◽  
Parvati Marandi ◽  
P. P. Neelakandan
Keyword(s):  
Supramolecular Chemistry ◽  
Liquid Crystalline ◽  
Photophysical Properties ◽  
Building Blocks ◽  
Crystalline Materials ◽  
Π Interactions ◽  
Collective Attention ◽  
Non Covalent Interactions ◽  
Liquid Crystalline Materials ◽  
Covalent Interactions

Boron-containing organic compounds are well accepted as a class of compounds having excellent photophysical properties. In addition to the unique photophysical properties, the ease of synthesis and structural robustness make tetracoordinate boron complexes ideal for a variety of applications. While significant light has been thrown on their luminescence properties, there is no collective attention to their supramolecular chemistry. In this mini review, we discuss the progress made in the supramolecular chemistry of these compounds which includes their utility as building blocks for liquid crystalline materials and gels largely driven by various non-covalent interactions like H-bonding, CH-π interactions, BF-π interactions and Van der Waals forces. The organoboron compounds presented here are prepared from easy-to-synthesize chelating units such as imines, diiminates, ketoiminates and diketonates. Moreover, the presence of heteroatoms such as nitrogen, oxygen and sulfur, and the presence of aromatic rings facilitate non-covalent interactions which not only favor their formation but also helps to stabilize the self-assembled structures.

scholarly journals Determination of Optical Purity of Lactic Acid-Based Chiral Liquid Crystals and Corresponding Building Blocks by Chiral High-Performance Liquid Chromatography and Supercritical Fluid Chromatography

Molecules ◽  
2019 ◽  
Vol 24 (6) ◽  
pp. 1099 ◽  
Author(s):  
Anna Poryvai ◽  
Terezia Vojtylová-Jurkovičová ◽  
Michal Šmahel ◽  
Natalie Kolderová ◽  
Petra Tomášková ◽  
...  
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Supercritical Fluid ◽  
Supercritical Fluid Chromatography ◽  
High Performance ◽  
Liquid Crystalline ◽  
Optical Purity ◽  
Building Blocks ◽  
Crystalline Materials ◽  
Liquid Crystalline Materials

Liquid crystals (LCs) are among the most prominent materials of the current information age, mainly due to their well-known application in liquid crystal displays (LCDs). Their unique electro-optical properties stem from their ability to form organised structures (mesophases) on the transition from solid state to isotropic liquid. Molecules of LCs in a mesophase still maintain the anisotropy of solid crystals, while simultaneously exhibiting the fluidity of liquids, which gives the system the ability to react immediately to external stimuli such as electric or magnetic fields, light, mechanical stress, pressure and, of course, temperature. For the proper function of LC-based devices, not only chemical, but also optical purity of materials is strongly desirable, since any impurity could be detrimental to the self-assembly of the molecules. Therefore, in this study we aimed to verify synthetic methods published in the literature, which are used nowadays to prepare chiral building blocks based on lactic acid, for their enantioselectivity. Moreover, we have focused on the development of an analytical chiral separation method for target liquid crystalline materials. Using a chiral polysaccharide-based column operated in liquid chromatography mode, we show that not all published methods of LC synthesis are enantioselective, which could lead to significant differences in the properties of the resulting materials. We show that high-performance liquid chromatography with UV detection and supercritical fluid chromatography with UV and mass spectrometry detection enable full control over the chemical and optical purity of the target LCs and the corresponding chiral building blocks. For the first time, we utilise supercritical fluid chromatography with mass detection for the direct chiral analysis of liquid crystalline materials and impurities formed during the synthesis.

Supramolecular organization of phthalocyanines: from solution to surface

2009 ◽  
Vol 13 (04n05) ◽  
pp. 471-480 ◽  
Author(s):  
M. Victoria Martínez-Díaz ◽  
Giovanni Bottari
Keyword(s):  
Photophysical Properties ◽  
Building Blocks ◽  
Supramolecular Interactions ◽  
Supramolecular Organization ◽  
Supramolecular Systems ◽  
Ligand Interactions ◽  
Donor Acceptor ◽  
Interesting Class ◽  
Non Covalent Interactions ◽  
Covalent Interactions

Phthalocyanines are an interesting class of aromatic macrocycles which possess exciting electrical, redox and photophysical properties that make them ideal building blocks for applications in different technological fields. However, the incorporation of phthalocyanines into devices is often tied to the possibility of organizing these macrocycles into arrays using supramolecular interactions. To date, several supramolecular motifs such as hydrogen-bonding, donor-acceptor or metal-ligand interactions have been used to promote the phthalocyanines' organization in solution. Furthermore, such weak, non-covalent interactions have also been widely employed to foster the organization of these macrocycles in condensed phases such as liquid-crystals or thin films. This micro-review provides a brief overview of the contribution made by some research groups in Spain towards the preparation of organized phthalocyanine-based supramolecular systems.

New cyanopyridone based luminescent liquid crystalline materials: synthesis and characterization

2014 ◽  
Vol 13 (11) ◽  
pp. 1496-1508 ◽  
Author(s):  
Ahipa T. N. ◽  
Airody Vasudeva Adhikari
Keyword(s):  
Liquid Crystalline ◽  
Photophysical Properties ◽  
Synthesis And Characterization ◽  
Materials Synthesis ◽  
Crystalline Materials ◽  
Polar Groups ◽  
Liquid Crystalline Materials

A series of new luminescent mesogens carrying cyanopyridone, triazole, and polar groups were successfully synthesized. Also, their liquid crystalline and photophysical properties were investigated.

scholarly journals Anion-π Catalysis: A Novel Supramolecular Approach for Chemical and Biological Transformations

2021 ◽  
Author(s):  
Ishfaq Ahmad Rather ◽  
Rashid Ali
Keyword(s):  
Activation Energy ◽  
Asymmetric Synthesis ◽  
Supramolecular Chemistry ◽  
Chemical Reaction ◽  
Activation Barrier ◽  
Significant Lowering ◽  
Π Interactions ◽  
Non Covalent Interactions ◽  
Covalent Interactions

Catalysts by virtue of lowering the activation barrier helps in the completion of a chemical reaction in a lesser amount of time without being themselves consumed. Utilizing the diverse non-covalent interactions in the design and construction of catalysts, recently anion-π interactions were also introduced, giving rise to an emerging field of anion-π catalysis. In the newly constructed anion-π catalysts, significant lowering of activation energy occurs by virtue of anion-π interactions. Till now, several important reactions generating chiral centers have been carried out on the π-acidic surfaces of anion-π catalysts, thereby revealing the significance of anion-π catalysis in the domain of asymmetric synthesis. The motive of this chapter is to highlight the role of anion-π catalysis in asymmetric synthesis and we surely believe that it will offer new opportunities in supramolecular chemistry.

On resolving fine periodic microstructures in the optical microscope

1989 ◽  
Vol 47 ◽  
pp. 364-365
Author(s):  
W.S. Putnam ◽  
C. Viney
Keyword(s):  
Liquid Crystalline ◽  
Numerical Aperture ◽  
Polarized Light ◽  
Normal Incidence ◽  
Optical Microscope ◽  
Angle Of Incidence ◽  
Resolution Limit ◽  
Crystalline Materials ◽  
Periodic Microstructures ◽  
Liquid Crystalline Materials

Many sheared liquid crystalline materials (fibers, films and moldings) exhibit a fine banded microstructure when observed in the polarized light microscope. In some cases, for example Kevlar® fiber, the periodicity is close to the resolution limit of even the highest numerical aperture objectives. The periodic microstructure reflects a non-uniform alignment of the constituent molecules, and consequently is an indication that the mechanical properties will be less than optimal. Thus it is necessary to obtain quality micrographs for characterization, which in turn requires that fine detail should contribute significantly to image formation.It is textbook knowledge that the resolution achievable with a given microscope objective (numerical aperture NA) and a given wavelength of light (λ) increases as the angle of incidence of light at the specimen surface is increased. Stated in terms of the Abbe resolution criterion, resolution improves from λ/NA to λ/2NA with increasing departure from normal incidence.

Designing Chemically Selective Liquid Crystalline Materials that Respond to Oxidizing Gases

2021 ◽  
Author(s):  
Nanqi Bao ◽  
Jake Gold ◽  
Tibor Szilvasi ◽  
Huaizhe Yu ◽  
Robert Twieg ◽  
...  
Keyword(s):  
Computational Methods ◽  
First Principles ◽  
Liquid Crystalline ◽  
Soft Materials ◽  
Crystalline Materials ◽  
Liquid Crystalline Materials ◽  
Chemically Selective ◽  
Kinetics Of

Computational methods can provide first-principles insights into the thermochemistry and kinetics of reactions at interfaces, but this capability has not been widely leveraged to design soft materials that respond selectively...

scholarly journals Probing the Interactions of Porphyrins with Macromolecules Using NMR Spectroscopy Techniques

Molecules ◽  
2021 ◽  
Vol 26 (7) ◽  
pp. 1942
Author(s):  
Ilche Gjuroski ◽  
Julien Furrer ◽  
Martina Vermathen
Keyword(s):  
Nmr Spectroscopy ◽  
Photophysical Properties ◽  
Optical Methods ◽  
Spectroscopic Techniques ◽  
Control Mechanisms ◽  
Dynamic Information ◽  
Non Covalent Interactions ◽  
And Control ◽  
And Diffusion ◽  
Covalent Interactions

Porphyrinic compounds are widespread in nature and play key roles in biological processes such as oxygen transport in blood, enzymatic redox reactions or photosynthesis. In addition, both naturally derived as well as synthetic porphyrinic compounds are extensively explored for biomedical and technical applications such as photodynamic therapy (PDT) or photovoltaic systems, respectively. Their unique electronic structures and photophysical properties make this class of compounds so interesting for the multiple functions encountered. It is therefore not surprising that optical methods are typically the prevalent analytical tool applied in characterization and processes involving porphyrinic compounds. However, a wealth of complementary information can be obtained from NMR spectroscopic techniques. Based on the advantage of providing structural and dynamic information with atomic resolution simultaneously, NMR spectroscopy is a powerful method for studying molecular interactions between porphyrinic compounds and macromolecules. Such interactions are of special interest in medical applications of porphyrinic photosensitizers that are mostly combined with macromolecular carrier systems. The macromolecular surrounding typically stabilizes the encapsulated drug and may also modify its physical properties. Moreover, the interaction with macromolecular physiological components needs to be explored to understand and control mechanisms of action and therapeutic efficacy. This review focuses on such non-covalent interactions of porphyrinic drugs with synthetic polymers as well as with biomolecules such as phospholipids or proteins. A brief introduction into various NMR spectroscopic techniques is given including chemical shift perturbation methods, NOE enhancement spectroscopy, relaxation time measurements and diffusion-ordered spectroscopy. How these NMR tools are used to address porphyrin–macromolecule interactions with respect to their function in biomedical applications is the central point of the current review.

Role of non-covalent interactions in the supramolecular architectures of mercury(ii) diphenyldithiophosphates: An experimental and theoretical investigation

2021 ◽  
Vol 45 (4) ◽  
pp. 2249-2263
Author(s):  
Pretam Kumar ◽  
Snehasis Banerjee ◽  
Anu Radha ◽  
Tahira Firdoos ◽  
Subash Chandra Sahoo ◽  
...  
Keyword(s):  
Theoretical Investigation ◽  
Supramolecular Organization ◽  
Π Interactions ◽  
Supramolecular Architectures ◽  
Non Covalent Interactions ◽  
Covalent Interactions

The H-bond, spodium bond and CH⋯π interactions playing an important role in the supramolecular organization of two mercury(ii) diphenyldithiophosphate complexes have been discussed.

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