Supramolecules Research Articles

(Invited, Digital Presentation) Molecular Nanocarbon Synthesis and Beyond

Our goal is the creation of super molecules, innovative functional molecules with significant properties and/or beautiful molecules. To this end, we have focused on catalyst-enabling synthetic chemistry with broad directions, including applications in molecular nanocarbons, pharmaceuticals, and plant/animal chemical biology, and the development of rapid molecule-assembly methods using unique catalysts. In particular, we have pioneered molecular nanocarbon science by the bottom-up synthesis of structurally uniform nanocarbons of fundamental and practical importance. Representative achievements include: (1) the development of single-step aromatic π-extension (APEX) methods for the rapid and programmable synthesis of nanocarbon molecules (Science 2018, Nature Commun. 2015, Nature Chem. 2015, Nature Commun. 2021); (2) the synthesis of carbon nanorings, nanobelts and pure nanotubes (ACIE 2009, Science 2017, Nature Chem. 2013, Nature Commun. 2018, Nature Commun. 2019, Nature Chem. 2021); and (3) the synthesis of topologically unique nanocarbons such as warped nanographenes, carbon nanocages, all-benzene catenanes, and trefoil knots (Science 2019, Nature Chem. 2013, Nature Catal. 2020). In this talk, most recent beautiful molecular nanocarbons will be presented. We will also describe about our exciting interdisciplinary research conducted at the Institute of Transformative Bio-Molecules (ITbM) in Nagoya University and Institute of Chemistry in Academia Sinica, Taiwan, where we aim at developing game-changing molecules for nanocarbon-based chemical biology. By using our original rapid molecule-assembling catalysts, a number of lead compounds were rapidly discovered.

APPLICATION OF IMAGE ANALYSIS USING TEXTURES OF Py14BA:nFA FOR MESOGEN PARAMETERS

Thermal and optical properties of two supra molecule mesognes: Py14BA:nFAs (n=14 and 16) (4-Pyridyl)- benzylidene-4’- n-tetradecyl aniline(PyB14A):aliphatic carboxylic acids (nFA where n = 14 and 16) are investigated. This study is carried out with a polarizing optical microscope and image analysis method. It is based on the temperature dependence of intensities of the mesogen textures. Intermolecular hydrogen bond formation between the two nonmesogens gives rise to mesogen complexes Py14BA:nFAs (n=14 and 16). The properties of these mesogen complexes are computed from the images (textures) through MATLAB software. Transition temperatures, heat enthalpy, thermal stability factor, Birefringence dispersion, Phase retardation, Transient transmission and order parameter studies are carried out. The results manifest that hydrogen-bonded mesogens exhibit good thermo-optical properties.

A Comprehensive Mini Review on Co-Crystallization Process

Co‑crystal chemistry has recently attracted supramolecular scientists. Co-crystals are comprising of hydrogen bonding assembly between different molecules. Many issues related to the performance characteristics of an active pharmaceutical ingredient (API) can be resolved using the co-crystallization approach. A proper understanding of the crystal structure of an API is required for the successful formation of co-crystals with the selected co‑former. Co-crystal chemistry has recently attracted scientists from the super molecules. Co crystals consist of the assembly of hydrogen bonds between various molecules. Many problems related to the performance characteristics of an active pharmaceutical ingredient (API) can be solved using the method of co-crystallization. Co-Crystals offer an alternate pathway where any API, paying little mind to be acidic, essential, or ionizable gatherings, might be co-gem. This aspect also helps to complement existing methods by reintroducing molecules with limited pharmaceutical profiles based on their non-ionizable functional groups.

Water and Dioxide Carbon Effects on Di or Tri Saccharides Degradation by Density Functional Theory at Level: B3LYP/6-311++G (d, p)

Storing paddy rice over a long period changes its physical properties. It transforms its chemical structure. But the mechanism of this degradation remains little known. This work aims to help elucidate it. It’s studying the possibilities of hydrogen bonding between the di or the trisaccharide with water or carbon dioxide. This research uses the methods of quantum chemistry. These make it feasible to determine the geometric and energy parameters of the complexes. These supramolecules consist of di or trisaccharide associated with water or carbon dioxide. The calculations lead to the following result. The trisaccharide remains stable during its interactions with water and carbon dioxide, the latter strengthening the hydrogen bonds of the complex disaccharide-water. It disadvantages its degradation.

Semi-conductive chiral Co-CPs with helixes based on lactic acid derivatives: Synthesis, structures and photocatalyic properties

Among various chiral compounds, semirigid lactic acid derivatives modified from lactic acids have been attractive synthons for the synthesis of chiral coordination polyers (CPs). Herein, lactic acid derivative (R)-4-(1-carboxyethoxy) benzoic acid ((R)-H2CBA) was used to reacted with Co(Ⅱ) ions and auxiliary ligands to obtain two chiral CPs, namely [Co2((R)-CBA)2(2,5-DIP)2]n (1, 2,5-DIP ​= ​2,5-bis(2-methyl-1H-imidazole-1-yl)pyridine) and [Co((R)-CBA)(1,3-DIB) 1.5]n (2, 1,3-DIB ​= ​1,3-di(1H-imidazole-1-yl)benzene). Although two complexes were synthesized under the similar condition, their structural motifs are still very different. Complex 1 has pillared-layer framework with 6-connected mab net and two types of helixes, while complex 2 is 3D supra molecule framework packed by 2D helical layers. UV/vis spectra, Mott-Schottky measurements and electrochemical impedance spectroscopy revealed complexes 1 and 2 are typical n-type semiconductors with low resistance in charge transportation and high charge-separation efficiency. Under UV irradiation, complexes 1 and 2 showed good photocatalytic activity in the degradation of methylene blue. The photocatalytic experiments confirmed that the conversion of MB was up to 88% for 1 and 73% for 2 after 3 ​h, respectively.

Development, characterization, and biocompatibility of zinc oxide coupled starch nanocomposites from different botanical sources

Starch nanoparticles (SNP) were prepared from different botanical sources (wheat, potato, mung bean, water chestnut and mango kernels) and these were further coupled with zinc oxide (ZnO) to form starch nanocomposites. The nanocomposites were characterized for their particle size, morphological properties, energy dispersive X-ray spectroscopy (EDX) and their biocompatibility was analyzed by MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay, using HeLa cells. From the morphological results, it was observed that ZnO forms super molecules with SNP. Further, EDX studies also confirmed the presence of zinc in coupled molecules. The size distribution of ZnO coupled SNP from different botanical sources revealed that the average diameter of nanocomposites ranged between 506 and 1209 nm. ZnO coupled starch nanocomposites were found to be biocompatible with 77–90% cell viability up to 24 h on HeLa cells. Among all botanical sources studied, ZnO coupled mung bean starch nanocomposite showed the highest cell viability (75% up to 50 h) while ZnO coupled potato starch nanocomposite showed the lowest cell viability (65% up to 50 h).

Hybrid supramolecule of azolium-linked cyclophane: Synthesis, structure and thermostability

Hybrid supramolecule of azolium-linked cyclophane: Synthesis, structure and thermostability

A Review on Micellar Catalyzed Oxidation Reactions of Organic Functional Groups in Aqueous Medium Using Various Transition Metals

Abstract The current requirement for science and research concerns the absolute sustainable development of a chemistry that is inherently safer, smarter and more environmentally friendly. The oxidation reaction is a very fundamental transformation reaction in organic synthesis and likely plays a significant role in the production of various value-added chemicals from biomass and others precursors. In the focus of making kinetic experiments greener several modified methodologies and safe chemicals have been employed. Surfactants are such suitable alternate that go with the requirments. Surfactant aggregates i. e. micelles are nano-sized supra molecules, able to act as catalysts. They can be used to catalyze the organic functional group transformation reactions mediated with transition metals and promoted with various aromatic bases. This allowed water to be used as a solvent, where the reactions became more sustainable. The recyclability of used surfactants, enhancement of reaction kinetics and speed of reaction with no consumption of energy has added more value to this type of catalytic oxidation. This article aims to contribute to the discussion of the mechanistic aspects of various types of surfactant-catalyzed oxidation of organic functional groups.

Giant supramolecules as molecular containers

Giant supramolecules as molecular containers

Self-assembly of emissive metallocycles with tetraphenylethylene, BODIPY and terpyridine in one system

ABSTRACT Tetraphenylethylene (TPE) related (supra)molecules have been intensively investigated due to their aggregation-induced emission (AIE) effect based on the restriction of intramolecular rotation (RIR). Meanwhile, boron-dipyrromethene (BODIPY) tends to emit intense fluorescence with high quantum yields. Herein, we combined TPE, BODIPY and terpyridine (TPY) into one system to study the emissive behaviour of organic building block as well as a self-assembled metallo-supramolecule. The TPY and BODIPY substituents with bulky sizes provide strong hindrance to restrict the rotation of the phenyl groups on TPE, leading to enhancement of emissive properties in both solution and aggregation states. Furthermore, the BODIPY-TPE-TPY ligand (L) was assembled with Zn (II) through coordination-driven self-assembly to form a cyclic dimer (D) with typical AIE characteristics.

Synthesis and characterisation of calix[4]arene based bis(triazole)-bis(hexahydroquinoline): Probing highly selective fluorescence quenching towards mercury (Hg2+) analyte

In the present study, we are reporting the synthesis of a triazoles incorporated fluorescent hexahydroquinoline appended calix[4]arene 7 and its highly selective optical recognition ability towards Hg2+. The optical sensor 7 was synthesized via two different synthetic pathways and unambiguously characterized by mass spectrometry and NMR spectroscopy. The stoichiometric ratio between 7 and Hg2+ was determined as 1:1 based on Job’s plot and ESI-MS analysis. The chemosensor 7 selectively recognized Hg2+ in the presence of competitive cations such as Cu2+, Cu1+, Co3+, Ni2+, Ag1+, Fe2+, Fe3+, Cr3+, Pb2+, Cd2+, Zn2+, Sn2+, Ti4+, Sb3+, In3+, Ba2+, Ca2+, and K1+. The limit of detection (LOD) was established as 0.5 μM on spectrofluorimetric analysis. According to world health organization (WHO) in guidelines for drinking-water quality, the mercury level in natural occurring ground and surface water is about ∼0.5 μM (μg/L). The supra molecule 7 with LOD (0.5 μM) could potentially serve effective receptors for Hg2+ cation. The probe 7 was applied effectively for detection of Hg2+ in real water samples (i.e. tap and deionized water), spiked with Hg2+ (10 μM) solution. Moreover, the compound 7 showed non-toxicity during cytotoxic assay against human B cells as they retain their morphology. The supramolecule 7 in living cells showed selectivity towards Hg2+ in cytotoxic assay with T lymphocytes, evident by morphological changes observed via AFM analysis.

Giant pentaphosphaferrocene-based supramolecules as molecular containers

Giant pentaphosphaferrocene-based supramolecules as molecular containers

Synthesis and Fabrication of Nanoparticle-Based Thin Layer of Natural Porphyrin

Synthesis and fabrication of nanoparticle-based thin layer of natural porphyrin was reported in this paper. The natural porphyrin solutions used in the experiments were synthesized by using a process of column chromatography techniques. Then natural porphyrin thin films were deposited by spin coating methods on Cu substrate. Experiment result showed that natural porphyrin thin films composed of discrete islands. More detailed observation show that the islands were formed from smaller islands that called supra molecule.

Correction: Boronic esters of corannulene: potential building blocks toward icosahedral supramolecules

Correction for ‘Boronic esters of corannulene: potential building blocks toward icosahedral supramolecules’ by Sara Da Ros et al., Org. Chem. Front., 2015, DOI: 10.1039/c5qo00009b.

Molecular recognition of curcumin (Indian Ayurvedic medicine) by the supramolecular probe, p-t-butyl calix(8)arene

The thermodynamic property of the host–guest complexes formed between the curcumin, component of Indian Ayurvedic medicine turmeric, a drug molecule, with the supra molecule, p-t-butyl calix(8)arene was studied. p-t-Butyl calix(8)arene has been used as a host molecule and curcumin as a guest molecule. Optical absorption spectral studies were carried out to investigate the molecular recognition properties of p-t-butyl calix(8)arene with curcumin. The stochiometry of the host–guest complexes formed and the binding constant were determined. An interesting 1:1 and 4:1 stochiometric host–guest complexes were formed. Job’s continuous method of variation and Benesi–Hildebrand expression were used for the determination of binding constant and the stochiometry of the host–guest complex formed.

Molecular recognition study of Carbamazepine, antiseizure drug, by p-t-butyl calix(8)arene

The formation of inclusion complex of Carbamazepine, a antiseizure drug molecule, with the supra molecule, p-t-butyl calix(8)arene was studied. p-t-Butyl calix(8)arene was the host molecule and Carbamazepine was the guest molecule. Optical absorption spectral studies were carried out to study the molecular recognition properties of p-t-butyl calix(8)arene with Carbamazepine. The stochiometry of the host–guest complex and the binding constant were determined.

Stilbene Molecular Probes as Potential Materials for Bioengineering: Real Time Analysis of Antioxidants and Nitric Oxide, Immunoassay in Solution and Biomembranes Fluidity

A series of fluorescent methods of analysis and investigation of system based on the use of stilbenes and potentially important in biochemistry, biophysics, biotechnology, and biomedicine were proposed and developed. In these methods, two new types of stilbene molecular probes have been used: (i) fluorescent photochrome molecules and (ii) super molecules containing fluorescent and fluorescent quenching segments. These methods utilize the following photochemical and photophysical phenomena: the fluorescence and phosphorescence quenching, photochrome photoisomerization, and triplet–triplet and singlet–singlet energy transfer. The fluorescence properties of the new probes were intensively exploited as the basis of several methodologies that include a real-time analysis of nitric oxide, immunoassay in solution, investigation of molecular dynamics of biomembranes in a wide range characteristic times, and characterization of sensors for antibodies. These techniques may be adapted to fibro-optic sensoring.

Pentadecker Supramolecules with a Lithium Alkoxo Nanobelt Sandwiched between Two Highly Charged Buckybowl Surfaces

Pentadecker Supramolecules with a Lithium Alkoxo Nanobelt Sandwiched between Two Highly Charged Buckybowl Surfaces

Excitation and Tuning of Higher-Order Fano Resonances in Plasmonic Oligomer Clusters

Plasmonic oligomer clusters are assemblies of closely packed metallic nanoparticles. They provide a rich set of spectral features such as Fano lineshapes and a simultaneous tunability of the supported resonances in the optical wavelength regime. In this study, we investigate numerically and experimentally clusters of plasmonic nanoparticles that exhibit multiple Fano resonances due to the interference of one broad superradiant mode and multiple narrow subradiant modes. In particular we investigate oligomers with multiple ring modes and elongated chains of nanoparticles surrounded by one ring of nanoparticles. We show that the number of nanoparticles and their respective arrangement in the cluster strongly influence the spectral position and modulation depth of the spectral signature of the supported modes. Our study opens up the pathway to "plasmonic super molecules" that show unprecedented tunability, which renders them highly suitable for applications such as multiwavelength surface-enhanced Raman scattering.

Photosensitization Reactions of Fluoroquinolones and Their Biological Consequences

This review focuses on damage photosensitized by the fluoroquinolone (FQ) antibacterial drugs. Different models are employed to study biosubstrate photodamage mediated by FQs (organisms, cells, isolated biomolecules and super molecules). Being that the effect of environment (polarity of the medium, ions, pH, binding with bio-molecules, etc.) is crucial in FQ photochemistry, photobiological reactions can be consequently dramatically influenced. Thus, the photosensitization processes induced by FQs are here discussed taking into account that such extensive and cross-targeted pathological implications request an excursus covering photosensitization in systems of increasing molecular complexity. In vivo and in vitro evidences for photoallergy, phototoxicity, photomutagenesis and photocarcinogenesis mediated by FQs are discussed.