Field Of Chemistry Research Articles

Photomanipulatable colloidal clusters from the aggregation of azo molecular glass spheres.

Colloidal clusters with well-controlled shapes have attracted extensive interest in the fields of materials, chemistry, physics, and biology. This communication reports the controllable fabrication of photoresponsive colloidal clusters with a wide range of adjustable sizes and complex architectures through an approach of microsphere formation and fusion. The clusters of colloidal spheres were obtained via adding ethanol dropwise into a tetrahydrofuran solution of an isosorbide-based azo compound (IAC-4). In the process, the colloidal spheres with soft and sticky shells were first formed in the dispersion. After stirring at an appropriate rate and time, clusters composed of controlled numbers of colloidal spheres were obtained. With increasing stirring time, the colloidal spheres in the clusters underwent fusion transforming into a range of structures with particular architectures. The structure formation, evolution and control were investigated by scanning electron microscopy (SEM) and dynamic light scattering (DLS). Under linearly polarized light irradiation, colloidal spheres in the clusters in the solid state were observed to be stretched along the direction of electric-field oscillation and these clusters were thus transformed into complex particles with unique morphologies. This exploration can lead to a new methodology to effectively fabricate colloidal clusters with complex architectures and shed new light on colloidal packing and organization under the driving forces of extrinsic energy input.

Gold‐Catalyzed Heck and Suzuki‐Type Reactions: Challenges and Recent Advances

AbstractTransition metal‐catalyzed Suzuki and Heck reactions are two of the most common carbon‐carbon bond formation reactions. Gold, unlike other transition metals (Pd, Ni, and Cu), offers unique reactivity profiles, and has emerged as an efficient tool in the field of synthetic organic chemistry. This mini‐review focused on the recent work in gold‐catalyzed Heck and Suzuki‐type reactions, especially by photocatalysts or ligand design, which show reactivities and features distinct from other transition metals. These discoveries will further facilitate the development of gold redox catalysis as well as applications in organic synthesis, biochemistry, and medicinal chemistry.

Advances in the Synthesis of 3‐Acyl‐2‐Pyridones: Strategies and Methods for Accessing the Versatile Scaffold

ABSTRACTThe syntheses and bioevaluation of 3‐acyl‐2‐pyridones have garnered significant interest in recent years as a novel class of compounds with diverse biological activities. The bioactivities cover a wide range of therapeutic areas including antimicrobial, antitumor, anti‐inflammatory, antifungal, antibiotic, neuritogenic, cytotoxic, and antiviral activities. Therefore, 3‐acyl‐2‐pyridone scaffold offers a versatile platform for the development of new molecules with potential applications in medicinal chemistry. The recent exploration on synthesis and bioevaluation of 3‐acyl‐2‐pyridones has yielded promising results, making them attractive targets for further optimization and development of new therapeutic agents. This review summarizes the available information on total synthesis of 3‐acyl‐2‐pyridone containing natural products, and the other synthetic strategies developed for accessing the 3‐acyl pyridones such as multicomponent synthesis, condensation reaction, microwave‐assisted synthesis, catalytic hydrogenation reactions, metalation reaction, Michael addition, and formylation reactions. The presented information may serve as a valuable resource for researchers working in the field of medicinal chemistry and drug discovery, stimulating further exploration and development of this intriguing scaffold.

The synthesis of N-Trifluoromethyl hydroxylamine from (trifluoromethyl)trimethylsilane

We have presented a straightforward approach for the synthesis of N-CF3 hydroxylamines, utilizing TMSCF3 for the N-trifluoromethylation of nitrosoarenes with the assistance of CsF. This method demonstrates excellent tolerance towards various functional groups and can be applied to a wide range of substrates, highlighting its versatility and utility in synthetic applications. The nucleophilic N-trifluoromethylation pathway for N-CF3 hydroxylamines provides a practical protocol for the synthesis of promising molecular architectures in the field of medicinal chemistry.

First TPymT-Ln complexes (TPymT = 2,4,6-Tris(2-pyrimidyl)-1,3,5-triazine; Ln = Eu, Gd, Tb, Dy): Solvothermal synthesis, structure, magnetic and photoluminescent properties

Four novel mononuclear lanthanide complexes, [Ln(TPymT)(NO3)3(H2O)2] (Ln: Eu3+ (1), Gd3+ (2), Tb3+ (3) and Dy3+ (4)), have been solvothermally synthesized using multidentate 2,4,6-tris(2-pyrimidyl)-1,3,5-triazine (TPymT). Compounds 1–3 have been characterized by means of elemental analysis, FT-IR, and single-crystal/powder X-ray diffraction analysis. Compound 4 was structurally characterized. The Ln3+ ion in 1–4 is ten-coordinated, where TPymT serves as an N3 donor in an isostructural series. The alternating-current magnetic studies showed frequency dependence below ca. 10 K for 3, as an indication of a single-ion magnet. The activation energy for the magnetization reorientation was estimated as Ueff/kB = 95(9) K after applying a dc bias field 2000 Oe for 3. The photoluminescent studies clarified that 1 and 3 behaved as red and green light emitters with quantum yields as high as 17 and 39 %, respectively. The TD-DFT calculation supports the energy level scheme of ground and excited states of TPymT together with the reference compound 4′-phenyl-2,2’:6′,2″-terpyridine. The present work suggests a broad chance and motivation to apply TPymT to the field of 4f coordination chemistry.

Bioorthogonal Synthetic Chemistry Enabled by Visible-Light Photocatalysis.

The field of bioorthogonal chemistry has revolutionized our ability to interrogate and manipulate biological systems at the molecular level. However, the range of chemical reactions that can operate efficiently in biological environments without interfering with the native cellular machinery, remains limited. In this context, the rapidly growing area of photocatalysis offers a promising avenue for developing new type of bioorthogonal tools. The inherent mildness, tunability, chemoselectivity, and external controllability of photocatalytic transformations make them particularly suitable for applications in biological and living systems. This minireview summarizes recent advances in bioorthogonal photocatalytic technologies, with a particular focus on their potential to enable the selective generation of designed products within biologically relevant or living settings.

Facile and Sustainable Electrostatic Integration of Eosin Y Dye for the Assay of the Atomoxetine Drug Through the Enhancement of the RRS Phenomenon.

The suggested study follows specific protocols to guarantee that the atomoxetine drug analysis approach is environmentally friendly and sustainable. A number of recently created methods were used as prospective evidence for environmental sustainability and applicability, which is an essential point to emphasize. The current study introduces a new and very unique technology using ultrasensitive spectrofluorimetry to identify the atomoxetine (AXT) medication. A one-step, one-pot, direct spectrofluorimetric technique was used in this study's methodology, which was determined to be effective and environmentally sustainable for the drug's evaluation and validation. When AXT and EY reagent were mixed in an acidic setting, a highly resonant Rayleigh scattering product was promptly generated. The application of fluorimetric analysis was built on a novel theory that the augmentation in dye response subsequent to the addition of AXT was directly correlated to the resultant complex's molecular mass, as determined at a wavelength of 365nm. The complexation progression caused a considerable rise in the molecular mass, from 292.82 (AXT+) to 983.68 (AXT-EY) g mol-1. The quantum yield for the coupled product was measured. The linearity was determined to be between 30 and 1500 ng mL-1, while the sensitivity values were found to be between 9.2 and 28.1 ng mL-1. Analyzing AXT-EY complexes allowed us to determine the best values for all of the system's adjustable parameters. The system showed adherence to International Council for Harmonization (ICH) criteria without difficulties. The recommended procedure was then evaluated for environmental friendliness using many current environmental safety metrics. Fortunately, the current analytical technique is also recognized as a white one by the WAC standards, which integrate functional and ecological features using the Green/Red/Blue (RGB 12) design. A novel instrument called BAGI was used to assess the feasibility of the proposed approach in the field of analytical chemistry.

Cyano-modified molecular cage silica gel stationary phase: Multi-functional chromatographic performance by high-performance liquid chromatography

This study successfully prepared different loading levels of cyano-functionalized RCC3 molecular cage silica gel stationary phase (RCC3-CN@SiO2) through aldehyde-amine condensation reaction and subsequent modification strategies. Fourier transform infrared spectroscopy, thermogravimetric analysis, nitrogen adsorption-desorption, and scanning electron microscopy confirmed the successful synthesis of RCC3-CN@SiO2 chromatographic stationary phase. The research demonstrates that due to hydrophobic/hydrophilic interactions, π-π interactions, hydrogen bonding, and size-selective porous structure, the stationary phase effectively separates moderately polar and weakly polar compounds in reversed-phase liquid chromatography (RPLC) mode, exhibiting hydrophobic selectivity comparable to the commercial DaisoC18-RP columns. Additionally, the tertiary amine and cyanogen groups on the molecular cage surface enhance the interaction with polar compounds, successfully separating nucleosides, sulfonamides, amino acids, and sugars in hydrophilic interaction chromatography (HILIC) mode. Further applications in the separation analysis of acidic drugs, alkaline drugs, cinnamic acid natural products, and chiral compounds demonstrate the multifunctional chromatographic capabilities for diverse compound types. Compared to Unitary Diol commercial columns, the prepared stationary phase showed significant advantages in wide polarity range separation performance. Moreover, through nucleoside compound separation mode switching analysis, RCC3-CN@SiO2 stationary phase further validates its favorable performance in both RPLC and HILIC modes, demonstrating extensive potential applications in the field of analytical chemistry. Importantly, the stationary phase exhibits efficient separation of nucleoside compounds in pure water systems, aligning with the principles of green analysis.

Bioorthogonal Synthetic Chemistry Enabled by Visible‐Light Photocatalysis

AbstractThe field of bioorthogonal chemistry has revolutionized our ability to interrogate and manipulate biological systems at the molecular level. However, the range of chemical reactions that can operate efficiently in biological environments without interfering with the native cellular machinery, remains limited. In this context, the rapidly growing area of photocatalysis offers a promising avenue for developing new type of bioorthogonal tools. The inherent mildness, tunability, chemoselectivity, and external controllability of photocatalytic transformations make them particularly well‐suited for applications in biological and living systems. This minireview summarizes recent advances in bioorthogonal photocatalytic technologies, with a particular focus on their potential to enable the selective generation of designed products within biologically relevant or living settings.

Nano Fertilizers: Revolutionizing Agriculture for a Sustainable Future

Nanotechnology, one of the advanced fields of study, is currently the focus of contemporary science and one of the most important ones in physics, chemistry, agriculture, and other fields. Nanotechnology provides superior quality, environmental safety, biological support, and financial stability as an environmentally sound substitute for traditional agriculture. Utilizing nanoparticles (NPs) in agriculture has introduced recently; examples like biosynthesis, the use of nanopesticides and fertilizers, improving biological function, and reducing heavy metal toxicity and abiotic stress. To focus on safe use and positive response of nano-particles, more research is required. There are gaps in the food supply compare to food production, which get worse over time due to rising food demands and nutrient depletion. Environmental degradation, changes in soil ecology, and problems with agricultural output are all brought on by synthetic fertilizer inputs. Adapting advanced agriculture technolgy for a sustainable future will be the main topic of this review.

Saponin is Essential for the Isolation of Proteins and RNA from Biological Nanoparticles.

Extracellular vesicles (EVs), biomimetics, and other biological nanoparticles (BNs) produced from human cells are gaining increasing attention in the fields of molecular diagnostics and nanomedicine for the delivery of therapeutic cargo. In particular, BNs are considered prospective delivery vehicles for different biologics, including protein and RNA therapeutics. Moreover, EVs are widely used in molecular diagnostics for early detection of disease-associated proteins and RNA. Technical approaches for measuring biologics mostly originated from the field of EVs and were later adopted for other BNs, such as extracellular vesicle-mimetic nanovesicles, membrane nanoparticles (nanoghosts), and hybrid nanoparticles, with minimal modifications. Here, we demonstrate that BNs are highly resistant to protocols that severely underestimate the protein and RNA content of BNs, and provide the relevance of these data both for general BNs characterization and practical applications of CRISPR/Cas-based therapies. We demonstrate that the addition of saponin leads to an ∼2- to 7-fold enhancement in protein isolation and an ∼2- to 242-fold improvement in RNA recovery rates and detection efficiency. Differences in the proteolipid contents of BNs, measured by Raman and surface-enhanced Raman spectroscopy, correlate with their susceptibility to saponin treatment for cargo extraction. Finally, we develop a unified protocol using saponin to efficiently isolate proteins and RNA from the BNs. These data demonstrate that previously utilized protocols underestimate BN cargo contents and offer gold standard protocols that can be broadly adopted into the field of nanobiologics, molecular diagnostics, and analytical chemistry.

Self-assembly of decavanadate and Ni(HCO3)2 into nanoparticles anchored on carbon nitride for efficient photocatalytic Minisci-type alkylation

Photocatalysis Minisci-type reactions involving carbon-centered radicals (CCRs) have emerged as a hot and significant topic in the field of organic synthesis chemistry. Herein, we present a nickel-vanadium nanoparticle anchored on carbon nitride catalyst (NiV-CN) and persulfate as a hydrogen atom transfer (HAT) precursor. This catalyst enables the photocatalytic Minisci-type CCR alkylation. The nickel-vanadium nanoparticles are synthesized via electrostatic attraction between [V10O28]6− anions and Ni(HCO3)2, with in situ self-assembly occurring during the hydrothermal process. In the model reaction of 4-methylquinoline with cyclohexane, the NiV-CN catalyst showed high stability, without significant loss its catalytic activity after three cycles. The CCRs was extended to cycloalkanes, adamantanes, and cyclic ethers, which react with quinoline, isoquinoline, and benzothiazole to provide the corresponding products in moderate to excellent yields. Mechanism studies indicate that nickel-vanadium nanoparticles play a crucial role in the formation process of carbon-centered radicals by activating the persulfate precursor into sulfate radicals under visible-light irradiation.

Long range self-transport of liquid droplets driven by electric field and roughness gradient

It is well known that roughness and charge gradients could be used for droplet self-transport. The key issue is how to synergize the two effects. The uniform density charge can form linearly increasing charge gradient on a roughness gradient surface. Under this condition, the influence on the droplet self-transport under the synergy of these two effects was obtained by statics analysis, and the driving function was presented. An energy equation was constructed to study the conditions for crossing periodic boundaries, and the problem of distance limitation on periodic surfaces due to energy dissipation was solved by converting electric potential into droplet kinetic energy. A periodic roughness gradient surface with K = 0.07 was designed and prepared via 3D printing. Water droplets can be transported over long distances and the maximum velocity increases with charge density up to 46 mm/s. Finally, the effect of different structures on the maximum charge density in the Cassie state was investigated by simulation. The biomimetic structures exhibit great compressive stability, which can increase the surface charge density of droplets in the Cassie state by 3.6 times compared to pillar structures. It can be widely used in the fields of materials science and interface chemistry, etc.

Eco-friendly solvents in liquid-liquid microextraction techniques for biological and environmental analysis: a critical review.

In recent years, green solvents have emerged as promising alternatives in the field of analytical chemistry, replacing conventional organic solvents known for their toxicity, volatility, and flammability. The combination of these solvents with liquid-liquid microextraction techniques has facilitated the development of simpler, faster, more economical, and environment-friendly methodologies for the analysis of samples of varying complexity. This review discusses the fundamental physicochemical properties and advantages of using deep eutectic solvents, ionic liquids, switchable-hydrophilicity solvents, supramolecular solvents, and surfactants as extractants. Furthermore, analytical methods based on liquid-liquid microextraction techniques developed in the last 5years for the determination of organic compounds and metals in biological and environmental samples are presented and discussed, highlighting their applications and benefits to improve analytical performance and sustainability.

Practical Multigram Approach to Conformationally Constrained α-Proline-Based Building Blocks with γ-Spiro Conjunction

AbstractUnusual amino acids have arisen as an indispensable instrument at the disposal of modern medicinal chemistry. While extensively exploited as building blocks in the search for new pharmaceuticals, their application goes far beyond. They are currently involved in explorations of the structure and conformational mobility of peptides, modification and amplification of peptidomimetic activity, and others. Herein, we report an effective synthetic approach to nonplanar, conformationally restricted, sp3-enriched spirocyclic α-prolines. The protocol employs readily available nitrile-based starting materials and conventional experimental procedures. The synthetic sequence is concise and includes three principal stages (one of them a four-step telescopic process). The reactions proceed on a multigram scale affording the target prolines in overall good yields. The possibility of chiral separation of the synthesized racemic spiro prolines to both pure enantiomers is shown. The building blocks synthesized in the study are expected to have practical uses in the field of medicinal chemistry.

Synthesis of 4-fluoroisocoumarins by copper-catalyzed annulation of 2-halobenzoic acids and 2-fluoro-1,3-diketones

Fluorinated heterocycles have been promising in the field of medicinal, agrochemical and materials chemistry due to their unique properties. However, despite the potentially very useful structures of fluorinated isocoumarins, the synthetic method of fluorinated isocoumarins remains a challenging topic. Herein, we describe the synthetic method of fluorinated isocoumarins by tandem coupling-cyclization-deacylation reaction of readily available 2-halobenzoic acids and 2-fluoro-1,3-diketones. This study provides one of the few synthetic methods of fluorinated isocoumarins.

Two-Step Noncatalyzed Hydrolysis Mechanism of Imines at the Air-Water Interface.

The hydrolysis of imines has long been assumed to be their main atmospheric fate, based on early studies in the field of organic chemistry. However, the hydrolysis mechanism and kinetics of atmospheric imines remain unclear. Here, an advanced Born-Oppenheimer molecular dynamics method was employed to investigate the noncatalyzed hydrolysis mechanism and kinetics at the air-water interface by selecting CH2NH as a model molecule. The results indicate that CH2NH exhibits a pronounced surface preference. The noncatalyzed hydrolysis of CH2NH follows a unique two-step reaction mechanism involving first proton transfer and then OH- transfer through the water bridge at the air-water interface, in contrast to the traditional one-step mechanism. The calculated reaction rate for the rate-determining step is 3.32 × 105 s-1, which is 2 orders of magnitude greater than that of the bulk phase. In addition, the involvement of the interfacial electric field further enhances the reaction rate by approximately 3 orders of magnitude. The noncatalyzed hydrolysis rate at both the air-water interface and the bulk phase is higher than that of the possible acid-catalyzed one, clarifying noncatalyzed hydrolysis as the dominant mechanism for CH2NH. This study elucidates that the noncatalyzed hydrolysis of atmospheric imines is feasible at the air-water interface and that the revealed unique two-step hydrolysis mechanism has significant implications in atmospheric and water environmental chemistry.

Supramolecular cyclodextrin complexes of biologically active nitrogen heterocycles

The review is devoted to the rapidly developing field of modern supramolecular chemistry - cyclodextrin complexes of biologically active nitrogen heterocycles, such as piperidines, piperazines, morpholines and pyridines. Interest in cyclodextrin complexes is growing due to the search and construction of supramolecular assemblies for targeted drug delivery. The latter is achieved as a result of supramolecular self-assembly, based on the principles of molecular recognition, and is one of the areas of modern chemistry, leading to the creation of new materials with new properties. This review fully demonstrates the ongoing scientific and practical interest in the problem of encapsulation with cyclodextrins, including nanoencapsulation. Encapsulation with cyclodextrins provides a wide range of advantages: obtaining solid dosage forms from liquid ones, stabilizing and protecting active substances from the adverse effects of external factors, increasing solubility, increasing bioavailability, reducing toxicity, prolonging action, etc. The presented review includes recent advances in the field of supramolecular complexes of biologically active nitrogen heterocycles with cyclodextrins and concludes with a discussion and identification of future promising directions for research. The review presents the results of supramolecular self-assembly of biologically active azaheterocycles with cyclodextrins.

Dicarbatriphyrin(2.1.1) and its Carbacalix[1]Phyrin Analogue: Structure-Property Relationships and Application as a Fe(III) Chemosensor.

The investigation of unsaturated or π-conjugated hydrocarbons, particularly within the macrocyclic framework, has garnered significant interest due to their fundamental properties and practical applications. This research focuses on the synthesis and characterization of a novel stable dicarbatriphyrin(2.1.1) which was constructed by amending the [14]triphyrin(2.1.1) framework by, replacing two pyrrole rings with meta-connected phenyl rings and introducing an o-benzene bridge at the C2 position. The structural modification resulted in a saddle-shaped macrocyclic core with negative Gaussian curvature, as confirmed by crystal structure analysis. This unique molecular topology offers acumens into the structure-property relationships in the curved locally π-conjugated contracted porphyrinoids. The macrocycle exhibits fluorescent emission in solution, which is selectively quenched by Fe(III) ions, highlighting its potential as a chemosensor for Fe(III) cations. Additionally, the formation of carbacalix[1]phyrin(2.1.1), a phlorin analogue of dicarbatriphyrin(2.1.1), which exhibits a chair conformation in contrast to the saddle-shaped structure of its oxidized counterpart. Remarkably, the emergence of a mono-pyrrolic calixbenziphyrin marks an unprecedented advancement in the field of calixphyrin chemistry. Moreover, theoretical studies provide strong support for the experimental findings, reinforcing the conclusions drawn from the structural and functional analyses.

Cardiovascular Drugs as Water Contaminants and Analytical Challenges in the Evaluation of Their Degradation

Cardiovascular drugs have been a burning topic in the field of environmental analytical chemistry in the last few decades. Growing modern healthcare has led to the widespread use of pharmaceuticals. Among these, antihypertensives (sartans, angiotensin-converting enzyme inhibitors) and lipid-regulating drugs (fibrates and statins) are the most frequently consumed and, thus, excreted into wastewater. Their chemical fate during conventional and advanced wastewater treatment, such as ozonation, remains unclear. Analytical chemistry, providing sample pretreatment followed by instrumental analysis, has a tremendous role in water treatment evaluation, mostly from the perspective of parent contaminants’ removals and also assessment of transformation pathways. Ultrasensitive liquid chromatography–mass spectrometry (LC-MS) systems provide many opportunities. By carefully using planned workflows for chromatographic and mass-spectrometric data processing, i.e., suspect and non-target screening approaches, LC-MS allows for the identification and structural elucidation of unknown, predicted, suspected or selected transformation products. Accordingly, some examples and case studies on selected cardiovascular drugs in this review are presented to show the applicability of the used analytical approaches and workflows.