Chemical Research Research Articles

BiVO4-based heterojunction nanophotocatalysts for water splitting and organic pollutant degradation: a comprehensive review of photocatalytic innovation

Abstract The novel semiconductor photocatalytic material bismuth vanadate (BiVO4) is gaining significant attention in research due to its unique characteristics, which include a low band gap, good responsiveness to visible light, and non-toxic nature. However, intrinsic constraints such as poor photogenerated charge transfer, slow water oxidation kinetics, and fast electron–hole pair recombination limit the photocatalytic activity of BiVO4. Building heterojunctions has shown to be an effective strategy for enhancing charge separation and impeding electron–hole pair recombination over the last few decades. This review covers the state-of-the-art developments in heterojunction nanomaterials based on BiVO4 for photocatalysis. It explores heterojunction design, clarifies reaction mechanisms, and highlights the current developments in applications including photocatalytic water splitting and organic matter degradation. Finally, it offers a preview of the development paths and opportunities for BiVO4-based heterojunction nanomaterials in the future. This comprehensive assessment of BiVO4-based heterojunctions provides insightful knowledge to researchers in materials science, chemistry, and environmental engineering that will drive advances and breakthroughs in these important fields.

Fast Exploring Literature by Language Machine Learning for Perovskite Solar Cell Materials Design

Making computers automatically extract latent scientific knowledge from literature is highly desired for future materials and chemical research in the artificial intelligence era. Herein, the natural language processing (NLP)‐based machine learning technique to build language models and automatically extract hidden information regarding perovskite solar cell (PSC) materials from 29 060 publications is employed. The concept that there are light‐absorbing materials, electron‐transporting materials, and hole‐transporting materials in PSCs is successfully learned by the NLP‐based machine learning model without a time‐consuming human expert training process. The NLP model highlights a hole‐transporting material that receives insufficient attention in the literature, which is then elaborated via density functional theory calculations to provide an atomistic view of the perovskite/hole‐transporting layer heterostructures and their optoelectronic properties. Finally, the above results are confirmed by device experiments. The present study demonstrates the viability of NLP as a universal machine learning tool to extract useful information from existing publications.

Moving scientific knowledge from the laboratory to the theatre: Humphry Davy's Lecture practice at the Royal Institution, 1801–1812

During the first decade of the nineteenth century, it was (almost) universally acknowledged that Humphry Davy's lectures at the Royal Institution on chemistry, electro-chemistry and geology, among other subjects, were by far the most attractive scientific spectacle in London. Much has been written about the popularity, the fashionability, the attractiveness and the patriotism (in time of war) of Davy's lectures. When Davy, aged 22, arrived in London in March 1801 he had never previously delivered a lecture, but within two months he had made his mark in the Royal Institution's new large lecture theatre, so much so that he immediately repeated his first course. How did his experimental demonstrations, full of spectacular sensory experience (noise, smell, light, touch) convey his scientific rhetoric? What resources, material and human, did he draw on? In this paper I will seek to understand how Davy constructed his practice as a lecturer and how it related to his chemical researches. As well as using Davy's lecture notes (now available through the Davy Notebooks Project), I will draw on the notes taken by some of his auditors, their comments in diaries and letters as well as administrative records and contemporary newspaper accounts.

From Protein Structures to Functional Biomimetics

AbstractThe development of complex molecular scaffolds with defined folding properties represents a central challenge in chemical research. Proteins are natural scaffolds defined by a hierarchy of structural complexity and have evolved to manifest unique functional characteristics; for example, molecular recognition capabilities that facilitate the binding of target molecules with high affinity and selectivity. Utilizing these features, proteins have been used as a starting point for the design of synthetic foldamers and enhanced biocatalysts, as well as bioactive reagents in drug discovery. In this account, we describe the strategies used in our group to stabilize protein folds, ranging from the constraint of bioactive peptide conformations to chemical protein engineering. We discuss the evolution of peptides into peptidomimetics to inhibit protein–protein and protein–nucleic acid interactions, and the selective chemical modification of proteins to enhance their properties for biotechnological applications. The reported peptide- and proteomimetic structures cover a broad range of molecular sizes and they highlight the importance of structure stabilization for the design of functional biomimetics.1 Introduction2 Constraining the Conformation of Peptides3 Peptide-Based Covalent Protein Modifiers4 Chemical Protein Engineering5 Conclusions

Mass Transport and Energy Conversion of Magnetic Nanofluids from Nanoparticles’ Movement and Liquid Manipulation

Magnetic nanofluids, also referred to as ferromagnetic particle levitation systems, are materials with highly responsive magnetic properties. Due to their magnetic responsiveness, excellent controllability, favorable thermal characteristics, and versatility, magnetic nanofluids have sparked considerable interest in both industrial manufacturing and scientific research. Magnetic nanofluids have been used and developed in diverse areas such as materials science, physics, chemistry and engineering due to their remarkable characteristics such as rapid magnetic reaction, elastic flow capacities, and tunable thermal and optical properties. This paper provides a full and in-depth introduction to the diverse uses of ferrofluids including material fabrication, fluid droplet manipulation, and biomedicine for the power and machinery sectors. As a result, magnetic nanofluids have shown promising applications and have provided innovative ideas for multidisciplinary research in biology, chemistry, physics and materials science. This paper also presents an overview of the device construction and the latest developments in magnetic-nanofluid-related equipment, as well as possible challenging issues and promising future scenarios.

Nitrogen Fixation by Manganese Complexes - Waiting for the Rush?

Manganese is currently experiencing a great deal of attention in homogeneous catalysis as a sustainable alternative to platinum group metals due to its abundance, affordable price and low toxicity. While homogeneous nitrogen fixation employing well-defined transition metal complexes has been an important area of research in coordination chemistry, manganese derivatives have been only sporadically used in this research area. In this contribution, the authors systematically cover manganese organometallic chemistry related to N2 activation spanning almost 60 years, identify apparent pitfalls and outline encouraging perspectives for its future development.

Enhancement of spectral model transferability in LIBS systems through LIBS-LIPAS fusion technique

BackgroundLaser-induced breakdown spectroscopy (LIBS) is extensively utilized a range of scientific and industrial detection applications owing to its capability for rapid, in-situ detection. However, conventional LIBS models are often tailored to specific LIBS systems, hindering their transferability between LIBS subsystems. Transfer algorithms can adapt spectral models to subsystems, but require access to the datasets of each subsystem beforehand, followed by making individual adjustments for the dataset of each subsystem. It is clear that a method to enhance the inherent transferability of spectral original models is urgently needed. ResultsWe proposed an innovative fusion methodology, named laser-induced breakdown spectroscopy fusion laser-induced plasma acoustic spectroscopy (LIBS-LIPAS), to enhance the transferability of support vector machine (SVM) original models across LIBS systems with varying laser beams. The methodology was demonstrated using nickel-based high-temperature alloy samples. Here, the area-full width at half maximum (AFCEI) Composite Evaluation Index was proposed for extracting critical features from LIBS. Further enhancing the transferability of the model, the laser-induced plasma acoustic signal was transformed from the time domain to the frequency domain. Subsequently, the feature-level fusion method was employed to improve the classification accuracy of the transferred LIBS system to 97.8 %. A decision-level fusion approach (amalgamating LIBS, LIPAS, and feature-level fusion models) achieved an exemplary accuracy of 99 %. Finally, the adaptability of the method was demonstrated using titanium alloy samples. Significance and noveltyIn this work, based on plasma radiation models, we simultaneously captured LIBS and LIPAS, and proposed the fusion of these two distinct yet origin-consistent signals, significantly enhancing the transferability of the LIBS original model. The methodology proposed holds significant potential to advance LIBS technology and broaden its applicability in analytical chemistry research and industrial applications.

Hydrogen isotopes 1,2,3H–A school lab concept for an exemplary insight into chemical research and the work of researchers in chemistry

AbstractIn diesem Beitrag wird ein Schülerlaborkonzept zum Graduiertenkolleg 1,2,3H vorgestellt. Aus diesem Forschungsprojekt wurde beispielhaft ein Teilprojekt zur photokatalytischen Deuterierung ausgewählt, um Schüler:innen einen Einblick in chemische Forschung und die Arbeit von in der Chemie Forschenden zu ermöglichen. Die Schüler:innen erarbeiten im Schülerlabor durch modellhafte Experimente Wissen zu Wasserstoff (1H) und Deuterium (2H), der Photokatalyse sowie der Deuterierung mittels Photokatalyse. Sie lernen zudem einzelne Forscher:innen aus diesem Projekt durch videobasierte Interviews kennen.

Quinoline based viologen as a multifunctional organic material – From crystal structures to photophysical and electrochemical properties, and application in DNA sensing and bioimaging

Developing new multifunctional organic materials is one of the current themes of research in organic materials chemistry. The class of N,N'-dialkylated bis-pyridinium compounds, namely, the viologens have been proven to offer such multifunctional materials. Herein, syntheses and crystal structure elucidation of trans-1,2-bis(4-quinolinyl)ethylene (BQE) and analogous N,N-dimethylated trans-1,2-bis(4′-quinolinium)ethylene (M2BQE) are discussed with their multifaceted materials properties. Two different crystal structures with significantly different molecular structures, namely, BQE and BQE⋅2H2O were obtained by tuning the solvent of crystallization. M2BQE showed a bathochromic shift both in its absorption by ∼ 3300 cm−1 and in emission by ∼2900 cm−1 in compared to BQE, which is the effect of quaternization. Large Stokes shifts were observed for both the BQE (∼8500 cm−1) and M2BQE (∼8050 cm−1). Both compounds showed two-step reduction events in cyclic voltammetry, of which the first steps were reversible. The pH dependent absorption and emission properties of BQE have been explored which revealed the stronger effect by methylation than protonation. M2BQE exhibited selective binding to ct-DNA, as confirmed by selective quenching of emission intensity, over AMP and ATP. Furthermore, both the BQE and M2BQE displayed very intriguing features in bioimaging by intracellular co-localization in HeLa cells. While BQE is predominantly localizes in lysosomes over mitochondria, M2BQE dication, on the other hand, explicitly localizes in mitochondria.

Bifonazole caffeate: The first molecular salt of bifonazole with enhanced biopharmaceutical property based on experiments and quantum chemistry research

In order to make novel breakthroughs in molecular salt studies of BCS class-IV antifungal medication bifonazole (BIF), a salification-driven strategy towards ameliorating attributes and aiding augment efficiency is raised. This strategy fully harnesses structural characters together attributes and benefits of caffeic acid (CAF) to concurrently enhance dissolvability and permeability of BIF by introducing the two ingredients into the identical molecular salt lattice through the salification reaction, which, coupled with the aroused potential activity of CAF significantly amplifies the antifungal efficacy of BIF. Guided by this route, the first BIF-organic molecular salt, BIF-CAF, is directionally designed and synthesized with satisfactorily structural characterizations and integrated theoretical and experimental explorations on the pharmaceutical properties. Single-crystal X-ray diffraction resolving confirms that there is a lipid-water amphiphilic sandwich structure constructed by robust charge-assistant hydrogen bonds in the salt crystal, endowing the molecular salt with the potential to enhance both dissolvability and permeability relative to the parent drug, which is validated by experimental evaluations. Remarkably, the comprehensive DFT-based theoretical investigations covering frontier molecular orbital, molecular electrostatic potential, Hirshfeld surface analysis, reduced density gradient, topology, sphericity and planarity analysis strongly support these observations, thereby allowing some positive relationships between macroscopic properties and microstructures of the molecular salt can be made. Intriguingly, the optimal properties, together with the stimulated activity of CAF markedly augment in vitro antifungal ability of the molecular salt, with magnifying inhibition zones and reducing minimum inhibitory concentrations. These findings fill in the gaps on researches of BIF-organic molecular salt, and adequately exemplify the feasibility and validity by integrating theoretical and experimental approaches to resolve BIF’s problems via the salification-driven tactic.

Studies on Comprehensive Total Synthesis of Natural and Pseudo-Natural Products for Drug Discovery.

Natural products are important for the development of pharmaceuticals and agrochemicals; thus, their synthesis and medicinal chemistry research is critical. Developing a total synthesis pathway for natural products confirms their structure and provides the opportunity to modify the structure in a targeted manner. A simple modification of a single oxidation step can increase the biological activity, or the complexity of the molecule can alter the property. Herein, we discuss the asymmetric total synthesis of dihydroisocoumarin-type natural products, the creation of novel antibacterial compounds through partial structural modification, and the development of antioxidants with high activity and low toxicity through dimerization strategies.

1,2,3-Triazole Containing Hybrids as Potential Pharmacological Agents: A Review

1,2,3-Triazoles constitute a versatile class of nitrogen containing five-membered heterocycles, exhibiting wide range of pharmacological properties which include antibacterial, antifungal, anticancer, antimalarial, antidiabetic, anti-inflammatory, antihypertensive and antioxidant, among various others. Medicinal chemists have been interested in this aromatic ring as a framework since the inception of click chemistry as considered as the building block of contemporary organic chemistry. Extensive research into this framework’s linker characteristic has led to the synthesis and evaluation of numerous 1,2,3-triazole hybrids bearing a wide range of heterocyclic moieties as potential leads for various biological targets. This molecular hybridization has also added advantage of the improved pharmacological activity overcoming the problem of multiple drug resistance and reduced toxicity. This review summarizes the pharmacological activities of various 1,2,3-triazole containing hybrids and conjugates, covering articles published in past decade (2013 till date) and will be of great assistance to medicinal chemistry researchers in providing a useful direction for the future drug discovery.

Synthesis and Characterization of Amido-Thiourea Based p-tert-butylcalix[4]arene Compound and Investigation of Transition Metal Complex Properties

In host-guest complexes, the compatibility of the size and shape of the host cavity and the guest molecule is essential in the formation of the host-guest complex. Considered third-generation macrocyclic hosts, calixarenes attract the attention of researchers in supramolecular chemistry as they offer a wide range of applications in fields such as biocatalysis, enzyme analysis, pharmaceuticals, and biosensing. The synthesis of host molecules for anionic and cationic guest compounds has a very important place in coordination chemistry. Calixarenes are known as one of the important types of supramolecular compounds and are an important class of easily synthesized compounds that can act as a suitable receptors for cations, anions, and organic molecules. When calixarene compounds, which have an important place in host-guest chemistry, are derivatized appropriately, the coordination ability of the molecule against metal cations increases. These derivatizations gained importance due to the sensory properties of the molecule, and different studies were started considering that a larger cavity and functional group are required for more guest molecules. In this study, a new ligand of 1,3-disubstituted p-tert-butylcalix[4]arene derivative with increased donor atomic number with amide and thiourea groups in its structure was synthesized. Co(II), Ni(II), Cu(II), and Zn(II) complexes were synthesized with the compound and the structures of the compounds were characterized by UV-vis, FT-IR, 1H-NMR, 13C-NMR, and mass spectrometry.

Green chemistry: current status and challenges in Zimbabwe

Abstract Green chemistry involves designing environmentally benign processes that either reduce or eliminate the use and production of hazardous substances in the production of safe chemical products. It aims at minimising waste; eliminating costly treatments; minimising energy and resource consumption, and yielding safer products. On this background, it becomes imperative to promote and establish Green chemistry worldwide, especially in developing countries by incorporating it into school curricula, thus placing it at its core for sustainable development purposes. While Zimbabwe, a sub-Saharan country, has made positive strides in key research areas such as the design of new chemicals, catalysis, solvents, renewable materials, and feedstocks, it still faces some challenges that inhibit the successful inception of the concept of green chemistry. An overview that includes educational curriculum, grants and awards, research, infrastructure, and facilities established to promote green chemistry research and education; challenges currently being faced in implementing the approaches and principles in selected universities; the role played by government bodies, and the public in influencing the criteria to promote the green chemistry concept is given.

Effect of Tether Length on endo/exo Stereoselectivity in Alkene–Arene meta‐Photocycloaddition Reactions towards the Aphidocolin/Stemodin Scaffolds

Intramolecular alkene‐arene meta‐photocycloadditions are powerful transformations that use the enhanced reactivity of photoexcited benzene rings to facilitate addition of an alkene 1,3 across donor groups and form complex three‐dimensional fused‐ring systems from readily accessible starting materials. Intramolecular examples have traditionally been restricted to 3‐membered tethers, with cycloaddition resulting from exo‐conformation. However, by judicious tether design we have demonstrated that a 4‐membered tether can also proceed in good yield; interestingly, via an endo‐exciplex (1.2:1) enabling access to both natural product skeletons and interesting scaffolds for medicinal chemistry research.

Ultrafast and efficient continuous flow organic synthesis with a modified extruder-grinder system

The study introduces a groundbreaking continuous system that combines an extruder and grinder to enable catalyst-free and solvent-free reactions under mild conditions. This temperature-controlled system facilitates the synthesis of highly functionalized chromenes, which have valuable applications in generating combinatorial libraries and complex target molecules. The newly developed mill extruder machine offers several advantages for industrial production on a large scale. It effectively reduces waste, saves energy, and enhances time efficiency. This system represents a significant advancement in the field, providing a new strategy for one-pot synthesis of various types of highly functionalized spirooxindoles and chromenes. Remarkably, these reactions can be accomplished within a short timeframe of 2–10 min, yielding impressive results of 75–98%. The results demonstrate superior performance compared to traditional reaction methods, making it an appealing tool and hotspot area of research in green chemistry.

Prenylated Flavonoids of the Moraceae Family: A Comprehensive Review of Their Biological Activities.

Prenylated flavonoids (PFs) are natural flavonoids with a prenylated side chain attached to the flavonoid skeleton. They have great potential for biological activities such as anti-diabetic, anti-cancer, antimicrobial, antioxidant, anti-inflammatory, enzyme inhibition, and anti-Alzheimer's effects. Medicinal chemists have recently paid increasing attention to PFs, which have become vital for developing new therapeutic agents. PFs have quickly developed through isolation and semi- or full synthesis, proving their high value in medicinal chemistry research. This review comprehensively summarizes the research progress of PFs, including natural PFs from the Moraceae family and their pharmacological activities. This information provides a basis for the selective design and optimization of multifunctional PF derivatives to treat multifactorial diseases.

Synthesis of Mixed Phosphonate Esters and Amino Acid-Based Phosphonamidates, and Their Screening as Herbicides.

While organophosphorus chemistry is gaining attention in a variety of fields, the synthesis of the phosphorus derivatives of amino acids remains a challenging task. Previously reported methods require the deprotonation of the nucleophile, complex reagents or hydrolysis of the phosphonate ester. In this paper, we demonstrate how to avoid these issues by employing phosphonylaminium salts for the synthesis of novel mixed n-alkylphosphonate diesters or amino acid-derived n-alkylphosphonamidates. We successfully applied this methodology for the synthesis of novel N-acyl homoserine lactone analogues with varying alkyl chains and ester groups in the phosphorus moiety. Finally, we developed a rapid, quantitative and high-throughput bioassay to screen a selection of these compounds for their herbicidal activity. Together, these results will aid future research in phosphorus chemistry, agrochemistry and the synthesis of bioactive targets.

Chemistry-Focused Conceptual Understanding Research Trends: A Systematic Review

Research related to conceptual understanding is often carried out, such as the influence of a model on conceptual understanding, or knowing students' level of understanding of chemistry concepts. However, there has been no systematic reflection on chemistry research focused on conceptual understanding. Based on this, this research aims to systematically synthesize articles related to chemistry focused on research trends in conceptual understanding with the year range of articles used 2014-2023. After conducting a national and international data search using keyword patterns (e.g., Pattern 1: conceptual and chemical understanding), 48 research papers emerged for systematic review. Then, primary and secondary codes were created by the authors for the research paper. The systematic review showed a variety of research scopes (e.g., relevance of chemistry education models) and dominant research focus for different themes (e.g., competencies and variables related to objectives, variables, samples, chemistry concepts, and conclusions). Furthermore, it was revealed that research on understanding chemical concepts includes various research fields.

Application and Prospect of Machine Learning in the Field of Materials and Chemical Engineering

With the rapid development of computer science, machine learning has gradually penetrated into various research fields and led to the development of related fields to different degrees. At recent stage, machine learning (ML) algorithms have been able to extensively search for variable relationships from a large amount of observed data, thus helping people to discover more laws that were once unnoticed. As an emerging approach, ML can efficiently utilize and process large-volume data generated from high-throughput experiments in the field of materials and chemicals. In recent years, with the continuous improvement of various algorithmic tools, more and more researchers have applied ML to materials and chemical research, which has greatly broadened the research ideas and methods. This paper briefly introduces the development of machine learning in recent years; summarizes the classification methods of common molecular descriptors and their types; introduces the classification, common algorithms and application scenarios of different types of ML; reviews the relevant research results in the field of materials prediction and inverse synthesis analysis of machine learning; puts forward related suggestions for the application of ML for research; and finally summarizes the prospects for the future development of machine learning applied to the field of materials and chemical engineering.