Organic Sonochemistry: A Chemist's Timely Perspective on Mechanisms and Reactivity

Unveiling Mechanically Driven Catalytic Processes: Beyond Piezocatalysis to Synergetic Effects

Mechanically driven catalysis (MDC) has emerged as an effective strategy for environmental remediation, renewable energy conversion, and cancer therapy; this functions by converting mechanical forces to drive catalytic reactions. This review examines four primary mechanisms, namely, piezocatalysis, flexocatalysis, tribocatalysis, and sonocatalysis, each involving specific catalytic pathways for harnessing mechanical energy at the nanoscale. However, significant challenges arise in decoupling the effects related to each individual mechanism in order to better understand and manipulate their synergies. In this review, the fundamental principles underpinning MDC are systematically interpreted. Beyond mechanistic insights, recent advancements in performance enhancement strategies for these catalysts are highlighted. Potential applications using these mechanistic approaches in environmental remediation (pollutant and antibiotic degradation and microbial disinfection), renewable energy conversion (hydrogen production and greenhouse gas conversion), and biomedical treatments (particularly cancer therapy) are discussed. Finally, the mechanistic synergies and limiting factors are explored, addressing challenges related to the overlooked combined effects of ultrasound as the activation source, complexities in mechanical force interactions at the nanoscale, and the need for targeted application strategies. Additionally, the industrial potential of these catalytic processes with consideration to scalability and practical deployment is evaluated. While challenges remain, this review provides a roadmap for advancing mechanically driven catalyst design and implementation toward real-world applications, offering potential into its future trajectory and transformative impact across numerous fields.

Sonochemically activated room temperature hydrosilylation of silicon nanoparticles

Hydrosilylation of terminal alkenes and alkynes on the surfaces of hydrogen-terminated silicon nanoparticles (H-SiNPs) has provided a convenient approach toward tailoring surface chemistry. These reactions have traditionally required thermal, photochemical, or chemical activation and are not necessarily compatible with all substrates and particle sizes. Herein, we demonstrate that hydrosilylation on silicon nanoparticles (Si NPs) can be promoted at room temperature by exposing the reaction mixture to a standard ultrasonic bath. This new approach provides surface coverages approaching 30% after 24 h. Introduction of traditional radical initiators to the reaction mixture followed by sonication reduced the reaction time by approximately 4-fold. The Si NPs functionalized using the presented sonochemical methods were compared with equivalent systems modified using conventional thermally- and radically-induced procedures and retain their appealing photoluminescent properties and were found to have slightly lower (i.e., 27 vs. 33%), albeit comparable degrees of functionalization.

Methanol Activation: Strategies for Utilization of Methanol as C1 Building Block in Sustainable Organic Synthesis

The development of efficient and sustainable chemical processes which use greener reagents and solvents, currently play an important role in current research. Methanol, a cheap and readily available resource from chemical industry, could be activated by transition metal catalysts. This review focuses in covering the recent five-years literature and provides a systematic summary of strategies for methanol activation and the use in organic chemistry. Based on these strategies, many new synthetic methods have been developed for methanol utilization as the C1 building block in methylation, hydromethylation, aminomethylation, formylation reactions, as well as the syntheses of urea derivatives and heterocycles. The achievements, synthetic applications, limitations, some advanced approaches, and future perspectives of the methanol activation methodologies have been described in this review.

Facile Synthesis of Silicone Oil-Based Ferrofluid: Toward Smart Materials and Soft Robots

Ferrofluids are stable colloidal dispersions of magnetic nanoparticles in carrier liquids. Their combination of magnetic and fluidic characteristics not only inspires fundamental inquiries into forms and functions of matter but also enables diverse applications ranging from sealants and coolants in mechanical devices to active components in smart materials and soft robots. Spurred by such fundamental and applied interests, a growing need for easy-to-synthesize, high-quality ferrofluid exists. Here, we report the facile synthesis and comprehensive characterization of a silicone oil-based ferrofluid that displays the characteristic surface instability of high-quality ferrofluids and demonstrate its functions in smart interfacial materials and soft robots. Silicone's chemical immiscibility with polar solvents and its biological inertness, when coupled with magnetic responsiveness and fluidic deformability, enable the manipulation of solid particles, gas bubbles, simple and complex liquids, as well as micro-organisms. We envision that the silicone oil-based ferrofluid will find applications in diverse areas, including magnetic digital microfluidics, multifunctional materials, and small-scale robotics.

Tuning synthesis and sonochemistry forges learning and enhances educational training: Protection of 1,3-diols under heterogeneous catalysis as sustainable case study

This research article describes the thermal and sonochemical enhancements of 1,3-diol protection, via acetal formation, catalyzed by a biomass-derived heterogeneous catalyst. This investigation was also conducted under the framework of a postgraduate program in green chemistry, and the application of ultrasonic activation represented an opportunity to expose the field to junior colleagues unaware of sonochemistry. Accordingly, we show not only a facile and high-yielding synthetic transformation, but also the pluses of performing a parallel protocol using low-frequency ultrasound, which provided new learning tools and skills in context. The main role of sound waves can be associated to enhanced mass transfer of the heterogeneous reaction (false sonochemistry). Acoustic energy was delivered into the reagents and solvent using so-called cavitation intensifying bags (CIB). The micropitted polymeric material enabled a greater focused radiation that proved to be highly reproducible at 25 °C and led to reaction completion much faster than the conventional external heating. Furthermore, sonication fine-tunes selectivity in ketal formation, as witnessed by a facile synthesis of solketal, a green solvent obtained by acetalization of glycerol. The pedagogical benefits of conveying education in sonochemistry are outlined, alongside the catalyst characterization of the ultrasound-driven reaction. Our ambition is to stimulate similar pursuits in synthesis and catalysis at other laboratories and educational institutions.

Mechanically Triggered Protein Desulfurization

The technology of native chemical ligation and postligation desulfurization has greatly expanded the scope of modern chemical protein synthesis. Here, we report that ultrasonic energy can trigger robust and clean protein desulfurization, and we developed an ultrasound-induced desulfurization (USID) strategy that is simple to use and generally applicable to peptides and proteins. The USID strategy involves a simple ultrasonic cleaning bath and an easy-to-use and easy-to-remove sonosensitizer, titanium dioxide. It features mild and convenient reaction conditions and excellent functional group compatibility, e.g., with thiazolidine (Thz) and serotonin, which are sensitive to other desulfurization strategies. The USID strategy is robust: without reoptimizing the reaction conditions, the same USID procedure can be used for the clean desulfurization of a broad range of proteins with one or more sulfhydryl groups, even in multi-hundred-milligram scale reactions. The utility of USID was demonstrated by the one-pot synthesis of bioactive cyclopeptides such as Cycloleonuripeptide E and Segetalin F, as well as convergent chemical synthesis of functionally important proteins such as histone H3.5 using Thz as a temporary protecting group. A mechanistic investigation indicated that USID proceeds via a radical-based mechanism promoted by low-frequency and low-intensity ultrasonication. Overall, our work introduces a mechanically triggered approach with the potential to become a robust desulfurization method for general use in chemical protein synthesis by both academic and industrial laboratories.

Scalable ultrasound-assisted synthesis of hydroxy imidazole N-oxides and evaluation of their anti-proliferative activities; mechanistic insights into the deoximation of dioximes

The development of synthetic methodologies that promote greener reactions have become so essential that it has slowly shaped the way chemists think about the construction of physiologically and chemically active compounds. The acid-catalyzed iminoketone - aldehyde condensations leading to Hydroxy imidazole N-oxides serve as robust strategies for forming C-N bonds. Considering all the existing challenges that come with the use of solvent and energy-intensive methodologies, herein a green synthetic strategy using ultrasound with optimization of reaction conditions and thorough investigation into the mechanism for obtaining the best yields are reported. Additionally, the importance of the Hydroxy Imidazole N-oxides synthesis is highlighted by their in vitro antiproliferative activity study. Though only satisfactory, the results are promising. It gives us scope for building upon this simple scaffold with appropriate functionalization, which may lead to furhter enhancement in their anti-proliferative activity.

An improved ultrasound-assisted synthesis of phenytoin suitable for undergraduate education

A convenient and efficient method for undergraduate student experiments involves the one-pot synthesis of phenytoin from benzoin. This method utilized ultrasonic irradiation in the presence of basic catalyst at room temperature and atmospheric pressure, resulting in shortened reaction times, good yields, and excellent reproducibility. By employing a low-cost ultrasonic cleaner for ultrasonic irradiation in student experiments, the need for expensive equipment investment during the teaching process can be minimized. Consequently, this approach is suitable for widespread promotion and application in undergraduate education.

Harnessing Ultrasound-Derived Hydroxyl Radicals for the Selective Oxidation of Aldehyde Functions

Ultrasonic irradiation holds potential for the selective oxidation of non-volatile organic substrates in the aqueous phase by harnessing hydroxyl radicals as chemical initiators. Here, a mechanistic description of hydroxyl radical-initiated glyoxal oxidation is constructed by gleaning insights from photolysis and radiation chemistry to explain the yields and kinetic trends for oxidation products. The mechanistic description and kinetic measurements reported herein reveal that increasing the formation rate of hydroxyl radicals by changing the ultrasound frequency increases both the rates of glyoxal consumption and the selectivity towards C2 acid products over those from C-C cleavage. Glyoxal consumption also occurs more rapidly and with greater selectivity towards C2 acids under acidic conditions, which favor the protonation of carboxylate intermediates into their less reactive acidic forms. Leveraging such pH and frequency effects is crucial to mitigating product degradation by secondary reactions with hydroxyl radicals and oxidation products (specifically hydrogen peroxide and superoxide). These findings demonstrate the potential of ultrasound as a driver for the selective oxidation of aldehyde functions to carboxylic acids, offering a sustainable route for valorizing biomass-derived platform molecules.

Synthesis of propargylamine: pioneering a green path with non-conventional KA2 coupling approach

The KA2 coupling reaction is a well-explored and versatile method for forming C-C bonds in synthetic chemistry. It is composed of ketone, amine, and alkyne, which play a major role in the synthesis of propargylamines, known for their diverse biological activities and are used in treating neurogenetical disorders. The KA2 coupling is highly challenging due to the low reactivity of ketimines toward nucleophilic attacks with metal acetylide intermediates formed by activating the C-H bond of the alkyne. Despite predominant studies conducted on thermal conditions for KA2 coupling reactions, green and sustainable approaches like non-conventional methods still have a lot to achieve. This review article provides a comprehensive introduction to the non-conventional approach in the KA2 coupling reaction, outlining its mechanisms and exploring future aspects.

Facile Mechanochemical Functionalization of Hydrophobic Substrates for Single-Walled Carbon Nanotube Based Optical Reporters of Hydrolase Activity

Single walled carbon nanotubes (SWCNT) have recently been demonstrated as modular, near-infrared (nIR) probes for reporting hydrolase activity; however, these have been limited to naturally amphipathic substrate targets used to noncovalently functionalize the hydrophobic nanoparticles. Many relevant substrate targets are hydrophobic (such as recalcitrant biomass) and pose a challenge for modular functionalization. In this work, a facile mechanochemistry approach was used to couple insoluble substrates, such as lignin, to SWCNT using l-lysine amino acid as a linker and tip sonication as the mechanochemical energy source. The proposed coupling mechanism is ion pairing between the lysine amines and lignin carboxylic acids, as evidenced by FTIR, NMR, SEM, and elemental analyses. The limits of detection for the lignin-lysine-SWCNT (LLS) probe were established using commercial enzymes and found to be 0.25 ppm (volume basis) of the formulated product. Real-world use of the LLS probes was shown by evaluating soil hydrolase activities of soil samples gathered from different corn root proximal locations and soil types. Additionally, the probes were used to determine the effect of storage temperature on the measured enzyme response. The modularity of this mechanochemical functionalization approach is demonstrated with other substrates such as zein and 9-anthracenecarboxylic acid, which further corroborate the mechanochemical mechanism.

Physicochemical reactions in e-waste recycling

Electronic waste (e-waste) recycling is becoming a global concern owing to its immense quantity, hazardous character and the potential loss of valuable metals. The many processes involved in e-waste recycling stem from a mixture of physicochemical reactions, and understanding the principles of these reactions can lead to more efficient recycling methods. In this Review, we discuss the principles behind photochemistry, thermochemistry, mechanochemistry, electrochemistry and sonochemistry for metal recovery, polymer decomposition and pollutant elimination from e-waste. We also discuss how these processes induce or improve reaction rates, selectivity and controllability of e-waste recycling based on thermodynamics and kinetics, free radicals, chemical bond energy, electrical potential regulation and more. Lastly, key factors, limitations and suggestions for improvements of these physicochemical reactions for e-waste recycling are highlighted, wherein we also indicate possible research directions for the future.

Novel nickel-immobilized-SiO2-TiO2 fine particles in the presence of cetyltrimethylammonium bromide as a catalyst for ultrasound-assisted-Kumada cross-coupling reaction

Kumada cross-coupling reaction is useful for producing biphenyls, where nickel and copper have been widely investigated as catalysts but mainly homogeneous ones. In this study, we investigated ultrasound-assisted-Kumada cross-coupling reaction over the heterogeneous catalysts in which Ni2+, Cu2+, or both was immobilized on aminopropylsilane-functionalized-SiO2-TiO2 prepared in the presence of cetyltrimethylammonium bromide (CTAB). The presence of CTAB effectively prevented the particle growth and therefore SiO2-TiO2 fine particles with high surface area (502 m2 g-1) were formed. The Ni2+-immobilized catalyst showed high catalytic activity for the ultrasound-assisted-Kumada cross-coupling reaction of a wide variety of substrates and was reusable three times. Performing the reaction under ultrasound irradiation was very effective in significantly accelerating the reaction rate compared with the conventional mechanical method. In contrast to Ni2+, Cu2+ was deposited on the support as crystalline Cu(OH)2 and the resulting catalysts with Cu2+ and Ni2+-Cu2+ were less active and less stable under the reaction conditions.

Telescoping Synthesis of 4-Organyl-5-(organylselanyl)thiazol-2-amines Promoted by Ultrasound

In this work, we describe the synthesis of new 4-organyl-5-(organylselanyl)thiazol-2-amine hybrids through a one-pot two-step protocol. The transition metal-free method involves the use of ultrasound as an alternative energy source and Oxone® as oxidant. To obtain the products, a telescoping approach was used, in which 4-organylthiazol-2-amines were firstly prepared under ultrasonic irradiation, followed by the addition of diorganyl diselenides and Oxone®. Thus, 16 compounds were prepared, with yields ranging from 61 % to 98 %, using 2-bromoacetophenone derivatives and diorganyl diselenides as easily available starting materials.

The Evolution of Sonochemistry: From the Beginnings to Novel Applications

Sonochemistry is the use of ultrasonic waves in an aqueous medium, to generate acoustic cavitation. In this context, sonochemistry emerged as a focal point over the past few decades, starting as a manageable process such as a cleaning technique. Now, it is found in a wide range of applications across various chemical, physical, and biological processes, creating opportunities for analysis between these processes. Sonochemistry is a powerful and eco-friendly technique often called "green chemistry" for less energy use, toxic reagents, and residues generation. It is increasing the number of applications achieved through the ultrasonic irradiation (USI) method. Sonochemistry has been established as a sustainable and cost-effective alternative compared to traditional industrial methods. It promotes scientific and social well-being, offering non-destructive advantages, including rapid processes, improved process efficiency, enhanced product quality, and, in some cases, the retention of key product characteristics. This versatile technology has significantly contributed to the food industry, materials technology, environmental remediation, and biological research. This review is created with enthusiasm and focus on shedding light on the manifold applications of sonochemistry. It delves into this technique's evolution and current applications in cleaning, environmental remediation, microfluidic, biological, and medical fields. The purpose is to show the physicochemical effects and characteristics of acoustic cavitation in different processes across various fields and to demonstrate the extending application reach of sonochemistry. Also to provide insights into the prospects of this versatile technique and demonstrating that sonochemistry is an adapting system able to generate more efficient products or processes.

JEDI: A versatile code for strain analysis of molecular and periodic systems under deformation

Stretching or compression can induce significant energetic, geometric, and spectroscopic changes in materials. To fully exploit these effects in the design of mechano- or piezo-chromic materials, self-healing polymers, and other mechanoresponsive devices, a detailed knowledge about the distribution of mechanical strain in the material is essential. Within the past decade, Judgement of Energy DIstribution (JEDI) analysis has emerged as a useful tool for this purpose. Based on the harmonic approximation, the strain energy in each bond length, bond angle, and dihedral angle of the deformed system is calculated using quantum chemical methods. This allows the identification of the force-bearing scaffold of the system, leading to an understanding of mechanochemical processes at the most fundamental level. Here, we present a publicly available code that generalizes the JEDI analysis, which has previously only been available for isolated molecules. Now, the code has been extended to two- and three-dimensional periodic systems, supramolecular clusters, and substructures of chemical systems under various types of deformation. Due to the implementation of JEDI into the Atomic Simulation Environment, the JEDI analysis can be interfaced with a plethora of program packages that allow the calculation of electronic energies for molecular systems and systems with periodic boundary conditions. The automated generation of a color-coded three-dimensional structure via the Visual Molecular Dynamics program allows insightful visual analyses of the force-bearing scaffold of the strained system.

Isocyanide-based synthesis of spirorhodanine-cyclopentadiene and spirorhodanine-iminobutenolide conjugates from Winterfeldt's zwitterions and 5-ylidene rhodanines

An ultrasonic-assisted isocyanide-based protocol to access a series of functionalized spirorhodanine-cyclopentadiene and spirorhodanine-iminobutenolide conjugates from alkyl isocyanides and dialkyl acetylenedicarboxylates in the presence of 5-ylidene rhodanines in MeCN, is described. The reaction proceeds via interception of the reactive Winterfeldt's zwitterions by 5-ylidene rhodanine derivatives. The structures of the target compounds were confirmed by X-ray diffraction studies.

Ultrasound and sonochemistry enhance education outcomes: From fundamentals and applied research to entrepreneurial potential

With this manuscript we aim to initiate a discussion specific to educational actions around ultrasonics sonochemistry. The importance of these actions does not just derive from a mere pedagogical significance, but they can be an exceptional tool for illustrating various concepts in other disciplines, such as process intensification and microfluidics. Sonochemistry is currently a far-reaching discipline extending across different scales of applicability, from the fundamental physics of tiny bubbles and molecules, up to process plants. This review is part of a special issue in Ultrasonics Sonochemistry, where several scholars have shared their experiences and highlighted opportunities regarding ultrasound as an education tool. The main outcome of our work is that teaching and mentorship in sonochemistry are highly needed, with a balanced technical and scientific knowledge to foster skills and implement safe protocols. Applied research typically features the use of ultrasound as ancillary, to merely enhance a given process and often leading to poorly conceived experiments and misunderstanding of the actual effects. Thus, our scientific community must build a consistent culture and monitor reproducible practices to rigorously generate new knowledge on sonochemistry. These practices can be implemented in teaching sonochemistry in classrooms and research laboratories. We highlight ways to collectively provide a potentially better training for scientists, invigorating academic and industry-oriented careers. A salient benefit for education efforts is that sonochemistry-based projects can serve multidisciplinary training, potentially gathering students from different disciplines, such as physics, chemistry and bioengineering. Herein, we discuss challenges, opportunities, and future avenues to assist in designing courses and research programs based on sonochemistry. Additionally, we suggest simple experiments suitable for teaching basic physicochemical principles at the undergraduatelevel. We also provide arguments and recommendations oriented towards graduate and postdoctoral students, in academia or industry to be more entrepreneurial. We have identified that sonochemistry is consistently seen as a 'green' or sustainable tool, which particular appeal to process intensification approaches, including microfluidics and materials science. We conclude that a globally aligned pedagogical initiative and constantly updated educational tools will help to sustain a virtuous cycle in STEM and industrial applications of sonochemistry.

Ultrasonic cavitation: Tackling organic pollutants in wastewater

Environmental pollution and energy shortages are global issues that significantly impact human progress. Multiple methods have been proposed for treating industrial and dyes containing wastewater. Ultrasonic degradation has emerged as a promising and innovative technology for organic pollutant degradation. This study provides a comprehensive overview of the factors affecting ultrasonic degradation and thoroughly examines the technique of acoustic cavitation. Furthermore, this study summarizes the fundamental theories and mechanisms underlying cavitation, emphasizing its efficacy in the remediation of various water pollutants. Furthermore, potential synergies between ultrasonic cavitation and other commonly used technologies are also explored. Potential challenges are identified and future directions for the development of ultrasonic degradation and ultrasonic cavitation technologies are outlined.

An introductory laboratory class in sonochemistry

This article proposes a substantive scope and scenario of a laboratory class that introduces students to the field of sonochemistry. The class requires only basic laboratory equipment - typical laboratory glassware like graduated pipettes and conical flasks, as well as simple inorganic chemicals. It is designed to acquaint students with fundamental aspects of sonochemistry. In the qualitative aspect, they will conduct and observe some sonochemical reactions like a synthesis of hydrogen peroxide and ultrasound-assisted degradation of toxic chromates(VI) which will demonstrate the indirect consequences of water sonolysis which is the most basic sonochemical reaction, as well as they will illustrate the applications of sonochemistry. In the quantitative aspect, students will learn about how to measure the power of ultrasound and the sonochemical efficiency of the reaction and will conduct experiments allowing for the calculation of these parameters. Finally, an introduction to and demonstration of the sonocatalytic effect is planned. An evaluation system, consisting of a report and test, is also proposed.

Effects of sound energy on proteins and their complexes

Mechanical energy in the form of ultrasound and protein complexes intuitively have been considered as two distinct unrelated topics. However, in the past few years, increasingly more attention has been paid to the ability of ultrasound to induce chemical modifications on protein molecules that further change protein-protein interaction and protein self-assembling behavior. Despite efforts to decipher the exact structure and the behavior-modifying effects of ultrasound on proteins, our current understanding of these aspects remains limited. The limitation arises from the complexity of both phenomena. Ultrasound produces multiple chemical, mechanical, and thermal effects in aqueous media. Proteins are dynamic molecules with diverse complexation mechanisms. This review provides an exhaustive analysis of the progress made in better understanding the role of ultrasound in protein complexation. It describes in detail how ultrasound affects an aqueous environment and the impact of each effect separately and when combined with the protein structure and fold, the protein-protein interaction, and finally the protein self-assembly. It specifically focuses on modifying role of ultrasound in amyloid self-assembly, where the latter is associated with multiple neurodegenerative disorders.

Polymer Mechanochemistry in Microbubbles

Polymer mechanochemistry is a promising technology to convert mechanical energy into chemical functionality by breaking covalent and supramolecular bonds site-selectively. Yet, the mechanochemical reaction rates of covalent bonds in typically used ultrasonication setups lead to reasonable conversions only after comparably long sonication times. This can be accelerated by either increasing the reactivity of the mechanoresponsive moiety or by modifying the encompassing polymer topology. Here, a microbubble system with a tailored polymer shell consisting of an N2 gas core and a mechanoresponsive disulfide-containing polymer network is presented. It is found that the mechanochemical activation of the disulfides is greatly accelerated using these microbubbles compared to commensurate solid core particles or capsules filled with liquid. Aided by computational simulations, it is found that low shell thickness, low shell stiffness and crosslink density, and a size-dependent eigenfrequency close to the used ultrasound frequency maximize the mechanochemical yield over the course of the sonication process.

Memory-friendly fixed-point iteration method for nonlinear surface mode oscillations of acoustically driven bubbles: from the perspective of high-performance GPU programming

A fixed-point iteration technique is presented to handle the implicit nature of the governing equations of nonlinear surface mode oscillations of acoustically excited microbubbles. The model is adopted from the theoretical work of Shaw [1], where the dynamics of the mean bubble radius and the surface modes are bi-directionally coupled via nonlinear terms. The model comprises a set of second-order ordinary differential equations. It extends the classic Keller-Miksis equation and the linearized dynamical equations for each surface mode. Only the implicit parts (containing the second derivatives) are reevaluated during the iteration process. The performance of the technique is tested at various parameter combinations. The majority of the test cases needs only a single reevaluation to achieve 10-9 error. Although the arithmetic operation count is higher than the Gauss elimination, due to its memory-friendly matrix-free nature, it is a viable alternative for high-performance GPU computations of massive parameter studies.

Plasmonic Nanodomains Decorated on Two-Dimensional Oxide Semiconductors for Photonic-Assisted CO2 Conversion

Plasmonic nanostructures ensure the reception and harvesting of visible lights for novel photonic applications. In this area, plasmonic crystalline nanodomains decorated on the surface of two-dimensional (2D) semiconductor materials represent a new class of hybrid nanostructures. These plasmonic nanodomains activate supplementary mechanisms at material heterointerfaces, enabling the transfer of photogenerated charge carriers from plasmonic antennae into adjacent 2D semiconductors and therefore activate a wide range of visible-light assisted applications. Here, the controlled growth of crystalline plasmonic nanodomains on 2D Ga₂O₃ nanosheets was achieved by sonochemical-assisted synthesis. In this technique, Ag and Se nanodomains grew on 2D surface oxide films of gallium-based alloy. The multiple contribution of plasmonic nanodomains enabled the visible-light-assisted hot-electron generation at 2D plasmonic hybrid interfaces, and therefore considerably altered the photonic properties of the 2D Ga₂O₃ nanosheets. Specifically, the multiple contribution of semiconductor-plasmonic hybrid 2D heterointerfaces enabled efficient CO₂ conversion through combined photocatalysis and triboelectric-activated catalysis. The solar-powered acoustic-activated conversion approach of the present study enabled us to achieve the CO₂ conversion efficiency of more than 94% in the reaction chambers containing 2D Ga₂O₃-Ag nanosheets.

Ultrasound-Assisted 1,3-Dipolar Cycloadditions Reaction Utilizing Ni-Mg-Fe LDH: A Green and Sustainable Perspective

Ultrasound-assisted synthesis of novel pyrazoles using Ni-Mg-Fe LDH as a catalyst in cyclopentyl methyl ether (CPME) is introduced. Different LDHs were tested as a catalyst for the synthesis of pyrazoles via a 1,3-dipolar cycloaddition reaction. Among them, Ni-Mg-Fe LDH was the superior catalyst for this reaction. This protocol offered high yields, a short reaction time, and a green solvent, and with the reuse of this catalyst six times with the same activity, it could be regarded as an ecofriendly, greener process. The NiMgFe LDH catalyst with the smallest particle size (29 nm) and largest surface area showed its superior efficacy for the 1,3 dipolar cycloaddition rection and can be successfully used in up to six catalytic cycles with little loss of catalytic activity. A plausible mechanism for this reaction over the Ni-Mg-Fe LDH is proposed.

Process intensification in continuous flow organic synthesis with enabling and hybrid technologies

Industrial organic synthesis is time and energy consuming, and generates substantial waste. Traditional conductive heating and mixing in batch reactors is no longer competitive with continuous-flow synthetic methods and enabling technologies that can strongly promote reaction kinetics. These advances lead to faster and simplified downstream processes with easier workup, purification and process scale-up. In the current Industry 4.0 revolution, new advances that are based on cyber-physical systems and artificial intelligence will be able to optimize and invigorate synthetic processes by connecting cascade reactors with continuous in-line monitoring and even predict solutions in case of unforeseen events. Alternative energy sources, such as dielectric and ohmic heating, ultrasound, hydrodynamic cavitation, reactive extruders and plasma have revolutionized standard procedures. So-called hybrid or hyphenated techniques, where the combination of two different energy sources often generates synergistic effects, are also worthy of mention. Herein, we report our consolidated experience of all of these alternative techniques.

Like Visiting an Old Friend: Fischer Glycosylation in the Twenty-First Century: Modern Methods and Techniques

Fischer glycosylation is typically the chemical reaction of a monosaccharide and an alcohol in presence of an acidic catalyst to afford glycosides in pyranosidic and furanosidic forms. This reaction is still applied today for the synthesis of specialized glycosides, and optimization and modification of the method have continued since its discovery by Emil Fischer in the 1890s. This review presents advancements in Fischer glycosylation described in literature of the past 15 years and its implementation in modern chemical methods.

Synthesis of Fluorinated 1-(2-Benzyl)-phthalazinone, 1-Phthalazinamine, and 1-Alkoxy/Benzyloxy-Phthalazine Derivatives by Ultrasonication Method

Fluorinated heterocyclic compounds have been proven to exhibit interesting potential biological activities. Therefore, various fluorinated 1(2-(N)-benzyl) phthalazinones, 1-Phthalazinamine, and non-fluorinated 1-alkoxy/benzyloxy phthalazines derivatives have been synthesized by the ultrasonication method. This protocol is more efficient than the conventional method in terms of product yield and reaction handling and timelines.

"Green Is the Color": An Update on Ecofriendly Aspects of Organoselenium Chemistry

Organoselenium compounds have been successfully applied in biological, medicinal and material sciences, as well as a powerful tool for modern organic synthesis, attracting the attention of the scientific community. This great success is mainly due to the breaking of paradigm demonstrated by innumerous works, that the selenium compounds were toxic and would have a potential impact on the environment. In this update review, we highlight the relevance of these compounds in several fields of research as well as the possibility to synthesize them through more environmentally sustainable methodologies, involving catalytic processes, flow chemistry, electrosynthesis, as well as by the use of alternative energy sources, including mechanochemical, photochemistry, sonochemical and microwave irradiation.

Sono-Cavitation and Nebulization-Based Synthesis of Conjugated Microporous Polymers for Energy Storage Applications

Conjugated microporous polymers (CMPs) are promising energy storage materials owing to their rigid and cross-linked microporous structures. However, the fabrication of nano- and microstructured CMP films for practical applications is currently limited by processing challenges. Herein, we report that combined sono-cavitation and nebulization synthesis (SNS) is an effective method for the synthesis of CMP films from a monomer precursor solution. Using the SNS, the scalable fabrication of microporous and redox-active CMP films can be achieved via the oxidative C-C coupling polymerization of the monomer precursor. Intriguingly, the ultrasonic frequency used during SNS strongly affects the synthesis of the CMP films, resulting in an approximately 30% improvement in reaction yields and ca. 1.3-1.7-times enhanced surface areas (336-542 m²/g) at a high ultrasonic frequency of 180 kHz compared to those at 120 kHz. Furthermore, we prepare highly conductive, three-dimensional porous electrodes [CMP/carbon nanotube (CNT)] by a layer-by-layer sequential deposition of CMP films and CNTs via SNS. Finally, an asymmetric supercapacitor comprising the CMP/CNT cathode and carbon anode shows a high specific capacitance of 477 F/g at 1 A/g with a wide working potential window (0-1.4 V) and robust cycling stability, exhibiting 94.4% retention after 10,000 cycles.