Search

Simultaneous inhibition of soluble epoxide hydrolase (sEH) and fatty acid amide hydrolase (FAAH) with a single small molecule represents a novel therapeutic approach in treating inflammatory pain, since both targets are involved in pain and inflammation processes. In this study using multi-target directed ligands methodology we designed and synthesized 7 quinolinyl-based dual sEH/FAAH inhibitors, using an optimized microwave-assisted Suzuki-Miyaura coupling reaction and tested their potency in human FAAH and human, rat, and mouse sEH inhibition assays. The structure-activity relationship study showed that quinolinyl moiety is well tolerated in the active sites of both enzymes, yielding several very potent dual sEH/FAAH inhibitors with the IC50 values in the low nanomolar range. The most potent dual inhibitor 4d was further evaluated in stability assay in human and rat plasma where it performed better than the standard Warfarin while in vivo study revealed that 1 mg/kg 4d can inhibit acute inflammatory pain in male rats to a similar degree as the traditional nonsteroidal anti-inflammatory drug ketoprofen (30 mg/kg) after intraperitoneal injection. ADMET prediction studies for this dual inhibitor show favorable pharmacokinetic properties which will guide the future in vivo evaluations.

Solar-thermal materials directly convert sunlight into heat, enabling the heating of reaction solutions without relying on electricity or fossil fuels. Although eco-friendly solar-thermal Suzuki coupling catalysis has recently been reported, its scalability must be enhanced for practical synthesis applications. In this study, an eco-friendly and scalable Suzuki coupling catalysis system was demonstrated using Pd nanoparticle monolayer-coated sponges, which exhibit exceptional solar-thermal and catalytic activities under multiphasic reaction conditions. The product mass per illuminated area was improved significantly compared with the earlier solar-thermal catalysis system. Gram-scale Suzuki coupling catalysis with Pd nanoparticle monolayer-coated sponges under simulated 1 sun illumination over an area of 3.14 cm2 was demonstrated successfully without the use of additional energy for solvent heating. The multicycle use of solar-thermal heating and heterogeneous catalytic activities of Pd nanoparticle monolayer-coated sponges was also demonstrated. [ABSTRACT FROM AUTHOR]

We wish to report a new synthetic approach for diphenylacetylene in which tetrachloroethylene was reacted with phenylboronic acid in the presence of Pd catalyst, followed by a workup procedure to provide the crude product, which was then allowed to react with n-butyllithium via the halogen lithium exchange of Cl atom and loss of Li and Cl atoms to afford the desired diphenylacetylene in good yield. [ABSTRACT FROM AUTHOR]

Simultaneous inhibition of soluble epoxide hydrolase (sEH) and fatty acid amide hydrolase (FAAH) with a single small molecule represents a novel therapeutic approach in treating inflammatory pain, since both targets are involved in pain and inflammation processes. In this study using multi-target directed ligands methodology we designed and synthesized 7 quinolinyl-based dual sEH/FAAH inhibitors, using an optimized microwave-assisted Suzuki-Miyaura coupling reaction and tested their potency in human FAAH and human, rat, and mouse sEH inhibition assays. The structure-activity relationship study showed that quinolinyl moiety is well tolerated in the active sites of both enzymes, yielding several very potent dual sEH/FAAH inhibitors with the IC50 values in the low nanomolar range. The most potent dual inhibitor 4d was further evaluated in stability assay in human and rat plasma where it performed better than the standard Warfarin while in vivo study revealed that 1 mg/kg 4d can inhibit acute inflammatory pain in male rats to a similar degree as the traditional nonsteroidal anti-inflammatory drug ketoprofen (30 mg/kg) after intraperitoneal injection. ADMET prediction studies for this dual inhibitor show favorable pharmacokinetic properties which will guide the future in vivo evaluations.

In this study, the total synthesis of osajin, scandenone and their analogues have been accomplished. The key synthetic steps include aldol/intramolecular iodoetherification/elimination sequence reactions and a Suzuki coupling reaction to assemble the tricyclic core, chemoselective propargylation and Claisen rearrangement reactions to obtain natural compounds. In addition, we also designed and synthesized twenty-five natural product analogues. All synthetic compounds were screened for anti-inflammatory activity against tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) in lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages. Collectively, Compound 39e and 39d were considered as promising lead compounds for further development. [ABSTRACT FROM AUTHOR]

The Comprehensive Science Training Experiment is a crucial component in the cultivation of top-notch talents in the field of scientific innovation. This article introduces a comprehensive experiment on the synthesis and characterization of a star-shaped polyamine in the organic chemistry science training course. Through this experiment, students can gain an understanding of the cutting-edge research and advancements in polyamine chemistry, apply their theoretical knowledge to design synthetic routes for target products, deepen their understanding of the basic principles and experimental methods of diazotization, Schiff base reaction, and Suzuki coupling reaction, master the techniques of monitoring reactions using thin-layer chromatography and separating products through column chromatography, and learn to characterize and identify compound structures using modern analytical methods such as nuclear magnetic resonance and infrared spectroscopy. This experiment not only cultivates students' rigorous scientific attitude and research innovation consciousness but also trains their practical research skills. Furthermore, through diversified experimental approaches, it fosters students' teamwork abilities, stimulates their enthusiasm, initiative, and creativity, and enhances their problem-analysis-and-solving capabilities. [ABSTRACT FROM AUTHOR]

In this work, the synthesis of magnetic recyclable catalyst (ZnFe2O4@PDA/COF@Pd) based on palladium nanoparticles immobilized on covalent organic framework (COF) carrier and polydopamine as the linking agent for zinc ferrite (ZnFe2O4) and COF is presented. The morphology, element composition, and surface energies of the compounds were characterized. The prepared ZnFe2O4@PDA/COF@Pd exhibits excellent catalytic activity for Suzuki coupling reaction under mild conditions (TON = 4.7 × 104, TOF = 4.7 × 104 h−1). In addition, p-nitrophenol can be completely reduced within 2–9 min in the presence of NaBH4. Besides, it has remarkable promoting effect on the degradation of dyes. The above characterizations and results indicate that COF is an ideal platform for homogeneously and dispersedly immobilizing Pd NPs, which prohibit the aggregation and leaching of Pd NPs. More importantly, in the recovery of p-nitrophenol reduction reaction, the yield of p-aminophenol can still reach more than 97% after five successive cycles, demonstrating the favorable stability and durability of ZnFe2O4@PDA/COF@Pd. ZnFe2O4@PDA/COF@Pd showed high activity in dye degradation and Suzuki reactions. The Kapp value of ZnFe2O4@PDA/COF@Pd in the reduction of p-NP was 0.0276 s−1. Polydopamine as a linker between ZnFe2O4 and COF enhanced the stability of the catalyst structure, resulting in excellent recovery efficiency and recyclability. [ABSTRACT FROM AUTHOR]

Herein, the synthesis and crystal structure identification of thymine‐modified β‐cyclodextrin (mono‐(6‐Thymine‐6‐deoxy)‐β‐CD, Thy‐CD) are reported. The catalyst system (Pd@Thy‐CD) was prepared by using the thymine‐modified β‐cyclodextrin as ligand and palladium acetate (Pd(OAc)2) as palladium source. The as‐obtained Pd@Thy‐CD catalyst was characterized by NMR, IR, SEM, and XPS analysis. The catalyst can efficiently catalyze the aqueous phase Suzuki coupling reaction in situ. Under mild reaction conditions, the catalyst system provides excellent yields for the Suzuki coupling reaction of aryl halides, including with aryl chlorides and aryl boronic acids in water. The major advantages of this technique are the ease of preparation of the palladium catalyst, the aqueous phase coupling reaction, the broad functional group tolerance, and the easy recyclability. [ABSTRACT FROM AUTHOR]

介绍了一个有机化学综合创新实验--应用Suzuki偶联反应来学习Hammett方程的实验教学方案。通过探究 不同取代基底物对Suzuki偶联反应速率的影响, 进一步得出Hammett方程的关系曲线图, 结果表明苯硼酸上的吸电 子取代基使反应速率减慢, 而给电子取代基会加快反应速率, 探索了Suzuki偶联反应中转金属化过程对偶联反应的 影响。在进行文献调研、实验设计、实验操作、结果分析和报告撰写的过程中, 学生既能学习Suzuki偶联反应的基 本原理, 更重要的是理解Hammett方程的意义, 激发学生对有机化学的科研兴趣, 提升学生综合素质. This study introduced an innovative, comprehensive experiment of organic chemistry -- "the experimental teaching scheme of learning the Hammett equation by Suzuki coupling reaction". The relationship curve of the Hammett equation was further obtained by exploring the influence of different substituted substrates on the reaction rate of the Suzuki coupling reaction. The results showed that the reaction rate was slowed down by the electronwithdrawing substituents on phenylboronic acid and accelerated by the electron-donating substituents. The influence of the metallization process on the Suzuki coupling reaction was also explored. In the process of literature research, experimental design, experimental operation, result analysis and report writing, students can learn the basic principle of Suzuki coupling reaction and understand the significance of the Hammett equation. The comprehensive experimental project is helpful to stimulate students' interest in scientific research of organic chemistry and improve their comprehensive quality. [ABSTRACT FROM AUTHOR]

In this study, the total synthesis of osajin, scandenone and their analogues have been accomplished. The key synthetic steps include aldol/intramolecular iodoetherification/elimination sequence reactions and a Suzuki coupling reaction to assemble the tricyclic core, chemoselective propargylation and Claisen rearrangement reactions to obtain natural compounds. In addition, we also designed and synthesized twenty-five natural product analogues. All synthetic compounds were screened for anti-inflammatory activity against tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) in lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages. Collectively, Compound 39e and 39d were considered as promising lead compounds for further development.

In this project, the main aim is the design and present a novel and unique heterogeneous nanocatalyst based on a metal–organic framework/covalently sulfonated magnetic SBA‐15 mesoporous silica composite with the emphasis on promoting clean and green synthetic transformations and increasing the catalytic properties. In more detail, initially, SBA‐15 containing magnetic nanoparticles was functionalized by a 1,3‐propane sultone ligand. In the next step, the functionalized mesoporous substrate was used as a scaffold for the growth and synthesis of the zeolite imidazolate framework‐8 (ZIF‐8) crystals. The obtained composite was further applied as a suitable support for the immobilization of Pd nanoparticles via a post‐modification procedure and the generation of heterogeneous catalysts. The prepared Fe3O4@SBA‐15‐SO3H@ZIF‐8@Pd was incorporated as a heterogeneous and green catalyst in the Suzuki coupling reaction in the natural deep eutectic solvent with efficient recyclability. [ABSTRACT FROM AUTHOR]

This review article covers the synthesis and design of conjugated polymers for carefully adjusting energy levels and energy band gap (EBG) to achieve the desired photovoltaic performance. The formation of bonds and the delocalization of electrons over conjugated chains are both explained by the molecular orbital theory (MOT). The intrinsic characteristics that classify conjugated polymers as semiconducting materials come from the EBG of organic molecules. A quinoid mesomeric structure (D-A ↔ D+ = A−) forms across the major backbones of the polymer as a result of alternating donor–acceptor segments contributing to the pull–push driving force between neighboring units, resulting in a smaller optical EBG. Furthermore, one of the most crucial factors in achieving excellent performance of the polymer is improving the morphology of the active layer. In order to improve exciton diffusion, dissociation, and charge transport, the nanoscale morphology ensures nanometer phase separation between donor and acceptor components in the active layer. It was demonstrated that because of the exciton's short lifetime, only small diffusion distances (10–20 nm) are needed for all photo-generated excitons to reach the interfacial region where they can separate into free charge carriers. There is a comprehensive explanation of the architecture of organic solar cells using single layer, bilayer, and bulk heterojunction (BHJ) devices. The short circuit current density (Jsc), open circuit voltage (Voc), and fill factor (FF) all have a significant impact on the performance of organic solar cells (OSCs). Since the BHJ concept was first proposed, significant advancement and quick configuration development of these devices have been accomplished. Due to their ability to combine great optical and electronic properties with strong thermal and chemical stability, conjugated polymers are unique semiconducting materials that are used in a wide range of applications. According to the fundamental operating theories of OSCs, unlike inorganic semiconductors such as silicon solar cells, organic photovoltaic devices are unable to produce free carrier charges (holes and electrons). To overcome the Coulombic attraction and separate the excitons into free charges in the interfacial region, organic semiconductors require an additional thermodynamic driving force. From the molecular engineering of conjugated polymers, it was discovered that the most crucial obstacles to achieving the most desirable properties are the design and synthesis of conjugated polymers toward optimal p-type materials. Along with plastic solar cells (PSCs), these materials have extended to a number of different applications such as light-emitting diodes (LEDs) and field-effect transistors (FETs). Additionally, the topics of fluorene and carbazole as donor units in conjugated polymers are covered. The Stille, Suzuki, and Sonogashira coupling reactions widely used to synthesize alternating D–A copolymers are also presented. Moreover, conjugated polymers based on anthracene that can be used in solar cells are covered. [ABSTRACT FROM AUTHOR]

[Display omitted] The development of efficient and recyclable heterogeneous Pd catalysts is an area of continuing attention due to their critical applications in organic synthesis and pharmaceutical production. In this study, two novel heterogeneous catalysts Pd@PAF–182 and Pd@PAF–183 were prepared by the immobilization/NaBH 4 reduction of PdCl 4 2− on hydrophilic cationic porous aromatic frameworks (PAF–182 and PAF–183), which were synthesized via a Yamamoto-type Ullmann coupling reaction from the corresponding aryl quaternary phosphonium salt monomer. Characterization by powder X-ray diffraction (PXRD), solid-state Cross-Polarization Magic-Angle-Spinning Nuclear Magnetic Resonance (CP/MAS NMR), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) established the structures of the as-prepared catalysts. Inductively coupled plasma atomic emission spectrometry (ICP-AES) detection showed that the loading of Pd nanoparticles (Pd NPs) were 29.4 wt% for Pd@PAF–182 and 37.5 wt% for Pd@PAF–183, much higher than those of similar porous materials. Evaluation of the catalytic activity of the Pd@PAFs using Suzuki coupling as the model reaction demonstrated that as little as 0.12 mol% of Pd NPs could catalyze the Suzuki coupling with high efficiency, achieving yields up to 99% at 80 °C in 8 h. Recycling experiments also suggested that Pd@PAF–182 and Pd@PAF–183 maintained high catalytic activity with negligible leaching of Pd NPs after five cycles. [ABSTRACT FROM AUTHOR]

Developing low-cost catalytic systems for C–C coupling reactions is desirable but challenging. Herein, a coordination polymer (Co-CP) was fabricated on the surface of γ-MnO 2 through a layer-by-layer growth technique to obtain a cost-effective heterogeneous catalyst. Various physicochemical analyses endorsed the presence of both components, γ-MnO 2 and Co-CP in the prepared composite. This compound demonstrated a remarkable catalytic performance (in some cases more than 99 %) in the Suzuki coupling reaction of a wide range of arylboronic acids and aryl bromides in water:DMF medium. In particular, the prepared catalyst was efficient and maintained its activity after five consecutive utilizations. From the viewpoint of economics, the present catalytic system gathers noticeable advantages, like the use of earth-abundant and cheap metals (Co and Mn). Co-BDC/γ-MnO 2 was fabricated by stepwise layer-by-layer growth of coordination polymer on the surface of γ-MnO 2 to produce a cost-effective heterogeneous catalyst with a remarkable catalytic performance in the Suzuki coupling reaction of a wide range of aryl bromides and arylboronic acids. [Display omitted] • Preparation of the new composite based on Co-CP and γ-MnO 2. • The excellent catalytic efficiency of the prepared composite in the Suzuki coupling reaction. • High recycling performance of the Co-CP/γ-MnO 2. [ABSTRACT FROM AUTHOR]

In this work, palladium was loaded into a zirconium based MOF with stable structure, and then calcined in argon atmosphere to synthesize a heterogeneous catalyst with Pd nanostructure.The catalyst showed excellent catalytic activity in the Suzuki-Miyaura coupling proceeding.The nanocomposites have been characterized by X-ray diffraction, transmission electron microscopy and mapping, showing that the Pd based nanomaterial has high dispersibility and good stability, before and after the cross-coupling reactions.Through the optimization of reaction conditions and the determination of palladium content in the catalyst by inductively coupled plasma, the Pd loading is calculated to be 0.09 mol%,which is lower than the amount of Pd based catalyst reported previously (0.2 mol%-2 wt%). Moreover, the reusability of as-synthesized nanocomposites was checked, and the catalytic activity was retained after five consecutive reaction runs. [ABSTRACT FROM AUTHOR]

In this study, we have used the one-pot polycondensation method to prepare novel 2D conjugated microporous polymers (Th-F-CMP) containing thiophene (Th) and fluorene (Fl) moieties through the Suzuki cross-coupling reaction. The thermogravimetric analysis (TGA) data revealed that Th-F-CMP (Td10 = 418 °C, char yield: 53 wt%). Based on BET analyses, the Th-F-CMP sample displayed a BET specific surface area of 30 m2 g−1, and the pore size was 2.61 nm. Next, to show the effectiveness of our study, we utilized Th-F-CMP as a fluorescence probe for the selective detection of Fe3+ ions at neutral pH with a linear range from 2.0 to 25.0 nM (R2 = 0.9349). Furthermore, the electrochemical experimental studies showed that the Th-F-CMP framework had a superior specific capacity of 84.7 F g−1 at a current density of 0.5 A g−1 and outstanding capacitance retention (88%) over 2000 cycles. [ABSTRACT FROM AUTHOR]

A palladium-zinc alloy nanoparticles decorated nitrogen-doped porous carbon catalyst (PdZn 30 -NC) was synthesized and utilized for Suzuki coupling reaction. The alloying palladium (Pd) with zinc (Zn) and pore expanding are realized simultaneously. Density functional theory (DFT) calculations and experimental studies reveal that the alloying Pd with Zn can lower the energy barrier in Suzuki coupling reaction. Nitrogen adsorption-desorption measurements uncover that pore expansion caused by the zinc nitrate hexahydrate assisted calcination gives rise to the multiplication of mesopore with a pore diameter of 6 nm, which facilitates mass transfer during the reaction. As a result, the alloying Pd with Zn and pore expanding together endow PdZn 30 -NC with excellent catalytic activity. PdZn 30 -NC demonstrates exceptional catalytic activity and stability in Suzuki coupling reaction. A high biphenyl yield of 97.7 % within 40 min and stable reusability of 93.3 % yield after five reuse cycles can be achieved. This work not only offers a viable method for Suzuki coupling reaction, but also provides insights for designing new catalysts toward Suzuki coupling reaction., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

The present work has successfully highlighted the synthesis of HHP/Pd nano‐sized particles carried out by using hair protein as a capping/stabilizing/reducing agent. Morphology of HHP@Pd nanoparticle was analysed by XRD, SEM, XPS, BET, TGA, TEM, EDX, FT‐IR and zeta potential. TEM image of HHP/Pd nanoparticles, flower shape at the average size of 3.4 nm, was observed. Additionally, we investigated the catalytic property of HHP/Pd nanoparticles in the Suzuki coupling (CC) reaction which is considered to be the most important coupling reaction in terms of organic synthesis. The reaction was optimized using response surface methodology (RSM). Here, we synthesized several types of coupling derivatives by various substituted boronic acids. The synthesized compounds were further confirmed using 1H, 13C NMR and HR‐MS analysis. The catalyst shows high catalyst activity to Suzuki coupling reactions under moderate responses. For all reactions, the HHP/Pd nanoparticle catalyst displayed excellent catalytic activity (>90%) with a wide range of substrates and provided five recycling runs without loss of activity. [ABSTRACT FROM AUTHOR]

Carbon-based photothermal catalysts represent a novel, energy-saving, and eco-friendly paradigm in catalysis. In this work, multiscale porous Pd/carbon nanofibers catalyst (Pd/MPCF) was synthesized by electrospinning, CO 2 thermal activating and atomic layer deposition (ALD) method. The multiscale pores of MPCF enable uniform Pd deposition on the carbon support, which showed better catalytic performance in Suzuki coupling reaction than commercial Pd/C catalyst through harnessing solar heat, resulting in a zero fossil energy consumption reaction process. [Display omitted] • Catalyst with multiscale porous structure was produced by electrospinning, CO 2 thermal activating, and ALD method. • The catalyst exhibits improved performance compared to commercial Pd/C in the Suzuki reaction under light irradiation. • Multiple reflection/refraction and thermal confinement effect in the porous structure of the catalyst enhanced performance. [ABSTRACT FROM AUTHOR]

L- p -Boronophehylalanine (BPA) is used in boron neutron capture therapy (BNCT), which is a novel selective cancer radiotherapy technique. It is important to measure BPA levels in human blood for effective radiotherapy; a prompt gamma-ray spectrometer, ICP-AES, and ICP-MS have been used for this purpose. However, these methods require sophisticated and expensive apparatuses as well as experienced analysts. Herein, we propose an HPLC-FL method for the determination of BPA after precolumn derivatization. A new fluorogenic reagent for aryl boronic acid derivatives, namely, 4-iodobenzonitrile, was employed for the fluorogenic derivatization of BPA based on the Suzuki coupling reaction. After the fluorogenic derivatization, a fluorescent cyanobiphenyl derivative is formed with maximum fluorescence at 335 nm after excitation at 290 nm. The developed method showed good linearity (r 2 =0.997) over the concentration range of 0.5–1000 nmol/L, and the detection limit (S/N = 3) was 0.26 nmol/L. The proposed method is more sensitive than previously reported methods for the determination of BPA, including the ICP-MS. Finally, the proposed method was successively applied to the measurement of BPA in human whole blood samples with a good recovery rate (≥95.7 %) using only 10 μL of blood sample. The proposed method offers a simple and efficient solution for monitoring BPA levels in BNCT-treated patients. 4-Iodobenzonitrile was investigated as a new fluorogenic reagent for BPA based on Suzuki coupling. A new HPLC-FL method for BPA in whole blood samples with ultrasensitivity was developed. The developed method is superior in sensitivity to all previously reported methods for BPA. The method requires only a very small sample volume, making it suitable for micro-blood analysis of BPA via fingerstick sampling. [Display omitted] • 4-Iodobenzonitrile as a new fluorogenic reagent for L- p -boronophenylalanine (BPA). • Characterization of the formed fluorescent cyano biphenyl derivative with tandem mass spectrometry. • HPLC-fluorescence method for BPA was ultra-sensitivity down to 0.26 nM. • Analysis of BPA in a very small volume of whole blood samples down to 10 μL. • The BPA was analyzed with excellent recovery not less than 95.7 % from whole blood. [ABSTRACT FROM AUTHOR]

A custom-made tubular flow reactor was utilized to develop a mathematical model and optimize the Suzuki-Miyaura cross coupling reaction. In this study, the experimentation was designed and executed through the statistical design of experiments (DoE) approach via response surface methodology. The effect of molar ratios of phenylboronic acid (1) and 4-bromophenol (2), temperature, the catalyst tetrakis(triphenylphosphine)palladium, and equivalence of aqueous tripotassium phosphate was studied in detail. The flow reactor profile was in good agreement with batch conditions and significant improvements to the overall reaction time and selectivity towards desired [1-1-biphenyl]-4-ol (3) was achieved. The Suzuki coupling reaction in batch condition would take on an average of 4 to 6 hours to complete, which was effectively accomplished in 60 to 70 minutes in this tubular reactor setup and could be operated continuously. The reaction model is in good agreement with the reaction conditions. Copyright © 2021 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

Subnanometer noble metal clusters have attracted much attention because of abundant low-coordinated metal atoms that perform excellent catalytic activity in various catalytic processes. However, the surface free energy of metals increases significantly with decreasing size of the metal clusters, which accelerates the aggregation of small clusters. In this work, new Schiff base–imidazole-functionalized MOFs were successfully synthesized via the postsynthetic modification method. Highly dispersed Pd clusters with an average size of 1.5 nm were constructed on this functional MOFs and behaved excellent catalytic activity in the Suzuki coupling of phenyboronic acid and bromobenzene (yield of biaryl >99%) under mild reaction conditions. Moreover, the catalyst can be reused six times without loss of activity. Such catalytic behavior is found to closely related to the surface functional groups that promote the formation of small Pd0 clusters in the metallic state.

The evolution of microbial resistance necessitates the development of new antimicrobial drugs that are more effective than those currently on the market. To address this problem, we have prepared a series of novel 4-(biphenyl-4-yl)-1,4-dihydropyridine and 4-(biphenyl-4-yl)pyridine derivatives via Hantzsch reaction using nine different compounds containing active methylene group. IR, NMR, and mass spectra were used to determine the structures. Using ampicillin and griseofulvin as standards, the titled compounds were investigated for their antibacterial activity against different bacteria and fungi. Compounds 1f, 1g, 2f, and 2g have the best antibacterial activity against Gram-negative bacteria (minimum inhibitory concentration = 50 µg/ml), while 1f, 1h, 2g, and 2h have high antifungal activity against Candida albicans (minimum inhibitory concentration = 100 µg/ml). To gain a better understanding of the binding process and affinity for the bacterial Staphylococcus epidermidis protein, researchers used molecular docking and molecular mechanics, as well as the generalized Born model and solvent accessibility-based binding free energy. The active compounds 1g, 1h, and 2f have good docking scores of -5.575, -5.949, and -5.234, respectively, whereas compound 2c has the greatest docking score (-6.23). The HOMO-LUMO energy gap and molecular electrostatic potential were used to evaluate the reactivity of promising compounds, which were then associated with antibacterial efficacy. [ABSTRACT FROM AUTHOR]

This review article covers the synthesis and design of conjugated polymers for carefully adjusting energy levels and energy band gap (EBG) to achieve the desired photovoltaic performance. The formation of bonds and the delocalization of electrons over conjugated chains are both explained by the molecular orbital theory (MOT). The intrinsic characteristics that classify conjugated polymers as semiconducting materials come from the EBG of organic molecules. A quinoid mesomeric structure (D-A ↔ D+ = A−) forms across the major backbones of the polymer as a result of alternating donor–acceptor segments contributing to the pull–push driving force between neighboring units, resulting in a smaller optical EBG. Furthermore, one of the most crucial factors in achieving excellent performance of the polymer is improving the morphology of the active layer. In order to improve exciton diffusion, dissociation, and charge transport, the nanoscale morphology ensures nanometer phase separation between donor and acceptor components in the active layer. It was demonstrated that because of the exciton’s short lifetime, only small diffusion distances (10–20 nm) are needed for all photo-generated excitons to reach the interfacial region where they can separate into free charge carriers. There is a comprehensive explanation of the architecture of organic solar cells using single layer, bilayer, and bulk heterojunction (BHJ) devices. The short circuit current density (Jsc), open circuit voltage (Voc), and fill factor (FF) all have a significant impact on the performance of organic solar cells (OSCs). Since the BHJ concept was first proposed, significant advancement and quick configuration development of these devices have been accomplished. Due to their ability to combine great optical and electronic properties with strong thermal and chemical stability, conjugated polymers are unique semiconducting materials that are used in a wide range of applications. According to the fundamental operating theories of OSCs, unlike inorganic semiconductors such as silicon solar cells, organic photovoltaic devices are unable to produce free carrier charges (holes and electrons). To overcome the Coulombic attraction and separate the excitons into free charges in the interfacial region, organic semiconductors require an additional thermodynamic driving force. From the molecular engineering of conjugated polymers, it was discovered that the most crucial obstacles to achieving the most desirable properties are the design and synthesis of conjugated polymers toward optimal p-type materials. Along with plastic solar cells (PSCs), these materials have extended to a number of different applications such as light-emitting diodes (LEDs) and field-effect transistors (FETs). Additionally, the topics of fluorene and carbazole as donor units in conjugated polymers are covered. The Stille, Suzuki, and Sonogashira coupling reactions widely used to synthesize alternating D–A copolymers are also presented. Moreover, conjugated polymers based on anthracene that can be used in solar cells are covered.

[Display omitted] • Coaxial double-nanotubular RE-doping Pd/CeO 2 are prepared by a facile electrospinning method. • The surface oxygen vacancies of the catalysts can be regulated by doping engineering. • An electron pathway from surface oxygen vacancies to nearby Pd nanoparticles is proposed. • Through doping, the increase of surface area and conductivity play a synergistic catalytic role. Doping engineering is considered as a facile and effective method for improving the physical and chemical properties of CeO 2. Herein, rare earth (RE) ions (La and Nd) doped Pd/CeO 2 with the coaxial double-nanotube structure were manufactured by the electrospinning and high-temperature calcination. Through the doping engineering, the original morphologies of Pd/CeO 2 were not destroyed and all the elements were uniformly distributed on the surface of nanotubes. XRD, Raman and UV–vis characterizations revealed that La3+ and Nd3+ ions were incorporated into the CeO 2 lattice, while the cubic fluorite structure of CeO 2 was maintained. Moreover, it has been proved that there were oxygen vacancies existed on the surface of CeO 2 and the concentration of oxygen vacancies increased significantly as the radius of RE ions increases. In addition, an electron transfer pathway between CeO 2 and Pd nanoparticles was proposed based on the experimental data and Density Functional Theory (DFT) calculations. The Pd/CeO 2 -La catalyst with abundant oxygen vacancies showed a high catalytic performance for Suzuki coupling reaction under mild conditions without any phase-transfer reagent, toxic solvent and inert protective atmosphere, which realizing the green catalysis. [ABSTRACT FROM AUTHOR]

Synthesis, structure and catalytic activity of two Pd(II) complexes have been described The complex 2 bears several non-bonding interactions that lead to 2D structure. [Display omitted] • Solvent free, catalyst free synthesis of imidazopyridine is described. • Two Pd(II) complexes of imidazopyridine have been synthesized and characterized. • Catalytic activities of two complexes tested. • DFT studies were performed to insight into the structure and bonding. The ligand 2-phenylimidazo(1,2-α)pyridine (1) was synthesized by neat reaction 2-aminopyridine and 1-bromo-acetophenone; reaction of 1 with acetonitrile solution of PdCl 2 leads to [Pd(1)Cl 2 (CH 3 CN)] (2). Refluxing [Pd(1)Cl 2 (CH 3 CN)] (2) in pyridine leads to [Pd(1)Cl 2 (py)] (3).The complexes were characterized by various spectroscopic techniques and the solid state structure of 2 was elucidated by single crystal X-ray diffraction (SCXRD) analyses. SCXRD analyses support the square planar geometry of 2. A series of DFT calculations were also performed to gain further insight into the respective structures of the complexes. From molecular hardness calculation it is observed slightly better reactivity of 2 compared to 3. Molecular Hirshfeld surface analyses support various non-covalent secondary interactions that observed in packing of solid state structure of 2. Complexes 2 and 3 were found to facilitate Suzuki coupling reactions under relatively mild conditions and slightly better yields were obtained in case of 2. [ABSTRACT FROM AUTHOR]

This work investigates the impact of immobilization supports on the performance of Pd nanocatalysts in light-induced Suzuki coupling reactions by utilizing two model supports, mesoporous silica (SBA-15) and covalent triazine framework (CTF-Ph). Despite comparable Pd loading (0.3–0.5 wt%) and chemical states, under visible light illumination, Pd/CTF-Ph demonstrated a remarkable 40% reduction in activation energy, outperforming the 16% decrease observed with Pd/SBA-15. This superior performance is attributed to the light-absorbing properties of CTF-Ph and its facilitated pi-pi interaction toward reagents on the catalyst surface. Our findings offer valuable insights into the development of effective catalysts for light-assisted C C bond formation reactions. • Explored Immobilization support impact in light-assisted Suzuki coupling reaction. • Compared SBA-15 and CTF-Ph as model supports to discern their effects. • Pd/CTF-Ph showed lower activation energy in dark and light than Pd/SBA-15. • CTF-Ph's enhanced light absorption, pi-pi interaction drive its superior performance. [ABSTRACT FROM AUTHOR]

In this article, we reported the synthesis of thermoresponsive palladium nanoparticles, stabilized by polymer‐tagged N‐heterocyclic carbenes (NHCs), using two different approaches. In one case, the nanoparticles were synthesized from the NHC–palladium complex, while in other cases, palladium nanoparticles and NHC were synthesized simultaneously for the in situ cappings of the nanomaterial. While the thermoresponsive nature of the nanomaterials was observed in both cases, differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) analyses showed distinct characteristics in the thermal behavior of those materials. High‐resolution transmission electron microscopic (HRTEM) and scanning electron microscopic studies separately revealed temperature‐dependent aggregation in both cases although separate patterns were observed when the nanomaterials were synthesized using different approaches. Finally, both the nanomaterials were successfully used as a recyclable catalyst for Suzuki reactions in an aqueous medium, with slightly different catalytic activity, plausibly due to variations in the size of the nanoparticles. [ABSTRACT FROM AUTHOR]

Chalcones form the core of a variety of medicinal compounds which possess a wide variety of cytoprotective and modulatory therapeutic potential for multiple disease states. A series of benzothiophene-chalcone hybrids were designed and prepared through the Claisen condensation of benzothiophene-substituted acetophenone with halogenated aldehydes. In some cases, products of aromatic substitution of halogen atom by methoxy group were obtained in addition to the expected condensation products. All new compounds were fully characterized. [ABSTRACT FROM AUTHOR]

A class of magnetic nanoparticles modified by 2‐(aminomethyl)phenols has been successfully designed and synthesized as a reusable catalyst for Knoevenagel reaction. What's more, such nanomaterial also proved as suitable carrier for immobilization of palladium nanoparticles and the obtained composite exerted potent catalytic activity in Suzuki coupling reactions. Both of the (aminomethyl)phenols‐modified nanoparticles and its related palladium nanocatalyst could be easily separated and reused for several consecutive runs by magnetic decantation without significant loss of their catalytic efficiency. [ABSTRACT FROM AUTHOR]

A custom-made tubular flow reactor was utilized to develop a mathematical model and optimize the Suzuki-Miyaura cross coupling reaction. In this study, the experimentation was designed and executed through the statistical design of experiments (DoE) approach via response surface methodology. The effect of molar ratios of phenylboronic acid (1) and 4-bromophenol (2), temperature, the catalyst tetrakis(triphenylphosphine)palladium, and equivalence of aqueous tripotassium phosphate was studied in detail. The flow reactor profile was in good agreement with batch conditions and significant improvements to the overall reaction time and selectivity towards desired [1-1-biphenyl]-4-ol (3) was achieved. The Suzuki coupling reaction in batch condition would take on an average of 4 to 6 hours to complete, which was effectively accomplished in 60 to 70 minutes in this tubular reactor setup and could be operated continuously. The reaction model is in good agreement with the reaction conditions. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Henan University of Science & Technology, Natural Science is the property of Editorial Office of Journal of Henan University of Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Natural clay, attapulgite was successfully employed to prepare reusable heterogeneous catalyst of ATP–APTES–Pd through simple and green steps. The catalyst was characterized by ICP, IR, XRD, XPS, SEM, and TG. The novel complex exhibited excellent activity for a wide scope of Suzuki and Heck cross-coupling reactions without phosphine ligand, respectively. Remarkably, the catalyst is easy to separate, stable and can be reused several times in good activity without any additional activation treatment. [ABSTRACT FROM AUTHOR]

New polysubstituted N -arylpyrazole derivatives were synthesized from N 1-arylsydnone with acetylene and boronic acid, including 2-thiophenyl, 3-thiophenyl, 2-benzo[ b ]thiophenyl, or dibenzothiophenyl-4-boronic acid, via 1,3-dipolar cycloaddition and Suzuki coupling reaction. Based on the growth inhibitory activity results against lung carcinoma (NCI-H226), nasopharyngeal (NPC-TW01), and T-cell leukemia (Jurkat) cancer cells, compounds 5d and 7d with dibenzothiophenyl bioisostere possessed the significant inhibitory activity for NPC-TW01 (32 μM and 16 μM) and NCI-H226 (16 μM and 8.9 μM), respectively. [ABSTRACT FROM AUTHOR]

In this study, we successfully used the Suzuki-Miyaura reaction to prepare three novel conjugated microporous polymers (CMPs) that include tetraphenylethene (TPE): TPE-Ph-Th, TPE-Ph-Tha, and TPE-Ph-BSu. Using methods like FTIR and solid-state NMR, we examined the chemical composition and functional groups in the TPE-Ph CMPs. The TPE-Ph-BSu CMP's thermal characteristics were also examined, and they showed remarkable features with a decomposition temperature (T d10) of 535 °C and a char yield of 73 wt%. We also looked at TPE-Ph-Th CMP, which had a pore size of 2.0 nm and a surface area (S BET) of 67 m2 g−1. We carried out photoluminescence (PL) and electrochemical investigations to evaluate the potential of TPE-Ph CMPs for supercapacitor applications and their capability to detect p-nitrophenol (PNP). According to our electrochemical investigation, the TPE-Ph-Tha and TPE-Ph-BSu CMPs both exhibited exceptional capacitance, reaching 51 and 52 F g−1 at a current density of 0.5 A g−1, respectively. Furthermore, even after 5000 cycles, these CMPs still retained 80% of their capacitance, demonstrating their remarkable capacitance retention. In conclusion, synthetic TPE-Ph CMPs have several benefits, including outstanding electrochemical performance and thermal stability. Additionally, they successfully detect PNP using fluorescence-based sensing without interference, making them adaptable materials suited for a variety of applications, including the detection of pollutants (as PNP has shown) and the usage of supercapacitors. [Display omitted] • TPE-Ph-Th, TPE-Ph-Tha, and TPE-Ph-BSu CMPs were synthesized. • The TPE-Ph-BSu CMP, displayed excellent T d10 of 535 °C and a char yield of 73 wt%. • The TPE-Ph-Th CMP, which had S BET of 67 m2 g−1 and a pore size of 2.0 nm. • Both TPE-Ph-Tha and TPE-Ph-BSu CMPs demonstrated excellent supercapacitive activity. • The TPE-Ph-BSu CMP-based fluorophores could be used for the detection of PNP. [ABSTRACT FROM AUTHOR]

Semiconductor-type carbon nanotubes, renowned for their exceptional optoelectronic properties, are considered as the most promising candidates to replace conventional silicon-based semiconductors. However, the obtaining high purity of semiconductor-type single-walled carbon nanotubes (sc-SWCNTs) is a challenging task. In this study, the Suzuki coupling reaction was employed to synthesize two structurally similar alternating copolymers, which effectively separated the sc-SWCNTs from commercially plasma single-walled carbon nanotubes. As result, the copolymers exhibited outstanding selectivity for sc-SWCNTs with 99.9% of purity. Generation of a complex film at the surface. Employing these polymer/sc-SWCNTs composite materials, the ammonia gas sensing devices were fabricated. The results showed that both devices demonstrated rapid and exceptional response towards ammonia gas vapor. Test results revealed that when the ammonia gas vapor concentration of 20 ppm, the two polymer/sc-SWCNTs-based sensors exhibited response values of 5.0% and 3.3%, respectively, and the calculated limits of detection (LOD) of the sensors were 64.5 ppb and 53.5 ppb. These sensors demonstrated significant advantages in response and selectivity towards ammonia gas vapor compared to previous studies. [Display omitted] • Synthesis of novel polymers for non-covalent bond modification of sc-SWCNT. • The response values of the two ammonia gas sensors were 5.0% and 3.3%. • The lowest theoretical detection limits for ammonia vapors were 64.5 ppb and 53.5 ppb, respectively. • Imine bonding can have some effect on ammonia sensor response. [ABSTRACT FROM AUTHOR]

Synthesis, characterization and catalytic application of a novel graphene oxide supported Schiff–base/palladium complex are developed In the current research, preparation, characterization and catalytic application of a novel Schiff-base/Pd complex immobilized onto graphene oxide (GO–SB/Pd) are investigated. The GO–SB/Pd was characterized using Fourier transform infrared spectroscopy, thermal gravimetric analysis, diffuse reflectance UV–Vis, Raman spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and energy-dispersive X-ray (EDX) analysis. It was found that the GO–SB/Pd is an efficient catalyst in the Suzuki–Miyaura cross-coupling of phenylboronic acid with aryl halides. Moreover, the catalyst could be easily recycled and reused for several times without discernible loss in activity. [ABSTRACT FROM AUTHOR]

The Suzuki cross‐coupling reaction has developed as one of the foremost effectual approaches for the synthesis of biaryls or substituted aromatic moieties from aryl halides and arylboronic acids with a palladium‐catalyst in the past two eras. In this study, Pd‐free layered double hydroxides (LDHs) nickel‐containing catalysts were prepared by a coprecipitation method under ultrasonic irradiation and N2 atmosphere with different molar ratios of Ni:Mg:Al and coded as (1NiLDHs−Dr), (1.5NiLDHs−Dr) and (2NiLDHs−Dr). A series of reduced catalysts under 5% H2/N2 at 200 °C were coded as 1NiLDHs−R200, 1.5NiLDHs−R200 and 2NiLDHs−R200. Deep investigation of all catalysts was done using different techniques such as inductively coupled plasma optical emission spectroscopy (ICP‐OES), X‐ray photoelectron spectroscopy (XPS), powder X‐ray diffraction (XRD), thermogravimetric analyses (TGA), Fourier transfer infrared (FTIR), scanning electron microscopy (SEM) connected with energy dispersive X‐ray (EDX), transmission electron microscopy (TEM) and N2‐physisorption at –196 °C. The results attained verified that ɑ‐Ni(OH)2 was fashioned for a 2NiLDHs−Dr catalyst and that the enclosure of nickel ions in the cationic sheet of the layered structure was responsible for the fascinating catalytic efficacy rather than the basic nature of material. The Ni‐containing LDHs catalysts encourage forthcoming studies in Pd‐free catalyzed C−C coupling reactions. [ABSTRACT FROM AUTHOR]

The process of synthesizing Pd-TiO 2 /CNFs and the Suzuki reaction catalyzed by Pd-TiO 2 /CNFs catalyst. This paper reported a method for loading TiO 2 and Pd atoms onto carbon nanofibers (CNFs) under a simple mild conditions. The catalyst prepared by the method greatly improved the reaction efficiency of Suzuki under the illumination of xenon lamp and reduced the difficulty of the reaction conditions. Compared with the previous catalysts, the catalysts developed in this paper have the characteristics of simple preparation method, easy recovery, good reaction performance, etc. The use of light energy reflected the importance of the catalyst in terms of resource utilization and environmental protection. [ABSTRACT FROM AUTHOR]

Abstract This work reports the design, synthesis and characterization of the (pbi-Cl) 2 Ir(acac) [pbi-Cl:2-(4-chlorophenyl)-1-phenyl-1H-benzimidazole, Ir: Iridium, acac: acetyl acetone]complex by Suzuki coupling reaction. X-ray diffraction disclosed its amorphous nature, Fourier transform infra-red spectra and nuclear magnetic resonance confirmed its structural formation, and scanning electron microscopy revealed highly agglomerated polygonal morphology. Thermo-gravimetric analysis and differential thermal analysis disclosed high thermal stability to about 307.40 °C. Absorption spectra of the solvated (pbi-Cl) 2 Ir(acac) complex showed intense absorption bands in the ultraviolet region with optical band gap of 3.0 and 3.70 eV in acetic acid and chloroform, respectively. Oscillator strength of the (pbi-Cl) 2 Ir(acac) complex in chloroform and acetic acid was in the range of 0.1146–0.543 and 0.0086–0.1530, respectively. The photoluminescence spectra of the (pbi-Cl) 2 Ir(acac) complex in solid state exhibited intense green emission, peaking at 543 nm under excitation wavelength of 380 nm, and in acetic acid and chloroform it peaked at λ emi = 513 and 538 nm, respectively. Commission International de l'Eclairage coordinates and phosphorescent quantum yield showed that the (pbi-Cl) 2 Ir(acac) complex has potential as a green-light emitter in electroluminescent devices. Highlights • We report synthesis of a (pbi-Cl) 2 Ir(acac) complex by Suzuki coupling reaction and its characterization. • Optical band gaps of the solvated complex were 3.0 and 3.70 eV in acetic acid and chloroform, respectively. • Oscillator strength of the complex in chloroform and acetic acid was 0.1146–0.543 and 0.0086–0.1530, respectively. • The photoluminescence spectra of the complex in solid state exhibited intense green phosphorescence. • The complex has potential as a green light emitter for organic electroluminescence. [ABSTRACT FROM AUTHOR]

Bimetallic Pd (II)/Fe (III) catalytic monolayer fixed on GO was prepared and its catalytic properties, synergetic effect and catalytic mechanism were investigated, in which dynamic studies presented difference catalytic process for GO@H-Pd 0.10 Fe 0.90 and Li 2 PdCl 4 /FeCl 3. [Display omitted] • Graphene oxide supported Pd (II)/Fe (III) bimetallic catalytic monolayer was prepared and characterized. • The noble Pd can be replaced by non-noble Fe for catalyzing Suzuki coupling reaction according to results obtained. • The synergic effect between Fe and Pd metals which made it easy for Pd 2 + reduced into Pd0 by designing the fine structure. Graphene oxide supported Pd (II)/Fe (III) bimetallic catalytic monolayer (denoted as GO@H-Pd/Fe) was prepared and characterized. Its catalytic performances for Suzuki coupling reaction, synergetic effect and catalytic mechanism were systematic investigated. Results showed that orientation, composition and distribution of catalyst had efficient effect on catalytic activity. Catalytic activity of GO@H-Pd 0.10 /Fe 0.90 was 475 times more than that of GO@H-Pd due to the ordered catalytic monolayer immobilized on GO , proper ratio of Pd/Fe and the synergetic effect between Pd(II) and Fe(III) which could form active cluster containing Pd and Fe. The Pd(II) could be made more negative by transferring electron from GO to Fe(III) via ligand and then to Pd, improving its catalytic activity since it was easy for oxide addition. It also exhibited better stability and recyclability at least 8 times due to proper functional ligand and support. Deactivation mechanism was confirmed to be the aggregation of active centre during the recycling. Heterogeneous catalytic mechanism was also proved by poison test, hot filtration and ReactIR. The results of ReactIR presented different dynamic catalytic process for GO@H-Pd 0.10 Fe 0.90 and homogeneous catalyst (Li 2 PdCl 4 /FeCl 3 ·6H 2 O).The activation energies were 9.7 KJ/mol and 3.7 KJ/mol obtained for heterogeneous and homogeneous catalyst, respectively. Considering the diffusion effect, the factor of supports on the activity was also investigated by ReactIR, with which that GO@H-Pd 0.10 Fe 0.90 catalytic activity was higher than that of homogeneous catalyst could be confirmed. [ABSTRACT FROM AUTHOR]

Highly dispersed nickel‐palladium bimetallic nanoparticles (∼2 nm) on ordered mesoporous carbon CMK‐3 (NiPd@CMK‐3) were simply prepared using a co‐infiltration method of the metal salts. The nanoparticles were successfully applied to the mild Suzuki‐Miyaura coupling reactions at 25∼50 °C using 4‐bromoanisole and phenylboronic acid, and showed excellent catalytic performance with the high activity (0.521×10−3 molc ⋅ gam−1 ⋅ s−1) and productivity (69.1 gp ⋅ gcat−1 ⋅ h−1). Ni & Pd infiltration: A highly NiPd@CMK‐3 nanocatalyst prepared via a co‐infiltration of Ni and Pd salts and subsequent thermal reduction under H2, was successfully applied to mild Suzuki‐Miyaura coupling reactions, showing excellent catalytic performance (activity: 0.521×10−3 molc ⋅ gam−1 ⋅ s−1, productivity: 69.1 gp ⋅ gcat−1 ⋅ h−1). [ABSTRACT FROM AUTHOR]

Abstract Palladium nanorods (PdNRs) into mesoporous channels of SBA-15 nanocatalyst (PdNRs/SBA-15) were synthesized by a green and surfactant-free ultrasonic method without any surfactants and complex chemical modification and chemical method in absence of ultrasound, respectively. The PdNRs/SBA-15 catalysts were characterized by XRD, TEM, XPS, N 2 absorption-desorption and FT-IR analysis. The results showed that PdNRs with 15.96 ± 3.89 nm long and 5.69 nm wide were highly dispersed into mesoporous channels exploiting the confine effect of SBA-15 pore channel, while reunited PdNPs were distributed on the outside surface of SBA-15 in PdNPS/SBA-15 prepared by chemical method. The in-situ ultrasonic reduction of PdNRs/SBA-15 by the reductive radical (induced by ultrasonic process) was good for higher dispersion of Pd species and the formation of Pd species inside the mesoporous channel of SBA-15 without any structure-directing agents or surfactants. The yield of Suzuki coupling reaction between 4-bromotoluene and phenylboronic acid catalyzed by PdNRs (5)/SBA-15 reached 96.4%, which was much higher than that of PdNPs(5)/SBA-15 prepared without ultrasound (76.3%). PdNRs (5)/SBA-15 could be reused up to five times without a significant activity loss due to the strong chemical interaction and the unblocked channel. Graphical abstract Image 1 Highlights • Providing a green and facile way to prepare supported Pd nanocatalysts. • Introduction of Pd2+ in pore channel by roasting instead of chemical modification. • In-situ ultrasonic reduction of Pd2+ fosters uniform dispersion of Pd in the pore. • PdNRs (5)/SBA-15 shows enhanced catalytic and cycle performance for Suzuki reaction. [ABSTRACT FROM AUTHOR]

The synthesis and study of a novel Pd(II) complex (2) supported by a new tetracoordinate ligand that is based on a bis(N‐heterocyclic carbene) with two pendant pyrimidinyl donors is described. The complex was characterized using a series of spectroscopic, analytical, and computational techniques. A preliminary assessment showed that 2 displayed good performance in Suzuki‐Miyaura coupling reactions between phenyl boronic acid and an assortment of substituted bromobenzenes. Finally, the intrinsic electronic characteristics of the complex were elucidated through DFT‐based molecular orbital calculations which revealed that the coordinated metal center was relatively electron deficient and stabilized by a series of ligand dominated interactions. A novel Pd(II) complex supported by tetracoordinate ligand that is based on a bis(N‐heterocyclic carbene) outfitted with pyrimidinyl groups is described. The complex was characterized by spectroscopic, analytical, and computational techniques and its catalytic activity was assessed in a range of contemporary coupling reactions. [ABSTRACT FROM AUTHOR]

We designed and synthesized a 2‐(4‐bromophenyl)‐1‐phenyl‐1H‐benzimidazole (pbi‐Br) ligand, which was then employed to create an innovative phosphorescent cyclometallated iridium(III) (pbi‐Br)2Ir(acac) metal complex with acetyl acetone as an ancillary ligand using the Suzuki coupling reaction. The complex was then characterized by X‐ray diffraction (XRD), Fourier transform infrared (FTIR) spectra and thermogravimetric analysis (TGA)/differential thermal analysis (DTA) for structural and thermal analysis, respectively. XRD confirmed its amorphous nature and the FTIR spectrum revealed the molecular structure confirmation of the metal complex. The TGA/DTA curve disclosed its thermal stability up to 310°C. Ultraviolet (UV)–vis absorption and photoluminescence (PL) spectra were measured to explore the photo‐physical properties of the (pbi‐Br)2Ir(acac) complex in basic and acidic media respectively. With the variation in solvent from acidic to basic media, optical absorption peaks blue shifted with variation in optical densities. These results facilitated the calculation of various photo‐physical parameters. When excited at 379 nm in the solid state, the synthesized complex gave out a green light emission, peaking at λemi = 552 nm. Staggering differences in optical density were observed in the PL spectra of the solvated complex. A Stokes' shift of 7140.45 cm−1 and 7364.94 cm−1 was observed when the complex was solvated in acetic acid and chloroform, respectively. Hence the synthesized iridium metal complex can be considered as promising green emissive material for optoelectronic applications. [ABSTRACT FROM AUTHOR]