Microwave-assisted One-pot Synthesis Research Articles

Efficient Green Synthesis and Characterization of Benzil and its Derivatives Using Microwave Irradiation

Abstract: The main aim of the present work was to conduct the one-pot microwave-assisted green synthesis of benzil and its derivatives. Benzil is acknowledged as a pivotal scaffold in the realm of medicinal and organic chemistry, owing to its extensive utilities. Due to the various merits of the green technology approach compared to classical methodology and the provision of sustainable chemistry, this reaction has received renewed interest for preparing benzil derivatives in an environmentally friendly manner with improved yields. We have, herein, presented a highly efficient route for the synthesis of benzil derivatives utilizing acetophenone and benzene derivatives as primary substrates. Notably, this synthesis obviates the necessity for any potentially hazardous catalyst and employs microwave irradiation and iodine green oxidant to facilitate the reaction. All synthesized compounds were characterized by spectroscopic techniques, such as IR, 1H NMR, and mass spectrometry. A green and efficient microwave-assisted synthesis methodology for benzil and its derivatives has been developed using iodine green oxidant. This approach has yielded the desired benzil derivatives with remarkable efficiency, achieving yields ranging from 91% to 97% within a short time of 10-15 minutes; the derivatives have been characterized using spectral techniques, viz., IR, 1H NMR, and mass spectrometry. It is noteworthy that the entire reaction optimization process has been conducted in an environmentally friendly manner, thereby exemplifying a synthetic methodology being both environmentally sustainable and economically viable, compared to conventional techniques.

Parmelia perlata mediated microwave-assisted one-pot green synthesis of NiO nanoparticles a noble approach: Antibacterial and photocatalytic activity evaluation

This study reports a green-mediated fabrication of NiO nanoparticles (NiO NPs) using Parmelia Perlata lichen extract as a sustainable source. The Physical, chemical, optical, and morphological behavior of the fabricated NiO NPs were analyzed by employing diverse analytical profiles like XRD, FTIR, UV, and SEM. FTIR spectrum demonstrates the involvement of various phytochemicals in the bio-fabrication of NiO NPs. Furthermore, the appearance of a band at 668 cm−1 indicates the successful formation of NiO NPs. The observations of the SEM analysis depicted that the average particle size was in the range of 40–50 nm. The result of the antibacterial study indicates that the NiO NPs significantly reduce the growth of Staphylococcus aureus (19 mm). The result of the photocatalytic research illustrated that the bio-fabricated NiO NPs exhibited superior photocatalytic activity in the degradation of acridine orange dye achieving 84 % degradation efficiency.

Microwave-assisted one-pot synthesis of carbon dots from biomass: Fe(III) ion sensing and in-situ methylene blue reduction catalytic activity

In this study, zero-dimensional fluorescent carbon dots were synthesized from affordable organic bio-precursors derived from chayote seeds using a one-pot microwave-assisted carbonization process. These biomass-derived carbon dots display excellent fluorescence properties, with an average size of approximately 3.3 nm and a fluorescence quantum yield about 9.56 %. The fluorescence emission spectra were recorded at different excitation peaks, with the highest intensity emission peak observed at 387 nm with an excitation wavelength of 320 nm. These carbon dots effectively detect Fe3+ ions, with a detection limit of 4.5 µmol. Carbon dots show strong catalytic reduction activity against a reduction of Methylene Blue dye, achieving an 81 % reduction in a short period. These biomass-derived carbon dots presents sustainable and promising option for applications in metal sensing and catalytic degradation.

A fluorescence switch-off nanosensor for sensitive determination of the antiandrogen drug flutamide in pharmaceutical and environmental samples. Analytical method greenness, blueness, and whiteness assessment

A fast, practical, and non-hazardous switch-off fluorescent nanosensor for the non-fluorescent antiandrogen drug flutamide (FLU) was developed from nitrogen/sulfur co-doping of carbon quantum dots (N,S-CQDs). For the first time, the highly fluorescent N,S-CQDs were generated via one-pot microwave-assisted synthesis in only 3 min using facilely available precursors (sweet yellow pepper and thiourea). The sensor is characterized by a narrow particle size distribution, high doping efficiency (N, 42.05 % and S, 8.28 %), reproducibility, and high emission at 410 nm after excitation at 330 nm. FLU efficiently and quantitatively turned off the fluorescence of the prepared N,S-CQDs via a synergistic combination of static quenching and inner filter effect. The furnished nanosensor showed good linearity (r = 0.9999) for FLU analysis within concentrations ranged from 1.0 to 30.0 µg mL−1 with a detection limit of 0.293 µg mL−1 and quantitation limit of 0.886 µg mL−1. The selectivity of the probe was confirmed in the presence of co-administered drugs, possible co-existing materials, and various metal ions. The N,S-CQDs interestingly showed acceptable cytocompatibility and low toxicity, as revealed by the MTT assay. This feature bestows the N,S-CQDs a practicability as an environmental sensor. Thus, the proposed approach was implemented for FLU analysis in pharmaceutical tablets, tap water, and river water with good percentage recoveries (99.59 ± 1.28%, 99.49 ± 1.75%, and 101.21 ± 1.67%, respectively) and without interferences. Furthermore, the approach was positively assessed with respect to greenness, blueness, and whiteness. The high values of the analytical greenness score AGREE (0.78), the chiefly green ComplexGAPI pictogram, the Blue Applicability Grade Index BAGI (72.5), and the RGB12 (93.6) show the high greenness, blueness, and whiteness features of the method that confirm its minor environmental impact, excellent applicability, and sustainability, respectively.

L-cysteine modified N-doped carbon quantum dots derived from peach palm (Bactris gasipaes) peels for detection of mercury ions

Establishing an effective strategy for Hg2+ determination with good sensitivity and high selectivity is of particular concern. In this work, N-doped carbon quantum dots (NCQDs) were obtained for the first time from peels of peach palm fruit (Bactris gasipaes) through microwave-assisted one-pot synthesis. Surface NCQDs was modified with l-cysteine (NCQDs/CYS) by a chemical reaction (known as amide coupling) between the nitrogen-containing groups (amine group) of l-cysteine ligand and the carboxyl groups of NCQDs. The chemical bonding was examined by Fourier Transform Infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). NCQDs/CYS nanoparticles exhibited a quantum yield of fluorescence (ΦFL) of 25.4%, high solubility in water, and a surface with thiol groups from l-cysteine. Mercury ions induced quenching of fluorescence of NCQDs/CYS at low concentrations (Limit of Detection, LOD = 0.19 μM) with great sensitivity. A significant preference for Hg2+ ions was found because of the high affinity between the thiolate groups of NCQDs/CYS and the analyte. Time-resolved fluorescence measurements were done to study the way that led to fluorescence quenching when Hg2+ ions were present, evidencing a static quenching fluorescence mechanism. The new NCQDs/CYS material could be applied to accurately measure the concentration of Hg2+ ions in water samples in a fast and cost-effective way.

Development of a facile one-pot synthesized fluorescent green polyesters as cooling water antiscalants for industrial application

Currently, antiscalants used in cooling water are expected to be environmental-friendly, good scale inhibitive, fluorescence tracing, and industrial-friendly. Aliphatic biodegradable photoluminescent polymers (BPLPs) synthesized from citric acid, aliphatic diols, and various amino acids are fluorescent polymers containing heteroatom six-membered conjugated ring chromophores. Their cross-linked BPLPs have potential for use as implant or device materials, and vivo bioimaging probes. However, so far, no one has found that BPLPs can be used as efficient antiscalants for cooling water. In this work, we demonstrate a facile one-pot microwave-assisted synthesis of BPLPs from cost-effective materials. The products were characterized by Fourier transforms infrared spectroscopy, 1H and 13C nuclear magnetic resonance spectroscopy, gel permeation chromatography, and fluorescence spectroscopy. Thus prepared BPLPs can be directly used as a novel type green fluorescent antiscalant without further purification. They have an excellent calcium phosphate inhibition efficiency that can reach 98.6 % with a dosage of 25 mg·L−1 in the static scale inhibition test at 80 °C.

Ultrafast one-pot microwave-assisted green synthesis of silver nanoparticles from Piper longum fruit extract as a sensitive fluorescent nanoprobe for carbamazepine and risperidone in dosage forms and human plasma

A rapid, simple, and green method was developed for the synthesis of highly fluorescent silver nanoparticles (Ag-NPs) using a microwave-assisted synthetic approach in about 30 sec. The developed method used the extract of Piper longum fruit as a reducing agent. Characterization of the obtained Ag-NPs was performed using various microscopic and spectroscopic techniques. The prepared Ag-NPs were applied as a fluorescent probe for the spectrofluorimetric determination of each of carbamazepine (CBZ) and risperidone (RIS). The developed Ag-NPs exhibited a strong emission peak at 354 nm when excited at 265 nm. The mean size of Ag-NPs was found to be 27.3 nm with a polydispersity of 0.351. The developed method is the first spectrofluorimetric method that uses Ag-NPs to determine CBZ or RIS and the only spectrofluorimetric one for RIS determination. Ag-NPs native fluorescence was found to be quantitatively and selectively quenched by both drugs, and method validation exhibited a linear relationship in the range of 20.0–120.0 µM and 5.0–100.0 µM with detection limits of 1.47 µM and 0.84 µM for CBZ and RIS, respectively. The quenching mechanism of Ag-NPs native fluorescence by each CBZ and RIS was studied. The proposed method was then applied to determine CBZ and RIS in their pharmaceutical dosage forms and human plasma samples with high % recoveries and low % RSD. Furthermore, the synthesized Ag-NPs showed noteworthy antimicrobial activities against four different bacterial strains and one species of candida. As a result, the proposed method may have potential uses in antimicrobial therapy and the study of related mechanisms. The greenness of the proposed method was evaluated using two different greenness metric tools, including the complementary green analytical procedure index (Complex GAPI) and Analytical GREEnness (AGREE). Validation of the proposed approach was carried out according to ICH guidelines.

2D/2D Heterojunction of BiOBr/BiOI Nanosheets for In Situ H2 O2 Production and Activation toward Efficient Photocatalytic Wastewater Treatment.

The presence of toxic organic pollutants in aquatic environments poses significant threats to human health and global ecosystems. Photocatalysis that enables in situ production and activation of H2 O2 presents a promising approach for pollutant removal; however, the processes of H2 O2 production and activation potentially compete for active sites and charge carriers on the photocatalyst surface, leading to limited catalytic performance. Herein, a hierarchical 2D/2D heterojunction nanosphere composed of ultrathin BiOBr and BiOI nanosheets (BiOBr/BiOI) is developed by a one-pot microwave-assisted synthesis to achieve in situ H2 O2 production and activation for efficient photocatalytic wastewater treatment. Various experimental and characterization results reveal that the BiOBr/BiOI heterojunction facilitates efficient electron transfer from BiOBr to BiOI, enabling the one-step two-electron O2 reduction for H2 O2 production. Moreover, the ultrathin BiOI provides abundant active sites for H2 O2 adsorption, promoting in situ H2 O2 activation for •O2 - generation. As a result, the BiOBr/BiOI hybrid exhibits excellent activity for pollutant degradation with an apparent rate constant of 0.141 min-1 , which is 3.8 and 47.3 times that of pristine BiOBr and BiOI, respectively. This work expands the range of the materials suitable for in situ H2 O2 production and activation, paving the way toward sustainable environmental remediation using solar energy.

Microwave-Assisted One-Pot Synthesis of Spiro[indole-3,4′-pyrano[2,3-c]pyrazoles] Using Polystyrene-Supported p-Toluenesulfonic Acid as Heterogeneous Catalyst under Solvent-Free Conditions

Microwave-Assisted One-Pot Synthesis of Spiro[indole-3,4′-pyrano[2,3-c]pyrazoles] Using Polystyrene-Supported p-Toluenesulfonic Acid as Heterogeneous Catalyst under Solvent-Free Conditions

Transforming Waste into Value: Eco-Friendly Synthesis of MOFs for Sustainable PFOA Remediation

In response to the need for sustainable solutions to address perfluorooctanoic acid (PFOA) contamination, we have developed an eco-friendly approach for synthesizing two types of metal-organic frameworks (MOFs) using waste polyethylene terephthalate (PET) bottles via a one-pot microwave-assisted strategy. Our innovative method not only avoids the initial depolymerization of PET bottles but also promotes environmental conservation by recycling waste materials. The La-MOF and Zr-MOF materials exhibit remarkable surface areas of 76.90 and 293.50 m2/g, respectively, with La-MOF demonstrating greater thermal stability than Zr-MOF. The maximum experimental PFOA adsorption for La-MOF and Zr-MOF was obtained at 310 and 290 mg/g, respectively. Both MOFs follow the Langmuir isotherm closely, with the adsorption of PFOA following a pseudo-2nd-order kinetic model. In packed-bed column tests, breakthrough positions of 174 and 150 min were observed for La-MOF and Zr-MOF, respectively, with corresponding bed volumes of 452 mL and 522 mL based on the PFOA limit of 0.07 µg/L in drinking water. These findings indicate that these MOFs can be used in industrial packed-bed columns to remove PFOA from contaminated water sources in an efficient and cost-effective manner. Importantly, the sorption performance of the fabricated MOFs for PFOA remained stable, decreasing by less than 10% over seven cycles. This study underscores the potential of recycled PET bottles and the one-pot microwave-assisted synthesis of MOFs as an effective and environmentally friendly solution for PFOA remediation. This innovative approach has several managerial implications, such as the use of waste materials as a feedstock, which can reduce the cost of production and minimize environmental impact by promoting recycling and repurposing, enhancing the reputation of companies operating in the chemical industry, and improving their sustainability metrics. By integrating sustainability principles and waste recycling, our approach offers promising avenues for addressing PFOA contamination while promoting resource efficiency and environmental conservation.

9-Methoxynaphtho[1,2-b]benzofuran

A highly selective one-pot microwave-assisted synthesis of 9-methoxynaphtho[1,2-b]benzofuran was obtained by treating 1-naphthol with 1-bromo-4-methoxy-2-nitrobenzene and two molar equivalents of potassium tert-butoxide in dimethyl sulfoxide. The selectivity in the production of the title compound was addressed by the suitable position of the bromine and nitro group on the aryl reagent. Moreover, we highlight how the nitro group plays a dual role, as activator in the first nucleophilic substitution with the release of bromide ion and then as the leaving group in the furan cyclization. Eventually, the product was structurally characterized by MS and extensive NMR analyses.

One-pot microwave-assisted synthesis of In2S3/In2O3 nanosheets as highly active visible light photocatalysts for seawater splitting

A facile one-pot microwave-assisted synthesis prepared a new noble metal-free heterostructure of In2S3/In2O3 nanosheets for blue LED-light-induced photocatalytic water splitting. The appropriate InCl3 concentrations and reaction temperatures can grow the In2S3/In2O3 nanosheets with higher photocatalytic water splitting for hydrogen production under blue-LED light irradiation. In addition, the optimized In2S3/In2O3 nanosheets exhibited a higher hydrogen production rate is 618.0 μmolh−1g−1 in seawater without adjusted pH values under blue-LED light irradiation. Furthermore, the reusability of In2S3/In2O3 nanosheets revealed the gradual increase of photocatalytic hydrogen production efficiency in four cycles. This phenomenon shall be attributed to the reaction of In2S3/In2O3 nanosheets and seawater to form In2S3/In2O3/In(OH)3 nanosheets, which can improve the recombination of the photogenerated charge carriers and light-harvesting capacity to promote their photocatalytic hydrogen production.

Facile one-pot microwave-assisted synthesis of rod-like and hexagonal plate-like AgNP@Ni-BTC composites for a potential salivary glucose sensor

Diabetes is a serious disease with a huge number of patients worldwide. Glucose levels in people with diabetes are above 6.6 mM in blood samples and 200 μM in saliva samples. Metal-organic frameworks (MOFs) have outstanding properties for glucose sensors, such as a large surface area and being rich in active sites. In this research, a silver nanoparticle@Ni-BTC (AgNP@Ni-BTC) composite was synthesized through one-pot synthesis using a microwave at 130 °C for 1 hour at 200 W. The results showed that the 4%AgNP@Ni-BTC-modified carbon paste electrode obtained better sensor performance than Ni-BTC with a limit of detection (LoD) of 14.73 μM, a sensitivity of 6584.89 μA mM−1 cm−2, and a linear range of 10–1250 μM. The 4%AgNP@Ni-BTC-modified carbon paste electrode also had better stability than Ni-BTC and had good reproducibility. Glucose detection tests on salivary samples showed that the 4%AgNP@Ni-BTC-modified carbon paste electrode could be used to measure glucose levels in salivary samples.

Synthesis of New Cyclohexenone Derivatives Using Potassium Phthalimide as a Green Organocatalyst. One-Pot Microwave-Assisted Synthesis and Antimicrobial Evaluation

Synthesis of New Cyclohexenone Derivatives Using Potassium Phthalimide as a Green Organocatalyst. One-Pot Microwave-Assisted Synthesis and Antimicrobial Evaluation

A facile one-pot synthesis of water-soluble CQDs for the evaluation of their anti-amyloidogenic propensity

Herein, a facile one-pot microwave-assisted synthesis of highly water-soluble CQDs is reported and their inhibitory effect towards amyloid fibrillation process using hen egg-white lysozyme in acidic and neutral pH is explored.

Microwave-assisted one-pot multicomponent synthesis of steroidal pyrido[2,3-d]pyrimidines and their possible implications in drug development

Protein misfolding can lead to fibrillar and non-fibrillar deposits which are the signs of countless human diseases. A promising strategy for the prevention of such diseases is the inhibition of protein aggregation, and the most crucial step toward effective prevention is the development of small molecules having the potential for protein-aggregation inhibition. In this search, a series of novel steroidal pyrido[2,3-d]pyrimidines have been synthesized employing steroidal ketone, substituted aldehydes, and 2,6-diaminopyrimidin-4(3H)-one through the microwave-assisted one-pot multicomponent methodology. The aggregation inhibition potential of newly synthesized compounds was evaluated on human lysozyme (HLZ). All the synthesized compounds were found to be efficient in the inhibition of protein aggregation in carefully designed in vitro experiments. Moreover, molecular docking studies also determine the binding interactions between all the synthesized compounds and native HLZ through hydrogen bonding. The structures of synthesized compounds were also elucidated using various spectroscopic techniques.

Fast one-pot microwave-assisted green synthesis of highly fluorescent plant-inspired S,N-self-doped carbon quantum dots as a sensitive probe for the antiviral drug nitazoxanide and hemoglobin

In this study, we report a one-pot, green, cost-efficient, and fast synthesis of plant-based sulfur and nitrogen self-co-doped carbon quantum dots (S,N-CQDs). By 4-min microwave treatment of onion and cabbage juices as renewable, cheap, and green carbon sources and self-passivation agents, blue emissive S,N-CQDs have been synthesized (λex/λem of 340/418 nm) with a fluorescence quantum yield of 15.2%. A full characterization of the natural biomass-derived quantum dots proved the self-doping with nitrogen and sulfur. The S,N-CQDs showed high efficiency as a fluorescence probe for sensitive determination of nitazoxanide (NTZ), that recently found wide applicability as a repurposed drug for COVID-19, over the concentration range of 0.25–50.0 μM with LOD of 0.07 μM. The nanoprobe has been successfully applied for NTZ determination in pharmaceutical samples with excellent % recovery of 98.14 ± 0.42. Furthermore, the S,N-CQDs proved excellent performance as a sensitive fluorescence nanoprobe for determination of hemoglobin (Hb) over the concentration range of 36.3–907.5 nM with a minimum detectability of 10.30 nM. The probe has been applied for the determination of Hb in blood samples showing excellent agreement with the results documented by a medical laboratory. The greenness of the developed probe has been positively investigated by different greenness metrics and software. The green character of the proposed analytical methods originates from the synthesis of S,N-CQDs from sustainable, widely available, and cheap plants via low energy/low cost microwave-assisted technique. Omission of organic solvents and harsh chemicals beside dependence on mix-and-read analytical approach corroborate the method greenness. The obtained results demonstrated the substantial potential of the synthesized green, safe, cheap, and sustainable S,N-CQDs for pharmaceutical and biological applications.

Superparamagnetic and Perfect-Paramagnetic Zinc Ferrite Quantum Dots from Microwave-Assisted Tunable Synthesis.

The properties of quantum dot (QD)-size material depend directly upon its unit cell structure. Spinel zinc ferrite QD powder is produced via a one-pot microwave-assisted hydrothermal synthesis for just 5 min. Varying initial pH values of the preparation sol from 6 to 12 enlarges the Zn/Fe atomic ratio (by ca. 10%), unit cell volume (by ca. 0.5%), particle size (3.5–4.5 nm), and degree of inversion. This leads to a change in the magnetic behavior of the QD-size zinc ferrite from a superparamagnetic to a perfect-paramagnetic type. This novel finding points that the significant changes in the inherent structural parameters of spinel ZnFe2O4 QDs (Zn/Fe ratio and degree of inversion) induced by the systematic pH change of the preparation sol are exclusively responsible for the observed unique magnetic behavior instead of mere QD (single domain) nanosizes.

Microwave-assisted one-pot synthesis of tetrahydrobenzo[b]pyrans in the presence of WEWFPA and their electrochemical studies

Microwave-assisted one-pot synthesis of tetrahydrobenzo[b]pyrans in the presence of WEWFPA and their electrochemical studies

One-pot microwave-assisted synthesis of Ag2Se and photothermal conversion

In this paper, broad-spectrum light-harvesting silver-selenium (Ag2Se) nanoparticles with an average size of about 1 μm were synthesized by a one-pot microwave-assisted method, and the sample particles were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), UV–visible, laser particle size analyzer and photothermal conversion. The results showed that the higher the concentration of the sample aqueous solution, the stronger the photothermal conversion ability under the same laser power, and the temperature of the sample aqueous solution with the concentration of 0.085 mol/L could reach 54.1 ℃. Under the same conditions, the higher the laser power, the stronger the photothermal conversion ability, and the temperature of the sample aqueous solution can reach 60.2 ℃. In addition, the experimental and theoretical results also show that the sample aqueous solution has good absorption ability in the UV–Vis-NIR absorption spectrum, which proves that the Ag2Se nanoparticles have good photothermal conversion properties.