Amphiphilic Self-Assembled Polymeric Copper Catalyst to Parts per Million Levels: Click Chemistry

Self-assembly of copper sulfate and a poly­(imidazole–acrylamide) amphiphile provided a highly active, reusable, globular, solid-phase catalyst for click chemistry. The self-assembled polymeric Cu catalyst was readily prepared from poly­(<i>N</i>-isopropylacrylamide-<i>co</i>-<i>N</i>-vinylimidazole) and CuSO₄ via coordinative convolution. The surface of the catalyst was covered with globular particles tens of nanometers in diameter, and those sheetlike composites were layered to build an aggregated structure. Moreover, the imidazole units in the polymeric ligand coordinate to CuSO₄ to give a self-assembled, layered, polymeric copper complex. The insoluble amphiphilic polymeric imidazole Cu catalyst with even 4.5–45 mol ppm drove the Huisgen 1,3-dipolar cycloaddition of a variety of alkynes and organic azides, including the three-component cyclization of a variety of alkynes, organic halides, and sodium azide. The catalytic turnover number and frequency were up to 209000 and 6740 h^–1, respectively. The catalyst was readily reused without loss of catalytic activity to give the corresponding triazoles quantitatively

Extraction of penicillin G from aqueous solution using a membrane contactor: numerical investigation

In the current study, the treatment of pharmaceutical wastewater containing penicillin G treatment using a hollow fibre membrane contactor was investigated. A mathematical model based on the finite element method was developed. The extraction was performed using Shellsol TK as organic solvent containing 5% Aliquat 336. The effect of feed pH, flow rate and temperature were examined for the extraction of penicillin G from aqueous solution. The results showed that there is reasonable good agreement between experimental data and modelling values. It was found that increasing temperature from 10 -C to 30 -C increases the penicillin G extraction from 33% to 54%. Also, penicillin G extraction was decreased from 34.7% to 25.1% with increasing pH from 5.5 to 6.5 while it grew to 45.8% when the pH of feed solution was 7. Furthermore, the results showed the diffusive flux is favourable for the system and penicillin G extraction but the convective flux has negative impact on the system in terms of penicillin G extraction. It was concluded that a hollow fibre membrane contactor has the potential for use in wastewater treatment through it is important to improve diffusive flux in the system to enhance penicillin G extraction

Recent advancement of ullmann condensation coupling reaction in the formation of aryl-oxygen (C-O) bonding by copper-mediated catalyst

Transition metal-catalyzed chemical transformation of organic electrophiles and organometallic reagents belong to the most important cross coupling reaction in organic synthesis. The biaryl ether division is not only popular in natural products and synthetic pharmaceuticals but also widely found in many pesticides, polymers, and ligands. Copper catalyst has received great attention owing to the low toxicity and low cost. However, traditional Ullmann-type couplings suffer from limited substrate scopes and harsh reaction conditions. The introduction of homogeneous copper catalyst with presence of bidentate ligands over the past two decades has totally changed this situation as these ligands enable the reaction promoted in mild condition. The reaction scope has also been greatly expanded, rendering this copper-based cross-coupling attractive for both academia and industry. In this review, we will highlight the latest progress in the development of useful homogeneous copper catalyst with presence of ligand and heterogeneous copper catalyst in Ullmann type C-O cross-coupling reaction. Additionally, the application of Ullmann type C-O cross coupling reaction will be discussed

Applications of bio-resource based sustainable heterogeneous Pd-Nanocatalyst for cross-coupling and michael addition reactions

The development of efficient and cost-effective catalysts from renewable sources is crucial for sustainable  chemistry. Herein, we developed a bio-heterogeneous Pd-nanocatalyst (PdNc@PA) by incorporating palladium  nanoparticles into biodegradable kenaf-cellulose modified with poly(amidoxime) ligands. The catalyst has  demonstrated remarkable stability and exceptional catalytic performance in a range of cross-coupling including  Mizoroki-Heck, Suzuki-Miyaura, and Tamejiro-Hiyama reactions of inactivated aryl chlorides resulting in high  yields of the desired coupling products. Additionally, PdNc@PA was also found to be effective in Michael  addition reactions producing N, S, O-alkylated products in high yields. Furthermore, the PdNc@PA catalyst  demonstrated robustness and recoverability allowing it to be reused across successive cycles without significant  loss of catalytic activity. The incorporation of renewable resources in catalyst development offers an environ?mentally conscious alternative to traditional synthetic approaches. This research highlights the potential of  utilizing biodegradable materials as catalyst supports, which could significantly diminish environmental impact  and waste production. Moreover, this study demonstrates the versatility of PdNc@PA as a proficient and  reusable catalyst for a diverse array of organic reactions. These discoveries provide an encouraging pathway  towards the development of sustainable and economically viable catalysts suitable for industrial applications. </p

Adsorption of thallium from wastewater using disparate nano-based materials: A systematic review

Development of promising technologies to remove thallium as a highly poisonous contaminant is of great attention to guarantee the sustainable supplement of safe potable water and human well-being all around the world. Recently, adsorption has been introduced as a noteworthy technique to remove trace amount of thallium. In the past, the rate of thallium removal using the adsorption technique was relatively low due to the fact that this method was significantly influenced by the co-existing cations. To overcome this problem, more promising adsorbents such as nano-based materials have been developed. These adsorbents have shown great potential in the process of thallium removal due to their large surface area and superior selectivity. The main objective of this paper is to present a state-of-the-art review about the potential of nano-based form of disparate materials (i.e., titanium compounds, MnO2, ZnO, Al2O3 and multiwall carbon nanotubes) to separate thallium from water/waste water sources. Then, a systematic overview about acute/chronic toxicities of thallium for humans is aimed to be provided. Throughout the review, the authors aim to compare the negative and positive aspects of each treatment technique and offer promising technologies for thallium removal. At the end, an outlook on the recent advancements in the adsorption process of thallium using nanomaterials is provided

Development of cellulose-supported Pd-nanocatalyst for the heck coupling and michael addition reactions

The development of reusable, bio-resource based nanocatalysts with high turnover numbers (TONs) is essential for increased sustainability in the chemical sector. Herein, cellulose-supported bio-resourced poly(hydroxamic acid) is employed as a ligand in the synthesis of a palladium nanocomposite (PdNc-PHA) that exhibits higher TONs that previously reported similar systems for the Mizoroki-Heck and Michael addition reactions. The PdNc-PHA catalyst was characterised using Fourier transform infrared spectroscopy (FTIR), field-emission scanning electron microscopy (FE-SEM), energy dispersive X-ray spectrometry (EDX), high-resolution transmission electron microscopy (HR-TEM), X-ray photoelectron spectroscopy (XPS), and inductively coupled plasma-atomic emission spectroscopy (ICP-AES) analyses. Results showed that the PdNc-PHA catalyst exhibits excellent durability and high catalytic activity in the Mizoroki-Heck and Michael addition reactions, leading to high yields of the desired corresponding products. The Mizoroki-Heck reaction of aryl/heteroaryl chlorides with olefins resulted in the production of cross-coupled products, while the Michael addition reaction of phenol/thiophenol and aliphatic cyclic/alicyclic amines with a variety of olefins synthesised the corresponding O-, S-, and Nalkylated products. The recycle and reusability of the catalyst were tested using 4-nitrochlorobenzene and butyl acrylate. The results demonstrated that the catalyst maintained its catalytic activity effectively for up to ten cycles without any noticeable loss in performance. This research represents a promising strategy for efficient catalysis based on bio-waste as a wealth material.</p

Synthesis of multi‑organo‑functionalized fibrous silica KCC‑1 for highly efficient adsorption of acid fuchsine and acid orange II from aqueous solution

Multi-functionalized fibrous silica KCC-1 (MF-KCC-1) bearing amine, tetrasulfide, and thiol groups was synthesized via a post-functionalization method and fully characterized by several methods such as FTIR, FESEM, EDX-Mapping, TEM, and N2 adsorption–desorption techniques. Due to abundant surface functional groups, accessible active adsorption sites, high surface area (572 m2 g−1), large pore volume (0.98 cm3 g−1), and unique fibrous structure, mesoporous MF-KCC-1 was used as a potential adsorbent for the uptake of acid fuchsine (AF) and acid orange II (AO) from water. Different adsorption factors such as pH of the dye solution, the amount of adsorbent, initial dye concentration, and contact time, affecting the uptake process were optimized and isotherm and kinetic studies were conducted to find the possible mechanism involved in the process. For both AF and AO dyes, the Langmuir isotherm model and the PFO kinetic model show the most agreement with the experimental data. According to the Langmuir isotherm, the calculated maximum adsorption capacity for AF and AO were found to be 574.5 mg g−1 and 605.9 mg g−1, respectively, surpassing most adsorption capacities reported until now which is indicative of the high potential of mesoporous MF-KCC-1 as an adsorbent for removal applications

Novel bimodal micro-mesoporous Ni50Co50-LDH/ UiO-66-NH2 nanocomposite for Tl(I) adsorption

Ni50Co50-layered double hydroxide/UiO-66-NH2 metal–organic framework nanocomposite (Ni50Co50-LDH/UiO-66-NH2 NC) was synthesized through a facile ultrasonic-assisted hydrothermal method. UiO-66-NH2 MOF nanocrystals were in situ grown on the surface of ultrathin 2-dimensional functionalized Ni50Co50-LDH nanosheets. Using this method, a uniform nanocomposite architecture was obtained by uniformly distributing MOF nanocrystals on Ni50Co50-LDH. The synthesized LDH/MOF NC possesses essential properties of potential nano adsorbent such as high surface area (907 m2 g 1 ), large pore volume (0.91 cm3 g1), bimodal micro mesoporous structure, and chemical functionality. Accordingly, Ni50Co50-LDH/UiO-66-NH2 NC was used as an adsorbent for the uptake of toxic thallium (I) from water. Isotherm, thermodynamic, and kinetic studies were conducted to gain a better insight into the adsorption mechanism (s) involved in the removal process. Langmuir and pseudo-first-order models present a better fit to the isotherm and kinetic data, respectively, and the maximum Langmuir adsorption capacity was found to be 601.3 mg g 1 after non-linear fitting analysis (pH=7.0, solution volume=30 mL, initial thallium (I) concentration=50 mg L–1, contact time=15 min, solution temperature=293 K

A novel and facile green synthesis method to prepare LDH/MOF nanocomposite for removal of Cd(II) and Pb(II)

To date, many nanoadsorbents have been developed and used to eliminate heavy metal contamination, however, one of the challenges ahead is the preparation of adsorbents from processes in which toxic organic solvents are used in the least possible amount. Herein, we have developed a new carboxylic acid-functionalized layered double hydroxide/metal–organic framework nanocomposite (LDH/MOF NC) using a simple, efective, and green in situ method. UiO-66-(Zr)- (COOH)2 MOF nanocrystals were grown uniformly over the whole surface of COOH-functionalized Ni50Co50-LDH ultrathin nanosheets in a green water system under a normal solvothermal condition at 100 °C. The synthesized LDH/MOF NC was used as a potential adsorbent for removal of toxic Cd(II) and Pb(II) from water and the infuence of important factors on the adsorption process was monitored. Various non-linear isotherm and kinetic models were used to fnd plausible mechanisms involved in the adsorption, and it was found that the Langmuir and pseudo-frst-order models show the best agreement with isotherm and kinetic data, respectively. The calculated maximum adsorption capacities of Cd(II) and Pb(II) by the LDH/MOF NC were found to be 415.3 and 301.4 mg g−1, respectively, based on the Langmuir model (pH= 5.0, adsorbent dose = 0.02 g, solution volume = 20 mL, contact time = 120 min, temperature= 25 ℃, shaking speed 200 rpm)

Silica supported Schiff-based palladium nanocatalyst for n-alkylation at room temperature

This works documents a new silica gel-supported nanocatalyst (Si@NSBPdNPs 3) with low Pd loadings for nalkylation reactions at room temperature. Post synthesis characterisation using SEM-EDX and ICP techniques provided a quantitative assessment of palladium species. Additionally, TEM analysis unveiled an average palladium nanoparticle size of 5.87 ± 0.2 nm. In-depth X-ray Photoelectron Spectroscopy (XPS) analysis revealed its predominant composition as Pd(0) complexed to a Schiff base ligand on low cost silica matrix. The nanocatalyst exhibited high efficacy in the catalysis of n-alkylation (Michael addition) reactions with various α,β-unsaturated Michael acceptors, yielding the corresponding n-alkyl products at room temperature with exceptional yields. Notably, the catalyst exhibited good stability and could be easily separated from the reaction mixture. Moreover, the catalyst displayed recyclability potential, maintaining its original catalytic efficacy for up to seven cycles without any discernible loss.</p