Bio-waste chitosan-derived N-doped CNT-supported Ni nanoparticles for selective hydrogenation of nitroarenes.

In this study, a facile method for the synthesis of leach proof and earth-abundant non-noble Ni nanoparticles on N-doped carbon nanotubes is reported. The catalyst was synthesized by an impregnation-carbonization method, wherein a Ni-chitosan complex upon carbonization in a 5% H2/N2 atmosphere at 800 °C yielded Ni-containing N-doped CNTs. Chitosan served as a single source of carbon and nitrogen, and the nanotube growth was facilitated by the in situ formed Ni nanoparticles.

Synthesis of Saponite Based Nanocomposites to Improve the Controlled Oral Drug Release of Model Drug Quinine Hydrochloride Dihydrate.

In the present research study, a 2:1 type of smectite clay minerals, namely natural saponite (NSAP) and synthetic saponite (SSAP), was demonstrated for the first time to be controlled drug release host materials for the model drug quinine hydrochloride dihydrate (QU). The popular sol-gel hydrothermal technique was followed for the synthesis of saponite. The QU was ion exchanged and intercalated into an interlayered gallery of synthetic as well as natural saponite matrices.

Synthesis Route Impact on BiVOâ‚„ Nanoparticles and their Visible Light Photocatalytic Activity Under Green LED Irradiation.

The present study demonstrates the BiVOâ‚„ nanoparticles synthesized by co-precipitation (CPM), hydrothermal (HTM) and solution combustion method (SCM) and their visible light photocatalytic activity under irradiation of green light emitting diodes. The synthesized catalysts were characterized by Powder X-ray Diffraction, UV-vis Diffuse reflectance spectroscopy, BET Surface area analysis, Fourier Transform Infrared spectroscopy and Scanning electron microscopy. Result demonstrated that the photocatalytic activity of BiVOâ‚„ catalyst synthesized by solution combustion method has 4.

Recovery of value-added products from cathode and anode material of spent lithium-ion batteries.

Herein we report a low cost and eco-friendly approach for the recovery of metals from cathode and anode materials of mobile phone spent lithium-ion batteries (LIBs). Li-based metal oxide and graphite were efficiently separated from their respective foils and used for lixiviation. Acetic acid (CHCOOH) and water were used as lixiviants for the recovery of metals from cathode and anode materials respectively.

Recent advances based on the synergetic effect of adsorption for removal of dyes from waste water using photocatalytic process.

The problem of textile dye pollution has been addressed by various methods, mainly physical, chemical, biological, and acoustical. These methods mainly separate and/or remove the dye present in water. Recently, advanced oxidation processes (AOP) have been focused for removal of dye from waste water due to their advantages such as ecofriendly, economic and capable to degrade many dyes or organic pollutant present in water.

Recovered spinel MnCoO from spent lithium-ion batteries for enhanced electrocatalytic oxygen evolution in alkaline medium.

A facile way of recovering 3d transition metals of industrial importance from spent lithium-ion batteries (LIBs) without using any surfactants has been developed. Mn- and Co-rich spent LIBs were chosen as sustainable sources for recovering the oxides of the respective elements. The physical dismantling of Li-ion batteries, chemical leaching with 2 M acetic acid, precipitation with ammonium carbonate, hydrothermal conditioning and calcination at 650 °C led to the facile formation of spherical spinel MnCoO with very high morphological selectivity.

Al-intercalated acid activated bentonite beads for the removal of aqueous phosphate.

The separation of fine spent sorbents from treated water after remediation is a major difficulty associated with phosphate wastewater treatment technology. In this study, a novel aluminium-pillared acid activated bentonite powder (Al-ABn) and alginate immobilized aluminium-pillared acid activated bentonite beads (Al-ABn-AB) were synthesized and used for the removal of aqueous phosphate. The phosphate removal behaviour of adsorbents were evaluated by batch experiments as a function of various parameters such as pH, initial concentration, contact time, temperature, adsorbent dose and presence of coexisting ions.

Self-Supported Chiral Polymeric Mn Salen Complexes as Highly Active and Recyclable Catalysts for Epoxidation of Nonfunctionalized Olefins.

A series of self-supported chiral polymeric Mn N,N'-ethylenebis(salicylimine) (salen) complexes were synthesized through metalation of the corresponding salen ligands obtained by condensation of several bis/tris-aldehydes with (1R,2R)-1,2-diaminocyclohexane. Upon employment in the asymmetric epoxidation reaction of nonfunctionalized olefins, all complexes showed enhanced activity and enantioselectivity relative to the classical Jacobsen's monomeric salen complex. However, 1,3,5-triazole-based polymeric Mn salen complex 7 was noticeably preferred over others owing to its ability to render higher enantioselectivity at the expense of lower catalyst loading.

Preferential adsorption behavior of methylene blue dye onto surface hydroxyl group enriched TiO2 nanotube and its photocatalytic regeneration.

The present manuscript focus on the synthesis of surface hydroxyl group enriched titanium dioxide nanotube (TNT) by hydrothermal method for preferential adsorption of methylene blue (MB) dye. The mixture of methylene blue (MB) and rhodamine B (RhB) dye was used to study the preferential adsorption nature of TNT. The synthesized TNT were characterized by various techniques such as powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), N2 adsorption, and ammonia-temperature programmed desorption (NH3-TPD) analysis.

Biodegradable gelatin-ciprofloxacin-montmorillonite composite hydrogels for controlled drug release and wound dressing application.

This work reports intercalation of a sparingly soluble antibiotic (ciprofloxacin) into layered nanostructure silicate, montmorillonite (MMT) and its reaction with bone derived polypeptide, gelatin that yields three-dimensional composite hydrogel. Drug intercalation results in changes in MMT layered space and drug loaded MMT and gelatin creates 3D morphology with biodegradable composite hydrogels. These changes can be correlated with electrostatic interactions between the drug, MMT and the gelatin polypeptides as confirmed by X-ray diffraction patterns, thermal, spectroscopic analyses, computational modeling and 3D morphology revealed by SEM and TEM analysis.

Synthesis and characterization of new chiral Cu(ii)-N4 complexes and their application in the asymmetric aza-Henry reaction.

Cu(ii) Schiff base complexes Cu(ii)- and Cu(ii)- based on 2-acetyl pyridine with both (1R,2R)-1,2-diaminocyclohexane and (1S,2S)-1,2-diaminocyclohexane were synthesized in a single step. Subsequent reduction of ligands and with NaBH4 followed by complexation with Cu(OTf)2 resulted in generation of two more additional chiral centers in complexes Cu(ii)- and Cu(ii)-. The ligands and their corresponding complexes were well characterized by several spectral techniques like (1)H-NMR, (13)C-NMR, LC-MS, CD, UV-Vis spectroscopy and microanalysis.

Unravelling a new class of chiral organocatalyst for asymmetric ring-opening reaction of meso epoxides with anilines.

Chiral sulfinamide based organocatalyst 11 was synthesized from readily available starting materials and used for the asymmetric ring-opening (ARO) reaction of meso epoxides with anilines. A high yield (up to 95%) of chiral β-amino alcohols with excellent enantioselectivity (ee up to 99%) was achieved in 24-30 h at rt under optimized reaction conditions. A probable mechanism for the catalytic ARO reaction is envisaged by (1)H and (13)C NMR experiments.

Evaluation of clay/poly (L-lactide) microcomposites as anticancer drug, 6-mercaptopurine reservoir through in vitro cytotoxicity, oxidative stress markers and in vivo pharmacokinetics.

Intercalation of 6-mercaptopurine (6-MP), an antineoplastic drug in interlayer gallery of Na(+)-clay (MMT) was further entrapped in poly (L-lactide) matrix to form microcomposite spheres (MPs) in order to reduce the cell toxicity and enhance in vitro release and pharmacokinetic proficiency. The drug-clay hybrid was fabricated via intercalation by ion-exchange method to form MPs from hybrid. In vitro drug release showed controlled pattern, fitted to kinetic models suggested controlled exchange and partial diffusion through swollen matrix of clay inter layered gallery.

Oxazoline-based organocatalyst for enantioselective strecker reactions: a protocol for the synthesis of levamisole.

A chiral oxazoline-based organocatalyst has been found to efficiently catalyze asymmetric Strecker reactions of various aromatic and aliphatic N-benzhydrylimines with trimethylsilyl cyanide (TMSCN) as a cyanide source at -20 °C to give α-aminonitriles in high yield (96 %) with excellent chiral induction (up to 98 % ee). DFT calculations have been performed to rationalize the enantioselective formation of the product with the organocatalyst in these reactions. The organocatalyst has been characterized by single-crystal X-ray diffraction analysis, as well as by other analytical methods.

Asymmetric aminolytic kinetic resolution of racemic epoxides using recyclable chiral polymeric Co(III)-salen complexes: a protocol for total utilization of racemic epoxide in the synthesis of (R)-Naftopidil and (S)-Propranolol.

Chiral polymeric Co(III) salen complexes with chiral ((R)/(S)-BINOL, diethyl tartrate) and achiral (piperazine and trigol) linkers with varying stereogenic centers were synthesized for the first time and used as catalysts for aminolytic kinetic resolution (AKR) of a variety of terminal epoxides and glycidyl ethers to get enantio-pure epoxides (ee, 99%) and N-protected β-amino alcohols (ee, 99%) with quantitative yield in 16 h at RT under optimized reaction conditions. This protocol was also used for the synthesis of two enantiomerically pure drug molecules (R)-Naftopidil (α1-blocker) and (S)-Propranolol (β-blocker) as a key step via AKR of single racemic naphthylglycidyl ether with Boc-protected isoproylamine with 100% epoxide utilization at 1 g level. The catalyst 1 was successfully recycled for a number of times.

Template free synthesis of mesoporous hectorites: efficient host for pH responsive drug delivery.

The organized mesoporous matrices with large surface area and large pore volumes are potential drug carriers and hence find good applications in the field of controlled and sustained drug delivery. Two novel mesoporous synthetic hectorite (MSH) materials, namely, MSH3 and MSH4 with diverse composition and pore performance have been synthesized by a template free route and studied for the controlled drug delivery applications. MSH3 with 0.

Synthetically amenable amide derivatives of tosylated-amino acids as organocatalysts for enantioselective allylation of aldehydes: computational rationale for enantioselectivity.

A phenylalanine derived chiral amide is developed that serves as an effective organocatalyst for the reaction of allyltrichlorosilane with aryl, hetero-aryl and α,β-unsaturated aldehydes to afford the desired homoallylic alcohols in good yield (up to 90%) and high enantioselectivity (up to 99%). The experimental results and DFT calculations suggest that para substituted aromatic aldehydes as substrate show higher ee in the product than their ortho/meta counterparts. The (1)H and (13)C NMR spectra study corroborated the calculated results.

DNA binding, antioxidant activity, and DNA damage protection of chiral macrocyclic Mn(III) salen complexes.

We are reporting the synthesis, characterization, and calf thymus DNA binding studies of novel chiral macrocyclic Mn(III) salen complexes S-1, R-1, S-2, and R-2. These chiral complexes showed ability to bind with DNA, where complex S-1 exhibits the highest DNA binding constant 1.20 × 10(6) M(-1).

Modified asymmetric Strecker reaction of aldehyde with secondary amine: a protocol for the synthesis of S-clopidogrel (an antiplatelet agent).

A first approach for catalytic asymmetric Strecker reaction of aldehydes with a secondary amine in the presence of sodium fluoride using hydroquinine as chiral catalyst was developed. The catalytic system gave α-aminonitriles in excellent yields (up to 95%) and high enantioselectivities (er up to 94:6). The efficacy of the chiral product was successfully fulfilled in the improved synthesis of (S)-clopidogrel (an antiplatelet agent).

A dechlorination pathway for synthesis of horn shaped carbon nanotubes and its adsorption properties for CO2, CH4, CO and N2.

Using metallic copper as reductant and tetrachloroethylene as carbon precursor, a simple, low temperature solvothermal method for the synthesis of horn shaped carbon nanotubes is reported. The detail study of reaction parameters such as temperature, time, carbon precursor amount, type and catalyst proportion has been carried out to optimize the conditions wherein that the copper metal (10 g) mediated reduction of tetrachloroethylene (25 mL) at 200°C for 5h resulted in the horn shaped carbon nanotubes with high yield and structural selectivity. The adsorption properties of horn shaped carbon nanotubes were investigated for carbon dioxide, methane, carbon monoxide and nitrogen as adsorbate by volumetric measurements up to 850 mm Hg.

Montmorillonite/poly-(ε-caprolactone) composites as versatile layered material: reservoirs for anticancer drug and controlled release property.

This work evaluates intercalation of tamoxifen (Tmx) in interlayer gallery of Na(+)-MMT (Montmorillonite, MMT) (Tmx-MMT), which is further compounded with poly-(ε-caprolactone) (PCL) (Tmx-MMT/PCL, MPs), for oral chemotherapy of breast cancer. The X-ray diffraction patterns, thermal and spectroscopic analyses indicated the intercalation of Tmx into the MMT interlayer that stabilized in the longitudinal monolayer mode by electrostatic interaction. No significant change in structural and functional properties of Tmx was found in the MMT layers.

C2-symmetric recyclable organocatalyst for enantioselective Strecker reaction for the synthesis of α-amino acid and chiral diamine--an intermediate for APN inhibitor.

Recyclable chiral amide-based organocatalyst 5 efficiently catalyzed asymmetric Strecker reaction of various aromatic and aliphatic N-benzhydrylimines with ethyl cyanoformate as cyanide source at -10 °C to give a high yield (95%) of α-aminonitriles with excellent chiral induction (ee, up to 99%) with the added advantage of recyclability. Based on experimental observations a probable mechanism was proposed for this reaction. This protocol with catalyst 5 was extended for the synthesis of (R)-phenylalanine and pharmaceutically important drug intermediate (R)-3-phenylpropane-1,2-diamine in high yield with high enantioselectivity.

Asymmetric hydrolytic kinetic resolution with recyclable macrocyclic Co(III)-salen complexes: a practical strategy in the preparation of (R)-mexiletine and (S)-propranolol.

A chiral cobalt(III) complex (1e) was synthesized by the interaction of cobalt(II) acetate and ferrocenium hexafluorophosphate with a chiral dinuclear macrocyclic salen ligand that was derived from 1R,2R-(-)-1,2-diaminocyclohexane with trigol bis-aldehyde. A variety of epoxides and glycidyl ethers were suitable substrates for the reaction with water in the presence of chiral macrocyclic salen complex 1e at room temperature to afford chiral epoxides and diols by hydrolytic kinetic resolution (HKR). Excellent yields (47% with respect to the epoxides, 53% with respect to the diols) and high enantioselectivity (ee>99% for the epoxides, up to 96% for the diols) were achieved in 2.

Layered inorganic nanocomposites: a promising carrier for 5-fluorouracil (5-FU).

We report here the intercalation of 5-fluorouracil (5-FU), an anticancer drug in interlayer gallery of Na(+) clay (Montmorillonite, MMT), with the assistance of biopolymer (chitosan, CS). The X-ray diffraction patterns, thermal and spectroscopic analyses indicated the drug intercalation into the clay interlayer space in support of CS and stabilized in the longitudinal monolayer by electrostatic interaction. In vitro drug release showed controlled release pattern.

Palladium supported on chitosan as a recyclable and selective catalyst for the synthesis of 2-phenyl ethanol.

Two different chitosan supported palladium based catalysts were prepared, wherein dispersed palladium nanoparticles were obtained via chemical reduction supported on chitosan (Pd/CTS) and amine functionalized modified chitosan (Pd/AFCTS). The catalytic activity of the Pd-based catalysts, Pd/CTS and Pd/AFCTS, were assessed in the hydrogenation of styrene oxide to 2-phenyl ethanol. Both Pd-based catalysts enhanced the formation of the desired 2-phenyl ethanol in contrast to a conventional Pd/C catalyst without the assistance of inorganic or organic base.