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1.
J Fluoresc ; 2023 Aug 18.
Article in English | MEDLINE | ID: mdl-37594587

ABSTRACT

A simple, efficient, and reversible fluorescent sensor probe, PBA (2,6-dimethyl pyrone barbituric acid conjugate), comprised of a pro-aromatic donor conjugated with a barbituric acid, was developed for the detection of highly toxic mercuric ions. The probe showed high selectivity and "Turn-On" fluorescence response towards Hg2+ among various metal cations such as Na+, Mg2+, Ca2+, Mn2+, Fe2+, Co2+, Ni2+, Cu2+, Zn2+, Cd2+, Ba2+, Hg2+, and Pb2+, in both homogeneous and microheterogeneous micelle medium sodium dodecyl sulphate (SDS). The binding stoichiometry, limit of detection (LOD), and binding constant for the PBA-Hg complex were determined. The mechanism of binding was ascertained using the N,N'-dimethylbarbituric acid conjugate of 2,6-dimethylpyran (PDMBA), where no binding interaction by deprotonation is possible. In the presence of cysteamine hydrochloride and trifluoroacetic acid (TFA), the complexation of Hg2+ with PBA was demonstrated to be reversible, indicating its potential for the development of reusable sensors. Moreover, the practical applicability of PBA in monitoring Hg2+ in living cells was also evaluated.

2.
Front Chem ; 11: 1175132, 2023.
Article in English | MEDLINE | ID: mdl-37304687

ABSTRACT

Anisotropic nanomaterials are materials with structures and properties that vary depending on the direction in which they are measured. Unlike isotropic materials, which exhibit uniform physical properties in all directions, anisotropic materials have different mechanical, electrical, thermal, and optical properties in different directions. Examples of anisotropic nanomaterials include nanocubes, nanowires, nanorods, nanoprisms, nanostars, and so on. These materials have unique properties that make them useful in a variety of applications, such as electronics, energy storage, catalysis, and biomedical engineering. One of the key advantages of anisotropic nanomaterials is their high aspect ratio, which refers to the ratio of their length to their width, which can enhance their mechanical and electrical properties, making them suitable for use in nanocomposites and other nanoscale applications. However, the anisotropic nature of these materials also presents challenges in their synthesis and processing. For example, it can be difficult to align the nanostructures in a specific direction to impart modulation of a specific property. Despite these challenges, research into anisotropic nanomaterials continues to grow, and scientists are working to develop new synthesis methods and processing techniques to unlock their full potential. Utilization of carbon dioxide (CO2) as a renewable and sustainable source of carbon has been a topic of increasing interest due to its impact on reducing the level of greenhouse gas emissions. Anisotropic nanomaterials have been used to improve the efficiency of CO2 conversion into useful chemicals and fuels using a variety of processes such as photocatalysis, electrocatalysis, and thermocatalysis. More study is required to improve the usage of anisotropic nanomaterials for CO2 consumption and to scale up these technologies for industrial use. The unique properties of anisotropic nanomaterials, such as their high surface area, tunable morphology, and high activity, make them promising catalysts for CO2 utilization. This review article discusses briefly about various approaches towards the synthesis of anisotropic nanomaterials and their applications in CO2 utilization. The article also highlights the challenges and opportunities in this field and the future direction of research.

3.
Molecules ; 27(16)2022 Aug 16.
Article in English | MEDLINE | ID: mdl-36014460

ABSTRACT

Coumarins are fused six-membered oxygen-containing benzoheterocycles that join two synthetically useful rings: α-pyrone and benzene. A survey of the literature shows that coumarins and their metal complexes have received great interest from synthetic chemists, medicinal scientists, and pharmacists due to their wide spectrum of biological applications. For instance, coumarin and its derivatives have been used as precursors to prepare a large variety of medicinal agents. Likewise, coumarin-derived imine-metal complexes have been found to display a variety of therapeutic applications, such as antibacterial, antifungal, anticancer, antioxidant, anthelmintic, pesticidal, and nematocidal activities. This review highlights the current synthetic methodologies and known bioactivities of coumarin-derived imine-metal complexes that make this molecule a more attractive scaffold for the discovery of newer drugs.


Subject(s)
Coordination Complexes , Antioxidants , Coordination Complexes/pharmacology , Coumarins/pharmacology , Coumarins/therapeutic use , Imines
4.
Adv Colloid Interface Sci ; 294: 102485, 2021 Aug.
Article in English | MEDLINE | ID: mdl-34274722

ABSTRACT

The nanomaterials intrinsic enzyme-like activity has gained enormous traction since its discovery in 2007 by Gao and colleagues. The wide range of applications with nanozymes made it more attractive among the scientific community across the world. The area of artificial-enzymes is still evolving, with the development of Single-Atom Nanozymes (SANs), and there is a lot of opportunity in the design and development of SANs that has plenty of real-time applications. The irregular active site distribution or truncated densities of active sites present on the surface of nanozymes can be result in the reduced activity and specificity of nanozymes. Individually spreading these active sites evenly on a solid support will help to curtail the uneven distribution of active sites, resulting in the formation of SANs. SANs, like homogeneous catalysts, are very effective and active due to the nearly uniform distribution of active sites on solid support, and their recovery and recyclability, like heterogeneous catalysts, make them green and sustainable. This review provides a brief overview of architecture, synthesis, and implementations of SANs in various fields. Also, the possibility of SANs in environmental catalysis is discussed along with the key challenges and prospects lying ahead in this field.


Subject(s)
Nanostructures , Catalysis
5.
J Environ Sci (China) ; 101: 189-204, 2021 Mar.
Article in English | MEDLINE | ID: mdl-33334515

ABSTRACT

In this paper, highly stable, powerful, and recyclable magnetic nanoparticles tethered N-heterocyclic carbene-palladium(II) ((CH3)3-NHC-Pd@Fe3O4) as magnetic nanocatalyst was successfully synthesized from a simplistic multistep synthesis under aerobic conditions through easily available low-cost chemicals. Newly synthesized (CH3)3-NHC-Pd@Fe3O4 magnetic nanocatalyst was characterized from various analytical tools and catalytic potential of the (CH3)3-NHC-Pd@Fe3O4 magnetic nanocatalyst was studied for the catalytic reduction of toxic 4-nitrophenol (4-NP), hexavalent chromium (Cr(VI)), Methylene Blue (MB) and Methyl Orange (MO) at room temperature in aqueous media. UV-Visible spectroscopy was employed to monitor the reduction reactions. New (CH3)3-NHC-Pd@Fe3O4 magnetic nanocatalyst exhibited excellent catalytic activity for the reduction of toxic environmental pollutants. Moreover, (CH3)3-NHC-Pd@Fe3O4 magnetic nanocatalyst could be easily and rapidly separated from the reaction mixture with the help of an external magnet and recycled minimum five times in reduction of 4-NP, MB, MO and four times in Cr(VI) without significant loss of catalytic potential and remains stable even after reuse.


Subject(s)
Environmental Pollutants , Palladium , Catalysis , Magnetic Phenomena , Magnetics
6.
Langmuir ; 36(19): 5208-5218, 2020 May 19.
Article in English | MEDLINE | ID: mdl-32320250

ABSTRACT

Anisotropic nanocatalysts have attracted considerable attention in comparison to bulk/nanocatalysts for their enhanced activity and reactivity. The demand toward anisotropic palladium (Pd) nanostructures has increased rapidly in the field of catalysis. Pd is a well-known active catalyst for several carbon-carbon (C-C) cross-coupling reactions; among them, the Suzuki-Miyaura cross-coupling reaction is one of the most versatile and dominant methods for constructing the extraordinarily useful unsymmetrical biaryls and also for hydrogenation of organic contaminants like p-nitrophenol (p-NP). This paper provides a brief explanation about the controlled synthesis, characterization, and catalytic activity of well-defined palladium nanocubes (Pd NCs) prepared by a seed-mediated method. The synthesized monodispersed Pd NCs were characterized by spectroscopic and microscopic tools such as UV-visible, XRD, FESEM, HRTEM, and EDS analyses. Pd NCs proved as an efficient catalyst for Suzuki-Miyaura cross-coupling reactions and p-NP reduction. The catalyst shows enhanced activity, greater stability, and higher selectivity with remarkable recyclability up to 92% for five consecutive cycles. The catalytic performance of the synthesized Pd NCs was also studied in the reduction of the organic contaminant p-NP, which showed an excellent performance screening of 99% conversion in 6 min.

7.
Carbohydr Polym ; 223: 115060, 2019 Nov 01.
Article in English | MEDLINE | ID: mdl-31427023

ABSTRACT

The core characteristics of a perfect catalyst include good activity, simple design, excellent stability, easy recovery from reaction mixture, recyclability, and have the provision for easy scale up. The ease in synthesis, recyclability and scale up makes the dip catalyst a major contender in this regard which possess most of the aforementioned characteristics. In this work, we report a dip catalyst made of cellulose, isolated from agriculture residue (sugarcane bagasse), in which biogenically synthesized palladium nanoparticles were dispersed. The prepared dip catalyst was characterized by FESEM, EDS, XRD, ATR-IR, TGA, TEM, XPS and ICP-OES analysis. Also, the activity of the dip catalyst was studied in the Suzuki-Miyaura cross-coupling reaction and was found to give excellent conversion with 15 recycles. Further, the activity of dip catalyst in C5-arylation of 2-substituted thiophenes was evaluated for which promising yields were obtained.

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