National Chemical Laboratory

About: National Chemical Laboratory is a facility organization based out in Pune, Maharashtra, India. It is known for research contribution in the topics: Catalysis & Nanoparticle. The organization has 8891 authors who have published 14837 publications receiving 387600 citations.

Activity, selectivity and stability of Ni and bimetallic Ni–Pt supported on zeolite Y catalysts for hydrogenation of acetophenone and its substituted derivatives

Abstract: The hydrogenation of acetophenone, p -hydroxy acetophenone ( p -HAP) and p -isobutyl acetophenone was studied using Ni and bimetallic Ni–Pt supported on zeolite Y catalysts. A 10% Ni-supported-on-zeolite Y catalyst showed the optimum activity when compared to other Ni-supported catalysts. The activity of this catalyst decreased very rapidly on recycle; however, the bimetallic Ni–Pt-supported-on-zeolite Y catalyst was highly stable and showed constant activity on recycle. The addition of Pt catalyses the reduction of Ni 2+ to Ni 0 , as characterised by X-ray photoelectron spectroscopy (XPS) and other techniques. For the Ni–Pt bimetallic catalyst, the hydrogen adsorption was found to be higher than that for monometallic catalysts; the adsorbed hydrogen reacts with the activated acetophenone complex to facilitate the catalytic process. The FTIR analysis of adsorbed acetophenone on the catalyst samples indicated that, in both monometallic and bimetallic catalysts supported on zeolite Y, the CO bond of acetophenone is highly activated due to the strong interactions with the acidic sites present on the zeolite. Zeolite interactions with intermediate products and solvent moieties also influenced the selectivity behaviour. A trace amount of a base like NaOH acts as a promoter in improving the selectivity towards alcohol. A plausible reaction mechanism has been proposed for the hydrogenation of acetophenone and its derivatives using monometallic as well as bimetallic catalysts.

Recent Advances in the N-Heterocyclic Carbene (NHC)-Organocatalyzed Stetter Reaction and Related Chemistry

Abstract: Recent developments in the N-heterocyclic carbene (NHC)-catalyzed umpolung of aldehydes followed by their interception with activated carbon–carbon double bonds, namely the Stetter reaction, are presented. Advances in the inter- and intramolecular versions of this reaction, enantioselective transformations as well as the use of unactivated olefins in this type of reaction are discussed. 1 Introduction 2 Proposed Mechanism of the Stetter Reaction 3 Intramolecular Stetter Reactions 4 Intermolecular Stetter Reactions 5 Hydroacylation Reactions 6 Applications in Total Synthesis 7 Conclusion

Isothermal Titration Calorimetry Studies on the Binding of DNA Bases and PNA Base Monomers to Gold Nanoparticles

Abstract: An isothermal titration calorimetric (ITC) investigation of the interaction of DNA bases and PNA base monomers with gold nanoparticles is described revealing a binding sequence in the order C > G > A > T. Direct measurement of the strength of interaction of ligands with nanogold by ITC has important implications in surface modification strategies for biomedical, catalysis, and nanoarchitecture applications.

Creating Spaces of Resistance: Development NGOs and their Clients in Ghana, India and Mexico

Abstract: Development NGOs have been accused by some of being new instruments of control, domesticated by the neoliberal project. For others, they elaborate and pursue alternative dreams. In this paper, we argue that, although the majority of NGOs have been co-opted to serve hegemonic development agendas, they nevertheless present a fluid, contradictory web of relations, within which a significant minority seeks to make spaces of resistance, and where even the most neoliberal NGOs are used by some clients to create new associational spaces. Drawing on work with NGOs in Ghana, India, Mexico and Europe, we explore various strategies deployed by this minority of “independent thinking NGOs”. We argue that there is an important production of Melucci's submerged networks or latent social movements, however limited their political impact to date.

Emulsifier from a tropical marine yeast, Yarrowia lipolytica NCIM 3589

Abstract: A tropical marine strain of Yarrowia lipolytica, NCIM 3589 produced emulsifier in the presence of alkanes or crude oil. The mode of alkane uptake in this organism was by attachment to large droplets. An emulsifier (lipid-carbohydrate-protein) complex was associated with the cell wall. This emulsifier increased the hydrophobicity of the cells during the growth phase. In the stationary phase, the organism produced the emulsifier extracellularly under conditions of carbon excess and nitrogen limitation. Other requirements for extracellular emulsifier production included an initial pH of 8.0 and the presence of sodium chloride at a concentration of 2 to 3% (342 to 513 mM). The cell-associated and extracellular emulsifier was shown to have similar properties.