Characterization of Trigonella foenum-graecum Derived Iron Nanoparticles and Its Potential Pesticidal Activity Against Tuta absoluta (Lepidoptera)

Journal of Cluster Science - Indiscriminate use of synthetic chemicals for pest management in agriculture leads to resistance development by the pests in addition to being toxic to non target...     

Imaging elastic property of surfaces at nanoscale using atomic force microscope

We present a simple technique to characterize and image the distribution of local elastic property using ultrasonic atomic force microscope (UAFM). We interpret the UAFM images using simple arguments. We have demonstrated the capability of the UAFM technique to image the distribution of the local elastic property of the sample surface and semi-quantitatively map the local stiffness of the sample surface using a few selected samples. The local stiffness of the sample surface was obtained by measuring the changes in the frequency of contact resonance peak values and could verify the same using force-distance measurement at the same regions on the sample surface.     

Facile, divergent route to bis-Zn(II)dipicolylamine type chemosensors for pyrophosphate

A new, two-step synthesis has been developed for a series of bis-DPA-type ligands whose dinuclear Zn(II) complexes function as fluorescent anion sensors. The Zn(II) complexes exhibit good selectivity for PP_i over other anions in aqueous medium (pH 7.5) and may be used to monitor the extent of enzyme-catalysed reactions, in which PP_i is produced or consumed.     

InCl3 mediated one-pot synthesis of indol-3-yl pyridine and 2,2′-bipyridine derivatives through multi-component reaction

A simple protocol for the efficient preparation of 2-(1H-Indol-3-yl)-6-methoxy-4-aryl pyridine-3,5-dicarbonitrile and 6-methoxy-4-aryl-2,2′-bipyridine-5-carbonitrile derivatives has been achieved through one-pot multi-component reaction under reflux condition. Particularly valuable features of this method include high yields of products in short reaction time and broad substrate scope. It is an efficient and promising synthetic strategy to build indol-3-yl pyridine and 2,2′-bipyridine skeletons.     

Determination of the absolute configuration of 19-OH-(-)-eburnamonine using a combination of residual dipolar couplings, DFT chemical shift predictions, and chiroptics

19-OH-(-)-eburnamonine 1 is a new indole alkaloid isolated from Bonafusia macrocalyx. A natural derivative from (-)-eburnamonine for which absolute configuration and conformation has been determined by making use of residual dipolar couplings enhanced NMR, circular dichroism spectra and high-level computations.     

Structure and dynamics in solvent-polarity-induced aggregates from a c60 fullerene-based dyad

A novel methanofullerene dyad based on a hydrophobic (acceptor C60 moiety)-hydrophilic (bridge with benzene and ester functionalities)-hydrophobic (donor didodecyloxybenzene) network is designed and synthesized. Electronic absorption spectral features revealed the molecule to exhibit a strong tendency to self-aggregate in binary solvent mixtures at room temperature, where the dielectric constant exceeds a critical value, approximately 30. The dynamic structure factors of these spherical aggregates revealed stretched exponential decay with sizes varying between 110 and 250 nm with an increasing concentration, estimated from the dynamic light scattering experiments. However, a loss of shape selectivity of these aggregates was noted at lower water volume fractions in the binary solvent mixtures. The water-extracted spherical clusters were identified to be fractals with a dimension of 1.85, leading to diffusion-limited cluster aggregation as the mechanistic route for clusterization.     

Physicochemical studies of phosphate based P2O5-Na2O-CaO-TiO2 glasses for biomedical applications

Glasses P₂O₅-Na₂O-CaO-TiO₂ with different TiO₂ contents and fixed P₂O₅ (45 wt%) and CaO (24 wt%) have been prepared employing the normal melting and annealing technique. Measurements such as ultrasonic velocity, attenuation, solubility and pH have been carried out in all the compositions of the glasses. It is interesting to note that the above measured ultrasonic parameters exhibit an abnormal behavior (minimum) at 0.5 wt% of TiO₂ content, beyond which an increase in these parameters with increasing TiO₂ content is observed. The maximum pH values and Ca²⁺ ion release have been observed for the TiO₂ free glass those compositions with and the low TiO₂(?1.0 wt%) content. As the content of the TiO₂ increases, the solubility of the glasses decreases. The observed weight loss reveals two stages of phosphate dissolution kinetics i.e. the first stage, in which the weight loss is proportional to t^1/2, and a second stage in which a linear behavior is observed.     

Chiral α-alkylation/arylation in 1-phenyl-2-(1-pyrrolidinyl)-1-propanol through Grignard reactions

Complete asymmetric induction has been achieved during Grignard alkylations/arylations resulting in (1S,2R)- and (1R,2R)-1-phenyl-1-alkyl/aryl-2-(1-pyrrolidinyl)-1-propanols which are isolated as hydrochlorides.