Measurement of excitation functions of the natAg(α,x) reactions up to 45 MeV

Journal of Radioanalytical and Nuclear Chemistry - We measured excitation functions for the production of the 108m,108g,109g,110m,110g,111gIn, the 109g,111mCd, and the 105g,106m,110m,111gAg in...     

Validated TLC-densitometry method for the simultaneous analysis of pyrethroid insecticides in agricultural and domestic products

ABSTRACT: BACKGROUND: Pyrethroids are widely used for the control of pests and insects, as pyrethroids are believed to pose very little risk to human health and environment. However, exposure to the pyrethroids exceeding the label directions might adversely affect human health and environment. Hence a careful selection of environment friendly household product is required that must contain exactly the label claimed pyrethroids amount. RESULTS: A sensitive and robust TLC-densitometric method for simultaneous quantification of commonly used synthetic pyrethroids including esbiothrin, alpha-cypermethrin and cis/trans permethrin in agricultural and domestic products has been developed and validated. TLC aluminum plates, precoated with 0.2 mm thick layer of silica gel 60 F-254, were used for chromatographic process. Densitometric analysis of chromatoplates was carried out in absorbance mode at corresponding lamdamax of each pyrethroid. Equally valid common mobile phase for all pyrethroids consisted of hexane-dichloromethane-ethylacetate-formic acid (8:1.5:0.4:0.1 v/v/v/v) which provided sharp and symmetrical peaks of esbiothrin, alpha-cypermethrin, trans-permethrin and cis-permethrin, at Rf 0.31, 0.53, 0.6 and 0.65, respectively. Linear regression data for respective calibration curves showed a good linearity for all pyrethroids with r = 0.991-0.996. Limits of detection (LOD) and limits of quantification (LOQ) for all pyrethroids were found in the range of 1.6-2.8 and 4.9-8.5 ng/spot, respectively. CONCLUSIONS: The developed method is applicable for separating the mixture of pyrethroids and at the same time, it is also valid for separating their isomers. The method is reproducible, precise and accurate for the quantitative determination of pyrethroids in agricultural and domestic products.     

Synthesis,spectral characterization and biological studies of transition metal(II) complexes with triazole Schiff bases

New metal based triazoles (1–12) have been synthesized by the interaction of novel Schiff base ligands (L¹–L³) with the Co(II), Ni(II), Cu(II) and Zn(II) metal ions. The Schiff base ligands and their all metal(II) complexes have been thoroughly characterized using various physical, analytical and spectroscopic techniques. In vitro bacterial and fungal inhibition studies were carried out to examine the antibacterial and antifungal profile of the Schiff bases in comparison to their metal(II) complexes against two Gram‐positive, four Gram‐negative and six fungal strains. The bioactivity data showed the metal(II) complexes to have more potent antibacterial and antifungal activity than their uncomplexed parent Schiff bases against one or more bacterial and fungal species. Copyright © 2012 John Wiley & Sons, Ltd.     

Double Suzuki cross‐coupling reaction of pyrimidine boronic acid: synthesis of new versatile dielectrophile

The double Suzuki cross‐coupling reaction has successfully been applied for the synthesis of 5,5′‐(5‐butoxy‐1,3‐phenylene)bis(2‐chloropyrimidine) with two reactive chloro groups and an alkoxy side chain starting from 2‐chloropyrimidin‐5‐ylboronic acid and 1,3‐dibromo‐5‐butoxybenzene. The reactivity of this dielectrophile was tested by reaction with aniline and phenol, a nitrogen and oxygen nucleophile, respectively. The new dielectrophile would further provide an ideal platform for the construction of large hetero‐atom bridged macrocycles for desired properties and functions in supramolecular and material chemistry. Copyright © 2012 John Wiley & Sons, Ltd.     

Cobalt titanate–cobalt oxide composite thin films deposited from heterobimetallic precursor

A single molecular heterobimetallic complex, [Co₂Ti(μ₃‐O)(TFA)₆(THF)₃] (1) [TFA = trifluoroacetate, THF = tetrahydrofuran], was synthesized, structurally and spectroscopically characterized and implemented as a single‐source precursor for the preparation of CoTiO₃–CoO composite thin films by aerosol‐assisted chemical vapour deposition (AACVD). The precursor complex was prepared by interaction of Co(OAc)₂.4H₂O [OAc = (CH₃COO^?)] with Ti(iso‐propoxide)₄ in the presence of trifluoroacetic acid in THF, and was analysed by melting point, CHN, FT‐IR, single‐crystal X‐ray diffraction and thermogravimetric analysis. The precursor complex thermally decomposed at 480 °C to give a residual mass corresponding to a CoTiO₃–CoO composite material. Good‐quality crystalline CoTiO₃–CoO composite thin films deposited at 500 °C by AACVD and characterized through powder X‐ray diffraction and scanning electron microscopy/energy‐dispersive X‐ray spectroscopy show that the crystallites have a rose‐flower‐like morphology with an average petal size in the range of 2–6 µm. Copyright © 2012 John Wiley & Sons, Ltd.