Distorted pentacoordinate copper(II) complexes containing a tridentate ligand

Summary Copper(II) complexes with a tridentate chelating ligand within the general 2N, X (X = O or S) donor class, containing abis(benzimidazolyl) donor set, were prepared and characterized. X-band e.p.r. spectra of the complexes indicateg >g and the largeg and lowA have been interpreted in terms of a distorted basal plane. Superimposed on theg component are five SHF lines withA _N = 16±2G, supporting the interaction of two nitrogen atoms with the copper nucleus. Thus, the basal plane of the complex comprises 2N atoms, with the ligand hetero atom being axially coordinated.     

Identification of the aromatic hydroxylamine group by mass spectrometry

The mass spectra of aromatic hydroxylamines are diagnostic; [M], [M – 2], [M – 16] and, in most instances, [M – 17] ions are observed.     

The investigation of sensing mechanism of ethanol vapour in polymer-nanostructured carbon composite

Polymer-nanostructured carbon composites (PNCC) using three different polymers as composite matrix materials (polyvinylacetate (PVAc), polyethylene glycol (PEG) and ethylene-vinylacetate copolymer (EVA)) have been developed. High structure carbon black Printex XE2 (Degussa AG) was used as a composites filler. Ethanol vapour sensor-effect of composites was determined as a change of electrical resistance as the composite was held in ethanol vapour for 30 seconds. Reversibility of electrical resistance of PNCC, response stability and repeatability have been measured and compared. The electrical resistance response of EVA-nanostructured carbon composite (EVA-NCC) to ethanol vapour as a function of vinylacetate content in the copolymer has been evaluated. Promising ethanol vapour sensor-effect has been observed for PEG-NCC followed by PVAc-NCC and EVA-NCC.     

Hydrolysis kinetics of the sulfonylurea herbicide Sulfosulfuron

The kinetics of hydrolytic degradation of Sulfosulfuron was investigated to predict the fate of the herbicide in an aqueous environment. The study revealed that the hydrolytic degradation of Sulfosulfuron followed first-order kinetics. The degradation of the herbicide was dependent on pH and temperature. Hydrolysis rate was faster in acidic condition (t _1/2 = 9.24 d at pH 4.0) than alkaline environment (t _1/2 = 14.14 d at pH 9.2). Several fold increase in the degradation rate was found when temperature was increased from 10 ± 1°C (t _1/2 = 518 h) to 50 ± 1°C (t _1/2 = 10 h). Activation energy (E _a) was also calculated as 63.87 KJ mol^?1, which is required for the hydrolytic degradation of the molecule. Both media pH and temperature effects were coupled together and derived a complex equation to estimate the overall effect of these two abiotic factors. The major degradation mechanism of the compound was the breaking of the sulfonylurea bridge yielding corresponding sulfonamide and aminopyrimidine. The possible significance of the results to persistence of the herbicide in the field condition is discussed.     

Synthesis and Biological Activity of Some Novel O-Phosphorylated Benzoxazole Derivatives

The phosphorylation of 2-(2′-hydroxyphenyl) benzoxazole has been accomplished with phosphorus oxychloride in a 1:1, 2:1, and 3:1 molar ratio in the presence of a base to yield O-phosphorylated benzoxazole derivatives. Their structures were confirmed by elemental analyses and IR, ¹H NMR, and ³¹P NMR spectral studies. These compounds have been screened for their insecticidal activity against Periplenata americana and were found to be quite active in this respect.     

Studies on Rare Earth Polyphosphate Glasses of the Composition [NaxM(1 − x)/2aGd(1 − x)/2aPO3]n

A fusion technique was used for the preparation of derivatives of the composition [Na _x M_{(1? x)/2a} Gd_{(1? x)/2a} PO₃] _n (where M = bivalent metal like Cu(II), Ca(II), Zn(II), Ni(II), and Mg (II); x = 1/2, 3/4, & 2/3; and a = valency of metal). Composition of these polyphosphate glasses was confirmed by their analyses for metals and phosphorus. The polymeric nature of all polyphosphate glasses was confirmed by the determination of a number average molecular weight (M _n ). The characteristic frequencies in the IR spectra are supportive of the presence of polyphosphate indicative of the polymeric nature of these derivatives. From X-ray diffraction, the amorphous nature of complex polyphosphates has been determined.