32459-62-4Relevant articles and documents
Alkynylisocyanide gold mesogens as precursors of gold nanoparticles
Chico, Ruben,Castillejos, Eva,Serp, Philippe,Coco, Silverio,Espinet, Pablo
experimental part, p. 8654 - 8662 (2011/10/05)
Gold nanoparticles (Au NPs) have been synthesized using simple thermolysis, whether from the mesophase or from toluene solutions, of mesogenic alkynyl-isocyanide gold complexes [Au(C=C-C6H4-C mH2m+1)(C=N-C6H4-O-C nH2n+1)]. The thermal decomposition from the mesophase is much slower than from solution and produces a more heterogeneous size distribution of the nanoparticles. Working in toluene solution, the size of nanoparticles can be modulated from ~2 to ~20 nm by tuning the chain lengths of the ligands present in the precursor. Different experimental conditions have been analyzed to reveal the processes governing the formation of the gold nanoparticles. Experiments on the effect of adding ligands or bubbling oxygen support that the thermal decomposition is a bimolecular process that starts by decoordination of the isocyanide ligand, producing an oxidative coupling of the akynyl group to [R-C=C-C=C-R] and reduction of gold(I) to gold(0) as nanoparticles. The nanoparticles obtained behave as a catalyst in the oxidation of isocyanide (CNR) to isocyanate (OCNR), which in turn cooperates to catalyze the decomposition.
Quantitative Structure-Activity Relationships of Insecticidal Pyrazolines
Hasan, Riaz,Nishimura, Keiichiro,Ueno, Tamio
, p. 291 - 298 (2007/10/03)
Methyl 3-(4-chlorophenyl)-4-methyl-1--2-pyrazoline-4-carboxylates and related compounds were prepared. Their convulsant activity was determined as the minimum dose required to bring about the symptom within 1 h after injection against male adult American cockroaches, Periplaneta americana (L.). Insecticidal activity with metabolic inhibitors for oxidation and hydrolysis was measured 24 h after injection of the test compounds. Variations in each of the activities were analysed by using physicochemical substituent parameters and regression analysis. The findings indicated that the greater the hydrophobicity and the more the electron-withdrawing property of the substituents, the higher were the activities. Variations in each of the two activities were parabolically related to the STERIMOL width parameter with an optimum value of about zero.