Acid dissociation constant (pKa) of some para-substituted benzohydroxamic, 4-XC6H4CONHOH, and N-methyl parasubstituted benzohydroxamic acids, 4XC6H4CON(OH)CH3, where X = H, CH3, CH3O, NO2, Cl, have been determined spectrophotometrically by nucleophilic substitution reactions of pnitrophenyl acetate with hydroxamate ions at 27± 0.1C. All reactions in this study follow pseudo-first order kinetics...

The substitution reaction of allylic derivatives (acetate, carbonate, and chloride) with tinacetylene proceeded in the presence of palladium as a catalyst to give a product having a 1-ene-4-yne system.

A nucleophilic substitution on a dichlorovinyl ketone was studied experimentally and computationally. A mixture of products is observed experimentally, but a conventional computational analysis does not account for the formation of the minor stereoisomer. Instead, the product mixture is predicted accurately from a dynamic trajectory study on a bifurcating energy surface. The dynamic origin of t...

Encapsulation complexes are reversibly formed assemblies in which small molecule guests are completely surrounded by large molecule hosts. The assemblies are held together by weak intermolecular forces and are dynamic: they form and dissipate on time scales ranging from milliseconds to days-long enough for many interactions, even reactions, to take place within them. Little information is avail...

1. INTRODUCTION. Although it is well known that every tetrahedron circum-scribes a sphere, the following two simple consequences apparently have not been previously recorded. First, any plane through the center of the inscribed sphere divides the tetrahedron into two smaller solids whose surface areas are equal if and only if their volumes are equal. Second, the centroid of the boundary surface...

We present a new shape measure for tetrahedral elements that is optimal in that it gives the distance of a tetrahedron from the set of inverted elements. This measure is constructed from the condition number of the linear transformation between a unit equilateral tetrahedron and any tetrahedron with positive volume. Using this shape measure, we formulate two optimization objective functions tha...

The high yield electrophilic substitution procedure for the synthesis of bis indolyl methanes at room temperature has been carried out effectively by using a novel metal supported organo catalyst. advantages this method include simple conditions, great yields, less work-up, an environmentally friendly process and reusable solid Several were synthesised confirmed IR, H1 13C NMR techniques. Catal...

functionalization of multiwalled carbon nanotubes (mwcnts) with nh2 groups under a one pot reaction is studied. during the first step of the reaction, cl and chcl2 groups were attached to the surfaces of mwcnts through an electrophilic addition reaction. in the second step of process, cl atoms were replaced with nh2 and amino groups (ethylene diamine and butyl amine) under a nucleophilic substi...

a facile and efficient one-pot three-step process for the synthesis of 5-acetyl-2-imino-4-methylthiazoles via the cyclocondensation of 3-thiocyanatoacetylacetone with various hydrazine or hydrazide derivatives in etoh has been developed. 3-thiocyanatoacetylacetone itself has been synthesized as the intermediate from substitution reaction of thiocyanate with 3-chloroacetylacetone. better results...