A model of the catalytic triad of chymotrypsin is built assuring the arrangement and properties as they are within the complete enzyme. The model contains 18 amino acid residues of chymotrypsin and its substrate. A total of 135 atoms (including 70 heavy atoms) were subjected to full ab initio geometry optimizations through 127 individual steps along the reaction coordinate of the complete catal...

the catalytic oxidation of toluene over copper oxide supported on natural diatomite was investigated. the catalyst was prepared by the wet impregnation method and characterized by using the brunauer emmett teller (bet), field emission scanning electron microscopy (fesem), x-ray diffraction (xrd), x-ray fluorescence (xrf) and temperature-programmed reduction (tpr) analysis. the highest catalytic ...

Monometallic and bimetallic Ni and Co catalytic nanoparticles supported on Titanium dioxide (rutile phase) substrate were prepared by wet impregnation method. These nanoparicles were used as catalysts for synthesis of multiwalled carbon nanotubes (MWCNTs) from acetylene decomposition at 700°C by the catalytic chemical vapor deposition (CCVD) technique. The nanomaterials (catalyst and CNTs) were...

a sequential process strategy was introduced for the synthesis of 2,3,4,5-tetrasubstituted pyrroles by the formation of benzoin from the corresponding aromatic aldehyde and followed by condensation reaction with 1,3-dicarbonyl compounds and ammonium acetate in the presence of diethylene glycol-bis(3-methylimidazolium) dihydroxide as catalyst in refluxing ethanol. the recycled catalyst could be ...

cis-polybutadiene was functionalized using in–situ generated dmd as oxidant and tetra-n-butyl ammonium bromide as phase transfer catalyst (ptc). the epoxidation process was investigated by 1hnmr spectroscopy. 1hnmr spectrum analysis of products confirms the absence of ring opening side products in epoxidation reaction. various factors such as reaction temperature, reaction time and the concentr...

a simple, rapid and sensitive method has been developed for determination of traces of tellurium (iv) (7.0-120.0 ng/ml) based on it’s catalytic effect on the reduction reaction of lauth’s violet by sulfide ion at ph 4.2. the reaction is monitored spectrophotometrically by measuring the decrease in absorbance of lauth’s viole at 600 nm by the fixed time method. the detection limit is 5.0 ng/ml a...

In this work, we present a mild method for direct conversion of primary alcohols into carboxylic acids with the use of water as an oxygen source. Applying a ruthenium dihydrogen based dehydrogenation catalyst for this cause, we investigated the effect of water on the catalytic dehydrogenation process of alcohols. Using 1 mol% of the catalyst we report up to high yields. Moreover, we isolated ke...

Oxacyclic structures such as tetrahydrofuran (THF) rings are commonly found in many bioactive compounds, and this has led to several efforts toward their stereoselective syntheses. However, the process of catalytic asymmetric cycloetherification for their straightforward synthesis has remained a challenge. In this study, we demonstrate a novel asymmetric synthesis method for THF via the catalyt...