ti-mcm-41 was synthesized at ph 3, 7 and 11. the titanium content was determined by aas and found to be 4%, 3.2% and 4.5%, respectively. in order to increase the titanium content in ti-mcm-41, ti(iv) ions were grafted onto ti-mcm-41 using ticl4 in toluene and ti(obu)4 in ethanol. the incorporation of ti was determined to be 28% and 30%, respectively. the oxidation of olefins such as cyclopenten...

The thermal conversion of cis-bicyclo[4.2.0]oct-7-ene to cis,cis-1,3-cyclooctadiene might involve a direct disrotatory ring opening, or it might possibly take place by way of cis,trans-1,3-cyclooctadiene. This cis,trans-diene might possibly form the more stable cis,cis isomer through a [1,5] hydrogen shift or a trans-to-cis isomerization about the trans double bond. Deuterium kinetic isotope ef...

Manganese (?) complex with 2, 2? bipyridine, 1, 1? dioxide (bpdo) ligand was immobilized within nanoreactors of MCM-41. The immobilized complex was characterized by powder x-ray diffraction (XRD), nitrogen adsorption desorption, and FTIR. The pore volume, surface area and pore diameter of MCM-41 decreased after immobilization of Mn complex. Three bands observed at 1250, 1220 cm?1 and 757 cm?1 a...

in the present study, theoretical chemical reactivates photo isomerization in cis-retinal as a natural photo switch in vision. dft hybrid functional, b3lyp and, post-hf method, were the theoretical methods applied utilizing g09 software. 6-31g+ (d,p) basis set employed for structural optimizations, and single point computations performed using b3lyp/6-31g+(d,p). the isomers cis molecule retinal...

Amide cis-trans isomerization (CTI) in methyl 2-deoxy-2-acylamido-d-glucopyranosides was investigated by (1)H and (13)C NMR spectroscopy. Singly (13)C-labeled methyl 2-deoxy-2-formamido-d-glucopyranoside (MeGlcNFm) anomers provided standard (1)H and (13)C chemical shifts and (1)H-(1)H and (13)C-(13)C spin-coupling constants for cis and trans amides that are detected readily in aqueous solution....

Ti-MCM-41 was synthesized at pH 3, 7 and 11. The titanium content was determined by AAS and found to be 4%, 3.2% and 4.5%, respectively. In order to increase the titanium content in Ti-MCM-41, Ti(IV) ions were grafted onto Ti-MCM-41 using TiCl4 in toluene and Ti(OBu)4 in ethanol. The incorporation of Ti was determined to be 28% and 30%, respectively. The oxidation of olefins such as cyclopenten...

Context. Observations of the different isomers molecules in interstellar medium (ISM) have revealed that both low- and high-energy can be present space despite low temperature conditions. It has been shown presence these may due to tunneling effects. Aims. We carried out a theoretical study cis–trans isomerization reactions two astrophysically relevant acids, formic acid (HCOOH) thioformic (HC(...