oxidation of ethylene to ethylene oxide over silver catalyst and selenium modified catalyst has been studied by continuous flow and pulse techniques over the temperature range of 230-280 °c. the results are discussed in terms of reaction mechanisms proposed by others, rejecting mechanisms which involve peroxide formation. it has been shown that not only selectivity towards ethylene oxide produc...

The main object of this study is to investigate the effect of plant growth regulators on the prolongation of vase life of two kinds of cut carnation under normal and ethylene. Carnation is one of the most popular flowers that has a short life due to its sensitivity to ethylene. Also, the effect of plant growth regulators on several physiological traits under ethylene stress and normal condition...

A highly functionalized intermediate in the synthesis of Taxol has been synthesized, which features the tricyclic core and the required oxygen substituents at C1, C2, C7, C10, and C13. The key step, a ring-closing dienyne metathesis (RCDEYM) reaction, has been thoroughly optimized to favor the tricyclic product over the undesired bicyclic product resulting from diene metathesis.

A series of 8 new complexes of titanium and zirconium with diamido ligands bearing an ethylene and propylene bridge between the two amido groups were synthesized and tested for ethylene polymerization. Titanium complexes bearing an ethylene bridge between the two amido groups showed higher activities than the derivatives with a propylene bridge. In the case of the zirconium complexes, the p...

Oxidation of ethylene to ethylene oxide over silver catalyst and selenium modified catalyst has been studied by continuous flow and pulse techniques over the temperature range of 230-280 °C. The results are discussed in terms of reaction mechanisms proposed by others, rejecting mechanisms which involve peroxide formation. It has been shown that not only selectivity towards ethylene oxide pr...

The synthesis and characterization of new zirconium permethylpentalene (form)amidinate complexes are described: Pn*Zr{N(Dipp)2CH}Cl (1), Pn* = ?8-C8Me6 Dipp 2,6-iPr-C6H3; [Pn*Zr{N(p-tol)2CH}Cl]2 (2), p-tol 4-Me-C6H4; [Pn*Zr{N(iPr)2CMe}Cl]2 (3); Pn*Zr{N(iPr)2CPh}Cl (4); Pn*Zr{N(4-Me-C6H4)2CH}2 (5); [Pn*Zr{N(iPr)2CCH2}]2 (6); Pn*Zr{N(iPr)2CPh}(O-2,6,-Me-C6H3) (7). monohalide derivatives 1–4 demon...

Phosphine-free ruthenium benzylidene complexes containing imidazole ligands are reported. These catalysts effective for ring-closing metathesis (RCM) and cross-metathesis (CM) reactions at high temperatures, where the more widely used phosphine-containing N-heterocyclic carbene-based show side reactions. This discovery opens up a pathway to develop selective requiring harsh conditions.