Search results
Results from the WOW.Com Content Network
In order to suppress this reaction, air-free techniques are often employed when handling say, trimethylphosphine. Less basic phosphines, such as methyldiphenylphosphine are converted to their oxides by treatment with hydrogen peroxide: [8] PMePh 2 + H 2 O 2 → OPMePh 2 + H 2 O. Phosphine oxides are generated as a by-product of the Wittig reaction:
The reaction with oxygen is spin-forbidden but still proceeds at sufficient rate that samples of tertiary phosphines are characteristically contaminated with phosphine oxides. Qualitatively, the rates of oxidation are higher for trialkyl vs triarylphosphines. Faster still are oxidations using hydrogen peroxide. Primary and secondary phosphines ...
The reaction is general, thus a vast number of such species are known. Phosphites are employed in the Perkow reaction and the Michaelis–Arbuzov reaction. They also serve as ligands in organometallic chemistry. Intermediate between phosphites and phosphines are phosphonites (P(OR) 2 R') and phosphinite (P(OR)R' 2).
In chemistry, the rate equation (also known as the rate law or empirical differential rate equation) is an empirical differential mathematical expression for the reaction rate of a given reaction in terms of concentrations of chemical species and constant parameters (normally rate coefficients and partial orders of reaction) only. [1]
Phosphine (IUPAC name: phosphane) is a colorless, flammable, highly toxic compound with the chemical formula P H 3, classed as a pnictogen hydride.Pure phosphine is odorless, but technical grade samples have a highly unpleasant odor like rotting fish, due to the presence of substituted phosphine and diphosphane (P 2 H 4).
where A and B are reactants C is a product a, b, and c are stoichiometric coefficients,. the reaction rate is often found to have the form: = [] [] Here is the reaction rate constant that depends on temperature, and [A] and [B] are the molar concentrations of substances A and B in moles per unit volume of solution, assuming the reaction is taking place throughout the volume of the ...
In his studies, Reppe discovered that this reaction more efficiently produced acrylic esters using NiBr 2 (PPh 3) 2 as a catalyst instead of NiBr 2. Shell developed cobalt-based catalysts modified with trialkylphosphine ligands for hydroformylation (now a rhodium catalyst is more commonly used for this process). [ 17 ]
Organophosphine oxides are organophosphorus compounds with the fromula O=PR 3. The preferred IUPAC name is ...