The reaction rate of a catalyzed reaction is faster than the reaction rate of the uncatalyzed reaction at the same temperature.1038-95-5, Name is Tri-p-tolylphosphine, molecular formula is C21H21P. In a Article，once mentioned of 1038-95-5, category: chiral-phosphine-ligands
Catalytic and noncatalytic conversions of tertiary phosphines to their oxides by hydrogen peroxide have been investigated. The catalyst is methylrhenium trioxide, CH3ReO3. The kinetics were investigated in acetonitrile-water (1:1 by volume) at 25C. Stepwise interactions between CH3ReO3 and H2O2 form CH3Re(eta2-O2)(O)2(OI2). A, and CH3Re(eta2-O2)2(O)(OH2), B. In CH3CN-H2O (1:1 v/v) the equilibrium constants are K1 = 13 ± 2 L mol-1 and K2 = 136 ± 28 L mol-1 at pH 1.0 and 25C. The forward and reverse rate constants for the formation of A in this medium are k1 = 32.5 ± 0.3 L mol-1 s-1 and k-1 – 3.0 ± 0.2 s-1. Systematic changes in the substituents on phosphorus were made to vary the nucleophilicity of the phosphine and its cone angles; the kinetic effects are discernible, although they lie in a narrow range. Triphenylarsine and triphenylstibine were also studied, and their rates are within a factor of 2 of that for PPh3. The rhenium peroxides A and B show a small difference in reactivity. The bimolecular reactions between A and most of the phosphines have rate constants of the order 105 L mol-1 s-1. The kinetic data support a mechanism that allows nucleophilic attack of the substrate at the rhenium peroxides.
The reactant in an enzyme-catalyzed reaction is called a substrate. Enzyme inhibitors cause a decrease in the reaction rate of an enzyme-catalyzed reaction.I hope my blog about 1038-95-5 is helpful to your research., Application In Synthesis of Tri-p-tolylphosphine
Reference：
Phosphine ligand,
Chiral phosphine ligands in asymmetric synthesis. Molecular structure and absolute configuration of (1,5-cyclooctadiene)-(2S,3S)-2,3-bis(diphenylphosphino)butanerhodium(I) perchlorate tetrahydrofuran solvate