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, Recommanded Product: 1038-95-5
The oxygen atom transfer (OAT) reactivity of two valence tautomers of a MnV(O) porphyrinoid complex was compared. The OAT kinetics of MnV(O)(TBP8Cz) (TBP8Cz = octakis(p-tert-butylphenyl)corrolazinato3-) reacting with a series of triarylphosphine (PAr3) substrates were monitored by stopped-flow UV-vis spectroscopy, and revealed second-order rate constants ranging from 16(1) to 1.43(6) × 104 M-1 s-1. Characterization of the OAT transition state analogues MnIII(OPPh3)(TBP8Cz) and MnIII(OP(o-tolyl)3)(TBP8Cz) was carried out by single-crystal X-ray diffraction (XRD). A valence tautomer of the closed-shell MnV(O)(TBP8Cz) can be stabilized by the addition of Lewis and Bronsted acids, resulting in the open-shell MnIV(O)(TBP8Cz?+):LA (LA = ZnII, B(C6F5)3, H+) complexes. These MnIV(O)(pi-radical-cation) derivatives exhibit dramatically inhibited rates of OAT with the PAr3 substrates (k = 8.5(2) × 10-3 – 8.7 M-1 s-1), contrasting the previously observed rate increase of H-atom transfer (HAT) for MnIV(O)(TBP8Cz?+):LA with phenols. A Hammett analysis showed that the OAT reactivity for MnIV(O)(TBP8Cz?+):LA is influenced by the Lewis acid strength. Spectral redox titration of MnIV(O)(TBP8Cz?+):ZnII gives Ered = 0.69 V vs SCE, which is nearly +700 mV above its valence tautomer MnV(O)(TBP8Cz) (Ered = -0.05 V). These data suggest that the two-electron electrophilicity of the Mn(O) valence tautomers dominate OAT reactivity and do not follow the trend in one-electron redox potentials, which appear to dominate HAT reactivity. This study provides new fundamental insights regarding the relative OAT and HAT reactivity of valence tautomers such as MV(O)(porph) versus MIV(O)(porph?+) (M = Mn or Fe) found in heme enzymes. (Figure Presented).
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., Recommanded Product: 1038-95-5
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