TY - JOUR

T1 - Oxidation of PPh3 by oxygen catalyzed by biomimetic tungsten complex: oxo-transfer process thermodynamics

AU - Симонова, Виктория Михайловна

AU - Пестова, Ольга Николаевна

AU - Ануфриков, Юрий Алексеевич

AU - Espósito, Breno

AU - Хрипун, Василий Дмитриевич

PY - 2024/4/12

Y1 - 2024/4/12

N2 - The thermal effect of a model oxo-transfer reaction with the participation of a tungsten-containing synthetic analog of the enzyme active site, [WO2(mnt)2]2− (mnt = maleonitriledithiolate), has been determined for the first time. The value of the thermal effect indicates that the driving force of the oxo-transfer is the enthalpy factor. To determine the thermal effect of oxo-transfer, the dissolution enthalpies of the reaction participants in acetonitrile were determined: ΔHsol0PPh3=24.9±0.8 kJ mol−1, ΔHsol0OPPh3=18.9±0.6 kJ mol−1, and ΔHsol0([Bu4N]2[WO2(mnt)2]) = (70.8 ± 1.9) kJ mol−1. In this study, the thermal effect of the transfer process of an oxygen atom from the tungsten complex [WO2(mnt)2]2− to the PPh3 substrate was determined at different ratios of reagents: ΔrH0 = (− 109 ± 4) kJ mol−1. The catalytic cycle of PPh3 oxidation with oxygen in the presence of [WO2(mnt)2]2− in acetonitrile solution was described calorimetrically. The absence of the reduced form of tungsten in the solution after the oxo-transfer reaction was shown spectroscopically, which confirms the role of the tungsten complex in the PPh3 oxidation as the catalyst.

AB - The thermal effect of a model oxo-transfer reaction with the participation of a tungsten-containing synthetic analog of the enzyme active site, [WO2(mnt)2]2− (mnt = maleonitriledithiolate), has been determined for the first time. The value of the thermal effect indicates that the driving force of the oxo-transfer is the enthalpy factor. To determine the thermal effect of oxo-transfer, the dissolution enthalpies of the reaction participants in acetonitrile were determined: ΔHsol0PPh3=24.9±0.8 kJ mol−1, ΔHsol0OPPh3=18.9±0.6 kJ mol−1, and ΔHsol0([Bu4N]2[WO2(mnt)2]) = (70.8 ± 1.9) kJ mol−1. In this study, the thermal effect of the transfer process of an oxygen atom from the tungsten complex [WO2(mnt)2]2− to the PPh3 substrate was determined at different ratios of reagents: ΔrH0 = (− 109 ± 4) kJ mol−1. The catalytic cycle of PPh3 oxidation with oxygen in the presence of [WO2(mnt)2]2− in acetonitrile solution was described calorimetrically. The absence of the reduced form of tungsten in the solution after the oxo-transfer reaction was shown spectroscopically, which confirms the role of the tungsten complex in the PPh3 oxidation as the catalyst.

KW - Calorimetry

KW - Catalytic cycle

KW - Dithiolene ligands

KW - Oxo-transfer

KW - Thermodynamic approach

KW - Tungsten and molybdenum enzymes

UR - https://www.mendeley.com/catalogue/4e8aeef8-333f-30c3-b382-716356bd4829/

U2 - 10.1007/s10973-024-13065-z

DO - 10.1007/s10973-024-13065-z

M3 - Article

VL - 149

SP - 4771

EP - 4781

JO - Journal of Thermal Analysis and Calorimetry

JF - Journal of Thermal Analysis and Calorimetry

SN - 1388-6150

IS - 10

ER -