Sánchez-Velandia Julián E, Becerra Jaime-Andrés, Mejía Sol M, Villa Aída L, Martínez O Fernando
Engineering Faculty, Chemical Engineering Department, Environmental Catalysis Research Group, Universidad de Antioquia UdeA, Calle 70 No. 52-21, 1226 Medellín, Colombia.
Facultad de Ciencias, Departamento de Química, Grupo de Investigación Fitoquímica Universidad Javeriana (GIFUJ)-Línea de investigación en Química Computacional, Pontificia Universidad Javeriana, 11001000 Bogotá, Colombia.
ACS Omega. 2021 Dec 9;6(50):34206-34218. doi: 10.1021/acsomega.1c03049. eCollection 2021 Dec 21.
In this contribution, the thermodynamic analysis of α- and β-pinene epoxide isomerization over Fe and Cu supported on MCM-41 is presented using computational chemistry and group contribution methods (GCMs). Some physical-chemical data ( , , , , ω, , ) and thermodynamic (°, , , Δ , Δ , Δ , Δ , ) properties obtained by different GCMs are reported for several monoterpenes and monoterpenoids, which significantly contribute to the knowledge of the properties of these compounds. Density functional theory (DFT), PBE-D3/6-311G(d,p), was employed for determining the Gibbs free energy and the heat of reaction associated with the transformation of monoterpene epoxides into aldehydes, ketones, and related oxygenated compounds in the presence of different solvents and at several temperatures. The calculations were compared with available data reported and the experimental results of the catalytic reactions. The transformation of α- and β-pinene epoxides into aldehydes appears to be more spontaneous and favorable than their transformations into alcohols in a wide range of temperatures. These results are in agreement with the experiments over Fe/MCM-41 and Cu/MCM-41, where α-pinene epoxide isomerization yields campholenic aldehyde (50-80% selectivity) as the main product. The 1.7Fe/MCM-41 material was more active in all solvents than 1.3Cu/MCM-41 for both α- and β-pinene epoxide isomerization. However, perillyl alcohol (20-70% selectivity) was the most favored for the isomerization reaction, except when ethyl acetate was the solvent. Enthalpy and Gibbs free energy of the studied reactions estimated by both GCMs and DFT calculations did not show large differences for most of the reactions at evaluated temperatures.
在本论文中，采用计算化学和基团贡献法（GCMs）对负载于MCM - 41上的铁和铜催化α-蒎烯环氧化物和β-蒎烯环氧化物异构化反应进行了热力学分析。报道了通过不同基团贡献法获得的几种单萜和单萜类化合物的一些物理化学数据（ 、 、 、 、ω、 、 ）以及热力学性质（°、 、 、Δ 、Δ 、Δ 、Δ 、 ），这些数据对了解这些化合物的性质有重要意义。采用密度泛函理论（DFT），即PBE - D3/6 - 311G(d,p)，来确定在不同溶剂和多个温度下，单萜环氧化物转化为醛、酮及相关含氧化合物的吉布斯自由能和反应热。将计算结果与已报道的现有数据以及催化反应的实验结果进行了比较。在较宽的温度范围内，α-蒎烯环氧化物和β-蒎烯环氧化物转化为醛的反应似乎比转化为醇的反应更自发且更有利。这些结果与在Fe/MCM - 41和Cu/MCM - 41上进行的实验结果一致，在这些实验中，α-蒎烯环氧化物异构化反应以樟脑醛（选择性为50 - 80%）作为主要产物。对于α-蒎烯环氧化物和β-蒎烯环氧化物异构化反应，在所有溶剂中，1.7Fe/MCM - 41材料都比1.3Cu/MCM - 41更具活性。然而，除了以乙酸乙酯为溶剂时，紫苏醇（选择性为20 - 70%）是异构化反应中最有利的产物。通过基团贡献法和DFT计算估计的所研究反应的焓和吉布斯自由能在评估温度下的大多数反应中差异不大。
