Nghiên cứu lý thuyết phản ứng tách hiđro giữa gốc metyl với một số anđehit
Author affiliations
DOI:
https://doi.org/10.15625/2525-2321.2017-00467Keywords:
Reaction abstraction, ankanal, methyl radical, Density Functional Theory, B3LYP, PESAbstract
Hydrogen abstraction reactions between the methyl radical and some aldehydes (CnH2n+1CHO, n = 0÷3) have been studied by the Density Functional Theory (DFT) using the B3LYP functional combined with the 6-311++G(d,p) and 6-311+G(3df,2p) basis sets. We have identified pathways of forming the methane and aldehyde’s radicals. Our results show that the energy barrier of these pathways ranges from 20.1 to 53.1 kJ/mol. Values of the barrier height and local softness also indicate that the methyl radical reacts easily with hydrogen atoms closed to the functional group position for any andehyde's isomers.
Keywords. Reaction abstraction, ankanal (RCHO), methyl radical (CH3), Density Functional Theory, B3LYP, PES.Downloads
References
Ahren W. Jasper, Stephen J. Klippenstein, Lawrence B. Harding, and Branko Ruscic. Kinetics of the Reaction of Methyl Radical with Hydroxyl Radical and Methanol Decomposition, J. Phys. Chem. A, 111, 3932-3950 (2007).
Gernot Friedrichs, Elke Goos, Joachim Gripp, Hauke Nicken, Jan-Boyke Schönborn , Henrik Vogel , and Friedrich Temps, Kinetics and thermochemistry of the reactions of alkyl radicals (methyl, ethyl, isopropyl, sec-butyl, tert-butyl) with hydrogen iodide: a reconciliation of the alkyl radical heats of formation, J. Am. Chem. Soc., 112(4), 1347-1353 (1990).
Paul G. Wenthold, Robert R. Squires, and W. C. Lineberger, Kinetics of acetyl radical formation from methyl radicals and carbon monoxide and crystal structures of two acetylcobalt complexes, J. Am.
Chem. Soc, 120, 5279-5290 (1998).
S. Zabarnick, J. W. Fleming and M. C. Lin. Kinetics of CH(X 2Π) radical reactions with cyclopropane, cyclopentane, and cyclohexane, Twenty-first Symposium (International) on Combustion/The Combustion Institute, 713-719 (1986).
Nguyễn Hữu Thọ, Nguyễn Thị Minh Huệ, Nghiên cứu lí thuyết cơ chế phản ứng của gốc CH với cis- và trans-HCHO, Tạp chí Hóa học, 49(4), 426-431 (2011).
Mangum J. G., Darling J., Menten K. M., Christian H. Formaldehyde Densitometry of Starburst Galaxies, J. Astrophys., 673(2), 832-846 (2008).
M. J. Frisch, G. W. Trucks, H. B. Schlegel, …, J. A. Pople; Gaussian, Inc., Pittsburgh PA, (2003).
Joseph W. Ocherski, PhD. Thermochemistry in Gaussian. http://www.gaussian.com.
Hue Minh Thi Nguyen, Jozef Peeters, and Minh Tho Nguyen. Use of DFT-Based Reactivity Descriptors for Rationalizing Radical Reactions: A Critical Analysis, J. Phys. Chem. A, 108, 484-489 (2004).
Yang W., Parr R. G. Hardness, softness, and the fukui function in the electronic theory of metals and catalysis, Proc. Nati. Acad. Sci. USA, 82, 6723-6726 (1985).
Chase M. W., Jr. NIST-JANAF Themochemical Tables, Fourth Edition, J. Phys. Chem. Ref. Data, Monograph 9, 1998, 1-1951.
Wiberg K. B., Crocker L. S., Morgan K. M. Thermochemical studies of carbonyl compounds. 5. Enthalpies of reduction of carbonyl groups, J. Am. Chem. Soc., 113, 3447-3450 (1991).
Tsang W. Heats of Formation of Organic Free Radicals by Kinetic Methods in Energetics of Organic Free Radicals, Martinho Simoes, J. A., Greenberg, A.; Liebman, J. F., eds., Blackie Academic and Professional, London, 22-58 (1996).