Nitrogen Inversion in N-Phenylaziridines: A Hammett Study via MP2

Document Type : Research Article

Authors

1 Department of Chemistry, Shahrood Branch, Islamic Azad University, Shahrood, Iran

2 Department of Chemistry, Shahrood Branch, Islamic Azad University, Shahrood, I.R. IRAN

Abstract

Trivalent nitrogen compounds are almost tetrahedral so that the lone pair occupies one of the tetrahedral positions. This, in turn, causes the inversion of these tetrahedral molecules. In this study, N-inversion in N-phenylaziridines (without substituent and with a substituent group (F, Cl, Br, CN, NH2, NO2, OH, and Me) in both para and meta positions of the phenyl ring) was studiedby the Gaussian 09 program. The optimum geometric structures of initial and transition states were obtained using ab initio calculations at the MP2\6-31G* level of theory and in both the gas phase and CH2Cl2 solvent. The effects of the different substituent groups on kinetic parameters were studied and then Hammett curves were plottedthrough the Hammett equation. With respect to the obtained rate constants and Hammett curves, it can be concluded that the electron-withdrawing substituents increase the rate of inversion due to withdrawing of nitrogen lone pair towards themselves, and therefore, generating a stabilizing resonance current. Conversely, the electron-donating substituents decrease the rate of inversion. The transition state in an inversion of a  n-phenylaziridine molecule with para-substituted NO2 group has the lowest activation energy.

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References

[1] Walsh A.D., The Properties of Bonds Involving Carbon, Discussions of Faraday Soc., 2:18-25 (1947).
[2] Glasstine S., Laidler K.J., Eyring H., "The Theory of Rate Processes", McGraw Hill Book Co., New York (1941).
[3] Carey F.A., Sundberg R.J., "Advanced Organic Chemistry",Springer, New York (2007).
[4] Ager D., East M.B., "Asymmetric Synthetic Methodology", CRC Press, Boca Raton, Florida (1996).
[5] Atkinson R.S., "Stereoselective Synthesis", John Wiley & Sons, New York (1995).
[6] Kuprianowicz M., Kaźmierczak M., Wójtowicz-Rajchel H., The Nitrogen Inversion in Fused Isoxazolidinyl Derivatives of Substituted Uracil: Synthesis, NMR and Computational Analysis, Struct. Chem., 27(4): 1265-1278 (2016).
[7] Tanner D., Chiral Aziridines-Their Synthesis and Use in Stereoselective Transformations, Angew. Chem., Int. Ed. Engl., 33(6): 599-619 (1994).
[8] Dermer O.C., Ham G.E., "Ethylenimine and Other Aziridines", Academic Press, New York (1969).
[9] Townes C.H., Schawlow A.L., "Microwave Spectroscopy", Dover Publications, New York (2012).
[10] Herzberg G., "Infrared and Raman Spectra of Polyatomic Molecules", D. Van Nostrand Co., New York (1945).
[11] رشیدی رنجبر، پرویز؛ تاج خورشید، عمادالدین، موفقیت­های طراحی مولکول­ها با کمک کامپیوتر، نشریه شیمی و مهندسی شیمی ایران، (16)1: 86 تا 100 (1371).
[12] Wales D.J., Berry R.S., Melting and Freezing of Small Argon Clusters, J. Chem. Phys.,92(7): 4283-4295 (1990).
[13] Brot C., The Pre-Exponential Factor in Activated Reorientational Processes, Chem. Phys. Letters, 3(5): 319-322 (1969).
[14] Frisch M.J., Trucks G.W., Schlegel H.B., Scuseria G.E., Robb M.A., Cheeseman J.R., Scalmani G., Barone V., Mennucci B., Petersson G.A., Nakatsuji H., Caricato M., Li X., Hratchian H.P., Izmaylov A.F., Bloino J., Zheng G., Sonnenberg J.L., Hada M., Ehara M., Toyota K., Fukuda R., Hasegawa J., Ishida M., Nakajima T., Honda Y., Kitao O., Nakai H., Vreven T., Montgomery, Jr. J.A., Peralta J.E., Ogliaro F., Bearpark M., Heyd J.J., Brothers E., Kudin K.N., Staroverov V.N., Kobayashi R., Normand J., Raghavachari K., Rendell A., Burant J.C., Iyengar S.S., Tomasi J., Cossi M., Rega N., Millam J.M., Klene M., Knox J.E., Cross J.B., Bakken V., Adamo C., Jaramillo J., Gomperts R., Stratmann R.E., Yazyev O., Austin A.J., Cammi R., Pomelli C., Ochterski J.W., Martin R.L., Morokuma K., Zakrzewski V.G., Voth G.A., Salvador P., Dannenberg J.J., Dapprich S., Daniels A.D., Farkas O., Foresman J.B., Ortiz J.V., Cioslowski J., Fox D.J., "Gaussian 09 Revision-A.02 SMP", Gaussian Inc., Wallingford CT (2009).
[15] Foresman J.B., Frisch Æ., "Exploring Chemistry with Electronic Structure Methods", Gaussian Inc., Wallingford CT (2015).
[16] Pilling M.J., Seakins P.W., "Reaction Kinetics", Oxford University Press, Oxford (1995).
[17] Andose J.D., Lehn J.M., Mislow K., Wagner J., Effect of Substituents on the Rate of Pyramidal Inversion of 1-aryl-2,2-Dimethylaziridines, J. Am. Chem. Soc., 92(13): 4050-4056 (1970).
[18] Hammett L.P., "Physical Organic Chemistry: Reaction Rates, Equilibria, and Mechanisms",McGraw-Hill, New York (1970).
[19] Hansch Corwin., Leo A., Taft R.W., A Survey of Hammett Substituent Constants and Resonance and Field Parameters, Chem. Rev., 91(2): 165-195 (1991).

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