Theoretical investigation of Curtius rearrangement of oxalyl di azide molecule using quantum calculations in gas phase and solution

Document Type : Original Article

Authors

• Roghaye Taheryan ¹
• Ehsan Zahedi ²

¹ PhD Student

² Associate Proffesor

Abstract

In this study, was investigated the Curtius rearrangement reaction of the molecule oxalyl diazide (ODA) for syn-syn and anti-anti-conformers in the gas and solvent phases ( water and cyclohexane ). the syn-syn and anti-anti-ODA conformers and transition states related to their rearrangement reactions are optimized in the gas phase using by Density functional theory (DFT) at computational levels WB97XD, M06-2X, B3LYP and the basis sets 6-311 ++ G (2d, d, p) and the CBS-QB3 method .in the solvent phase, calculations have been performed at the level of B3LYP / 6-311 ++ G (2d, d, p).the syn-syn conformer through a concerted mechanism and anti-anti-conformer using a stepwise mechanism product Carbonyl di isosyanate (CAI) , respectively by passing 1 and 2 transition states under curtius rearrangement.in the concerted mechanism the Gibbs free activation energy of the path went is less than the return path of the reaction, in other words, the Gibbs free activation energy of the return path is about 4 times the path went reaction.in the step wise mechanism, the first stage is the endothermic and the second stage is the exothermic process.

Keywords

• Cortius rearrangement
• Transition state
• Oxalyl diazide
• Molecular mechanism
• Density functional theory

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