On the question of the molecular mechanism of N-nitropyrazole rearrangement

A New Insight into the Molecular Mechanism of the Reaction between 2-Methoxyfuran and Ethyl (Z)-3-phenyl-2-nitroprop-2-enoate: An Molecular Electron Density Theory (MEDT) Computational Study

The molecular mechanism of the reaction between 2-methoxyfuran and ethyl (Z)-3-phenyl-2-nitroprop-2-enoate was investigated using wb97xd/6-311+G(d,p)(PCM) quantum chemical calculations. It was found that the most probable reaction mechanism is fundamentally different from what was previously postulated. In particular, six possible zwitterionic intermediates were detected on the reaction pathway. Their formation is determined by the nature of local nucleophile/electrophile interactions. Additionally, the channel involving the formation of the exo-nitro Diels-Alder cycloadduct was completely ruled out. Finally, the electronic nature of the five- and six-membered nitronates as potential TACs was evaluated.

Carbon fixation of CO2 via cyclic reactions with borane in gaseous atmosphere leading to formic acid (and metaboric acid); A potential energy surface (PES) study

Carbon dioxide (CO₂), a stable gaseous species, occupies the troposphere layer of the atmosphere. Following it, the environment gets warmer, and the ecosystem changes as a consequence of disrupting the natural order of our life. Due to this, in the present reasearch, the possibility of carbon fixation of CO₂ by using borane was investigated. To conduct this, each of the probable reaction channels between borane and CO₂ was investigated to find the fate of this species. The results indicate that among all the channels, the least energetic path for the reaction is reactant complex (RC) to TS (A-1) to Int (A-1) to TS (A-D) to formic acid (and further meta boric acid production from the transformation of boric acid). It shows that use of gaseous borane might lead to controlling these dangerous greenhouse gases which are threatening the present form of life on Earth, our beautiful, fragile home.

Understanding the molecular mechanism of γ-elimination of nitrous acid in the framework of the molecular electron density theory

The reactions of γ-dehydronitration of furaxanenitrolic acids have been studied within the density functional theory using molecular electron density theory scheme at the MPWB1K(PCM)/6-311G(d,p) level of theory. The alteration of bonding along the course of the reaction is studied in the topology of the electron density functional within the bonding evolution theory perspective. The characteristics of electron density changes indicate that we can distinguish six different phases in the nitrous acid extrusion from furaxanenitrolic acid 1a. These different phases related to the intrinsic reaction coordinate path of the analyzed reaction denote the non-concerted nature of the molecular mechanism.