Insights into the reaction mechanism between propadienylidene and ethylene: a DFT study

Abstract

The reaction mechanism between propadienylidene and ethylene has been systematically investigated employing the B3LYP/6-311??G** and MP2/cc-pVTZ levels of theory to better understand the reactivity of propadienylidene with unsaturated hydrocarbons. Geometry optimization, vibrational analysis, and energy property for the involved stationary points on the potential energy surface have been calculated. Two important initial reaction complexes characterized by three-and four-membered ring structures have been located firstly. After that, three different products possessing three-, four-, and five-membered ring characters have been obtained through three reaction pathways. In the first reaction pathway, a threemembered ring alkyne compound has been obtained. As for the second reaction pathway, it is a diffusion-controlled reaction, resulting in the formation of the four-membered ring conjugated diene compound. A five-membered conjugated diene compound has been obtained in the third reaction pathway, which is the most stable product in the available products thermodynamically. On the other hand, the second reaction pathway is the most favorable reaction to proceed kinetically.

A Theoretical Study on the Mechanism of the Addition Reaction Between Cyclopropenylidene and Ethylene

“…In consideration of the high reactivity and the importance of addition reaction involving C 3 H 2 carbenes, we have explored the reaction between propadienylidene and alkene using theoretical calculations 40 . However, less is known about the reaction mechanism between cyclopropenylidene and unsaturated hydrocarbon compound to the best of our konwledge.…”