Contribution to Reactivity, Stability and Selectivity of Monodentated Free Phosphines

Abstract

Phosphines having a high degree of instability in their syntheses, it is necessary to find conditions for obtaining stable products in order to propose new stable and active compounds. It is this concern that responds to the theoretical study of stability and selectivity. This theoretical study of chemical reactivity was carried out using the Density Functional Theory (DFT) method, at the B3LYP/6-31G (p) calculation level. The use of the Frontier Molecular Orbital (FMO) theory, with the Single Orbital Molecular Orbital (SOMO) cation model, made it possible to study the stability of some isomers formed during the addition of free phosphines to the carbon-carbon triple bond. The analysis of these reactivity quantities allowed us to conclude that the presence of halogens on acetylene influences the stability of the stereoisomers during their formation. This stability increases as the electronegativity of the halogen decreases. The large number of π conjugation favors the formation of Cis isomers and the lack or small amount of π conjugation orients the formation of Trans isomers. The nature of the aryl substituent and the number of low electronegativity halogen on the phosphine are capable of promoting the production of stable products.