Title of article :
A Theoretical Study on Applying Conformational Analysis of 2-Halo-2-Oxo-1,3,2-Dioxaphosphorinanes
Author/Authors :
Azarakhshi, Fatemeh Department of Chemistry - Varamin-Pishva Branch, Islamic Azad University, Varamin , Farhadyar, Nazanin Department of Chemistry - Varamin-Pishva Branch, Islamic Azad University, Varamin , Khaleghian, Mehrnoosh Department of Chemistry - Islamshahr Branch, Islamic Azad University, Islamshahr
Abstract :
The quantum-chemical calculations on the conformational properties of 2-flouro-2-oxo1,3,2-dioxaphosphorinane (1), 2-choloro-2-oxo-1,3,2-dioxaphosphorinane (2) and 2-bromo2-oxo-1,3,2 dioxaphosphorinane (3) have been investigated by means of ab initio molecular orbital (HF/6-311+G**) and hybrid density functional theory (B3LYP/6-311+G**) based methods and Natural Bond Orbital (NBO) interpretation in solid state was performed. Geometrical analysis supports clearly the participation of hyperconjugative endo-anomeric (LPO→σ*P-X) effect in the stabilization of axial series of compounds and the participation of exo-anomeric (LPX→σ*P-O) effect in the stabilization of the equatorial phosphinanes in chair conformations. The stereoelectronic effects associated with bonding-anticoding delocalization electron are more significant for the explanation of the conformational behavior of compounds 1-3 than the dipole-dipole interaction effects.
Keywords :
Ab initio , Dioxaphosphorinanes , Natural Bond Orbital , Density Functional Theory , Generalized Anomeric Effects , Stereoelectronic effects
