Conformational Analysis of 2-Methoxy-2-oxo-1,3,2-dioxaphosphorinane and Its Methylthio and Methylselenyl Analogues

This research aimed at exploring the stabilities of the conformers of 2-methoxy-2-oxo-1,3,2-dioxaphosphorinane and its methylthio and methylselenyl analogs at the B3LYP/6-311+G( d,p ) theory level. To this goal, estimations of the total energies and dipole moments of the axial and equatorial conformations were first done for the mentioned molecules. Bond distances of P=O, P–E ax , and P–E eq bonds were calculated and these variations were explained with negative hyperconjugative anomeric effects. The partitioning of the total electronic energy E (tot) into Lewis E (L) and non-Lewis E (NL) parts was performed using the concept of natural bond orbital (NBO) analysis. Then, the Natural Coulomb Electrostatic (NCE) potential energies, total energies into Lewis components, and total steric exchange energies were estimated. Also, Gauge independent atomic orbital (GIAO) method was employed to study NMR parameters of these molecules followed by calculating the spin–spin coupling ( J ) of the bond distances of P=O, P–E ax , and P–E eq bonds.