Conformational changes by ring puckering and inversion in 1,3,2-dioxaphospholene

Abstract

The optimized geometric parameters for 1,3,2-dioxaphospholene, OCHCHOPH were determined using the standard 6–31G∗ basis set. The OCCO portion of the ring is essentially coplanar, with the P atom.at a ring puckering angle of 21°. The PH bond is in the endo conformation and is roughly perpendicular to the OCCO plane. The corresponding exo conformation was found not to be a stable minimum. Energy contours were followed along coordinates for ring puckering, a symmetric inversion path around the phosphorus atom, an asymmetric inversion route in which the PH bond follows a path which can be described as a wagging as well as the inversion motion, and a two-dimensional combination of these motions.