STRUCTURE AND INVERSION BARRIER OF PHOSPHIRENE AND 1,2-DIHYDROPHOSPHETE - AN ABINITIO STUDY

The geometry of 1H-phosphirene (1), 2H-phosphirene (2), and 1,2-dihydrophosphete (3) were optimized at HF/6-31G*, and single-point calculations at MP2 were performed. The transition structure for inversion at P of 1 and 3 were also optimized (1pl and 3pl). The inversion barrier of 1 and 3 is 92.65 kcal mol-1 and 46.62 kcal mol-1, respectively. 1 is not antiaromatic based on the highly pyramidal P atom and no energetic destabilization. Analysis of the electron density distribution and comparison with the inversion barriers of N analogues indicate that the antiaromatic contribution in 1pl is small.