Conformational Analysis of 1,4-Heterophosphinanes

Abstract

Structure of 1,4-heterophosphinanes in solution was studied by the methods of dipole moments, Kerr effect, molecular mechanics, and density functional theory calculations. It was determined that chair conformation with an equatorial orientation of the exocyclic phenyl substituent is preferred for 1,4-heterophosphinanes independent of the second heteroatom in six-membered phosphorus heterocycle (oxygen, sulfur or silicon), and the coordination state of the phosphorus atom (σ³P or σ⁴P).

Keywords:

• Conformational analysis
• dipole moments
• heterophosphinanes
• quantum chemical calculations

Notes

^a The P = Se bond and the Ph ring are parallel; and

^b the P = Se bond and the Ph ring are perpendicular.