Organophophazenes 28: the Nature of the Exocyclic Phosphorus–Carbon Bond in Organophosphazenes

GRAPHICAL ABSTRACT

Abstract

The electronic effects operative in a series of cyclophosphazenes with organic substituents N₃P₃F₅R (R = ethynyl, vinyl, allyl, ethyl, styrenyl) were explored using ab initio and density functional calculations followed by natural bond order (NBO) analyses. The effects of organic group on the phosphazene ring and that of phosphazene on the organic center were examined using NBO charges, atomic orbital coefficients, Wiberg bond orders, and orbital populations. The electronic effect of the P₃N₃F₅ moiety on an unsaturated carbon center is best described as electron donating from phosphorus to carbon through a polarized σ bond and strong electrostatic polarization of the organic π system toward the C1 carbon atom.

Keywords:

• Organocyclophosphazenes
• MO calculations
• phosphorus–carbon bond