Phosphonitrilic derivatives. Part XVI. Triphosphonitrilic and tetraphosphonitrilic fluoride chlorides

Abstract

Two series of phosphonitrilic fluoride chlorides, N₃P₃F_nCl_{6 –n}(n= 1–5) and N₄P₄F_nCl_{8 –n}(n= 1–7), have been prepared by improved methods, and their physical properties determined. In the reaction of the corresponding chlorides with anionic fluorinating agents, geminal substitution occurs as far as possible, and, where alternative routes are open, the second phosphorus atom to be attacked is that nearest to the first. The orientation pattern is explicable in terms of simple electrostatic effects, but qualitative observations on the relative rates of successive fluorination steps suggest that π-inductive effects, involving chiefly a homomorphic π-system, are also important.