Iminophosphorane-substituted proton sponges. Part 1. X-ray molecular structures of 1,8-diaminonaphthalene and 1-amino-8-triphenylphosphoranylideneaminonaphthalene

Abstract

The molecular structures of 1,8-diaminonaphthalene (1) and 1-amino-8-triphenylphosphoranylideneaminonaphthalene·0.5 C₆H₆(2) have been solved by X-ray crystallography. The benzene guest molecule is discussed in relation to the host matrix hole in which it is included. The molecular structure of compound 1 has been compared with the results of a theoretical analysis at the AM1 level. The complete potential-energy surface, as a function of the conformation of both NH₂ groups (ϕ₁, ϕ₂), has also been calculated. The absolute minimum (ϕ₁=ϕ₂= 47.0°) is very close to the experimental geometries of the two independent molecules of compound 1.