Nitrilohexaphosphonitrilic Chloride: A Chemical and Spectroscopic Study

Abstract

The preparation of nitrilohexaphosphonitrilic chloride N7P6Cl9 is described; its infrared, Raman, mass and nuclear magnetic resonance spectra indicate a tricyclic condensed ring structure of C3ν symmetry. The molecule decomposes on attempted substitution of the chlorine atoms by fluorine and by methoxy-groups, but with dimethylamine both addition and substitution take place. One central bond is broken, and a bridged ring imide N6P6(NH)(NMe2)8Cl2 is formed, in which the ring structure is sufficiently rigid for axial and equatorial groups to be distinguished. The detailed molecular structure of N7P6Cl9 shows evidence of a compromise between the requirements for optimum σ- and π-bonding, the central N—P bonds being strained. Its substitution behavior, base strength, ultraviolet spectrum, mass spectrum, and molecular geometry are interpreted in these terms.