Structure and basicity. Part VI. Miscellaneous derivatives of hexachlorocyclotriphosphazatriene with mixed substituents including dimethylamino-, methoxy-, phenoxy-, phenyl-, thioethoxy-, and thiophenoxy-groups: calculation of substituent constants

Abstract

The basicities of a number of derivatives of hexachlorocyclotriphosphazatriene with mixed substituents are reported and discussed. The substituents include p-chlorophenyl-, dimethylamino-, methoxy-, phenoxy-, phenyl-, thioethoxy-, thiophenoxy-, tolyl-, and 2,2,2-trifluoroethoxy-groups. In many cases, structures previously assigned on the basis of other evidence are confirmed by the basicity data. Substituent constants for these groups are calculated, and important differences from the monosubstituted pyridines are found. In particular the values of the substituent constants support the proposition, made earlier in the Series, that the effects of multiple-bonding on basicity are markedly attenuated for a substituent γ to a given cyclic nitrogen atom. An Appendix gives a detailed discussion of the relationship between the basicities of geminal and non-geminal isomers of general formula N₃P₃B₄A₂ and extends the treatment briefly to the corresponding isomers of N₃P₃B₃A₃.