Studies on nitroaromatic compounds. Part I. Nuclear magnetic resonance investigation of complexes of benzene with trinitrotoluenes

Abstract

The formation of complexes of benzene with the six isomeric trinitrotoluenes has been studied by n.m.r. spectroscopy. Chemical-shift data have shown that the relative positioning of the components within the complexes depends upon the placement of substituents in the trinitrotoluenes. Where possible, association constants (K_c) for complex formation have been evaluated from chemical-shift measurements on nonequivalent protons, and it has been found that for a particular acceptor the values of K_c so obtained are the same within experimental error. The relative stabilities of the complexes are discussed in terms of steric effects and Lewis acidities of the trinitrotoluenes.