Molecular complexes of anilines with DDQ

Abstract

Molecular complexes of DDQ with anilines have been studied spectrophotometrically by stabilising the complexes in a low polar solvent (CCl₄), at low temperatures and under low donor concentrations. All the complexes exhibit well resolved charge transfer bands in the visible region where neither of the components has any absorption. The stoichiometry of each of the complex is found to be 1:1 and is unaffected by the variation of temperature. A

linear relationship is observed between the <i>v</i>_CT of DDQ- anilines and the <i>v</i>_CT of TCNE-anilines indicating <i>a </i>π<i>-</i>π<i> </i>interaction between the DDQ and the donors. The stabilities and thermodynamic parameters have been determined from the absorption studies on the CT bands. A linear relationship has been observed between logarithmic functions of stability constants and Hammett σ<i> </i>constants. Both ring and N-substituents affect the position of CT band and 0 the stabilities of the complexes.