BASICITY OF PRIMARY AMINES - A GROUP PROPERTIES BASED STUDY OF THE IMPORTANCE OF INDUCTIVE (ELECTRONEGATIVITY AND SOFTNESS) AND RESONANCE EFFECTS

The group properties of substituents are invoked to explain the gas ph ase proton affinity of a variety of primary amines XNH(2). A triple co rrelation using the group electronegativity, group softness and a reso nance parameter of the substituent was successful for interpreting the proton affinity sequence. The group electronegativity and resonance p arameter were found to be important in determining this sequence, the group softness being of minor importance. Density functional theory ba sed as well as more traditional quantum chemical properties in the nei ghbourhood of the nitrogen atom were found to be inadequate for our pu rpose.