The relationship of gas phase proton affinity (PA) of aliphatic amines, alcohols and ethers, inductive effect index ( I) of alkyl group, atomic charge ( qx), electronegativity of element ( X-N) of affinity atom in RX molecules was studied. The results indicate that PA of aliphatic amines, alcohols and ethers can be quantitatively described as follow:q PA (kJ·mor~-1) =2732.0333-2457. 1510∑I- 1492.2351 q -x-732.6277 Z-N On the basis of this corelation, the gas phase basicities of 64 aliphatic amines, alcohols and ethers are predicted with average relative error ≤0.34% .

Key words: ALIPHATIC AMINES, ALCOHOL, ETHER, ELECTRONEGATIVITY, INDUCTIVE EFFECT