APPARENT DONOR-ACCEPTOR INTERACTION BETWEEN NITROAROMATICS AND ACETONITRILE

The partitioning behavior of nitro-aromatics in octanol-water and acetonitrile/NaCl-saturated water was examined. The nitro group contribution is opposite in the two systems, from which two different bonding mechanisms were inferred. In addition to cavity effects the octanol-water system is characterized by H-bonding of water to the nitro groups, while in the acetonitrile/NaCl-saturated water system electron donor-acceptor complexation predominates. A linear free energy relationship which relates the partition coefficients in the two systems was log P(aw) = 0.727 log P(ow) + 0.395 n + 0.742 where n is the number of nitro groups per ring.