INTERACTIONS BETWEEN ACYCLIC AND CYCLIC PERALKYLAMMONIUM COMPOUNDS AND DNA .33.

Increments of 5 +/- 1 kJ mol-1 per salt bridge satisfactorily yield the energy of ionic interactions between polyamines and calf thymus DNA. This value lies in the same range as those of numerous inorganic and organic ion pairs. Peralkylated polyamines have almost the same affinity for DNA as protonated polyamines; hydrogen bonds thus have little effect on the binding. Relatively rigid azoniacyclophanes sometimes have a higher affinity although the arene units are not intercalated.