COOPERATIVE HYDROGEN-BONDING OF ATRAZINE

Formation constants are determined for hydrogen-bond complexes between atrazine and compounds commonly found in soil organic matter. Weak to moderately strong complexes (K(f) = 2-30 L/mol) are formed with amine, hydroxyl, and carbonyl functional groups. Strong complexation is observed with the carboxylic acid (K(f) = 212 L/mol) and amide (K(f) = 276 L/mol) functional groups, which interact cooperatively with atrazine by simultaneously donating and accepting a hydrogen bond. These results confirm that hydrogen bonding provides a mechanism for atrazine adsorption to soil surfaces and identifies functional groups that have high affinity for atrazine.