2-Aminopyrimidine Derivatives Exhibiting Anion-π Interactions: A Combined Crystallographic and Theoretical Study

In this manuscript, we report the synthesis and the solid-state characterization of five new Compounds based on the 2-aminopyrimidine building block. Some of them exhibit interesting anion-pi interactions. In addition, we report a high level ab initio study of anion-pi interactions involving 2-methylaminopyrimidine and its dimer. We demonstrate that these compounds are able to interact favorably with anions. The dimer of 2-methylaminopyrimidine interacts with the anion more strongly than the monomer due to cooperativity effects between the noncovalent hydrogen bonding and anion-pi interactions. This pattern, that is, coexistence of hydrogen bonding and anion-pi bonding, is observed experimentally in the solid state.