An AAA-DDD Triply Hydrogen-Bonded Complex Easily Accessible for Supramolecular Polymers

For a complementary hydrogen-bonded complex, when every hydrogen-bond acceptor is on one side and every hydrogen-bond donor is on the other, all secondary interactions are attractive and the complex is highly stable. AAA-DDD (A=acceptor, D=donor) is considered to be the most stable among triply hydrogen-bonded sequences. The easily synthesized and further derivatized AAA-DDD system is very desirable for hydrogen-bonded functional materials. In this case, AAA and DDD, starting from 4-methoxybenzal-dehyde, were synthesized with the Hantzsch pyridine synthesis and Friedlander annulation reaction. The association constant determined by fluorescence titration in chloroform at room temperature is 2.09 x 10(7)m(-1). The AAA and DDD components are not coplanar, but form a V shape in the solid state. Supramolecular polymers based on AAA-DDD triply hydrogen bonded have also been developed. This work may make AAA-DDD triply hydrogen-bonded sequences easily accessible for stimuli-responsive materials.