Recognition of dicarboxylic acid by 6,6′-dipivaloylamino-3,3′-bipyridine and the supramolecular solid state locking of the carboxyls in the anti form

A new crystal-engineering motif has been developed where a ditopic receptor 1 having anti binding hindered pyridine pivaloylamide groups instead of normally used acetylamino groups shows a novel anti-anti hydrogen bonded polymeric supramolecular complex giving rise to hydrogen bonded stair like polymeric ribbon structure between the receptor pyridine amides and the carboxyl groups of the guest substrate (1,4-phenylenediacetic acid).