A Multiple Hydrogen-Bond Scaffold Based on Dipyrimidin-2-ylamine

A multiple hydrogen-bond array based on dipyrimidin-2-ylamine is presented, which is easily accessible. The influence of a preorganizing intramolecular hydrogen bond, tautomeric equilibria, and steric effects on the association behavior were investigated. X-ray diffraction shows that the molecules feature an ADA (acceptor−donor−acceptor) array of hydrogen-bonding sites in the solid state. The array persists in solution, and ¹H NMR titrations show that molecules with sterically nondemanding DAD arrays are selectively bound.