Hydrogen bond directed self-assembly of core-substituted naphthalene bisimides with melamines in solution and at the graphite interface

Abstract
A series of red and blue highly fluorescent core-substituted naphthalene bisimide dyes has been synthesized and they have been investigated as supramolecular building blocks. NMR and UV-Vis titration experiments of these dyes with complementary melamines revealed the formation of triple hydrogen bonds (DAD–ADA arrays) in solution. At stoichiometric ratios, ditopic melamine receptors could dissolve otherwise insoluble bisimides by means of hydrogen bonding, even in aliphatic solvents. At the solution/graphite interface, one-dimensional chains of hydrogen bonded naphthalene bisimides and two-dimensional adlayers of ditopic melamines are formed for the pure compounds but little evidence for heterocomplexes between the two complementary building blocks could be obtained.