Ditopic receptors capable of hydrogen bonding: Synthesis and complexation behaviour of diaza crown-ethers having melamine sidearms

The new ditopic receptors 1-3 (Figure 1) have been synthesized and their binding ability for alkaline and transition metal cations has ben investigated by halide and UV-Vis titrations. The recognition of complementary molecules through hydrogen bonding has been studied by H-1-NMR. The simultaneous recognition of these two guests is an anti-cooperative event.