Abstract:
New results are presented on the multicomponent supramolecular synthesis of pseudo[1]rotaxanes, achieved by designing pairs of structurally matching N-monoalkyl-4,4\'-bipyridinium/2,7-diazapyrenium-based ligands having complementary π-donor/acceptor features, and intended to self-assemble into the targeted supramolecules by following integrative self-sorting processes. In all the studied cases, it was found that the envisioned species, characterized by NMR spectroscopy and MS spectrometry, arise as the main products of the self-assembly in aqueous media by using palladium(II)/platinum(II) metal centers as the guiding force. Crucially, we have also found that by improving the π-donor/acceptor properties of the matching pairs of ligands (L4 and L5 ), the integrative self-sorting processes prevail even in the absence of metallic ions to afford the heterodimeric species with an association constant being 756±43 M-1 .