Postsynthetic modification of a coordination compound with a paddlewheel motif via click reaction: DOSY and ESR studies

Postsynthetic strategy based on organic coupling reactions has been explored for the synthesis of novel coordination complexes with larger dimensions. A discrete coordination species with a paddlewheel motif, dicopper(II) tetracarboxylate Cu2(OOC-C6H4-N3)4(quinoline)2 (SBU1), was covalently modified with methyl propiolate via “Click” reaction to generate a new coordination compound Cu2(OOC-C6H4-C2N3H-COOCH3)4·(quinoline)2 (1). The combination of single-crystal X-ray diffraction, diffusion NMR and ESR has confirmed the success of covalently modifying SBU1 and the retention of the structural integrity after the postsynthetic modification.

Graphical abstractWe report on the postsynthetic modification (PSM) of a dicopper(II) coordination compound with a paddlewheel motif via Click reaction. DOSY and ESR studies have successfully confirmed the structural integrity of the coordination chromophore.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► A dicopper (II) coordination compound with a paddlewheel motif was covalently modified via Click reaction. ► The coordination chromophore of SBU1 was retained throughout the Click reaction process. ► The combination of NMR and ESR techniques has proved to be powerful tools to characterize structures of non-single-crystalline coordination complexes.