“Click” tetradentate ligands

Abstract

A series of triazole-based N4 tetradenate ligands 1a–d are efficiently synthesized using Cu^I-catalyzed azide-alkyne “click” strategy and are readily coordinated to many metal ions (e.g. Mn^II, Ni^II, Zn^II and Fe^II). The X-ray structures of the resultant metal-complexes (4a–d, 5a, 6a and 7a) reveal an octahedral mononuclear structure with two co-ligands bonded in cis sites and the two triazoles as nitrogen donors to the metal center. The Mn^II-complexes (4a–d) show efficient catalytic activities in the epoxidation of various aliphatic terminal olefins with peracetic acid, and feature with low catalyst loading, fast conversion and high yields.