Synthesis and Characterization of Novel Substituted 3,6‐Di(2‐pyridyl)pyridazine Metal‐Coordinating Ligands

The synthesis of novel functionalized 3,6‐di(2‐pyridyl)pyridazines via an inverse electron demand Diels−Alder reaction between the corresponding 3,6‐di(2‐pyridyl)‐1,2,4,5‐tetrazine and various alkynes is reported. The resulting 3,6‐di(2‐pyridyl)pyridazines were investigated using X‐ray crystallography, IR spectroscopy, and NMR spectroscopy, whereby several 2D NMR spectroscopic techniques were exploited to conclusively assign all proton‐ and carbon‐resonances. In addition, it was demonstrated that the functionalized 3,6‐di(2‐pyridyl)pyridazines are capable of forming [2 × 2] grid‐like metal complexes with copper(I) and silver(I) ions. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)