Synthesis and Metal‐Complexation of a Trimer of Dendrimers with Bipyridine Cores in the Center of Conjugated Chains

Two types of dendrimers with a bipyridine unit in the center of their rigid backbones were prepared. One dendrimer has two azide groups and the other has one ethynyl terminal. These dendrimers were coupled by the copper‐mediated Hüisgen 1,3‐dipolar cycloadditions of the ethynyl and azide terminals to afford a trimer with three bipyridine cores. The addition of Fe(II) to a solution of the trimer resulted in an absorption change characteristic of the formation of tris(bipyridine)Fe(II) complexes. The structural properties of the tris(bipyridine)Fe(II) core are likely reflected in the conformation of the timer because the bipyridine units are attached to the rigid backbones. Click chemistry was used to prepare a dendrimeric trimer with bipyridine cores in the centers of its conjugated chains. The addition of Fe(II) ions to a solution of the trimer resulted in the formation of a characteristic structure folded around a metal center, with the conjugated and branched chains around the metal center providing a unique environment.