Synthesis and characterization of metal-centered, six-membered, mixed-valent, heterometallic wheels of iron, manganese, and indium

Heptanuclear metal-centered, six-membered, mixed-valent, heterometallic wheels 1-3 of iron, manganese, and indium were prepared in a one-pot reaction from N-benzyldiethanolamine (H2L1), cesium carbonate, [PPh4](2)[MnCl4], and FeCl3 or InCl3. All three complexes were characterized by the combination of elemental analysis, FAB mass spectroscopy, X-ray diffraction and cyclic voltammetry. and in the case of 1. additionally by Mossbauer spectroscopy. In 1, four Mn-II ions in the periphery are arranged in pairs alternating with one Fe-III ion each, with an Fe-III ion located in the center. In 2, three Mn-II ions alternate with three In-III ions, whereas in 3, four In-III ions are arranged in pairs and alternate with one Mn-II ion each. In 2 and 3 an Mn-II ion is encapsulated in the center.