Synthesis and Characterization of Cp₄Fe₄(CO)₄-Functionalized Terpyridine Molecule and Its Iron(II) and Ruthenium(II) Complexes

Reaction of Cp3Fe4(CO)4(C5H4CHO) (1) and 2-acetylpyridine produces Cp3Fe4(CO)4(C5H4CHCHC(O)(2-C5H4N)) (2) and Cp3Fe4(CO)4(C5H4CH(CH2C(O)(2-C5H4N))2) (3), which can convert to Cp3Fe4(CO)4(4′-C5H4-2,2′:6′,2′′-terpyridine) (4) in moderate yields. Coordination of 4 to Fe(II) and Ru(II) ions afford the double-cluster complexes [(Cp3Fe4(CO)4(4′-C5H4-2,2′:6′,2′′-terpyridine))2Ru](PF6)2 (5) and [(Cp3Fe4(CO)4(4′-C5H4-2,2′:6′,2′′-terpyridine))2Fe](PF6)2 (6), respectively. Compounds 4−6 have been characterized by mass, NMR, and UV−vis spectroscopy, and the structure of 4 was determined by an X-ray diffraction study.