Synthesis, Crystal Structures and Properties of Tetrametallic Complexes: [M 2 (phen) 4 (FCA) 2 ](ClO 4 ) 2 ·(H 2 O) 2 (M=Zn or Co, phen=1,10‐phenanthroline, FCA=anion of 3‐ferrocenyl‐2‐crotonic acid)

Two new complexes [Zn 2 (phen) 4 (FCA) 2 ](ClO 4 ) 2 ·(H 2 O) 2 ( 1 ) and [Co 2 (phen) 4 (FCA) 2 ](ClO 4 ) 2 ·(H 2 O) 2 (2) (FCA=anion of 3‐ferrocenyl‐2‐crotonic acid, phen=1,10‐phenanthroline) have been synthesized, and characterized by elemental analysis, IR, UV‐Vis spectra, thermal analyses, and single‐crystal X‐ray diffraction. Two M(II) (M=Zn or Co) ions are bridged by two FCA anions with syn‐anti bridging ligands, leading to dimeric cores, [M 2 (phen) 4 (FCA) 2 ] 2+ , and each M(II) ion is six‐coordinated in a distorted octahedral geometry by two chelate phen ligands and two μ 2 ‐carboxylate oxygen atoms from two FCA groups. The M(II)…M(II) intradimer distances are 0.4391 and 0.4462 nm in 1 and 2 , respectively. Electrochemical properties of the complexes have been discussed.