Synthesis and Structural Study of the (N,N,N′,N′-Tetraethylethylenediamine)CdFe(CO)4 Dimer

The new [(teeda)CdFe(CO)4]2 complex has been isolated from the reaction of [(NH3)2CdFe(CO)4]n with tetraethylethylenediamine. Unlike previous structural reports of ligand adducts of [L2CdFe(CO)4]x complexes, which have all been trimeric species composed of six-membered Cd3Fe3 rings, the teeda complex crystallized as a dimer, analogous to [(2,2-bpy)ZnFe(CO)4]2. As in the zinc dimer, significant distortion arises from steric interactions between the axial carbonyl ligands on opposing iron centers. The complex sits on an inversion center, leading to two independent Cd–Fe distances, 2.7244(6) and 2.7433(6) Å, and crystallizes in the monoclinic space group P21/a with a = 14.8546(2) Å, b = 15.1647(3) Å, c = 15.5252(3) Å, β = 90.9517(12)°, and Dcalc = 1.719 g/cm3 at 150(1) K