The first-row transition-metal series of tris(ethylenediamine) diacetate complexes [M(en)3](OAc)2 (M is Mn, Fe, Co, Ni, Cu, and Zn)

Abstract

The crystal structures of the first-row transition-metal series of tris(ethylenediamine-κ2 N,N′)metal(II) diacetate, [M(C2H8N2)3](CH3CO2)2, with M = Mn, Fe, Co, Ni, Cu, and Zn, are reported. The complexes are all isostructural, crystallizing in a centrosymmetric triclinic cell and possessing an asymmetric unit composed of one [M(en)3]2+ cation and two symmetrically independent acetate anions. In the unit cell, the two complex cations are inversion-generated enantiomers, possessing the energetically favoured Δ(λλλ) and Λ(δδδ) configurations. The complex cations and acetate anions combine through a series of N—H...O hydrogen bonds to generate a three-dimensional network in the crystals. The other notable feature of the series is a significant Jahn–Teller distortion for the d 9 Cu2+ complex.