Crystal Structures of Tris(hydroxamato) Complexes of Iron(III)

Abstract

The crystal structures of [Fe(aha)₃]·1.5H₂O and [Fe(bha)₃]·3H₂O (ahaH = acetohydroxamic acid, bhaH = benzohydroxamic acid) have been determined. [Fe(aha)₃]·1.5H₂O crystallizes in the monoclinic space group P2₁/ c (a 19.169(4), b 8.5738(3), c 12.257(3) Å, α = γ = 90°, β 92.255(4)°). The two isomeric forms (fac and mer) cocrystallize. The structure of [Fe(bha)₃]·3H₂O is as reported previously (monoclinic, P2₁/n, a 12.9998(16), b 13.2196(16), c 14.1154(17) Å, α = γ = 90°, β 90.809(2)°) but with improved refinement giving an R value of 0.03 compared to 0.12. In each complex the geometry of the Fe centre is octahedral but with significant distortion.