Fe4 cluster and a buckled macrocycle complex from the reduction of [(dmgBF2)2Fe(L)2] (L = MeCN, (t)Bu(i)NC)

We report the syntheses, X-ray structures, and reductive electrochemistry of the Fe(II) complexes (dmgBF(2))(2)Fe(MeCN)(2)] (1; dmg = dimethylglyoxime, MeCN = acetonitrile) and (dmgBF(2))Fe((t)Bu(i)NC)(2)] (2; (t)Bu(i)NC = tert-butylisocyanide). The reaction of 1 with Na/Hg amalgam led to isolation and the X-ray structure of (dmgBF(2))(2)Fe(glyIm)] (3; glyIm = glyimine), wherein the (dmgBF(2))(2) macrocyclic frame is bent to accommodate the binding of a bidentate apical ligand. We also report the X-ray structure of a rare mixed-valence Fe(4) cluster with supporting dmg-type ligands. In the structure of (dmg(2)BF(2))(3)Fe(3)((1)/(2)dmg)(3)Fe(O)(6)] (4), the (dmgBF(2))(2) macrocycle has been cleaved, eliminating BF(2) groups. Density functional theory calculations and electron paramagnetic resonance data are in accordance with a central Fe(III) ion surrounded by three formally Fe(II)dmg(2)BF(2) units.