Unprecedented Five-Coordinate Iron(IV) Imides Generate Divergent Spin States Based on the Imide R-Groups.

Three five-coordinate iron(IV) imide complexes have been synthesized and characterized. These novel structures have disparate spin states on the iron as a function of the R-group attached to the imide, with alkyl groups leading to low-spin diamagnetic (S=0) complexes and an aryl group leading to an intermediate-spin (S=1) complex. The different spin states lead to significant differences in the bonding about the iron center as well as the spectroscopic properties of these complexes.

A Chromium(II) Tetracarbene Complex Allows Unprecedented Oxidative Group Transfer.

Multiple distinct oxidative group transfer reactions to low valent chromium were examined. Six new chromium complexes were prepared from a highly electronically unsaturated Cr(II) square planar complex that was supported by a macrocyclic tetracarbene ligand. This complex's reactivity with MeNO and disparate azides was investigated.

The Addition of Gold and Tin to Bismuth-Triiridium Carbonyl Complexes.

The reaction of Ir3(CO)9(μ3-Bi) with PhAu(NHC) (1), where NHC = 1,3-bis(2,6-diisopropylphenylimidazol-2-ylidene), has yielded the compound Ir3(CO)8(Ph)(μ3-Bi)[μ-Au(NHC)] (2) by the loss of one CO ligand and the oxidative addition of the Au-C (phenyl) bond of 1 to one of the iridium atoms. The Au(NHC) group bridges one of the Ir-Bi bonds of the cluster. On the basis of X-ray crystal structural analysis and molecular orbital and quantum theory of atoms in molecules calculations, the Au-Bi interaction was determined to be substantial and is comparable in character to the Ir-Bi and Ir-Ir bonds in this cluster.