Mixed-Valence Tetrametallic Iridium Chains.

Neutral [X-{Ir }-{Ir }-X] (X=Cl, Br, SCN, I) and dicationic [L-{Ir }-{Ir }-L] (L=MeCN, Me CO) tetrametallic iridium chains made by connecting two dinuclear {Ir } units ({Ir }=[Ir (μ-OPy) (CO) ], OPy=2-pyridonate) by an iridium-iridium bond are described. The complexes exhibit fractional averaged oxidation states of +1.5 and electronic delocalization along the metallic chain.

Rhodium Complexes Promoting C-O Bond Formation in Reactions with Oxygen: The Role of Superoxo Species.

C-O bond formation in reactions of olefins with oxygen is a long standing challenge in chemistry for which the very complicated-sometimes controversial-mechanistic panorama slows down the design of catalysts for oxygenations. In this regard, the mechanistic details of the oxidation of the complex [Rh(cod)(Ph N )] (1) (cod=1,5-cyclooctadiene) with oxygen to the unique 2-rhodaoxetane compound [{Rh(OC H )(Ph N )} ] (2) has been investigated by DFT calculations. The results of this study provide evidences for a novel bimetallic mechanism in which two rhodium atoms redistribute the four electrons involved in the cleavage of the O=O bond.

Discrete iridium pyridonate chains with variable metal valence: nature and energetics of the Ir-Ir bonding from DFT calculations.

The structure of the Ir(I) complex [Ir2(mu-OPy)2(CO)4] (Opy = 2-pyridonate) has been fully characterized in its head-to-head (A) configuration as a "dimer of dimers" AA in which two binuclear complexes are connected by means of a weak, but unsupported, iridium-iridium interaction (Ir(2)...