Bimetallic nickel-lutetium complexes: tuning the properties and catalytic hydrogenation activity of the Ni site by varying the Lu coordination environment.

We present three heterobimetallic complexes containing an isostructural nickel center and a lutetium ion in varying coordination environments. The bidentate and nonadentate ligands were used to prepare the Lu metalloligands, Lu(PrPCHNPh) () and Lu{(PrPCHNAr)tacn} (), respectively. Reaction of Ni(COD) (where COD is 1,5-cyclooctadiene) and afforded NiLu(PrPCHNPh) (), with a Lu coordination number (CN) of 4 and a Ni-Lu distance, (Ni-Lu), of 2.

Adaptable ligand donor strength: tracking transannular bond interactions in tris(2-pyridylmethyl)-azaphosphatrane (TPAP).

Flexible ligands that can adapt their donor strength have enabled unique reactivity in a wide range of inorganic complexes. Most examples are composed of flexible multi-dentate ligands containing a donor that can vary its interaction through its distance to the metal center. We describe an alternative type of adaptable ligand interaction in the neutral multi-dentate ligand tris(2-pyridylmethyl)-azaphosphatrane (TPAP), which contains a proazaphosphatrane unit.

Influence of Copper Oxidation State on the Bonding and Electronic Structure of Cobalt-Copper Complexes.

Heterobimetallic complexes that pair cobalt and copper were synthesized and characterized by a suite of physical methods, including X-ray diffraction, X-ray anomalous scattering, cyclic voltammetry, magnetometry, electronic absorption spectroscopy, electron paramagnetic resonance, and quantum chemical methods. Both Cu(II) and Cu(I) reagents were independently added to a Co(II) metalloligand to provide (py3tren)CoCuCl (1-Cl) and (py3tren)CoCu(CH3CN) (2-CH3CN), respectively, where py3tren is the triply deprotonated form of N,N,N-tris(2-(2-pyridylamino)ethyl)amine. Complex 2-CH3CN can lose the acetonitrile ligand to generate a coordination polymer consistent with the formula "(py3tren)CoCu" (2).

Configuring bonds between first-row transition metals.

Alfred Werner, who pioneered the field of coordination chemistry, envisioned coordination complexes as a single, transition metal atom at the epicenter of a vast ligand space. The idea that the locus of a coordination complex could be shared by multiple metals held together with covalent bonds would eventually lead to the discovery of the quadruple and quintuple bond, which have no analogues outside of the transition metal block. Metal-metal bonding can be classified into homometallic and heterometallic groups.

Pushing the Limits of Delta Bonding in Metal-Chromium Complexes with Redox Changes and Metal Swapping.

Into the metalloligand Cr[N(o-(NCH2P((i)Pr)2)C6H4)3] (1, CrL) was inserted a second chromium atom to generate the dichromium complex Cr2L (2), which is a homobimetallic analogue of the known MCrL complexes, where M is manganese (3) or iron (4). The cationic and anionic counterparts, [MCrL](+) and [MCrL](-), respectively, were targeted, and each MCr pair was isolated in at least one other redox state. The solid-state structures of the [MCrL](+,0,-) redox members are essentially the same, with ultrashort metal-metal bonds between 1.