Chalcogen Impact on Covalency within Molecular [Cu(μ-E)] Clusters (E = O, S, Se): A Synthetic, Spectroscopic, and Computational Study.

Reaction of the tricopper(I)-dinitrogen tris(β-diketiminate) cyclophane, Cu(N)L, with O-atom-transfer reagents or elemental Se affords the oxido-bridged tricopper complex Cu(μ-O)L (2) or the corresponding Cu(μ-Se)L (4), respectively. For 2 and 4, incorporation of the bridging chalcogen donor was supported by electrospray ionization mass spectrometry and K-edge X-ray absorption spectroscopy (XAS) data. Cu L-edge X-ray absorption data quantify 49.

A Tricopper(I) Complex Competent for O Atom Transfer, C-H Bond Activation, and Multiple O Activation Steps.

Oxygenation of a tricopper(I) cyclophanate (1) affords reactive transients competent for C-H bond activation and O atom transfer to various substrates (including toluene, dihydroanthracene, and ethylmethylsulfide) based on H NMR, gas chromatography/mass spectrometry (MS), and electrospray ionization (ESI)/MS data. Low product yields (<1%) are determined for C-H activation substrates (e.g, toluene, ethylbenzene), which we attribute to competitive ligand oxidation.

Countercations and Solvent Influence CO Reduction to Oxalate by Chalcogen-Bridged Tricopper Cyclophanates.

One-electron reduction of CuEL (L = tris(β-diketiminate)cyclophane, and E = S, Se) affords [CuEL], which reacts with CO to yield exclusively CO (95% yield, TON = 24) and regenerate CuEL. Stopped-flow UV/visible data support an A→B mechanism under pseudo-first-order conditions ( k = 115(2) s), which is 10 larger than those for reported copper complexes. The k values are dependent on the countercation and solvent (e.

A family of tri- and dimetallic pyridine dicarboxamide cryptates: unusual O,N,O-coordination and facile access to secondary coordination sphere hydrogen bonding interactions.

A series of tri- and dimetallic metal complexes of pyridine dicarboxamide cryptates are reported in which changes to the base and metal source result in diverse structure types. Addition of strong bases, such as KH or KN(SiMe3)2, followed by divalent metal halides allows direct access to trinuclear complexes in which each metal center is coordinated by a dianionic N,N,N-chelate of each arm. These complexes bind a guest K(+) cation within the central cavity in a trigonal planar coordination environment.

Modeling biological copper clusters: synthesis of a tricopper complex, and its chloride- and sulfide-bridged congeners.

The synthesis and characterization of a family of tricopper clusters housed within a tris(β-diketimine) cyclophane ligand (H3L) that bear structural similarities to biological copper clusters are reported. In all complexes, each Cu atom is held within the N2-chelate of a single β-diketiminate arm. Reaction of L(3-) with CuCl affords an anionic complex containing a μ3-chloride donor in the central cavity, whereas there is no evidence for bromide incorporation in the product of the reaction of L(3-) with CuBr (Cu3L).