Crystal structure of a methyl benzoate quadruple-bonded dimolybdenum complex.

Quadruple-bond dimolybdenum complexes provide invaluable insight into the two-electron bond, with structural chemistry providing a foundation for examination of bond properties. The synthesis and solid-state structure of the quadruple-bonded dimolybdenum(II) complex tetra-kis-(µ-4-methyl-benzoato-κ 2 O:O')bis[(tetra-hydro-furan-κO)molybdenum(II)] tetra-hydro-furan disolvate, [Mo2(C8H7O2)4(C4H8O)2]·2C4H8O, are presented. This complex crystallizes in a triclinic cell with low-symmetry space group P . The dimolybdenum paddlewheel structure comprises four methyl-benzoate ligands and two axial THF ligands. The dimolybdenum bond distance of 2.1012 (4) Šis exemplary of this class of compounds.

Generation of Pure Oxygen from Briny Water by Binary Catalysis.

Whereas the emphasis of water splitting is typically on hydrogen generation, there is value in the oxygen produced, especially in the undersea environment and for medicinal applications in the developing world. The generation of pure and breathable oxygen from abundant and accessible sources of water, such as brine and seawater, is challenging owing to the prevalence of the competing halide oxidation reaction to produce halogen and hypohalous acids. We show here that pure O2 may be generated from briny water by using an oxygen evolution catalyst with an overlayer that fulfills the criteria of (i) possessing a point of zero charge that results in halide anion rejection and (ii) promoting the disproportionation of hypohalous acids.

Synthesis, Characterization, and Hydrogen Evolution Activity of Metallo-meso-(4-fluoro-2,6-dimethylphenyl)porphyrin Derivatives.

Zn(II), Cu(II), and Ni(II) 5,10,15,20-tetrakis(4-fluoro-2,6-dimethylphenyl)porphyrins (TFPs) have been synthesized and characterized. The electronic spectroscopy and cyclic voltammetry of these compounds, along with the free-base macrocycle (2H-TFP), have been determined; 2H-TFP was also structurally characterized by X-ray crystallography. The Cu(II)TFP exhibits catalytic activity for the hydrogen evolution reaction (HER). The analysis of linear sweep voltammograms shows that the HER reaction of Cu(II)TFP with benzoic acid is first-order in proton concentration with an average apparent rate constant for HER catalysis of k app = 5.79 ± 0.47 × 103 M-1 s-1.

Crystal structure of a tri-fluoro-methyl benzoato quadruple-bonded dimolybdenum complex.

The study of quadruple bonds between transition metals, in particular those of dimolybdenum, has revealed much about the two-electron bond. The solid-state structure of the quadruple-bonded dimolybdenum(II) complex tetra-kis-[µ-4-(tri-fluoro-methyl)-benzoato-κ2 O:O']bis[(tetra-hydro-furan-κO)molybdenum(II)] 0.762-pentane 0.238-tetra-hydro-furan solvate, [Mo2(p-O2CC6H4CF3)4·2THF]·0.762C5H12·0.238C4H8O or [Mo2(C8H4F3O2)4(C4H8O)2]·0.762C5H12·0.238C4H8O is reported. The complex crystallizes within a triclinic cell and low symmetry (P ) results from the inter-calated penta-ne/THF solvent mol-ecules. The paddlewheel structure at 100 K has inversion symmetry and comprises four bridging carboxyl-ate ligands encases the Mo2(II,II) core that is characterized by two axially coordinated THF mol-ecules and an Mo-Mo distance of 2.1098 (7) Å.

Superatomic solid solutions.

In atomic solids, substitutional doping of atoms into the lattice of a material to form solid solutions is one of the most powerful approaches to modulating its properties and has led to the discovery of various metal alloys and semiconductors. Herein we have prepared solid solutions in hierarchical solids that are built from atomically precise clusters. Two geometrically similar metal chalcogenide clusters, Co6Se8(PEt3)6 and Cr6Te8(PEt3)6, were combined as random substitutional mixture, in three different ratios, in a crystal lattice together with fullerenes. This does not alter the underlying crystalline structure of the [cluster][C60]2 material, but it influences its electronic and magnetic properties. All three solid solutions showed increased electrical conductivities compared with either the Co- or Cr-based parent material, substantially so for two of the Co:Cr ratios (up to 100-fold), and lowered activation barriers for electron transport. We attribute this to the existence of additional energy states arising from the materials' structural heterogeneity, which effectively narrow transport gaps.