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A novel, mixed-valent copper(I)-copper(II) complex, {[bis(ethylene-diamine)copper(II)] bis[diiodocuprate(I)]} (1), has been prepared by electrochemical dissolution of a sacrificial copper anode in a solution of ethylenediamine (en), I2 and tetraethylammoniumperchlorate (TEAP) as supporting electrolyte in acetonitrile (AcN)and characterized by single-crystal X-ray structure determination. The crystal structure of the complex 1 shows that it consists of a CuI2 polymer formed from I- ligands bridging Cu(I) ions, with a nearly square planar geometry of bivalent Cu(II) atoms chelated by two ethylenediamine ligands. The results also show that direct electrosynthesis of the complex had high current efficiency, purity and electrolysis yield.

We report on the design of a bio-inspired composite as a noble-metal-free electrocatalyst for the oxygen reduction reaction (ORR). The composite is made from the assembly of pyridine-functionalized graphene (G-py) and a 3 D metal-organic framework (MOF) deposited onto a glassy carbon electrode (GCE). The 3 D heme-like MOF was synthesized from tetrakis(4-carboxyphenyl)porphyrin iron(III) chloride and Zr6 clusters for the assembly of the stable porous coordination network. G-py, which possesses an axial ligand to anchor to the centers of porphyrin in the MOF, results in a significant change in the electronic and geometric structure of centers, which enhances the rate of ORR and durability during cycling in acidic media. The occurrence potential of the ORR by the composite is shifted to the positive potential near 100 mV. Our results introduce a new strategy for the rational design of inexpensive and highly stable oxygen reduction electrocatalysts for fuel cells without the requirement of pyrolysis. [ABSTRACT FROM AUTHOR]

Four rhenium(I) complexes, [Re(CO)3Br(Ln)] (n = 1–4), [Ln = (4-fluorophenyl)pyridin-2-ylmethyleneamine (L1), (4-chlorophe nyl)pyridin-2-ylmethyleneamine (L2), (4-bromophenyl)pyridin-2- ylmethyleneamine (L3), and (4-iodophenyl)pyridin-2-ylmethylenea mine, (L4)] have been synthesized and characterized by CHN analyses, 1H, 13C-NMR, IR, and UV-vis spectroscopy. The molecular structure of [Re(CO)3Br(L1)] is a distorted octahedron around rhenium with one Br, facial arrangement of three COs, and one diimine. UV-vis absorption and emission properties of the complexes have been studied at room temperature and the redox potentials are approximately insensitive to the substituent on the phenyl ring of ligands. [ABSTRACT FROM PUBLISHER]

Abstract: Four platinum(II) complexes, [PtCl2L] (L=(4-fluorophenyl)pyridin-2-ylmethylene-amine, 1; (4-chlorophenyl)pyridin-2-ylmethyleneamine, 2; (4-bromophenyl)pyridin-2-ylmethyleneamine, 3 and (4-iodophenyl)pyridin-2-ylmethyleneamine, 4) have been synthesized and characterized by CHN analysis, IR and UV–Vis spectroscopy. The crystal structures of 1 and 2 were determined using single crystal X-ray diffraction. The coordination polyhedron about the platinum (II) center in the complexes is best described as distorted square planar. The complexes undergo stacking to form a zigzag Pt···Pt···Pt chain containing both short (3.57(7)Å in 1 and 3.62(8)Å in 2) and long (5.16(7)Å in 1 and 5.41(9)Å in 2) Pt···Pt separations through the crystal. The compounds absorb moderately in the visible region, owing to a charge-transfer-to-diimine electronic transition. The redox potentials are approximately insensitive to the substituents on the phenyl ring of the ligands. [Copyright &y& Elsevier]

Two rhenium(I) complexes, [Re(CO)3Br(Ln)] (n = 1, 2), (L1= N,N'-bis[1-(4-chlorophenyl)ethylidene]ethane-1,2-diamine and L2 = N,N'-bis[1-(4-nitrophenyl)ethylidene]ethane-1,2-diamine) have been synthesized and characterized by CHN analyses, 1H NMR, IR, and UV-Vis spectroscopy. The molecular structure of [Re(CO)3Br(L1)] is a distorted octahedron around rhenium with one Br, facial arrangement of three CO's, and one diimine. The UV-Vis spectra of the complexes have metal-to-ligand charge transfer bands increasing in wavelength when the L2 ligand is replaced by L1, in agreement with the oxidation potential of the complexes. [ABSTRACT FROM AUTHOR]

The ligand, N,N'-bis-(4-methoxy-benzylidene)-ethane-1,2-diamine (mb2en), and its corresponding copper(I) complexes, [Cu(mb2en)2]ClO4 (1), and [Cu(mb2en)(PPh3)2]BPh4 (2), have been synthesized and characterized by CHN analyses, 1H and 13C-NMR, IR, and UV-Vis spectroscopies. The crystal and molecular structure of [Cu(mb2en)2]ClO4 (1), were determined by X-ray crystallography from a single-crystal. The coordination polyhedron about copper(I) is best described as a distorted tetrahedron. Quasi-irreversible redox behavior was observed for 1 and 2 (E1/2 = 0.55 and 0.95 V, respectively). [ABSTRACT FROM AUTHOR]

Abstract: The synthesis, characterization, properties and crystal structure of {(bis[4-(2-pyridylmethyleneamino)phenyl]methane)[Re(CO)3Br]2} complex are reported. The 1H NMR data for this complex shows downfield shift of the bis-diimine ligand protons upon coordination to the Re center. The molecular structure of the dinuclear rhenium(I) complex exhibits distorted octahedral geometries around the each metal center with one Br and facial arrangement of three CO and a cis-bonded diimine ligands. The bis-diimine ligand, twists via a half-turn around the metal–metal axis. Electrochemical investigation reveals two oxidation waves and two irreversible reduction waves. [Copyright &y& Elsevier]