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Abstract The rational design and synthesis of an efficient bielectrocatalyst for the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) by tuning the chemical composition, structure and the catalytic sites of the hybrid materials is always of a great challenge. In this work, an innovative strategy based on the highly active N,N′-carbonyldiimidazole (CDI) is described to one-pot synthesis of a novel precursor for bifunctional O 2- electrocatalyst. The coordination of Co2+ with the in situ generated ligands imidazole and carbonate results in ultrafine cobalt carbonate (CoCO 3)-involved cobalt-based zeolitic imidazole framework (CoCO 3 /Co-ZIF). Owing to the presence of ultrafine CoCO 3 , carbonization of CoCO 3 /Co-ZIF at 800 °C under N 2 atmosphere endows the pyrolysis product with a special skeleton of carbon nanotube (CNT)-tipped end CoO x , multivalent CoO x wrapped in graphitic carbon layers. Thus, the resulting CoO x /Co-N-C exhibits the enhanced and durable ORR/OER performance in alkaline media, due to the fast electron and mass transfers. For ORR, a large limiting current density of 4.59 mA cm−2 can be obtained by CoOx/Co-N-C, which is comparable to that of Pt/C. For OER, it only needs an over potential of 1.65 V to achieve a current density of 10 mA cm−2, merely 30 mV behind IrO 2 (1.62 V). [ABSTRACT FROM AUTHOR]

Abstract: The structures and some molecular properties of the complexes M(mnt)2 2− (M=Ni, Pd, Pt and Zn, Cd, Hg; mnt2− =deprotonated maleonitriledithiolate) have been studied by using density functional theory (DFT) B3LYP/LanL2DZ level of theory. Computed binding energies show that the sequences of binding strengths are Ni

3D lanthanide metal–organic frameworks (Ln–MOFs) with honeycomb cavities shown photocatalytic activities for the degradation of organic dyes. Using rational designed chalcone dicarboxylic acid ligand (H 2 L), a series of lanthanide metal–organic frameworks (Ln–MOFs) with the general formula Ln(HL) 3 (Ln = La ; Ce ; Pr ; Nd ; Sm ; Eu ; Gd) have been obtained under the solvothermal reaction. The crystal structure analysis displays that all the Ln – MOFs are the isomorphic three-dimensional (3D) metal–organic frameworks with honeycomb cavities, in which the porosity is ∼20% that calculated via PLATON software. In addition, photocatalytic activities of Ln–MOFs for the degradation of several organic dyes have been explored, suggesting that Ln–MOFs can be used as efficient heterogeneous photocatalyst for the degradation of organic dyes. [ABSTRACT FROM AUTHOR]

Abstract: A novel iron(II) complex, trans-[FeL2(NCS)2][FeL2(CH3OH)2](NCS)2 (1) with 4-amino-3-(p-chlorophenyl)-5-(2-pyridyl)-1,2,4-triazole (L) has been successfully synthesized and characterized. X-ray crystallography analysis shows that 1 is the first example in the mononuclear triazole-based complexes consisting of two distinct molecules: trans-[FeL2(NCS)2] and trans-[FeL2(CH3OH)2](NCS)2 with each octahedral iron(II) center coordinated axial by two NCS− ions in Fe1 but two MeOH molecules in Fe2. Moreover, 1 can lose two MeOH molecules at 220°C to form trans-[FeL2(NCS)2] (2) which can be transformed to 1 when recrystallizing 2 in methanol. Both 1 and 2 are high-spin species in the range of 1.8–300K. [Copyright &y& Elsevier]

Abstract: In the title complexes, {[(η-C5H5)Fe(η-C5H4)(CO)](C22H21N4)Ni} (1) and {[(η-C5H5)Fe(η-C5H4)(CO)]2(C22H20N4)Ni} (2), one and two electroactive ferrocenes (Fc) were grafted onto the methine of the nickel complex Nitmtaa (H2tmtaa=4,11-dihydro-5,7,12,14-tetramethyldibenzo[b,i][1,4,8,11]tetraazacyclotetradecine) through the carbonyl groups. The two new complexes were characterized by IR, UV, MS and NMR spectra as well as by DSC measurements. The crystal structure of 1 was determined. Ni coordinates to four nitrogen atoms of tmtaa, and it is almost in the same plane as the N4 plane. The mean Ni–N bond distance in the N4 plane is 1.866Å. The non-planar, saddle-shaped conformation of H2tmtaa is almost retained in the nickel complex. The symmetry axis of ferrocene is almost parallel to the N4 plane in Nitmtaa. The dihedral angle between the N4 plane in Nitmtaa and the cyclopentadienyl ring in ferrocene is 98.5°. The electrochemistry of 1 and 2 was studied by cyclic voltammetry in CH2Cl2/1×10−1 M n-Bu4NClO4 using a glass carbon working electrode. Because of the electron transfer between the electroactive ferrocene and the completely conjugated system of Nitmtaa, the complexes show novel electrochemical properties and the ferrocenes in 1 and 2 act as electron acceptors. [Copyright &y& Elsevier]