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The coordination diversity of a novel N4-ligand and its sodium complex toward cobalt(ii) ions was studied.

The reaction between aryl substituted sodium 1,2,3-triphospholides or disodium bis(1,2,3-triphospholide) and [Fe(η6-(C6H5CH3)Cp]+[PF6]- in boiling diglyme results in pure 1,2,3-triphosphaferrocenes 1-3 or bis(1,2,3-triphosphaferrocene) 4, respectively, in good yields. The structure of all obtained 1,2,3-triphosphaferrocenes 1-4 has been extensively studied experimentally (NMR, UV-Vis spectroscopy, and X-ray analysis for 1 and 4) and quantum chemically. The electrochemical properties of 1,2,3-triphosphaferrocenes 1-4 in the solid state were studied for the first time and a reversible one-electron oxidation (E1/2 = 0.52-0.92 V vs. Fc+/Fc) was demonstrated for 1, 3, and 4. In the case of 1,4-bis(5-phenyl-4-(1,2,3-triphospaferrocenyl))benzene 4, consecutive oxidation in the solid state is observed in contrast to other 1,2,3-triphosphaferrocenes 1-3. According to the ESR data, the g-factor of the oxidized bis(1,2,3-triphosphaferrocene), 4 (g = 2.12) is different from the g-factors of oxidized 1,2,3-triphosphaferrocenes 1-3 (g = 2.01). This is the first example of multi(ferrocenyl) systems based on the phosphaferrocene motif, which in turn opens up a new fundamental platform for the preparation of compounds with stimuli-responsive properties.

Rational design and synthesis of efficient metal-organic frameworks (MOFs) as electrode modifiers for energy-related electrocatalytic applications are crucial for the development of clean-energy technologies. The present review focuses on recent work on robust earth-abundant heterogeneous catalysts based on pristine MOFs for the hydrogen evolution reaction (HER) and overall water splitting. These catalysts have been extensively studied as alternatives for noble metal-based ones, demonstrating "hydrogen economy" development prospects. In addition, novel strategies to enhance the conductivity, chemical stability and efficiency of MOF-based electrocatalysts are discussed. The best electrocatalysts even surpass the achievements of the platinum group of metals and MOF-derived catalysts in catalytic performance. The electrolytic cells with MOF-modified electrodes demonstrated excellent catalytic activity and can deliver a high current density at a voltage lower than that using the precious metal-based Pt/C cathodes and IrO2 anodes. In this review article, current approaches to design such MOF and MOF-modified electrode materials are summarized and analyzed.

The interaction of manganese(II) phthalocyanine with 7,7,8,8-tetracyanoquinodimethane and its perfluoro derivative proceeds with the oxidation of Mn and the reduction of the acceptor molecules to give the first mixed single crystals of manganese(III) phthalocyanine with TCNQ/F4-TCNQ radical anions. The crystals have unusual structures with C–H⋯π interactions between the ions and their orthogonal arrangement, as well as remarkable redox properties. The charge transfer was proved by spectroscopic and magnetic studies.

We have developed Ni(III)-doped silica nanoparticles ([(bpy)xNi(III)]@SiO2) as a recyclable, low-leaching, and efficient oxidative functionalization nanocatalyst for aromatic C-H bonds. The catalyst is obtained by doping the complex [(bpy)3Ni(II)] on silica nanoparticles along with its subsequent electrooxidation to [(bpy)xNi(III)] without an additional oxidant. The coupling reaction of arenes with perfluoroheptanoic acid occurs with 100% conversion of reactants in a single step at room temperature under nanoheterogeneous conditions. The catalyst content is only 1% with respect to the substrates under electrochemical regeneration conditions. The catalyst can be easily separated from the reaction mixture and reused a minimum of five times. The results emphasize immobilization on the silica support and the electrochemical regeneration of Ni(III) complexes as a facile route for developing an efficient nanocatalyst for oxidative functionalization.