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This article describes a density functional theory (DFT) study to explore a bio‐inspired NiFe complex known for its experimental activity in electro‐reducing CO2 to CH4 when adsorbed on graphite. The coordination properties of the complex are investigated in isolated form and when physisorbed on a graphene surface. A comparative analysis of DFT approaches for surface modeling is conducted, utilizing either a finite graphene flake or a periodic carbon surface. Results reveal that the finite model effectively preserves all crucial properties. By examining predicted structures arising from CO2 insertion within the mono‐reduced NiFe species, whether isolated or adsorbed on the graphene flake, a potential species for subsequent electro‐reduction steps is proposed. Notably, the DFT study highlights two positive effects of complex adsorption: facile electron transfers between graphene and the complex, finely regulated by the complex state, and a lowering of the thermodynamic demand for CO2 insertion. [ABSTRACT FROM AUTHOR]

Nitrene transfer reactions have emerged as one of the most powerful and versatile ways to insert an amine function to various kinds of hydrocarbon substrates. However, the mechanisms of nitrene generation have not been studied in depth albeit their formation is taken for granted in most cases without definitive evidence of their occurrence. In the present work, we compare the generation of tosylimido iron species and NTs transfer from FeII and FeIII precursors where the metal is embedded in a tetracarbene macrocycle. Catalytic nitrene transfer to reference substrates (thioanisole, styrene, ethylbenzene and cyclohexane) revealed that the same active species was at play, irrespective of the ferrous versus ferric nature of the precursor. Through combination of spectroscopic (UV‐visible, Mössbauer), ESI‐MS and DFT studies, an FeIV tosylimido species was identified as the catalytically active species and was characterized spectroscopically and computationally. Whereas its formation from the FeII precursor was expected by a two‐electron oxidative addition, its formation from an FeIII precursor was unprecedented. Thanks to a combination of spectroscopic (UV‐visible, EPR, Hyscore and Mössbauer), ESI‐MS and DFT studies, we found that, when starting from the FeIII precursor, an FeIII tosyliodinane adduct was formed and decomposed into an FeV tosylimido species which generated the catalytically active FeIV tosylimide through a comproportionation process with the FeIII precursor. [ABSTRACT FROM AUTHOR]

It is recently demonstrated that diaryl‐naphthopyran photochromic dyes are efficient for sensitization of TiO2 mesoporous electrodes, thus allowing the fabrication of photochromo‐voltaic cells that can self‐adapt their absorption of light and their generation of electricity with the light intensity. Herein, the synthesis and characterization of two photochromic dyes based on a diaryl‐naphthopyran core, NPI‐ThPh and NPIFuPh, for use in dye sensitized solar cells is reported. Compared to the reference dye NPI, the molecules vary by the nature of the spacer, a thiophene or a furan, connecting the photochromic unit and the anchoring function. It was found that swapping a phenyl for a thiophene or a furan leads to an improvement of the absorption properties of the molecules, both in solution and after grafting on TiO2 electrodes, however their photochromic process becomes not fully reversible. Despite better absorption in the visible range, the new dyes show poorer photochromic and photovoltaic properties in devices compared to NPI. Thanks to UV–Vis spectroscopy, theoretical modelling, electrical characterization of the cells, and impedance spectroscopy, the factors limiting their performances have been unraveled. This study contributes to better understand the connection between photochromic and photovoltaic properties, which is key to develop better performing molecules of this class. [ABSTRACT FROM AUTHOR]

Experimental data and theoretical calculations have failed to rationalize the role of covalnecy in real experimental BTP (2,6-Di(1,2,4-trianzin-3-yl)pyridine) complexes. DFT calculations on [M(BTP).sub.3].super.3} (M-La, U, Cm, Gd) were used to show that even if back-bonding effects are significant in the U-BTP bond, it is the contrast of donation on 6d and 5f [Cm.super.III] orbitals that explains, at least in part, its selective complexation to BTP.

The stability of a peroxo-iron species in the second time scale when reacted with H2O2 is due to the E47A mutation in superoxide reductase (SOR) from Desulfoarculus baarsii. Further characterization on the basis of Mossbauer and spin Hamiltonian parameters shows that the peroxo-Fe(super +3) species is a high-spin side-on complex.

Research has been conducted on the triosodide octanocoordinated uranium(III) complexes and their lanthanum(III) analogues. The crystal structures of these complexes has been investigated and the details are reported.

Research was conducted to examine various spectroscopic studies of WOs and MoRu porphyrin dimers using variable-temperature 1H NMR, resonance Raman, magnetic susceptibility and X-ray crystallography. The objective was to determine a proper molecular orbital diagram for the dimers. Results demonstrate an unusual molecular orbital diagram which has never been observed before in metal-metal bonded metalloporphyrin dimers.

A theoretical study was conducted to analyze bonding in lanthanide trihalides using density functional techniques. The local spin density approximation accommodated exchange and correlation potentials. Geometries were then optimized in the pyramidal and planar conformations by an energy-only minimizer. Results indicated the effectiveness of density functional computations to duplicate both structural and thermodynamic experimental information on the compounds.

Research was conducted to examine the magnetic properties of several mixed-valent diruthenium long-chain carboxylates with the general formula Ru2(RCO2)4X in temperatures ranging from 6-400 K. Magnetic susceptibility calculations were performed on the carboxylates. The columnar mesophase of the mesomorphic congeners suggests that there is no substantial structural change that takes place at the crystal-liquid crystal transition.

Chemical research has established the solid state magnetic susceptibility properties of group eight metal-to-metal doubly bonded porphyrin and tetraazaporphyrin dimers [Ru(Octaethylporphyrin)]2, Ru(octaethyltetraazaporphyrin)]2 and [Os(OEP)]. Nuclear magnetic resonance analysis indicates that each of the group eight dimers exhibits similar behaviour in zero-field splitting of the triplet ground electronic state.

The structural characterization of stable complexes of pentavalent uranyl synthesized from the reaction of the complex with the bulky amine-phenolate ligand potassium salt [K.sub.2](salan-[super]t[Bu.sub.2]) or the Schiff base ligand potassium salt [K.sub.2](salophen-[super]t[Bu.sun.2]) in pyridine is described. The presence of a back-bonding interaction in the pentavalent uranyl complexes possibly contributed significantly to the observed solution stability of the [U[O.sub.2](salan-[super]t[Bu.sub.2])(py)K] and [U[O.sub.2](salophen-[super]t[Bu.sub.2])(py)K] complexes with respect to disproportionation and hydrolysis.