Antoine Railliet

Water channels and zipper structures in Schiff base-like Cu(II) and Ni(II) mononuclear complexes

The crystal structures of four Cu(ii) complexes and one Ni(ii) complex bearing a square planar N2O2 coordination sphere are discussed. In all cases a distorted square planar coordination sphere is observed that is independent of the metal centre and the ligand and is only influenced by the packing of the molecules in the crystal. For the less distorted copper complexes metal-aromatic interactions are observed, while no significant intermolecular interactions are found for the nickel complexes. This can be explained by the different electronic character of Cu(ii) and Ni(ii) and is also reflected in the differences in the solvatochromism of these complexes.

Reaction of aminobenzoate esters with N,N′-dimethylformamide azine dihydrochloride: Crucial influence of intramolecular hydrogen bonding for the formation of 1,2,4-triazoles

The reaction of N,N′-dimethylformamide azine (DMFA) or its dihydrochloride derivative (DMFA·2HCl) with o-RO(O)CC 6H 4NH 2 (R = Me, Et) leads to co-crystallization products o-RO(O)CC 6H 4NH 2·DMFA (R = Me, Et), while the same reaction of DMFA·2HCl with m- and p-RO(O)CC 6H 4NH 2 (R = Me, Et) provides the corresponding 4-substituted 1,2,4-triazoles (1-4). Reaction of the same m- and p-substituted amines with DMFA has failed, while addition of a few drops of HCl or HNO 3 in this reaction mixture has allowed us to obtain the corresponding triazole derivatives. Thus, the direct transamination reaction with the formation of triazoles 1-4 is catalysed by acidic catalysts. Molecular structures of DMFA, o-EtO(O)CC 6H 4NH 2·DMFA and 3 were elucidated by X-ray diffraction.

Spin-canted ferromagnetic behaviour and unusual thermal decomposition of [Co{MeO(O)CC6H4NHC(S)NP(S)(OiPr)2}2]

Reaction of the deprotonated N-thiophosphorylated thiourea o-MeO(O)CC 6H4NHC(S)NHP(S)(OiPr)2 (HL) with Co II leads to the [CoL2] complex, the structure of which was studied by IR, UV-Vis, diffuse reflectance and NMR spectroscopy, ESI +/- mass spectrometry and microanalysis. The thermal properties of [CoL2] in an air atmosphere were studied by means of simultaneous TG/DTA analyses with the observed unprecedented final residue corresponding to CoPS3. Investigation of the thermal dependence of the magnetic susceptibility has shown that [CoL2] behaves as a spin-canted ferromagnet. The molecular structures of [CoL2] at 100 and 173 K were elucidated by a single crystal X-ray diffraction analysis. The metal was found to be in a tetrahedral 1,5-S2S′2 environment formed by the C=S and P=S sulfur atoms.

Complexes and salts of the nitrogen-rich triazole-tetrazole hybrid ligand with alkali and alkaline earth metal cations: experimental and theoretical findings

Reaction of the nitrogen-rich triazole–tetrazole hybrid ligand 5-(4H-1,2,4-triazol-yl)-2H-tetrazole (trz–tetH) with Li+, Na+, K+ and Ba2+ in water leads to the coordination polymers [Li(trz–tet)H2O]n, [Na(trz–tet)(H2O)2]n, [K(trz–tetH)(trz–tet)(H2O)2]n and [Ba2(trz–tet)4(H2O)9]n, exhibiting different topologies and coordination modes. Salt-like structures with anionic triazole–tetrazole building blocks [Mg(H2O)6](trz–tet)2 and [Ca(H2O)8](trz–tet)2 were also obtained. All structures were simplified by topological analysis, which showed that the structures of [Mg(H2O)6](trz–tet)2 and [Ca(H2O)8](trz–tet)2 can be considered as underlying networks, constructed from the hydrogen bonded [Mg(H2O)6]2+ or [Ca(H2O)8]2+ cations and trz–tet ligands, with the rare binodal 5,10-connected topology alb-5,10,P21/c-1 and a unique binodal 5,12-connected topology, respectively. According to TGA/DTA analysis, all compounds show endothermic mass losses below 200 °C due to dehydration processes. The dehydrated residues are stable up to 300 °C. It was also established that the anionic form of the coordinated ligand trz–tet decomposes with an abrupt mass loss accompanied by a sharp and intense exothermic effect, while the non-coordinated trz–tet, as in the structures of the Mg- and Ca-based compounds, decomposes with a more gradual mass loss and significantly broad exothermic effect. Static DFT, ab initio molecular dynamics simulations as well as charge and energy decomposition (ETS-NOCV) based studies are performed in order to shed light on the stability of the newly obtained crystals.