Florula officinale della bassa valle di Bunnari (Sardegna settentrionale)

The officinal flora of the low valley of Bunnari (Northern Sardinia) has been examined. In order to emphasize the percentage of the officinal species in ratio to the amount of total species, the whole flora has been listed; and the aspects of the vegetation have been briefly referred to so as to set the flora in its environment. 334 taxa and 331 species, belonging to 225 genera and 69 families, have been singled out; of this group, whose distribution in the area and biological cycle has been studied, about 69% are officinal, and about 45% are classical medicinal plants. The belt appears interesting from the point of view of the landscape, the vegetational milieus and the officinal flora, and merits consideration. It could be regarded as a natural «officinal» garden

Switchable π-coordination and C–H metallation in small-cavity macrocyclic uranium and thorium complexes

New, conformationally restricted ThIV and UIV complexes, [ThCl2(L)] and [UI2(L)], of the small-cavity, dipyrrolide, dianionic macrocycle trans-calix[2]benzene[2]pyrrolide (L)2− are reported and are shown to have unusual κ5:κ5 binding in a bent metallocene-type structure. Single-electron reduction of [UI2(L)] affords [UI(THF)(L)] and results in a switch in ligand binding from κ5-pyrrolide to η6-arene sandwich coordination, demonstrating the preference for arene binding by the electron-rich UIII ion. Facile loss of THF from [UI(THF)(L)] further increases the amount of U–arene back donation. [UI(L)] can incorporate a further UIII equivalent, UI3, to form the very unusual dinuclear complex [U2I4(L)] in which the single macrocycle adopts both κ5:κ5 and η6:κ1:η6:κ1 binding modes in the same complex. Hybrid density functional theory calculations carried out to compare the electronic structures and bonding of [UIIII(L)] and [UIII2I4(L)] indicate increased contributions to the covalent bonding in [U2I4(L)] than in [UI(L)], and similar U–arene interactions in both. MO analysis and QTAIM calculations find minimal U–U interaction in [U2I4(L)]. In contrast to the reducible U complex, treatment of [ThCl2(L)] with either a reductant or non-nucleophilic base results in metallation of the aryl rings of the macrocycle to form the (L−2H)4− tetraanion and two new and robust Th–C bonds in the –ate complexes [K(THF)2ThIV(μ-Cl)(L−2H)]2 and K[ThIV{N(SiMe3)2}(L−2H)]

Nanostructured anti-corrosion coating, structure including same and method for anti-corrosion protection of a substrate

The invention relates to a nanostructured anti-corrosion coating containing polyelectrolytes, including: at least one main compartment including a multilayer (1) of polyelectrolyte(s), doped with at least one anti-corrosion agent (4), and an upper multilayer (2a) acting as a barrier against the diffusion of the doping agents and having an upper surface corresponding to the upper surface of the main compartment; and optionally one or more secondary compartments each including a multilayer (8, 11) of polyelectrolyte(s), doped with at least one functional agent different from an anti-corrosion agent, and an upper multilayer (2b; 2c) acting as a barrier against the diffusion of the doping agents and having an upper surface corresponding to the upper surface of the secondary compartment. The invention also relates to a structure including a metal substrate and such a coating, to the use thereof in the field of aeronautics or aerospace, and to a method for making the same

Organometallic radiopharmaceuticals: rhenium(I) carbonyl complexes of natural bile acids and derivatives

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