Calixarenes are cyclic oligomers obtained by condensation of suitable p-functionalised phenols with formaldehyde, usually allowing for the synthesis of the well known small calixarenes (including up to eight phenolic subunits). We report here the discovery of much larger members of this family, exhibiting sizes up to 90 phenolic subunits: the giant calixarenes. These macrocycles are obtained according to simple, easily scalable processes, in yields up to 65%. We show that the formation of these giant macrocycles is favored by an oxygen-containing-group at the para-position of the starting phenol, high concentrations of heavy alkaline bases (rubidium or cesium hydroxides) and long reaction times. A mechanism is proposed to rationalize these observations. These giant macrocycles can also be obtained in the quasi-solid state, opening interesting perspectives in the field of calixarenes chemistry. Along with their intrinsic fundamental interest, these objects are also opening interesting applicative potentialities.

At the nanoscale, the synthesis of a random alloy (i.e. without phase segregation, whatever the composition) by chemical synthesis remains a difficult task, even for simple binary type systems. In this context, a unique approach based on the colloidal route is proposed enabling the synthesis of face-centred cubic and monodisperse bimetallic, trimetallic, tetrametallic and pentametallic nanoparticles with diameters around 5 nm as solid solutions. The Fe–Co–Ni–Pt–Ru alloy (and its subsets) is considered a challenging task as each element has fairly different physico-chemical properties. Particles are prepared by temperature-assisted co-reduction of metal acetylacetonate precursors in the presence of surfactants. It is highlighted how the correlation between precursors’ degradation temperatures and reduction potential values of the metal cations is the driving force to achieve a homogeneous distribution of all elements within the nanoparticles.

Recent advances in structural control during the synthesis of SWCNTs have in common the use of bimetallic nanoparticles as catalysts, despite the fact that their exact role is not fully understood.

Plasmonic catalysis enables the realization of reactions using solar light with less energy and time consumption. Pd nanoflowers synthesized by a radiolytic reduction of Pd^II(acac)₂ in ethanol under a CO atmosphere exhibit a broad plasmon band in the visible–near infrared domain. These plasmonic nanostructures showed remarkably enhanced the photocatalytic activity for Suzuki–Miyaura reactions under visible light irradiation.

We report a new and versatile colloidal route towards the synthesis of nanoalloys with controlled size and chemical composition in the solid solution phase (without phase segregation such as core–shell structure or Janus structure) or chemical ordering. The principle of the procedure is based on the correlation between the oxidation–reduction potential of metal cations present in the precursors and the required synthesis temperature to nucleate particles without phase segregation. The procedure is demonstrated via the synthesis of Face Centered Cubic (FCC) Ni_xPt_1−x nanoparticles, which was elaborated by the co-reduction of nickel(II) acetylacetonate and platinum(II) acetylacetonate with 1,2-hexadecanediol in benzyl ether, using oleylamine and oleic acid as surfactants. The chemical composition and solid solution FCC structure of the nanoalloy are demonstrated by crosslinking imaging and chemical analysis using transmission electron microscopy and X-ray diffraction techniques. Whatever the chemical composition inspected, a systematic expansion of the lattice parameters is measured in relation to the respective bulk counterpart.