Lead nanoparticles ranging from 10-200 nm were prepared by reacting [Pb{N(SiMe 3 ) 2 } 2 ] with the reducing agent tert-butoxy alane, [H 2 Al(OtBu)] 2 , in non-aqueous media. By this reaction, Pb nuclei on the molecular scale can be produced imparting a high regularity of shape and size to the resulting nanoparticles. The amino-alkoxo-alane {[(Me 3 Si) 2 N][tBuO]Al-H} 2 is formed as the main molecular by-product. The molecular structure of this amino-alkoxo-alane was determined by single crystal X-ray diffraction techniques revealing a centro-symmetric molecule with a central Al 2 O 2 ring (Al-O = 1.848(1) Å) to which tert-butyl (on oxygen) and hexamethyldisilazyl and hydrogen atoms (on aluminium) are bonded. Coloured sols of lead particles were obtained using donor solvents containing N, S and O atoms. The optical absorption spectra of colloids obtained at different concentrations of the starting materials indicate that the colour change (yellow -orange -burgundy red) is related to the particle size and/or the aggregation of particles in more concentrated solutions. The particles are nanoscopic and can be redispersed after a short ultrasonic treatment. This phase-separation is related to the nature of Pb-ligand interactions and to the aggregation of particles in the colloidal solution. Particle growth and inter-particle aggregation were observed by electron microscopy studies and absorption spectra of lead particles present in different solutions. A variation of concentration of lead clusters present in the colloids shows a shift in the absorption spectra related to plasmon-plasmon interaction typically observed in the aggregates of metal nanoparticles. Porous anodic alumina membranes were filled with lead nanoparticles either by vacuum-induced infiltration of lead particles or by reduction of the Pb(II) precursor within the pores. The latter approach proved to be more successful in obtaining Pb/Al 2 O 3 composites. The chemical composition and morphology of Pb particles in colloidal solutions and those present in and on the porous alumina membrane were investigated by XRD, FT-IR, SEM and TEM analysis.

The Reaction Behaviour of the Polycylic Oligoalumosiloxane [Ph2SiO]8[AlO(OH)]4 towards Hexamethyldisilazane The reaction of the oligoalumosiloxane [Ph2SiO]8[AlO(OH)]4 (1) with hexamethyldisilazane leads to the triple ionic [Ph2SiO]8[AlO2]2[AlO(O‐SiMe3)]2[NH4·THF]2·2 THF (2) and in the presence of pyridine to [Ph2SiO]8[AlO1.5]4·2py·1.5 C7H8 (3). Apart from the usual characterization techniques (NMR and IR spectroscopy) the molecular structures of 2 and 3 have been determined by single‐X‐ray diffraction analyses. Both alumosiloxanes 2 and 3 present new types of molecular structures with a central four membered Al2O2‐ring, on which the further aluminium atoms are attached via oxygen atoms. This leads to an Al4‐lozenge, which is centered in subtriangles by oxygen atoms.

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