The facile chemical precipitation method and subsequent thermal treatment were shown to be suitable for preparation of crystalline ThO2 nanoparticles (NPs) in a wide range of particle sizes (from 2.5 to 34.3 nm). The obtained NPs were investigated with X-ray diffraction, high-resolution transmission electron microscopy and X-ray absorption techniques to find out the possible size effects associated with nanocrystalline thoria. For 2.5 nm NPs, the lattice parameter of ThO2 was found to increase by up to 1.1 %, in comparison with the bulk material. The decrease in the particle size was also accompanied by a significant decrease in the Th-Th coordination number.

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In this work we presented a synthesis and investigation of relative acyclic and macrocyclic polyamines with picolinate pendant arms as potential chelators for copper radiopharmaceuticals. It has been shown that linear chelators lacking bisamide moiety are much more basic and form complexes with higher stability constants compared to macrocyclic ones. Both types of ligands possess many donor sites due to picolinate groups enabling formation of polynuclear complexes in the solution and solid state. According to crystal structures metal cations coordinates with studied ligands through the binding with aminogroups and picolinates donor atoms, while terminal aminogroups of acyclic ligands do not take part in the complex formation. Tripicolinate azacrown ligand coordinates cations outside the macrocyclic cavity in non-equivalent positions. However this out-cage location as well as a moderate logK value do not induce fast release of cation from this complex in the challenging medium of serum proteins.