The new mono-, di- and tetranuclear coordination compounds [Cu(HL¹)]·H₂O (1), [Cu₂(L¹)(OAc)(MeOH)]·2H₂O·MeOH (2), [Cu₄(L²)₂(OAc)₂]·4MeOH (3), and [Cu₄(L²)₂(OAc)₂]·4H₂O·4MeOH (4) were synthesized by the direct reaction of 2,2′-{(2-hydroxypropane-1,3-diyl)bis[nitrilomethylidene]}bis(4-bromo-6-methoxyphenol) (H₃L¹) or 2,2′-{(2-hydroxypropane-1,3-diyl)bis(nitriloeth-1-yl-1-ylidene)}diphenol (H₃L²) and the Cu(II) salt. They were characterized by elemental analysis, X-ray fluorescence (XRF), Fourier transform infrared (FTIR) spectroscopy, simultaneous thermal analysis and differential scanning calorimetry (TG/DSC), and thermal analysis coupled with Fourier transform infrared spectroscopy (TG-FTIR) techniques and the single crystal X-ray diffraction study. In the dinuclear complex 2, the copper(II) ions are bridged by an alkoxo- and a carboxylato bridges. The tetranuclear complexes 3 and 4 are formed from dinuclear species linkage through the phenoxo oxygen atoms of the fully deprotonated H₃L². Compounds 1–4 are stable at room temperature. During heating in air, at first, the solvent molecules (water and/or methanol) are lost and after that, the organic part undergoes defragmentation and combustion. The final decomposition solid product is CuO. The main gaseous products resulting from the thermal degradation of 1–4 in a nitrogen atmosphere were: H₂O, MeOH, CH₃COOH, CH₄, C₆H₅OH, CO₂, CO, and NH₃.

A series of racemic, heteronuclear complexes [Zn₂Nd(ac)₂(HL)₂]NO₃·3H₂O (1), [Zn₂Sm(ac)₂(HL)₂]NO₃·3CH₃OH·0.3H₂O (2), [Zn₂Ln(ac)₂(HL)₂]NO₃·5.33H₂O (3–5) (where HL is the dideprotonated form of N,N′-bis(5-bromo-3-methoxysalicylidene)-1,3-diamino-2-propanol, ac = acetate ion, and Ln = Eu (3), Tb (4), Dy (5), respectively) with an achiral multisite coordination Schiff base ligand (H₃L) were synthesized and characterized. The X-ray crystallography revealed that the chirality in complexes is centered at lanthanide(III) ions due to two vicinally located μ-acetato-bridging ligands. The presented crystals have isoskeletal coordination units but they crystallize in monoclinic (1, 2) or trigonal crystal systems (3–5) with slightly different conformation. In 1 and 2 the Zn^II–Ln^III–Zn^II coordination core is linear, whereas in isostructural crystals 3–5 the chiral coordination cores are bent and lie on a two-fold axis. The complexes 1, 3–5 show a blue emission attributed to the emission of the ligand. For Zn^II₂Sm^III complex (2) the characteristic emission bands of f-f* transitions were observed. The magnetic properties for compounds 1, 4 and 5 are characteristic for the paramagnetism of the corresponding lanthanide(III) ions.

The paper presents the synthesis of a hydroxyapatite/iron oxide composite utilizing the wet chemical method, as well as the comparison of several selected material characteristics. As follows from the literature reports, hydroxyapatite is a common mineral possessing numerous significant properties. Nowadays, there is an increase in the amount of research on possible modifications of this compound. The promising way to improve hydroxyapatite features is its combination with iron oxide. Particularly, there can be two forms that are distinguished, namely Fe₃O₄ and γ-Fe₂O₃. These oxides exhibit valuable properties, particularly magnetism. A combination of the mentioned materials leads to multifunctional composite formation with many potential applications, as follows from several studies. However, this area of science is not fully developed. There are still many aspects to be examined. The synthesized composite and its components were analyzed by employing the following methods. The X-ray diffraction analysis revealed formation of hydroxyapatite and Fe₂O₃ crystalline phases. Moreover, porosimetry proved a larger specific area for the composite sample in comparison with other materials. The results obtained using the SEM method confirmed an external layer of hydroxyapatite and spherical shapes of internal Fe₂O₃ particles. Furthermore, the X-ray photoelectron spectroscopy data presented characteristic peaks of Fe, Ca, P, and O atoms in all samples. The Fourier Transform Infrared spectra displayed all the specific vibrations typical of the analyzed materials. What is more, the Vibrating Sample Magnetometer method confirmed the paramagnetic nature of the samples. It could be concluded that the synthesized composite has intermediate properties between the components used in the formation process. The results suggest that these composites are superparamagnetic. This type of material architecture would be well suited for biomedical applications.