Thermal processing of Zr-loaded ion-exchangers is a facile route to synthetize (ZrO2, ZrC)@C composites. The chemical character of the functional groups in the cation exchanger is an essential factor in the composition and properties of the (ZrO2, ZrC)@C composites. In the present paper furnace and RF-thermal plasma processing of ZrOCl2 loaded thiourea-functionalized styrene-divinylbenzene copolymer was investigated that led to various composites containing ZrO2 and ZrC. Depending on the synthesis conditions, different ZrO2@C composites were formed between 1000 and 1400 °C in 2 h, whereas the composite containing ZrC was created at 1400 °C in 8 h. The ratio of ZrO2/ZrC, the prevailing ZrO2 modifications, and the crystallite sizes strongly depend on the synthesis conditions. The ZrC-containing composites formed only at 1400 °C in 8 hours and by the plasma treatment of the ZrO2@C sample prepared in the furnace, resulting in 8 and 16% ZrC content, with 44 and 41 nm ZrC crystallite sizes, respectively. The ZrO2-containing composites (tetragonal, monoclinic, and cubic modifications with 65–88 nm ZrO2 crystallite sizes and 15–43 m2/g BET surface areas, depending on the carbonization temperature) formed in a tube furnace between 1000 and 1400 °C in 2 h. The tube furnace–prepared sample formed at 1400 °C in 8 h contained ZrC, ZrO2 modifications, and amorphous carbon, whereas the plasma-treated sample contained ZrC, ZrO2 modifications, and graphite. All ZrO2@C composites had both amorphous carbon and graphite, and their ratio is temperature-dependent. The carbonaceous compounds of the prepared composites were characterized by Raman spectroscopy, with analysis of the G and D band intensities. XPS studies showed the surface oxidation of ZrC.

Three octahedral iron(III) nitrate complexes with dimethylated urea ligand isomers, [hexakis(N,N’-dimethylurea-O)iron(III)] nitrate (compound 1), trans-[diaquatetrakis(N,N-dimethylurea-O)iron(III)] nitrate (compound 2) and [hexakis(N,N-dimethylurea-O)iron(III)] nitrate trihydrate (compound 3) were prepared and characterized with single crystal X-ray diffraction, IR, Raman and UV-VIS methods. In compounds 1 and 3, six dimethylurea ligands coordinate to the central FeIII ion via the oxygen in octahedral geometry and the ligands are arranged in a propeller-like manner, dividing the complex cations into two sides. In compound 1, the dimethylurea propellers screw in the opposite direction on the two sides of the complex and in compound 3, they are arranged with the same handedness on the two sides. The complexes have helical chirality. The two sides of the complex cations differ not only in the rotation direction of the ligands but also in the hydrogen bond formation. On one side of the complex cation, the ligands form intermolecular hydrogen bonds only with the crystal waters, meanwhile on the other side of the complex, the ligands form hydrogen bonds only with the nitrate ions. In compound 2, [Fe(N,N-dimethylurea)4(H2O)2]3+ cations form layers that are separated by interconnected NO3- ions forming a hydrogen bonding system and connecting the complex cations A-s and B-s. The three crystallographically different nitrate ions each form four hydrogen bonds in a way that they have one bidentate O atom and two monodentate O atoms, however, the anions differ in their hydrogen bonding. The spectroscopic characteristics of compound 2 were determined by IR measurements on the deuterated compound 2 as well.