Zdeněk Moravec

Synthesis and evolution of crystalline garnet phases in Y3Sc5-xGaxO12

Mixed-metal oxides with the composition Y3Sc x Ga5− x O12 (x = 2.0, 2.1, 2.2, 2.25, 2.3, 2.4, 2.5, and 3.0) have been prepared by an aqueous sol–gel method. The effects of scandium substitution on the garnet phase formation were studied by IR spectroscopy and X-ray powder diffraction (XRD). The XRD data indicate that single-phase Y3Sc x Ga5− x O12 ceramic samples were obtained for x = 2.0, 2.1, 2.2, 2.25, 2.3, and 2.4. The results also show that the formation of Y3Sc x Ga5− x O12 garnets depends on the molar ratio of scandium and gallium in the investigated composition, and consequently on the mean cationic radius at the Al3+ sites. The variation of lattice parameters for the Y3Sc x Ga5− x O12 phases with different x is reported.

Syntheses and X-ray structures of heteroleptic octahedral Mn(II)-xanthato complexes involving N-donor ligands

A series of octahedral manganese(II) complexes involving xanthates and N-donor ligands, [Mn(S2COiBu)2(phen)] (1), [Mn(S2COiBu)2(2,2′-bpy)] (2), [Mn(S2COnPr)2(phen)] (3), [Mn(S2COnPr)2(2,2′-bpy)] (4), [Mn(S2COMe)2(2,2′-bpy)] (5), [Mn(S2COnPr)2(4,4′-bpy)]n, and [Mn2(S2COnPr)4(4,4′-bpy)3] (6) (phen = 1,10-phenanthroline, bpy = bipyridine) was prepared. Complexes were characterized by elemental analysis, FTIR spectroscopy, TG/DSC analysis, and single-crystal X-ray diffraction. The structures are built of monomeric molecules of the complexes, except for 6 with the 4,4′-bipyridine ligand, which contains a binuclear complex and 1D polymeric zigzag chain in one crystal.