Syntheses, structure and rare earth metal photoluminescence of new and known isostructural A2Mo4Sb2O18 (A=Ce, Pr, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu) compounds

Syntheses and Characterizations of Two New Octamolybdate-Based Polyoxometalates Decorated by Isoquinoline Ligands

“…1), which contains one molecular isoquinoline (C 9 H 7 N), two protonate isoquinoline octahedron, which is comparable with those previous reported molybdate compounds. [29][30][31][32] Bond valence sum calculations reveal that all Mo atoms are in the +6 oxidation state, the calculated total bond valences for Mo (1), Mo(2), Mo(3) and Mo(4) are 5.904, 6.120, 5.955 and 6.081, respectively. [33,34] Furthermore, one crystallographical distinct protonated isoquinoline and one Fig.…”

Solid-state synthesis and lanthanide photoluminescence of doped yttrium molybdo-antimonites, Y2−nAnMo4Sb2O18 (A=Pr, Sm, Eu, Tb, Dy, Ho, and Er; n=0.02–2) solid solutions

“…This systematic study of photoluminescence in lanthanide-doped solid solutions, revealed the existence of partial quenching in photoluminescence of neat A 2 Mo 4 Sb 2 O 18 compounds. As mentioned previously [2], the nonbonding distances of $ 6.00 Ǻ between the nearest lanthanide A 3 þ ions in these compounds are apparently not short enough for complete quenching of neat lanthanide photoluminescence.…”

“…For example, Y 1.5 Eu 0.5 Mo 4 Sb 2 O 18 shows maximum intensity in both of its emission and excitation spectra, presented in red and blue colors respectively. The spectral features of all the Y 2À n A n Mo 4 Sb 2 O 18 solid solutions are similar to those of neat A 2 Mo 4 Sb 2 O 18 compounds [2] and, therefore, assigned accordingly. These assigned spectral values compared well with the literature [14][15][16][17][18][19].…”

“…All of these 15 isostructural A 2 Mo 4 Sb 2 O 18 (A¼rare-earth metal) compounds have "zero-dimensional" structures and contain A 3 þ cations and discrete, centrosymmetric tetra-molybdo-diantimonite [1,2]. There are two crystallographically different A 3 þ ions, which reside on 4e Wyckoff sites with twofold symmetry (Fig.…”

“…We reported [1,2] previously solid-state syntheses and structural characterization, by X-ray diffraction, of 15 isostructural A 2 Mo 4 Sb 2 O 18 (A¼ Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu) molybdo-antimonites in quaternary A/Mo/Sb/O (A¼rare-earth metal) systems. These compounds possess discrete (Mo 4 Sb 2 O 18 ) 6À anions and represent the first examples of rare-earth molybdoantimonites.…”