RESUMEN
Three novel polyoxovanadoborates namely [V12B18O46(OH)14(H2O)0.75]·20.5H2O 1, Na2[V12B18O48(OH)12(H2O)0.5]·26.5H2O 2 and Cd0.5{[Na(H2O)2]2[Na(H2O)]2[Na(H2O)3]2V12B18O53(OH)7(H2O)0.5}·11H2O 3 have been hydrothermally synthesized and structurally characterized. The boratopolyoxovanadate cage [V12B18O60] backbones in 1-3 are constructed by the combination of two hexameric oxovanadate units [V6O9] and one puckered [B18O42] ring via sharing O atoms. All three compounds were obtained under alkaline conditions, and the cluster anions were all [V12B18O60]. But the cations were different, it is inferred that the protonation of the three compound cluster ions is different, respectively [V12B18O46(OH)14(H2O)0.75] in 1, [V12B18O48(OH)12(H2O)0.5]2- in 2 and [V12B18O53(OH)7(H2O)0.5]7- in 3. The V oxidation states ratio of VIV to VV were 2:1 confirmed by valence bond calculation and XPS. We studied the magnetic properties of three compounds by two methods: The variable temperature magnetic susceptibility and the 2D IR COS under magnetic perturbation. From the 2D IR COS under magnetic perturbation map, it is showed that all three: (1) the presence of VIV. (2) Certain quasi-aromaticity from B3O3 six-membered ring. (3) The difference of protonation and the charge of the cluster anions. This work enriches the theory of two-dimensional correlation spectroscopy and also provides a new approach to the study of magnetic materials.
RESUMEN
Two novel inorganic-organic hybrids containing the pyramidal SbO3 group in Dawson-like POMs based on an organic ligand with different coordination modes, namely {Ni(phen)3}3[SbW18O60]·(H3O)3·7H2O (1) and [CuI(phen)(H2O)3]{[Cu(phen)2(H2O)2]2[SbW18O60]}·2H2O (2) (phen = 1,10-phenanthroline), have been synthesized. The catalytic property of compound 1 was studied as the first case for an {M18} cluster containing the pyramidal SbO3 group. Remarkably, compound 1 has excellent photocatalytic activity for RhB degradation and the probable mechanism of degradation was discussed. Additionally, the 2D-IR correlation spectra (2D-IR COS) under magnetic perturbation were recorded to analyze the magnetic properties of compound 1. The 2D-IR COS under thermo perturbation were recorded to verify the presence of H-bonding interactions.