Catalysis of “outer-phase” oxygen atom exchange reactions by encapsulated “inner-phase” water in {V15Sb6}-type polyoxovanadates

A water molecule encapsulated inside water-soluble {V15Sb6} antimonato polyoxovanadate cages accelerates oxygen-exchange reactions in the cluster periphery.


Contents
-S10 Bond length and angles of the transition metal amine comples in I -IV S12-S17 Table S11 -S14 Hydrogen interactions in I -IV S18-S19 Figure S8 Molar magnetization M m as a function of the applied field B S20

IR Spectra
In Figure S1, the IR spectra of compounds I -III are displayed. As compound IV is a (pseudo)polymorph of I, both have equal IR spectra. All bands were assigned to the organic molecules or to the cluster vibrations. The values and assignments are listed in Table S1. Figure S1. IR spectra of compounds I -III.

Calibration of the UV/Vis Absorption at 320 nm for Solubility Studies
The absorption vs. concentration calibration curve was obtained by dissolving I in different, defined concentrations in water (1.31·10 -5 M, 2.30·10 -5 M, 3.28·10 -5 M, 4.27·10 -5 M, 5.58·10 -5 M) and measuring the UV/Vis spectra of these solutions. The peak maximum at 320 nm was evaluated and its absorption plotted against the sample concentration. A saturated solution of I in water was diluted by a factor of 1:25 to be in the concentration range of the calibration curve. The concentration was determined from its absorption at 320 nm and calculated back to that of the to determine the maximal solubility of I in water (1.19 g L -1 ).

Figure S6
. UV/Vis spectrum of I dissolved in water (top) and the calibration curve obtained from the peak maxima at 320 nm used to determine the maximal solubility (bottom). Table S2 summarizes information on single crystal structure refinement and shows clearly the similarity of the isostructural compounds I -III and the differences to the (pseudo)polymorphic compound IV. Bond valence sum (BVS) [2] yield following values:      Figure S7 shows the arrangement of the (pseudo)polymorph compound IV with its discrete cluster anions and the Ni amine complexes as counter cations. Table S7 shows the TM-N bond length and angles. All values are in typical ranges for known TM amine complex acting as counter cations in heteroatom incorporated POVs. S12 Figure S7. Arrangement of the cluster anions and transition metal complex cations of IV. Hydrogen atoms are not displayed for clarity.

Bond Lengths Bond Angles
Table S10 Selected bond lengths and angles of the Ni(en) 3 2+ cations in the crystal structure of compound IV.

Bond Lengths Bond Angles
The discrete cluster anions and the discrete M(en) 3 2+ cations form a complex hydrogen network. The hydrogen bond lengths and the corresponding interacting atoms for all four compounds are listed in Tables S8 -S11.     1971; b) ligand field parameter in Wybourne notation; c) mean field parameter ("-2J" notation) d) goodness of fit. analogy to the parent cluster. It can thus be assumed that they belong to structurally closely related cluster species, for which we were nevertheless unable to find a fully convincing elemental composition, which is in line with all experimental data.

Electrospray ionization mass spectrometry
As the powder diffraction patterns of a sample that was used for the mass spectrometric experiments clearly showed the sample not to contain significant amounts of impurities, we assume that these signals correspond to a marginal level of impurities, which are more easily ionized and thus appear with higher intensities in the mass spectra than expected from their abundance in the sample.