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Host–guest assemblies open up opportunities for developing novel functional CLUSPOM multicomponent systems based on transition metal clusters (CLUS), polyoxometalates (POMs) and macrocyclic organic ligands. In water–ethanol solution γ-cyclodextrin (γ-CD) interacts with halide metal clusters [M6Cl14]2– (M = Mo, W) to form sandwich-type structures. The supramolecular association between the clusters and CDs, however, remains weak in solution, and the interactions are not strong enough to prevent the hydrolysis of the inorganic guest. Although analysis of the resulting crystal structures reveals inclusion complexation, 1H NMR experiments in solution show no specific affinity between the two components. The luminescent properties of the host–guest compounds in comparison with the initial cluster complexes are also studied to evaluate the influence of CD. [ABSTRACT FROM AUTHOR]

Slow evaporation of water solution of [{ReS}(HO)] generated in situ from [{ReS}(OH)] in presence of γ-cyclodextrin (CD) leads to crystallization of {[{ReS}(HO)] ⊂ [γ-CD]}(NO)·12HO ( 1·12HO) supramolecular complex, which was characterized by single-crystal X-ray diffraction crystallography, IR-spectroscopy, thermogravimetric and elemental analyses. X-ray analysis confirms the formation of 1:1 {[{ReS}(HO)] ⊂ [γ-CD]} inclusion compound in the solid state. However, no adduct formation was detected between [{ReS}(HO)] and γ-cyclodextrin in solution, according to H NMR spectroscopy. In the case of in situ generated [{ReSe}(HO)] the reaction solution with γ-cyclodextrin is unstable and during the crystallization only amorphous precipitate has been obtained. [ABSTRACT FROM AUTHOR]

The potential of high-field NMR to measure solid-state 95Mo and 183W NMR in polyoxometalates (POMs) is explored using some archetypical structures like Lindqvist, Keggin and Dawson as model compounds that are well characterized in solution. NMR spectra in static and under magic angle spinning (MAS) were obtained, and their analysis allowed extraction of the NMR parameters, including chemical shift anisotropy and quadrupolar coupling parameters. Despite the inherent difficulties of measurement in solid state of these low-gamma NMR nuclei, due mainly to the low spectral resolution and poor signal-to-noise ratio, the observed global trends compare well with the solution-state NMR data. This would open an avenue for application of solid-state NMR to POMs, especially when liquid-state NMR is not possible, e.g., for poorly soluble or unstable compounds in solution, and for giant molecules with slow tumbling motion. This is the case of Keplerate where we provide here the first NMR characterization of this class of POMs in the solid state. Copyright © 2017 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Two dimethyldioctadecylammonium (DODA+) salts of a new keplerate with the general formula [Mo132O312S60(SO4)x(H2O)132–2x](12 + 2x)−and abbreviatedDODAn−Mo132S60(n= 44, 56) were synthesised and characterised. Both clusters were fully characterised by the combination of Polarised Optical Microscopy, Differential Scanning Calorimetry and Small-angle X-Ray Diffraction showing self-organisation in lamellar (L) liquid crystalline phases. We demonstrated that the lamellar periodicityhof the mesophases can be controlled with the number of DODA+associated to the clusters. Finally, these new results were compared to those gained from a previously published analogue, the fully oxo keplerate noted DODA36−Mo132that also self-organise with temperature, but in a slightly more structured lamellar liquid crystalline phase. [ABSTRACT FROM AUTHOR]

Thermal studies of a DODA+ salt of the nanoscopic hollow sphere [Mo132O372(H2O)72(CH3CO2)30]42− revealed ionic liquid crystalline properties, which were evidenced by Polarised Optical Microscopy, DSC and SA-XRD. [ABSTRACT FROM AUTHOR]

Reaction of the [Mo2VS2O2]2+ oxothiocation with a stochiometric amount of C2O42− in water, at pH around 5, affords the novel anion [Mo6S6O6(OH)4(C2O4)3]4−. The structure has been solved by single-crystal X-ray diffraction and consists in a six-membered incomplete wheel encapsulating a template oxalate anion and showing two external bridging oxalate ligands. In the solid state, two potassium ions bound to the terminal oxygen atoms of the [Mo6S6O6(OH)4(C2O4)3]4− anion direct the formation of a 1D chain. The four members of this family of products obtained by condensation of the oxothiocation with oxalate ligands are thus now perfectly characterized and can be easily distinguished by infrared spectroscopy. [Copyright &y& Elsevier]

Tripotassium-tris[(µ 3 -oxido)triaqua-hexakis(acetato)triiron(III)](octadecatungsto-diphosphato(V))ditriacontahydrate, K 3 [Fe 3 O(CH 3 COO) 6 (H 2 O) 3 ] 3 [P 2 W 18 O 62 ]·32H 2 O ( 1 ) is constructed from Wells–Dawson type polyanion [α-P 2 W 18 O 62 ] 6− and triiron(III) cluster cations [Fe 3 O(CH 3 COO) 6 (H 2 O) 3 ] + which are assembled by potassium ions to form a supramolecular structure with nanoscale tunnels running parallel to the c -axis. The structure was confirmed by single crystal X-ray analysis, FT-IR, 1 H and 31 P NMR and UV–Vis spectroscopy studies, cyclic voltammetry and TGA-DSC thermal analyses. Compound 1 crystallizes in the monoclinic space group P 2 1 / n with cell parameters: a = 17.81830(10) Å, b = 29.6939(3) Å, c = 29.7691(2) Å, β = 91.4700 (10)° and Z = 4. [ABSTRACT FROM AUTHOR]

A new organic–inorganic hybrid polyoxotungstate [Ni{OCH-N(CH 3 ) 2 } 6 ] 2 [Ni{OCH-N(CH 3 ) 2 } 5 (α-P 2 W 18 O 62 )]·C 3 H 7 NO·C 3 H 8 O ( 1 ), functionalized by nickel dimethylformamide complex, have been successfully prepared, at room temperature, by simple one step method and structurally characterized by FT-IR, 31 P NMR and UV–visible spectroscopy studies, powder and single crystal X-ray diffraction (XRD), cyclic voltammetry and by ATG-DSC thermal analyses. Compound ( 1 ) crystallizes in the triclinic P 1 ¯ space group with cell parameters: a = 15.7969(2) Å, b = 15.9399(2) Å, c = 30.6800(7) Å, α = 80.258(2)°, β = 87.661(2)°, γ = 72.540(1)° and Z = 2. It exhibits a supramolecular structure with nanoscale cavities arranged in rows parallel to the b axis. The powder X-ray diffractogram confirmed that compound ( 1 ) has been obtained as a single phase. [ABSTRACT FROM AUTHOR]

Thermal studies of a DODA+ salt of the nanoscopic hollow sphere [Mo132O372(H2O)72(CH3CO2)30]42− revealed ionic liquid crystalline properties, which were evidenced by Polarised Optical Microscopy, DSC and SA-XRD. [ABSTRACT FROM AUTHOR]