Supramolecular Entrapping and Extraction of Selenate, Molybdate and Tungstate Ions from Water by Nanojars.

The supramolecular binding exclusively by H-bonds of SeO, MoO and WO ions to form nanojars of the formula [EO⊂{-Cu(μ-OH)(μ-pz)}] (; E = Se, Mo, W; = 28-34; pz = pyrazolate) was studied in solution by electrospray ionization mass spectrometry, variable temperature, paramagnetic H NMR and UV-vis spectroscopy, and in the solid state by single-crystal X-ray crystallography. These large anions allow for the observation of a record nanojar size, (E = Mo, W). Six crystal structures are described of nanojars of varying sizes with either SeO, MoO or WO entrapped ions, including the first example of a cocrystal of two different nanojars in crystallographically unique positions, and . The latter provides unprecedented structural information about the Cu+Cu+Cu ring combination of a nanojar with an entrapped tetrahedral anion. Also, the first crystal structure of a supramolecular host-guest complex with an entrapped WO ion, is reported in this work. The relative strength of binding of SeO, MoO and WO ions by nanojars of different sizes was assessed by reactivity studies toward Ba ions and NH. Thermal stability studies of the various nanojars were conducted in DMSO- solutions over a 22-150 °C range. Furthermore, liquid-liquid extraction of SeO, MoO and WO ions from water into an organic solvent by nanojars was investigated.