Redetermination of the crystal structure of 3,5-dimethylpyrazolium β-octamolybdate tetrahydrate

Abstract

The title compound, (C5H9N2)4[Mo8O26]·4H2O, was reported previously from a room-temperature data collection from which only the metal atoms could be refined anisotropically [FitzRoy et al. (1989 ▸). Inorg. Chim. Acta, 157, 187–194]. The current redetermination at 180 (2) K models all the non-H atoms with anisotropic displacement parameters and fully describes the supra­molecular N—H⋯O and O—H⋯O hydrogen-bonded network connecting the 3,5-di­methyl­pyrazolium cations, the water mol­ecules of crystallization and the β-octa­molybdate anion. All H atoms involved in the three-dimensional hydrogen-bonding network could be located from difference Fourier maps, with the exception of those of one disordered water mol­ecule, firstly seen in this structural report [refined over two distinct locations with site-occupancy factors of 0.65 (2) and 0.35 (2)]. The complete β-octa­molybdate anion is generated by a crystallographic inversion centre.

Non-hydrothermal synthesis and structure determination of two new β-octamolybdate (VI) stabilized with dialkylammonium counterions

“…In addition, for both compounds (1) and 2 . This was also reported in the literature for similar compounds but was not yet interpreted [33,34]. We suggest here that some variations in the MoeO bond lengths in the b-[Mo 8 O 26 ] 4cluster can be explained at least partially by the fact that the junction of two MoO 6 octahedra by edge sharing brings the two positive (Mo VIþ ) ions closer, which enhances their mutual repulsive interaction (Coulomb interaction).…”

Supramolecular interaction-induced assemblies of polyanions and 2-aminopyridinium in two polyoxometalate-based hybrids

“…In contrast to these modes, Mo3 is surrounded by two O t , three O b and one O d atom. Correspondingly, the Mo-O bond lengths are all in the normal range and are comparable with those of a reported octamolybdate anion (Amarante et al, 2016).…”

“…The second type of organic cation, i.e. protonated organic molecules, despite some related literature, requires further investigation because of the vast amount of organic molecule structural types, which not only results in different assembled structures, but also exhibits various interactions (Amarante et al, 2016;Lukashuk et al, 2011). Of all the organic molecules, pyridine-containing compounds represent an important category due to easy protonation of the N atoms on the ring and their high structural stability (Gong et al, 2006;Liu & Xu, 2007;Zhang et al, 2012).…”