Crystal structure of bis-(diiso-propyl-ammonium) molybdate.

Bougar Sarr,Petra Hellwig,Frederic Melin,Mamadou Sidibé,Yoann Rousselin,Abdou Mbaye,Cheikh Abdoul Khadir Diop

doi:10.1107/s2056989018014755

Bougar Sarr, Petra Hellwig + Show 5 more

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https://doi.org/10.1107/s2056989018014755

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Abstract

The organic-inorganic title salt, (C6H16N)2[MoO4] or ( i Pr2NH2)2[MoO4], was obtained by reacting MoO3 with diiso-propyl-amine in a 1:2 molar ratio in water. The molybdate anion is located on a twofold rotation axis and exhibits a slightly distorted tetra-hedral configuration. In the crystal structure, the diiso-propyl-ammmonium ( i Pr2NH2)+ cations and [MoO4]2- anions are linked to each other through N-H⋯O hydrogen bonds, generating rings with R 12 12(36) motifs that give rise to the formation of a three-dimensional network. The structure was refined taking into account inversion twinning (ratio of ca 4:1 between the two domains).

Highlights

As a result of the photochromic properties of alkylammonium molybdates (Arnaud-Neu & Schwing-Weill, 1974), molybdenum chemistry is an exciting research area
In the crystal structure of (CyNH2)2MoO4Á2H2O (Cy = cyclohexyl; Pouye et al, 2014) the four Mo—O bond lengths are equal with 1.7613 (12) A. In this structure similar N—HÁ Á ÁO intermolecular interactions between the (CyNH2)+ cation and the molybdate anion are present in comparison with the+ cation in the title compound, the small differences in the hydrogen-bonding pattern result in slightly different Mo—O bond lengths between the two structures
At least the strengths of the N—HÁ Á ÁO hydrogen bonds do not seem to have a noticeable effect on the different Mo—O

Summary

Chemical context

As a result of the photochromic properties of alkylammonium molybdates (Arnaud-Neu & Schwing-Weill, 1974), molybdenum chemistry is an exciting research area. Mononuclear and binuclear anions as well as polyoxidomolybdates with a much higher nuclearity are known (Gatehouse & Leverett, 1969; Matsumoto et al 1975; Modec et al, 2004; Muller & Gouzerh, 2012; Pouye et al, 2014; Sarr et al, 2018). Salts containing the tetrahedral molybdate anion [MoO4]2– combined with cations such as K+, Na+, (CH6N3)+, ((C6H11)2NH2)+, (NH3(CH2)2NH3)+, (OHRNH3)+ and (CyNH2)+ have been isolated in the past (Gatehouse & Leverett, 1969; Matsumoto et al, 1975; Ozeki et al, 1987; Thiele & Fuchs, 1979; Bensch et al, 1987; Sheikhshoaie & Ghazizadeh, 2013; Pouye et al, 2014), but never with the diisopropylammonium cation (iPr2NH2)+.

Structural commentary

Supramolecular features

Database survey

Synthesis and crystallization