Crystal structure of bis( N , N , N - trimethylbutanaminium) tetrathiotungstate(VI), (BuMe 3 N) 2 [WS 4 ]

C 14 H 36 N 2 S 4 W, monoclinic, C 2/ c (no. 15), a = 16.175(3) Å, b = 9.7755(15) Å, c = 15.452(3) Å, β = 115.183(7) ° , V = 2211.0(7) Å 3 , Z = 4, R gt ( F ) = 0.0190, wR ref ( F 2 ) = 0.0490, T = 223 K.

1 Source of material (NH 4 ) 2 WS 4 (0.030 g, 0.086 mmol) and BuMe 3 NI (0.063 g, 0.26 mmol) were charged to a Pyrex tube with diameter of 9 mm and about 0.3 mL 1:2 (v/v) H 2 O/MeOH mixture was added as a solvent.While the solvent was being frozen, the Pyrex tube was evacuated under vacuum and sealed with the use of a flame.The sealed tube was placed in an oven and heated at 90 °C for a day, then cooled to room temperature.Yellow orange polyhedral crystals were isolated by filtration and washed with MeOH and diethyl ether several times.Crystals of (BuMe 3 N) 2 [WS 4 ] were obtained in 13 % yield, based on the W metal used.

Experimental details
H atoms were positioned geometrically and treated as riding, with C-H = 0.98 (CH 2 ) and 0.97 (CH 3 ) Å with U iso (H) = 1.2 (1.5 for methyl) U eq (C).H atoms of the CH 3 were positioned to be staggered with respect to the shortest other bond to the atom to which the CH 3 is attached.

Comment
The title compound, (BuMe 3 N) 2 [WS 4 ], prepared by the solvothermal reaction of (NH 4 ) 2 WS 4 and BuMe 3 NI with a 1:2 (v/v) Soluble tetrathiotungstate compounds have focused much attention mainly due to their potential as precursors for the WS 2 HDS (HydroDeSulfurization) catalyst and the soft synthesis of WS 2 nanomaterials. 5,64][15][16][17] As an unsymmetrical mixed tetraalkylammonium cation, BuMe 3 N + can be considered a new type of cation suitable for the stabilization of the [WS 4 ] 2− anion.It is noteworthy that attempts to obtain (PhMe 3 N) 2 [WS 4 ] using the same solvothermal synthetic approach resulted in the stabilization of the [W 3 OS 8 ] 2− anion instead of the [WS 4 ] 2− anion. 18n the (BuMe 3 N) 2 [WS 4 ] compound, the structure of the discrete [WS 4 ] 2-anion shows that the central W(1) atom lies on a twofold axis and only two S atoms, S(1) and S(2) are crystallographically unique.The tetrahedral coordination behavior around the W(1) atom is quite ideal as S-W-S bond angles range from 108.54(3) to 111.02(5)°and W-S distances are nearly identical ranging from 2.1846 (7)

Table  :
Data collection and handling.
to 2.1877(7)Å.The ideal tetrahedral coordination behavior of the [WS 4 ] 2− anion implies that there is minimal influence caused by the packing of unsymmetrical BuMe 3 N + cations and no strong interaction between the BuMe 3 N + cations and the [WS 4 ] 2− anions.Compared to the shortest S⋯H distance of 2.31 Å observed in ((CH 3 )H 2 NCH 2 CH 2 NH 3 )[WS 4 ], 17 the shortest S⋯H distance in this compound is significantly longer, measuring 2.8477(9) Å between S(1) and H(2B), indicating a lack of H-bonding between the BuMe 3 N + cations and the [WS 4 ] 2− anions.All the authors have accepted responsibility for the entire content of this submitted manuscript and approved submission.Competing interests: The authors declare no conflicts of interest regarding this article.Research funding: This work was supported by the Incheon National University Research Grant in 2020.

Table  :
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å  ).