Bis(tetra­methyl­guanidinium) hexa­chlorido­tellurate(IV)

Giltzau, N.O.; Köckerling, M.

doi:10.1107/S2414314618014888

organic compounds

IUCrDATA

ISSN: 2414-3146

Volume 3| Part 10| October 2018| x181488

https://doi.org/10.1107/S2414314618014888

Open

access

Bis(tetramethylguanidinium) hexachloridotellurate(IV)

Niels Ole Giltzau ^a and Martin Köckerling ^a ^*

^aUniversität Rostock, Institut für Chemie, Anorganische Festkörperchemie, Albert-Einstein-Str. 3a, D-18059 Rostock, Germany
^*Correspondence e-mail: Martin.Koeckerling@uni-rostock.de

Edited by C. Massera, Università di Parma, Italy (Received 20 September 2018; accepted 20 October 2018; online 31 October 2018)

The title compound, 2C₅H₁₄N₃⁺·TeCl₆²⁻, is an easily accessible salt with a relatively low melting point. The asymmetric unit consists of a Te_0.25Cl_1.5 fragment and half a cation. Weak hydrogen bonds of the type C—H⋯Cl and N—H⋯Cl are present in the crystal structure.

Keywords: crystal structure; tetramethylguanidinium; hexachloridotellurate(IV).

CCDC reference: 1874699

Structure description

The asymmetric unit of the title salt consists of a Te_0.25Cl_1.5 unit (with the tellurium atom located on the 8a Wyckoff site of the space group Fddd with 222 symmetry) and of one half of the TMG cation (the C1 and N1 atoms are located on a twofold rotation axis, site 16g). The molecular structure is shown in Fig. 1.

Figure 1
The molecular structure of the title compound with displacement ellipsoids drawn at the 50% probability level. Symmetry codes: (i) −x + $[{7\over 4}]$ , y, −z + $[{3\over 4}]$ ; (ii) −x + $[{7\over 4}]$ , −y + $[{3\over 4}]$ , z; (iii) −x + $[{3\over 4}]$ , −y + $[{3\over 4}]$ , z; (iv) x, −y + $[{3\over 4}]$ , −z + $[{3\over 4}]$ .

The distances between the tellurium atom and the surrounding chlorine atoms of the [TeCl₆]²⁻ anion are 2.5363 (4) and 2.5394 (3) Å, in agreement with published Te—Cl bond lengths (Allen et al., 1987 ). The angle between the carbon atom C1 and the two nitrogen atoms N2 in the cation is 120.14 (6)°. The distance between N1 and C1 is 1.323 (2) Å, while that between C1 and N2 is 1.342 (1) Å, indicating that C1 is involved in a double bond. The bond lengths between N2 and atoms C2 and C3 are longer, 1.464 (2) and 1.459 (1) Å, respectively, as expected for N—C single bonds. Consistent with the d glide planes of the space group Fddd, the tetramethylguanidinium cations and the hexachloridotellurate(IV) anions are arranged in chains with an alternating orientation of the cations in the three unit-cell directions (see Fig. 2).

Figure 2
View along the a axis of the unit cell showing the arrangement of the ions of the title compound.

Weak hydrogen bonds (Table 1) are found between the NH₂ groups of the cation and the chlorine atoms of the anion with a shortest Cl⋯N distance of 3.3875 (8) Å.

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N1—H1⋯Cl2ⁱⁱ	0.83 (2)	2.57 (2)	3.3875 (8)	167 (1)
C2—H2B⋯Cl2^v	0.98	2.84	3.712 (1)	149
C3—H3B⋯Cl1^v	0.98	2.82	3.644 (1)	142
Symmetry codes: (ii) $[x, -y+{\script{3\over 4}}, -z+{\script{3\over 4}}]$ ; (v) -x+1, -y+1, -z+1.

The number of published X-ray structures of tetramethylguanidinium (TMG) metal salts is limited. The first publication is from the 1960s (Longhi & Drago, 1965 ). Different metal salts with the TMG cation have been published since then (Snaith et al., 1970 ; Bujak et al., 1999 ; Jones & Thonnessen, 2006 ; Bujak & Zaleski, 2007 ; Due-Hansen et al., 2011 ; Ndiaye et al., 2016a ,b ; Şendıl et al., 2016 ). Tetramethylguanidinium salts find applications in the capture of SO₂ or the removal of sulfur-carrying organic materials (Berg et al., 2013 ; Meng et al., 2017 ). An example of the properties of ionic liquids with the [TeCl₆]²⁻ anion was published recently (Shen et al., 2018 ).

Synthesis and crystallization

N,N,N′,N′-tetramethylguanidinium chloride (0.5156 g, 0.0034 mol) and tellurium tetrachloride (0.458 g, 0.0017 mol) were dissolved in ethanol (10 ml). The yellow liquid was stirred at ambient temperature for one day. The reaction mixture was filtered and the solvent was removed with a rotary evaporator. A yellow solid was obtained in nearly stoichiometrical yields. The melting point was determined using DSC to be 134°C. A stoichiometric amount of the compound was dissolved in ethanol (approx. 10 mg per ml of ethanol) and crystals were grown through slow diffusion of diethyl ether into the solution.

Refinement

Crystal data, data collection and structure refinement details are summarized in Table 2. The reflection 022 was omitted from the refinement because its intensity was affected by the beam stop.

Table 2
Experimental details

Crystal data
Chemical formula	2C₅H₁₄N₃⁺·Cl₆Te²⁻
M_r	572.68
Crystal system, space group	Orthorhombic, Fddd
Temperature (K)	123
a, b, c (Å)	7.3899 (5), 22.447 (2), 28.512 (2)
V (Å³)	4729.6 (6)
Z	8
Radiation type	Mo Kα
μ (mm⁻¹)	1.92
Crystal size (mm)	0.45 × 0.35 × 0.12

Data collection
Diffractometer	Bruker APEXII CCD
Absorption correction	Multi-scan (SADABS; Bruker, 2017 )
No. of measured, independent and observed [I > 2σ(I)] reflections	47585, 2158, 2057
R_int	0.027
(sin θ/λ)_max (Å⁻¹)	0.757

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.013, 0.034, 1.26
No. of reflections	2158
No. of parameters	62
H-atom treatment	H atoms treated by a mixture of independent and constrained refinement
Δρ_max, Δρ_min (e Å⁻³)	0.39, −0.37
Computer programs: APEX3 and SAINT (Bruker, 2017), SHELXS2014 (Sheldrick, 2008 ), SHELXL2014 (Sheldrick, 2015 ), DIAMOND (Brandenburg & Putz, 2014 ) and publCIF (Westrip, 2010 ).

Structural data

CCDC reference: 1874699

Crystal structure: contains datablock I. DOI: https://doi.org/10.1107/S2414314618014888/xi4001sup1.cif

Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S2414314618014888/xi4001Isup2.hkl

checkCIF report

Computing details top

Data collection: APEX3 (Bruker, 2017); cell refinement: SAINT (Bruker, 2017); data reduction: SAINT (Bruker, 2017); program(s) used to solve structure: SHELXS2014 (Sheldrick, 2008); program(s) used to refine structure: SHELXL2014 (Sheldrick, 2015); molecular graphics: DIAMOND (Brandenburg & Putz, 2014); software used to prepare material for publication: publCIF (Westrip, 2010).

Bis(tetramethylguanidinium) hexachloridotellurate(IV) top

Crystal data top

2C₅H₁₄N₃⁺·Cl₆Te²⁻	D_x = 1.609 Mg m⁻³
M_r = 572.68	Melting point: 407 K
Orthorhombic, Fddd	Mo Kα radiation, λ = 0.71073 Å
a = 7.3899 (5) Å	Cell parameters from 9942 reflections
b = 22.447 (2) Å	θ = 2.3–32.5°
c = 28.512 (2) Å	µ = 1.92 mm⁻¹
V = 4729.6 (6) Å³	T = 123 K
Z = 8	Stick, yellow
F(000) = 2272	0.45 × 0.35 × 0.12 mm

Data collection top

Bruker APEXII CCD diffractometer	2057 reflections with I > 2σ(I)
Radiation source: microfocus sealed tube	R_int = 0.027
φ and ω scans	θ_max = 32.6°, θ_min = 2.9°
Absorption correction: multi-scan (SADABS; Bruker, 2017)	h = −11→11
	k = −34→33
47585 measured reflections	l = −42→42
2158 independent reflections

Refinement top

Refinement on F²	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: mixed
R[F² > 2σ(F²)] = 0.013	H atoms treated by a mixture of independent and constrained refinement
wR(F²) = 0.034	w = 1/[σ²(F_o²) + (0.0103P)² + 6.2116P] where P = (F_o² + 2F_c²)/3
S = 1.26	(Δ/σ)_max = 0.001
2158 reflections	Δρ_max = 0.39 e Å⁻³
62 parameters	Δρ_min = −0.37 e Å⁻³
0 restraints	Extinction correction: SHELXL2014 (Sheldrick, 2015), Fc^*=kFc[1+0.001xFc²λ³/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.000156 (17)

Special details top

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

Refinement. All non-hydrogen atoms were refined anisotropically. The methyl H atoms were positioned with idealized geometry and refined isotropically with U_iso(H) = 1.5 U_eq(C) using a riding model. The positions of the hydrogen atoms of the NH₂ group of the guanidinium cation were taken from the electron density map and refined isotropically.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å²) top

	x	y	z	U_iso*/U_eq
Te1	0.8750	0.3750	0.3750	0.01545 (4)
Cl1	0.8750	0.3750	0.46396 (2)	0.02182 (6)
Cl2	0.63226 (3)	0.45506 (2)	0.37388 (2)	0.02254 (5)
N1	0.3750	0.3750	0.45159 (4)	0.0222 (2)
H1	0.447 (2)	0.3533 (6)	0.4372 (5)	0.030 (4)*
C1	0.3750	0.3750	0.49798 (5)	0.0184 (2)
N2	0.3004 (1)	0.42051 (4)	0.52161 (3)	0.0241 (2)
C2	0.1980 (2)	0.41017 (6)	0.56481 (4)	0.0381 (3)
H2A	0.0721	0.4226	0.5602	0.057*
H2B	0.2517	0.4333	0.5904	0.057*
H2C	0.2017	0.3677	0.5727	0.057*
C3	0.2619 (2)	0.47675 (5)	0.49795 (4)	0.0307 (2)
H3A	0.3543	0.4842	0.4740	0.046*
H3B	0.2629	0.5092	0.5209	0.046*
H3C	0.1426	0.4746	0.4831	0.046*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Te1	0.01545 (5)	0.01243 (5)	0.01847 (6)	0	0.00	0.00
Cl1	0.0257 (1)	0.0190 (1)	0.0207 (1)	0.0020 (1)	0.00	0.00
Cl2	0.0214 (1)	0.01873 (9)	0.0274 (1)	0.00211 (7)	−0.00547 (8)	−0.00431 (7)
N1	0.0221 (5)	0.0269 (5)	0.0178 (5)	0.0099 (4)	0.00	0.00
C1	0.0161 (5)	0.0192 (5)	0.0200 (5)	−0.0008 (4)	0.00	0.00
N2	0.0272 (4)	0.0224 (4)	0.0226 (4)	0.0008 (3)	0.0022 (3)	−0.0052 (3)
C2	0.0439 (7)	0.0409 (6)	0.0296 (5)	−0.0080 (5)	0.0141 (5)	−0.0145 (5)
C3	0.0316 (5)	0.0213 (4)	0.0391 (6)	0.0060 (4)	−0.0049 (4)	−0.0062 (4)

Geometric parameters (Å, º) top

Te1—Cl1	2.5363 (4)	C1—N2	1.342 (1)
Te1—Cl1ⁱ	2.5364 (4)	N2—C3	1.459 (1)
Te1—Cl2ⁱⁱ	2.5394 (3)	N2—C2	1.464 (2)
Te1—Cl2	2.5394 (3)	C2—H2A	0.9800
Te1—Cl2ⁱ	2.5394 (3)	C2—H2B	0.9800
Te1—Cl2ⁱⁱⁱ	2.5394 (3)	C2—H2C	0.9800
N1—C1	1.323 (2)	C3—H3A	0.9800
N1—H1	0.83 (2)	C3—H3B	0.9800
C1—N2^iv	1.342 (1)	C3—H3C	0.9800

Cl1—Te1—Cl1ⁱ	180.0	N1—C1—N2	120.14 (6)
Cl1—Te1—Cl2ⁱⁱ	89.282 (5)	N2^iv—C1—N2	119.7 (1)
Cl1ⁱ—Te1—Cl2ⁱⁱ	90.718 (5)	C1—N2—C3	120.43 (9)
Cl1—Te1—Cl2	90.718 (5)	C1—N2—C2	120.93 (9)
Cl1ⁱ—Te1—Cl2	89.282 (5)	C3—N2—C2	115.15 (9)
Cl2ⁱⁱ—Te1—Cl2	90.12 (1)	N2—C2—H2A	109.5
Cl1—Te1—Cl2ⁱ	89.283 (5)	N2—C2—H2B	109.5
Cl1ⁱ—Te1—Cl2ⁱ	90.717 (5)	H2A—C2—H2B	109.5
Cl2ⁱⁱ—Te1—Cl2ⁱ	178.57 (1)	N2—C2—H2C	109.5
Cl2—Te1—Cl2ⁱ	89.90 (1)	H2A—C2—H2C	109.5
Cl1—Te1—Cl2ⁱⁱⁱ	90.717 (5)	H2B—C2—H2C	109.5
Cl1ⁱ—Te1—Cl2ⁱⁱⁱ	89.283 (5)	N2—C3—H3A	109.5
Cl2ⁱⁱ—Te1—Cl2ⁱⁱⁱ	89.90 (1)	N2—C3—H3B	109.5
Cl2—Te1—Cl2ⁱⁱⁱ	178.57 (1)	H3A—C3—H3B	109.5
Cl2ⁱ—Te1—Cl2ⁱⁱⁱ	90.12 (1)	N2—C3—H3C	109.5
C1—N1—H1	120 (1)	H3A—C3—H3C	109.5
N1—C1—N2^iv	120.14 (6)	H3B—C3—H3C	109.5

Symmetry codes: (i) −x+7/4, y, −z+3/4; (ii) x, −y+3/4, −z+3/4; (iii) −x+7/4, −y+3/4, z; (iv) −x+3/4, −y+3/4, z.

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1···Cl2ⁱⁱ	0.83 (2)	2.57 (2)	3.3875 (8)	167 (1)
C2—H2B···Cl2^v	0.98	2.84	3.712 (1)	149
C3—H3B···Cl1^v	0.98	2.82	3.644 (1)	142

Symmetry codes: (ii) x, −y+3/4, −z+3/4; (v) −x+1, −y+1, −z+1.

Acknowledgements

We gratefully acknowledge the maintenance of the XRD equipment through Dr Alexander Villinger (University of Rostock).

Funding information

We gratefully acknowledge the financial support of the DFG-SPP 1708, Material Synthesis Near Room Temperature.

References

Allen, F. H., Kennard, O., Watson, D. G., Brammer, L., Orpen, A. G. & Taylor, R. (1987). J. Chem. Soc. Perkin Trans. 2, S1–S19. CSD CrossRef Web of Science Google Scholar
Berg, R. W., Harris, P., Riisager, A. & Fehrmann, R. (2013). J. Phys. Chem. A, 117, 11364–11373. CrossRef PubMed Google Scholar
Brandenburg, K. & Putz, H. (2014). DIAMOND. Crystal Impact GbR, Bonn, Germany. Google Scholar
Bruker (2017). APEX3, SADABS and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Bujak, M., Osadczuk, P. & Zaleski, J. (1999). Acta Cryst. C55, 1443–1447. Web of Science CSD CrossRef CAS IUCr Journals Google Scholar
Bujak, M. & Zaleski, J. (2007). Acta Cryst. E63, m102–m104. Web of Science CSD CrossRef IUCr Journals Google Scholar
Due-Hansen, J., Ståhl, K., Boghosian, S., Riisager, A. & Fehrmann, R. (2011). Polyhedron, 30, 785–789. Google Scholar
Jones, P. G. & Thonnessen, H. (2006). Private communication (refcode CEPXIF). CCDC, Cambridge, England. Google Scholar
Longhi, R. & Drago, R. S. (1965). Inorg. Chem. 4, 11–14. CrossRef Google Scholar
Meng, X., Wang, J., Jiang, H., Zhang, X., Liu, S. & Hu, Y. (2017). J. Chem. Technol. Biotechnol. 92, 767–774. CrossRef Google Scholar
Ndiaye, M., Samb, A., Diop, L. & Maris, T. (2016a). Acta Cryst. E72, 1–3. CrossRef IUCr Journals Google Scholar
Ndiaye, M., Samb, A., Diop, L. & Maris, T. (2016b). Acta Cryst. E72, 1047–1049. CrossRef IUCr Journals Google Scholar
Şendıl, K., Özgün, H. B. & Üstün, E. (2016). J. Chem. pp. 1–7. Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Sheldrick, G. M. (2015). Acta Cryst. C71, 3–8. Web of Science CrossRef IUCr Journals Google Scholar
Shen, N.-N., Cai, M.-L., Song, Y., Wang, Z.-P., Huang, F.-Q., Li, J.-R. & Huang, X.-Y. (2018). Inorg. Chem. 57, 5282–5291. CrossRef PubMed Google Scholar
Snaith, R., Wade, K. & Wyatt, B. K. (1970). J. Chem. Soc. A, pp. 380. Google Scholar
Westrip, S. P. (2010). J. Appl. Cryst. 43, 920–925. Web of Science CrossRef CAS IUCr Journals Google Scholar