Bis[2,2′-(2-amino­ethyl­imino)­di(ethyl­ammonium)] di-μ-sulfido-bis[disulfido­stannate(IV)]

Abstract

The asymmetric unit of the title compound, (C₆H₂₀N₄)₂[Sn₂S₆], comprises half of a [Sn₂S₆]⁴⁻ anion and a diprotonated tris­(2-amino­eth­yl)amine cation. The anion lies on an inversion center, while the atoms of the cation occupy general positions. An intra­molecular N—H⋯N hydrogen bond is observed in the cation. In the crystal, strong N—H⋯S hydrogen bonding between the terminal sulfur atoms of the anion and the protonated amine N atoms of the cations result in a three-dimensional network.

Related literature

For synthetic conditions and the structure of the hydrated form of this complex, see: Näther et al. (2003 ▶). For solvothermal syntheses of compounds with [Sn₂S₆]⁴⁻ anions, see: Behrens et al. (2003 ▶); Jia et al. (2005 ▶); Jiang et al. (1998a ▶); Li et al. (1997 ▶). For other thio­stannate anions, see: Jiang et al. (1998b ▶). For a review article covering related compounds, see: Zhou et al. (2009 ▶).

Experimental

Crystal data

• (C₆H₂₀N₄)₂[Sn₂S₆]

• M _r = 363.13

• Monoclinic,

• a = 9.9280 (2) Å

• b = 14.8845 (3) Å

• c = 10.2498 (2) Å

• β = 115.758 (1)°

• V = 1364.15 (5) ų

• Z = 4

• Mo Kα radiation

• μ = 2.31 mm⁻¹

• T = 296 K

• 0.61 × 0.57 × 0.39 mm

Data collection

• Bruker SMART APEX diffractometer

• Absorption correction: multi-scan (SADABS; Sheldrick, 2002 ▶) T _min = 0.334, T _max = 0.467

• 25432 measured reflections

• 4907 independent reflections

• 4460 reflections with I > 2σ(I)

• R _int = 0.023

Refinement

• R[F ² > 2σ(F ²)] = 0.021

• wR(F ²) = 0.058

• S = 1.04

• 4907 reflections

• 132 parameters

• H-atom parameters constrained

• Δρ_max = 1.22 e Å⁻³

• Δρ_min = −0.51 e Å⁻³

Data collection: SMART (Bruker, 1998 ▶); cell refinement: SAINT (Bruker, 1998 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: CrystalMaker (Palmer, 2010 ▶); software used to prepare material for publication: publCIF (Westrip, 2010 ▶).

Supplementary Material

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Table 1. Selected bond lengths (Å).

Sn1—S1	2.3307 (4)
Sn1—S2	2.3447 (4)
Sn1—S3i	2.4550 (4)
Sn1—S3	2.4564 (4)

Symmetry code: (i) .

Table 2. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N9—H9C⋯N10	0.89	2.10	2.965 (3)	163
N9—H9B⋯S1ii	0.89	2.44	3.314 (2)	167
N9—H9A⋯S2iii	0.89	2.49	3.370 (2)	168
N7—H7C⋯S1i	0.89	2.36	3.243 (2)	174
N7—H7B⋯S2iv	0.89	2.40	3.278 (2)	170
N7—H7A⋯S2v	0.89	2.57	3.411 (2)	159

Symmetry codes: (i) ; (ii) ; (iii) ; (iv) ; (v) .

supplementary crystallographic information

Comment

While solvothermal syntheses have produced an assortment of anionic thiostannate building blocks, the [Sn₂S₆]^4- moiety has been one of the most common (Zhou et al., 2009). It has also been shown that under certain conditions [Sn₂S₆]^4- anions can be converted to forms such as [Sn₃S₇]^2- and [Sn₄S₉]^-, forming two-dimensional layered anionic networks (Jiang et al., 1998a,b). In 2003, solvothermal experiments aimed at preparing [Co(tren)₂][Sn₂S₆] using the chelating ligand tris(2-aminoethyl)amine (C₆H₁₈N₄, tren), resulted in the isolation and characterization of (H₂tren)₂[Sn₂S₆]^.2H₂O (Näther et al., 2003) as a side product. We have now shown that the anhydrous version of this compound, (I) can be accessed when the reaction is carried out in anhydrous conditions and without any transition metal present. In the title compound, (H₂tren)₂[Sn₂S₆], (Fig. 1), the terminal Sn—S bonds, at 2.3307 (4) and 2.3447 (5) Å, are shorter than the Sn—S bond of 2.4565 (6) Å formed with the bridging sulfur. The interior S—Sn—S angle of 92.78 (2)° is tighter than those involving terminal sulfurs, where these angles range from 108.22 (2) to 120.55 (2)°. Collectively, the geometric parameters of the [Sn₂S₆]^4- anion are in reasonable accordance with similar structures (Näther et al., 2003; Behrens et al., 2003). In the (H₂tren)²⁺ cation, the C—N bond lengths for the two protonated pendant amines are slightly longer, at 1.490 (3) and 1.473 (3) Å, than the 1.446 (5) Å C—N bond for the neutral arm. The most distinct structural difference between the anhydrous structure and the previously reported hydrated form (Näther et al., 2003) is the positioning of the NH₂ pedant amine. In the hydrated structure, it is aligned to facilitate a H-bonding interaction (H···N—H of 2.08 Å) with an NH₃⁺ amine on a neighboring cation. In the anhydrous structure, the hydrogen bonding interaction (N9—H9C···N10, 2.10 Å) is formed within the same ligand, Fig. 2. Strong hydrogen bonding between the terminal sulfur atoms on the anion and the protonated amine centers on the cation (Fig. 2, Table 2) results in a three-dimensional network, Fig. 3.

Experimental

The title compound was prepared by solvothermal synthesis, using conditions comparable to Näther et al. (2003). 5.0 ml of tris-2-aminoethylamine (tren) was mixed with 1.00 mmol Sn and 3.0 mmol S in a 23 ml Parr^(R); acid digestion apparatus. The mixture was heated to 423 K over 5 h and maintained at that temperature for 144 h. It was cooled to 363 K at 2 K/h, then cooled to 313 K at 6 K/h. The clear, colorless crystals were washed with hexane and recovered by vacuum filtration. This protocol produced large crystals, often several mm on the longest axis, and in one instance measuring over 20 mm.

Refinement

All H atoms except for those on N(10) were placed at calculated positions (C—H at 0.97 Å, N—H at 0.87 Å) and refined as riding atoms with U_iso(H) = 1.2U_eq(C) and U_iso(H) = 1.5U_eq(N). The two H atoms on N(10) were identified from the difference Fourier map and refined as a rigid group with U_iso(H) = 1.5U_eq(N).

Figures

Fig. 1.

The structure of (C6H20N4)2[Sn2S6].The thermal ellipsoids have been drawn at the 50% probability level. Symmetry code: (i) = -x, -y + 1, -z + 1.

Fig. 2.

Hydrogen bonding interactions within the (H2tren)2+ cation and between the cation and the terminal sulfurs of the [Sn2S6]4- anion. Symmetry codes as presented in Table 2.

Fig. 3.

View down the a axis illustrating the three-dimensional hydrogen bonding network.

Crystal data

(C6H20N4)2[Sn2S6]	F(000) = 728
Mr = 363.13	Dx = 1.768 Mg m−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 9995 reflections
a = 9.9280 (2) Å	θ = 2.3–33.1°
b = 14.8845 (3) Å	µ = 2.31 mm−1
c = 10.2498 (2) Å	T = 296 K
β = 115.758 (1)°	Clear, colourless
V = 1364.15 (5) Å3	0.61 × 0.57 × 0.39 mm
Z = 4

Data collection

Bruker SMART APEX diffractometer	4907 independent reflections
Radiation source: fine-focus sealed tube	4460 reflections with I > 2σ(I)
graphite	Rint = 0.023
φ and ω Scans scans	θmax = 33.1°, θmin = 2.3°
Absorption correction: multi-scan (SADABS; Sheldrick, 2002)	h = −14→14
Tmin = 0.334, Tmax = 0.467	k = −22→22
25432 measured reflections	l = −15→15

Refinement

Refinement on F2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.021	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.058	H-atom parameters constrained
S = 1.04	w = 1/[σ2(Fo2) + (0.0298P)2 + 0.7916P] where P = (Fo2 + 2Fc2)/3
4907 reflections	(Δ/σ)max = 0.002
132 parameters	Δρmax = 1.22 e Å−3
0 restraints	Δρmin = −0.51 e Å−3

Special details

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

Refinement. Refinement of F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > σ(F2) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2 are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
Sn1	0.01082 (1)	0.468130 (7)	0.66292 (1)	0.02312 (4)
S1	0.18598 (5)	0.52916 (3)	0.87984 (5)	0.03186 (9)
S2	−0.15015 (5)	0.35310 (3)	0.66377 (5)	0.03259 (9)
S3	0.13815 (5)	0.41901 (3)	0.51649 (5)	0.03229 (9)
C1	0.1339 (2)	0.3225 (1)	0.0717 (2)	0.0349 (3)
H1A	0.1600	0.3833	0.0573	0.042*
H1B	0.1715	0.2818	0.0213	0.042*
C2	0.2059 (2)	0.3005 (1)	0.2327 (2)	0.0380 (4)
H2A	0.1620	0.3379	0.2817	0.046*
H2B	0.1862	0.2382	0.2463	0.046*
C3	0.4166 (3)	0.4070 (2)	0.3308 (4)	0.0552 (6)
H3A	0.4711	0.4130	0.4351	0.066*
H3B	0.3308	0.4468	0.2984	0.066*
C4	0.5166 (3)	0.4348 (2)	0.2610 (3)	0.0528 (6)
H4A	0.4596	0.4337	0.1565	0.063*
H4B	0.5507	0.4959	0.2895	0.063*
C5	0.4481 (3)	0.2526 (2)	0.4178 (2)	0.0466 (5)
H5A	0.5397	0.2814	0.4852	0.056*
H5B	0.3875	0.2407	0.4689	0.056*
C6	0.4856 (3)	0.1665 (2)	0.3699 (3)	0.0510 (5)
H6A	0.5435	0.1297	0.4538	0.061*
H6B	0.3942	0.1344	0.3106	0.061*
N7	−0.0318 (2)	0.3140 (1)	0.0112 (2)	0.0350 (3)
H7A	−0.0551	0.2610	0.0361	0.053*
H7B	−0.0715	0.3181	−0.0849	0.053*
H7C	−0.0677	0.3577	0.0462	0.053*
N8	0.3655 (2)	0.3154 (1)	0.2955 (2)	0.0340 (3)
N9	0.6473 (2)	0.3752 (1)	0.3030 (2)	0.0393 (4)
H9A	0.7035	0.3791	0.3981	0.059*
H9B	0.7009	0.3916	0.2564	0.059*
H9C	0.6165	0.3187	0.2799	0.059*
N10	0.5705 (3)	0.1814 (1)	0.2875 (3)	0.0535 (5)
H10A	0.6363	0.1388	0.2887	0.080*
H10B	0.5046	0.1868	0.1857	0.080*

Atomic displacement parameters (Ų)

	U11	U22	U33	U12	U13	U23
Sn1	0.02520 (5)	0.02399 (6)	0.02090 (5)	−0.00209 (3)	0.01070 (4)	−0.00039 (3)
S1	0.0316 (2)	0.0363 (2)	0.0254 (2)	−0.0069 (1)	0.0102 (1)	−0.0050 (1)
S2	0.0325 (2)	0.0375 (2)	0.0268 (2)	−0.0115 (2)	0.0120 (1)	0.0009 (1)
S3	0.0400 (2)	0.0321 (2)	0.0300 (2)	0.0127 (2)	0.0201 (2)	0.0057 (1)
C1	0.0357 (8)	0.0370 (9)	0.0362 (9)	0.0016 (7)	0.0196 (7)	0.0056 (7)
C2	0.0316 (8)	0.049 (1)	0.0347 (9)	−0.0045 (7)	0.0157 (7)	−0.0022 (8)
C3	0.052 (1)	0.036 (1)	0.089 (2)	−0.0123 (9)	0.041 (1)	−0.019 (1)
C4	0.049 (1)	0.037 (1)	0.075 (2)	−0.0066 (8)	0.022 (1)	0.011 (1)
C5	0.042 (1)	0.062 (1)	0.037 (1)	−0.0056 (9)	0.0190 (9)	−0.0023 (9)
C6	0.043 (1)	0.056 (1)	0.053 (1)	0.0121 (9)	0.020 (1)	0.021 (1)
N7	0.0356 (7)	0.0375 (8)	0.0291 (7)	0.0014 (6)	0.0112 (6)	0.0019 (6)
N8	0.0280 (6)	0.0343 (7)	0.0407 (8)	−0.0060 (5)	0.0160 (6)	−0.0056 (6)
N9	0.0330 (7)	0.0461 (9)	0.0379 (8)	−0.0106 (7)	0.0146 (6)	0.0023 (7)
N10	0.055 (1)	0.049 (1)	0.067 (1)	−0.0051 (9)	0.037 (1)	−0.009 (1)

Geometric parameters (Å, °)

Sn1—S1	2.3307 (4)	C4—H4A	0.9700
Sn1—S2	2.3447 (4)	C4—H4B	0.9700
Sn1—S3i	2.4550 (4)	C5—C6	1.477 (4)
Sn1—S3	2.4564 (4)	C5—N8	1.491 (3)
S3—Sn1i	2.4550 (4)	C5—H5A	0.9700
C1—N7	1.490 (2)	C5—H5B	0.9700
C1—C2	1.521 (3)	C6—N10	1.446 (3)
C1—H1A	0.9700	C6—H6A	0.9700
C1—H1B	0.9700	C6—H6B	0.9700
C2—N8	1.445 (2)	N7—H7A	0.8900
C2—H2A	0.9700	N7—H7B	0.8900
C2—H2B	0.9700	N7—H7C	0.8900
C3—N8	1.444 (3)	N9—H9A	0.8900
C3—C4	1.512 (4)	N9—H9B	0.8900
C3—H3A	0.9700	N9—H9C	0.8900
C3—H3B	0.9700	N10—H10A	0.9066
C4—N9	1.474 (3)	N10—H10B	0.9645
S1—Sn1—S2	120.55 (2)	C6—C5—N8	113.0 (2)
S1—Sn1—S3i	113.87 (2)	C6—C5—H5A	109.0
S2—Sn1—S3i	108.22 (2)	N8—C5—H5A	109.0
S1—Sn1—S3	109.28 (2)	C6—C5—H5B	109.0
S2—Sn1—S3	108.51 (2)	N8—C5—H5B	109.0
S3i—Sn1—S3	92.78 (1)	H5A—C5—H5B	107.8
Sn1i—S3—Sn1	87.22 (1)	N10—C6—C5	110.8 (2)
N7—C1—C2	110.3 (1)	N10—C6—H6A	109.5
N7—C1—H1A	109.6	C5—C6—H6A	109.5
C2—C1—H1A	109.6	N10—C6—H6B	109.5
N7—C1—H1B	109.6	C5—C6—H6B	109.5
C2—C1—H1B	109.6	H6A—C6—H6B	108.1
H1A—C1—H1B	108.1	C1—N7—H7A	109.5
N8—C2—C1	110.9 (2)	C1—N7—H7B	109.5
N8—C2—H2A	109.5	H7A—N7—H7B	109.5
C1—C2—H2A	109.5	C1—N7—H7C	109.5
N8—C2—H2B	109.5	H7A—N7—H7C	109.5
C1—C2—H2B	109.5	H7B—N7—H7C	109.5
H2A—C2—H2B	108.0	C2—N8—C3	117.1 (2)
N8—C3—C4	111.8 (2)	C2—N8—C5	112.0 (2)
N8—C3—H3A	109.3	C3—N8—C5	112.1 (2)
C4—C3—H3A	109.3	C4—N9—H9A	109.5
N8—C3—H3B	109.3	C4—N9—H9B	109.5
C4—C3—H3B	109.3	H9A—N9—H9B	109.5
H3A—C3—H3B	107.9	C4—N9—H9C	109.5
N9—C4—C3	111.9 (2)	H9A—N9—H9C	109.5
N9—C4—H4A	109.2	H9B—N9—H9C	109.5
C3—C4—H4A	109.2	C6—N10—H10A	119.0
N9—C4—H4B	109.2	C6—N10—H10B	110.6
C3—C4—H4B	109.2	H10A—N10—H10B	102.6
H4A—C4—H4B	107.9

Symmetry codes: (i) −x, −y+1, −z+1.

Hydrogen-bond geometry (Å, °)

D—H···A	D—H	H···A	D···A	D—H···A
N9—H9C···N10	0.89	2.10	2.965 (3)	163.
N9—H9B···S1ii	0.89	2.44	3.314 (2)	167.
N9—H9A···S2iii	0.89	2.49	3.370 (2)	168.
N7—H7C···S1i	0.89	2.36	3.243 (2)	174.
N7—H7B···S2iv	0.89	2.40	3.278 (2)	170.
N7—H7A···S2v	0.89	2.57	3.411 (2)	159.

Symmetry codes: (ii) −x+1, −y+1, −z+1; (iii) x+1, y, z; (i) −x, −y+1, −z+1; (iv) x, y, z−1; (v) x, −y+1/2, z−1/2.