(2-Thienylmethyl)ammonium ­trichlorostannate(II): a hybrid salt

The structure of the title hybrid salt, (C₅H₈NS)[SnCl₃], is built up from segregated layers of organic cations and Sn polyhedra. [SnCl₃]⁻ groups are linked together by weak Sn...Cl interactions to form a one-dimensional polymeric chain of anions.

S1. Comment

Organic and inorganic compounds have distinct properties and advantages, and the possibility of combining organic and inorganic elements in a single hybrid compound appears very interesting. Among such hybrids, organic-inorganic perovskites are the most extensively studied group (Mitzi, 1999). These layered systems, in the simplest examples, are built up from M^II[X₄^2-] (M is Pb or Sn, and X is Cl, Br or I) perovskite single layers separated either by double layers of organic monoammonium cations, e.g. [R—NH₃]₂[MX₄], or monolayers of organic diammonium cations, e.g. [H₃N—R—NH₃][MX₄], R being an aliphatic chain, a phenyl derivative or a tetrathiophene derivative. To date, the only reported structure containing the 2-thienylmethylammonium cation, A, is that of 2-thienylmethylammonium 5-hydroxy-4-methoxycarbonyl-1-(2-thienyl)-1,2,3-triazole (Murray-Rust et al., 1984). We present here the structure of the second such compound, the title salt, A[SnCl₃], (I). \sch

The structure of (I) consists of sheets of organic cations alternating with inorganic anion layers stacked in the [010] direction (Fig. 1). At first sight, the presence of face-to-face and head-to-tail pairs of 2-thienylmethylammonium cations may suggest that perovskite layers of corner-sharing divalent tin octahedra do not occur. However, recent results have shown that bilayers of these organic ammonium cations appear in the perovskite compound A₂[PbCl₄] (Mercier & Riou, 2001).

In the structure of (I), isolated Sn^II polyhedra are present. The coordination of Sn^II (Table 1) consists of three short Sn—Cl [2.4951 (13)–2.5837 (13) Å] bonds and two longer weaker Sn···Cl bonds [3.4071 (17)–3.5990 (15) Å] distributed along the axes of an octahedron, the vacancy probably being occupied by the lone pair of Sn^II. A valence bond calculation, as proposed by Brown (1981), using the bond valence parameters of Brese & O'Keeffe (1991) {calculated valence S = Σs with s = exp[(R₀ - d)/0.37], where d is the metal-ligand distance and R₀ a value taken from Brese & O'Keeffe (1991) [R₀(Sn^II—Cl) = 2.36]}, suggests that the coordination of the divalent metal is well represented by an SnCl₃ trigonal pyramid, the two remote Cl atoms contributing only 5% of the Sn^II valence (calculated valence: S = 2.02 and 1.99 for Sn1 and Sn2, respectively). However, taking the Sn···Cl interactions into account, the anions can be considered to form polymeric species, as often described in Sn^II compounds, e.g. Cs[SnCl₃] (Poulsen & Rasmussen, 1970) or [(C₃H₇)₄N][SnI₃] (Lode & Krautscheid, 2000), where such (3 + 2) coordination is also encountered.

In (I), two types of polymeric anion chain are found, both propagating in the [100] direction, one for the [SnCl₃]^- groups containing Sn1, and the other for the [SnCl₃]^- groups containing Sn2 (Fig. 2). The chains are separated by the ammonium groups of the cations which participate in N—H···Cl hydrogen bonds (Table 2), thus preventing the formation of polymeric sheets of anions such as those present in Cs[SnCl₃].

S2. Experimental

Compound (I) was obtained from a slowly cooled saturated solution containing 2-thienylmethylamine and SnCl₂·2H₂O in aqueous HCl. Typically, 2-thienylmethylamine (56 mg, 0.5 mmol) and SnCl₂·2H₂O (52 mg, 0.2 mmol) were added under an inert atmosphere to aqueous HCl (4 mol dm^-3) at 343 K. After slight evaporation of the solution, slow cooling afforded colourless prismatic crystals of (I).

S3. Refinement

H atoms were treated as riding, with C—H = 0.93 or 0.97 Å and N—H = 0.89 Å, and with U_iso(H) = 1.5U_eq(N) or 1.2U_eq(C).

Computing details

Data collection: CAD-4 EXPRESS (Enraf-Nonius, 1994); cell refinement: CAD-4 EXPRESS; data reduction: MolEN (Enraf-Nonius, 1997); program(s) used to solve structure: SIR97 (Altomare et al., 1999); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); software used to prepare material for publication: CIFGEN in MolEN.

Figures

	Fig. 1. The structure of (I). The atoms are shown as spheres of arbitrary radii and dashed lines represent weak Sn···Cl bonds.
	Fig. 2. A view of the two types of polymeric species formed by [SnCl3]^- anions, together with the labelling scheme used in Table 1. Displacement ellipsoids are drawn at the 50% probability level.

2-Thienylmethylammonium trichlorostannate(II)

Crystal data

[NH3(C5H5S)][SnCl3]	Z = 4
Mr = 339.22	F(000) = 648
Triclinic, P1	Dx = 2.093 Mg m^−3
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 5.9937 (4) Å	Cell parameters from 25 reflections
b = 11.9746 (6) Å	θ = 12.1–15°
c = 15.734 (1) Å	µ = 3.26 mm^−1
α = 75.604 (5)°	T = 293 K
β = 79.802 (6)°	Prism, colourless
γ = 86.418 (5)°	0.4 × 0.2 × 0.1 mm
V = 1076.32 (11) Å^3

Data collection

Enraf-Nonius CAD-4 diffractometer	4790 reflections with I > 2σ(I)
Radiation source: xray tube	Rint = 0.074
Graphite monochromator	θmax = 30.0°, θmin = 2.7°
θ/2θ scans	h = 0→8
Absorption correction: part of the refinement model (ΔF) (DIFABS; Walker & Stuart, 1983)	k = −16→16
Tmin = 0.453, Tmax = 0.722	l = −21→22
6286 measured reflections	3 standard reflections every 120 min
6282 independent reflections	intensity decay: none

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.038	H-atom parameters constrained
wR(F^2) = 0.118	w = 1/[σ^2(Fo^2) + (0.0541P)^2 + 1.9104P] where P = (Fo^2 + 2Fc^2)/3
S = 1.12	(Δ/σ)max = 0.001
6282 reflections	Δρmax = 1.24 e Å^−3
202 parameters	Δρmin = −0.93 e Å^−3
0 restraints	Extinction correction: SHELXL97 (Sheldrick, 1997), Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.0052 (6)

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. Least-squares planes (x,y,z in crystal coordinates) and deviations from them (* indicates atom used to define plane) 1.9384 (0.0110) x - 3.2820 (0.0321) y + 13.3070 (0.0226) z = 4.2317 (0.0275) * 0.0111 (0.0027) C2 * -0.0092 (0.0026) S1 * -0.0086 (0.0032) C3 * 0.0009 (0.0039) C4 * 0.0059 (0.0036) C5 0.0656 (0.0091) C1 - 1.2889 (0.0104) N1 Rms deviation of fitted atoms = 0.0080 - 1.8272 (0.0137) x + 11.1472 (0.0106) y + 2.2136 (0.0475) z = 6.5217 (0.0117) A ngle to previous plane (with approximate e.s.d.) = 65.84 (1/4) * 0.0073 (0.0030) C7 * -0.0049 (0.0029) S2 * -0.0075 (0.0038) C8 * 0.0033 (0.0047) C9 * 0.0017 (0.0041) C10 - 0.0131 (0.0100) C6 1.2114 (0.0111) N2 Rms deviation of fitted atoms = 0.0054

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.

All non-H atoms are refined anisotropically.

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

	x	y	z	Uiso*/Ueq
Sn1	0.03367 (5)	1.09917 (3)	0.35546 (2)	0.03669 (10)
Cl1	−0.0115 (3)	1.16334 (14)	0.49688 (9)	0.0544 (3)
Cl2	0.0505 (3)	1.30203 (12)	0.26068 (10)	0.0605 (4)
Cl3	−0.4008 (2)	1.09900 (12)	0.36399 (9)	0.0484 (3)
Sn2	0.19024 (6)	0.90690 (3)	0.09874 (2)	0.03901 (10)
Cl4	0.0602 (2)	0.83168 (13)	0.26325 (8)	0.0503 (3)
Cl5	0.5878 (2)	0.93492 (13)	0.12343 (10)	0.0502 (3)
Cl6	0.0959 (2)	1.11072 (11)	0.11288 (11)	0.0522 (3)
N1	0.5216 (8)	0.8334 (4)	0.3507 (4)	0.0514 (10)
H1A	0.6283	0.8356	0.3032	0.077*
H1B	0.5282	0.8964	0.3704	0.077*
H1C	0.3859	0.8301	0.336	0.077*
C1	0.5590 (10)	0.7300 (5)	0.4216 (4)	0.0489 (11)
H1D	0.4637	0.7359	0.477	0.059*
H1E	0.7158	0.7267	0.4302	0.059*
S1	0.7092 (3)	0.54236 (17)	0.34777 (13)	0.0654 (4)
C2	0.5060 (9)	0.6221 (4)	0.3986 (3)	0.0410 (9)
C3	0.2787 (9)	0.5704 (3)	0.4174 (3)	0.0393 (9)
H3	0.1433	0.5997	0.4432	0.047*
C4	0.3109 (12)	0.4658 (5)	0.3877 (4)	0.0572 (14)
H4	0.1916	0.4171	0.3932	0.069*
C5	0.5228 (14)	0.4423 (5)	0.3514 (4)	0.0630 (17)
H5	0.5624	0.3766	0.3302	0.076*
N2	0.4229 (9)	0.7935 (4)	−0.1532 (3)	0.0518 (11)
H2A	0.3033	0.8338	−0.1339	0.078*
H2B	0.4365	0.8034	−0.2118	0.078*
H2C	0.5475	0.8176	−0.1403	0.078*
C6	0.3920 (14)	0.6698 (5)	−0.1091 (4)	0.0626 (16)
H6A	0.2573	0.6434	−0.124	0.075*
H6B	0.521	0.6258	−0.1312	0.075*
S2	0.1336 (3)	0.59464 (19)	0.05973 (15)	0.0721 (5)
C7	0.3693 (9)	0.6485 (4)	−0.0116 (4)	0.0430 (10)
C8	0.5333 (9)	0.6637 (5)	0.0406 (4)	0.0493 (12)
H8	0.6785	0.6909	0.0164	0.059*
C9	0.4544 (16)	0.6345 (6)	0.1273 (5)	0.074 (2)
H9	0.54	0.6409	0.1697	0.089*
C10	0.2456 (16)	0.5959 (6)	0.1489 (5)	0.073 (2)
H10	0.17	0.5721	0.2072	0.088*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Sn1	0.03522 (16)	0.03751 (17)	0.03874 (16)	0.00005 (11)	−0.00533 (11)	−0.01262 (12)
Cl1	0.0592 (8)	0.0648 (8)	0.0457 (6)	−0.0067 (6)	−0.0077 (5)	−0.0249 (6)
Cl2	0.0820 (10)	0.0395 (6)	0.0548 (7)	−0.0088 (6)	−0.0015 (7)	−0.0069 (5)
Cl3	0.0386 (5)	0.0512 (7)	0.0548 (7)	−0.0036 (5)	−0.0101 (5)	−0.0094 (5)
Sn2	0.04184 (18)	0.04127 (18)	0.03579 (16)	−0.00135 (12)	−0.00828 (12)	−0.01141 (12)
Cl4	0.0449 (6)	0.0621 (8)	0.0381 (5)	−0.0043 (5)	−0.0043 (4)	−0.0021 (5)
Cl5	0.0355 (5)	0.0566 (7)	0.0573 (7)	−0.0008 (5)	−0.0087 (5)	−0.0112 (6)
Cl6	0.0460 (6)	0.0398 (6)	0.0707 (8)	0.0044 (5)	−0.0122 (6)	−0.0125 (6)
N1	0.049 (2)	0.041 (2)	0.064 (3)	−0.0040 (18)	−0.014 (2)	−0.007 (2)
C1	0.054 (3)	0.044 (3)	0.051 (3)	−0.005 (2)	−0.019 (2)	−0.010 (2)
S1	0.0600 (9)	0.0692 (10)	0.0658 (10)	0.0074 (7)	−0.0076 (7)	−0.0181 (8)
C2	0.043 (2)	0.037 (2)	0.042 (2)	0.0015 (18)	−0.0108 (18)	−0.0061 (18)
C3	0.057 (3)	0.0200 (17)	0.040 (2)	−0.0045 (17)	−0.0139 (19)	−0.0008 (15)
C4	0.071 (4)	0.041 (3)	0.061 (3)	−0.010 (3)	−0.022 (3)	−0.004 (2)
C5	0.093 (5)	0.042 (3)	0.057 (3)	0.018 (3)	−0.023 (3)	−0.016 (2)
N2	0.058 (3)	0.054 (3)	0.037 (2)	0.004 (2)	−0.0047 (19)	−0.0025 (18)
C6	0.092 (5)	0.045 (3)	0.050 (3)	0.008 (3)	−0.005 (3)	−0.015 (2)
S2	0.0547 (9)	0.0748 (11)	0.0809 (12)	−0.0120 (8)	−0.0013 (8)	−0.0120 (9)
C7	0.046 (2)	0.034 (2)	0.048 (3)	0.0060 (18)	−0.007 (2)	−0.0091 (19)
C8	0.041 (2)	0.041 (2)	0.065 (3)	0.0040 (19)	−0.021 (2)	−0.004 (2)
C9	0.101 (6)	0.055 (4)	0.070 (4)	0.000 (4)	−0.044 (4)	−0.001 (3)
C10	0.109 (6)	0.046 (3)	0.050 (3)	0.005 (3)	0.009 (3)	−0.001 (3)

Geometric parameters (Å, º)

Sn1—Cl1	2.4951 (13)	C2—C3	1.483 (7)
Sn1—Cl2	2.5122 (15)	C3—C4	1.433 (8)
Sn1—Cl3	2.5837 (13)	C3—H3	0.93
Sn1—Cl1^i	3.4071 (17)	C4—C5	1.341 (10)
Sn1—Cl3^ii	3.4159 (13)	C4—H4	0.93
Cl1—Sn1^i	3.4071 (17)	C5—H5	0.93
Sn2—Cl4	2.5165 (13)	N2—C6	1.478 (8)
Sn2—Cl6	2.5257 (14)	N2—H2A	0.89
Sn2—Cl5	2.5366 (13)	N2—H2B	0.89
Sn2—Cl5^iii	3.5662 (13)	N2—H2C	0.89
Sn2—Cl5^iv	3.5990 (15)	C6—C7	1.475 (8)
Sn2—Sn2^v	4.2726 (7)	C6—H6A	0.97
N1—C1	1.481 (7)	C6—H6B	0.97
N1—H1A	0.89	S2—C10	1.663 (9)
N1—H1B	0.89	S2—C7	1.693 (6)
N1—H1C	0.89	C7—C8	1.433 (7)
C1—C2	1.491 (7)	C8—C9	1.328 (10)
C1—H1D	0.97	C8—H8	0.93
C1—H1E	0.97	C9—C10	1.319 (12)
S1—C5	1.672 (8)	C9—H9	0.93
S1—C2	1.710 (5)	C10—H10	0.93
Cl1—Sn1—Cl2	93.16 (5)	C2—C1—H1E	109.3
Cl1—Sn1—Cl3	91.16 (5)	H1D—C1—H1E	108
Cl2—Sn1—Cl3	90.81 (5)	C5—S1—C2	92.2 (3)
Cl1—Sn1—Cl1^i	80.67 (5)	C3—C2—C1	125.3 (5)
Cl2—Sn1—Cl1^i	173.79 (4)	C3—C2—S1	112.3 (4)
Cl3—Sn1—Cl1^i	90.03 (4)	C1—C2—S1	122.4 (4)
Cl1—Sn1—Cl3^ii	83.98 (4)	C4—C3—C2	105.7 (5)
Cl2—Sn1—Cl3^ii	91.06 (5)	C4—C3—H3	127.1
Cl3—Sn1—Cl3^ii	174.88 (6)	C2—C3—H3	127.1
Cl1^i—Sn1—Cl3^ii	87.60 (4)	C5—C4—C3	116.2 (6)
Sn1—Cl1—Sn1^i	99.33 (5)	C5—C4—H4	121.9
Sn1—Cl3—Sn1^iii	174.88 (6)	C3—C4—H4	121.9
Cl4—Sn2—Cl6	90.34 (5)	C4—C5—S1	113.6 (5)
Cl4—Sn2—Cl5	91.23 (5)	C4—C5—H5	123.2
Cl6—Sn2—Cl5	88.05 (5)	S1—C5—H5	123.2
Cl4—Sn2—Cl5^iii	76.30 (4)	C6—N2—H2A	109.5
Cl6—Sn2—Cl5^iii	74.16 (4)	C6—N2—H2B	109.5
Cl5—Sn2—Cl5^iii	157.98 (6)	H2A—N2—H2B	109.5
Cl4—Sn2—Cl5^iv	168.17 (4)	C6—N2—H2C	109.5
Cl6—Sn2—Cl5^iv	79.77 (4)	H2A—N2—H2C	109.5
Cl5—Sn2—Cl5^iv	82.03 (4)	H2B—N2—H2C	109.5
Cl5^iii—Sn2—Cl5^iv	106.79 (3)	C7—C6—N2	111.7 (5)
Cl4—Sn2—Sn2^v	128.81 (3)	C7—C6—H6A	109.3
Cl6—Sn2—Sn2^v	67.82 (4)	N2—C6—H6A	109.3
Cl5—Sn2—Sn2^v	131.07 (4)	C7—C6—H6B	109.3
Cl5^iii—Sn2—Sn2^v	53.75 (2)	N2—C6—H6B	109.3
Cl5^iv—Sn2—Sn2^v	53.04 (2)	H6A—C6—H6B	107.9
Sn2—Cl5—Sn2^ii	157.98 (6)	C10—S2—C7	93.0 (4)
Sn2—Cl5—Sn2^iv	97.97 (4)	C8—C7—C6	128.9 (6)
Sn2^ii—Cl5—Sn2^iv	73.21 (3)	C8—C7—S2	107.6 (4)
C1—N1—H1A	109.5	C6—C7—S2	123.5 (5)
C1—N1—H1B	109.5	C9—C8—C7	112.4 (6)
H1A—N1—H1B	109.5	C9—C8—H8	123.8
C1—N1—H1C	109.5	C7—C8—H8	123.8
H1A—N1—H1C	109.5	C10—C9—C8	115.0 (7)
H1B—N1—H1C	109.5	C10—C9—H9	122.5
N1—C1—C2	111.4 (4)	C8—C9—H9	122.5
N1—C1—H1D	109.3	C9—C10—S2	112.0 (6)
C2—C1—H1D	109.3	C9—C10—H10	124
N1—C1—H1E	109.3	S2—C10—H10	124

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

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1B···Cl3^ii	0.89	2.46	3.306 (5)	158
N1—H1A···Cl4^ii	0.89	2.55	3.278 (5)	139
N1—H1A···Cl5	0.89	2.83	3.438 (5)	127
N1—H1C···Cl4	0.89	2.43	3.303 (5)	168
N2—H2B···Cl3^v	0.89	2.43	3.269 (5)	157
N2—H2A···Cl6^v	0.89	2.43	3.256 (5)	155
N2—H2C···Cl6^iv	0.89	2.50	3.386 (6)	177

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