Bis(2-amino-3,5-di­chloro­pyridinium) hexa­chlorido­stannate(IV) dihydrate

The crystal structure of a hybrid material containing 2-amino-3,5-di­chloro­pyridinium cations, a hexa­chlorido­stannate(IV) anion and water mol­ecules is described.

Abstract

The title hybrid compound, (C₅H₅N₂Cl₂)₂[SnCl₆]·2H₂O, was synthesized and its structure was identified by single-crystal X-ray diffraction. The structure is non-polymeric (0D) in terms of containing isolated [SnCl₆]²⁻ polyhedra. The special position (0,0,0) of the Sn^IV atom in the crystal structure gives rise to a stacking structure with alternating cationic and anionic layers parallel to (001). The water mol­ecules are inter­calated between these layers, which are linked by cation–anion hydrogen bonds and dominant non-covalent inter­actions. The stability of the three-dimensional network for this compound is also discussed.

Structure description

Bis(2-amino-3,5-di­chloro­pyridinium) hexa­chlorido­stannate(IV) dihydrate, (C₅H₅N₂Cl₂)₂[SnCl₆]·2H₂O, crystallizes in the triclinic space group P (Fig. 1 ▸). The tin(IV) atom is hexa­coordinated by chlorine atoms, generating a weakly distorted octa­hedron. The Sn—Cl bond lengths range from 2.4162 (5) to 2.4389 (5) Å while the Cl—Sn—Cl angles have a deviation of about ±1° [89.277 (19)–90.723 (19)°], see Table 1 ▸. These values are comparable to those of the same anion associated with other types of cations (Bouchene et al., 2018 ▸). The absence of larger distortions can probably be attributed to the fact that the hexa­chlorido­stannate(IV) anions are free, i.e. none of the chloride ions are bridging, although they do accept N—H⋯Cl, O—H⋯Cl and C—H⋯Cl hydrogen bonds (Table 2 ▸).

Figure 1.

The molecular components in the crystal structure of the title compound, showing displacement ellipsoids at the 30% probability level [symmetry code: (i) −x + 2, −y, −z].

Table 1. Selected geometric parameters (Å, °).

Sn1—Cl1	2.4162 (5)	C1—N2	1.315 (3)
Sn1—Cl2	2.4389 (5)	C2—C3	1.356 (3)
Sn1—Cl3	2.4253 (5)	C2—Cl4	1.713 (2)
N1—C1	1.345 (3)	C3—C4	1.393 (3)
N1—C5	1.350 (3)	C4—C5	1.348 (3)
C1—C2	1.417 (3)	C4—Cl5	1.726 (2)
Cl1—Sn1—Cl2	90.722 (19)	N2—C1—N1	119.49 (18)
Cl1i—Sn1—Cl2	89.278 (19)	N2—C1—C2	124.50 (19)
Cl1—Sn1—Cl2i	89.277 (19)	C1—C2—Cl4	117.52 (16)
Cl1—Sn1—Cl3	89.906 (19)	C3—C2—C1	120.82 (18)
Cl1—Sn1—Cl3i	90.093 (19)	C3—C2—Cl4	121.66 (15)
Cl1i—Sn1—Cl3	90.093 (19)	C2—C3—C4	119.71 (18)
Cl3i—Sn1—Cl2	89.81 (2)	C3—C4—Cl5	120.22 (16)
Cl3—Sn1—Cl2	90.19 (2)	C5—C4—C3	119.70 (19)
Cl3—Sn1—Cl2i	89.81 (2)	C5—C4—Cl5	120.08 (18)
C1—N1—C5	124.32 (17)	C4—C5—N1	119.4 (2)
N1—C1—C2	116.00 (18)

Symmetry code: (i) .

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

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N1—H1⋯O1W	0.86	1.86	2.685 (2)	160
O1W—H1WA⋯Cl1ii	0.85	2.67	3.296 (2)	131
O1W—H1WB⋯Cl2	0.85	2.47	3.301 (2)	168
N2—H2A⋯Cl3iii	0.86	2.78	3.381 (2)	129
N2—H2A⋯O1W	0.86	2.38	3.065 (3)	137
N2—H2B⋯Cl2iv	0.86	2.67	3.435 (2)	149
C3—H3⋯Cl3v	0.93	2.77	3.695 (2)	177
C5—H5⋯Cl2ii	0.93	2.80	3.615 (2)	147

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

In the cation, we note an increase in C1—C2 and C2—Cl4 bond lengths and a decrease in C1—N2 bond lengths (Table 1 ▸). This phenomenon is due to resonance-assisted hydrogen bonding, commonly observed for this kind of mol­ecule (Bertolasi et al., 1998 ▸). The C—N—C angle is 124.32 (17)°. This large angle can be attributed to the protonation of the N atom. These values are comparable with those of the same cation associated with other types of anions (Ghallab et al., 2020 ▸). The inter­molecular inter­actions in the title compound were analysed using PLATON (Spek, 2020 ▸), which shows that the structural cohesion in the crystal structure is ensured by N—H⋯O, N—H⋯Cl, O—H⋯Cl and C—H⋯Cl hydrogen bonds (Fig. 2 ▸ a, Table 2 ▸). We also note the presence of Cl⋯Cl halogen bonds (Fig. 2 ▸ a), and of π-stacking inter­actions between centrosymmetrically related aromatic rings of the cations as well as Y—X⋯Cg inter­actions (Fig. 2 ▸ b).

Figure 2.

(a) Hydrogen bonds [yellow, purple and violet dashed lines; symmetry codes: (ii) −x + 1, −y, −z; (iii) x, y + 1, z; (iv) −x + 2, −y + 1, −z; (v) x, y + 1, z + 1] and halogen bonds (red dashed lines) in the title compound. (b) A view of the π-stacking inter­actions [blue dashed lines; symmetry codes: (i) 1 − x, 1 − y, 1 − z; (ii) 2 − x, 1 − y, 1 − z] and C—Cl⋯Cg [green dashed lines; symmetry operations: (i) 2 − x, 1 − y, 1 − z; (ii) 1 − x, 1 − y, 1 − z] inter­actions.

Synthesis and crystallization

Tin(II) chloride dihydrate (2.25 mmol) was mixed with 2-amino-3,5-di­chloro­pyridine (3.3 mmol) in 1:2 molar ratio and a few drops of hydro­chloric acid in an aliquot of distilled water were added. After stirring, the mixture was refluxed for one h at 343 K. After two weeks of slow solvent evaporation, single crystals suitable for X-ray analysis were obtained.

Refinement

Crystal data, data collection and structure refinement details are summarized in Table 3 ▸.

Table 3. Experimental details.

Crystal data
Chemical formula	(C5H5Cl2N2)2[SnCl6]·2H2O
M r	695.44
Crystal system, space group	Triclinic, P
Temperature (K)	296
a, b, c (Å)	7.4624 (2), 8.4715 (2), 10.1324 (2)
α, β, γ (°)	101.434 (1), 90.043 (1), 107.554 (1)
V (Å3)	597.34 (2)
Z	1
Radiation type	Mo Kα
μ (mm−1)	2.20
Crystal size (mm)	0.17 × 0.13 × 0.11
Data collection
Diffractometer	Bruker APEXII CCD
Absorption correction	Multi-scan (SADABS; Bruker, 2016 ▸)
T min, T max	0.716, 0.785
No. of measured, independent and observed [I > 2σ(I)] reflections	13446, 3617, 3320
R int	0.017
(sin θ/λ)max (Å−1)	0.714
Refinement
R[F 2 > 2σ(F 2)], wR(F 2), S	0.025, 0.057, 1.02
No. of reflections	3617
No. of parameters	125
H-atom treatment	H-atom parameters constrained
Δρmax, Δρmin (e Å−3)	0.43, −0.55

Computer programs: APEX2 and SAINT (Bruker, 2016 ▸), olex2.solve (Bourhis et al., 2015 ▸), SHELXL (Sheldrick, 2015 ▸) and OLEX2 (Dolomanov et al., 2009 ▸).

Supplementary Material

CCDC reference: 2152891

Additional supporting information: crystallographic information; 3D view; checkCIF report

full crystallographic data

Crystal data

(C5H5Cl2N2)2[SnCl6]·2H2O	Z = 1
Mr = 695.44	F(000) = 338
Triclinic, P1	Dx = 1.933 Mg m−3
a = 7.4624 (2) Å	Mo Kα radiation, λ = 0.71073 Å
b = 8.4715 (2) Å	Cell parameters from 8759 reflections
c = 10.1324 (2) Å	θ = 2.9–30.9°
α = 101.434 (1)°	µ = 2.20 mm−1
β = 90.043 (1)°	T = 296 K
γ = 107.554 (1)°	Block, clear light white
V = 597.34 (2) Å3	0.17 × 0.13 × 0.11 mm

Data collection

Bruker APEXII CCD diffractometer	3320 reflections with I > 2σ(I)
φ and ω scans	Rint = 0.017
Absorption correction: multi-scan (SADABS; Bruker, 2016)	θmax = 30.5°, θmin = 3.6°
Tmin = 0.716, Tmax = 0.785	h = −10→10
13446 measured reflections	k = −11→12
3617 independent reflections	l = −14→14

Refinement

Refinement on F2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: mixed
R[F2 > 2σ(F2)] = 0.025	H-atom parameters constrained
wR(F2) = 0.057	w = 1/[σ2(Fo2) + (0.0221P)2 + 0.2999P] where P = (Fo2 + 2Fc2)/3
S = 1.02	(Δ/σ)max < 0.001
3617 reflections	Δρmax = 0.43 e Å−3
125 parameters	Δρmin = −0.55 e Å−3
0 restraints	Extinction correction: SHELXL (Sheldrick 2015), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
Primary atom site location: iterative	Extinction coefficient: 0.0164 (12)

Special details

Refinement. Approximate positions for all H atoms were first obtained from difference Fourier maps. H atoms were then placed in idealized positions and refined using the riding-atom approximation: C—H = 0.93 Å and N—H = 0.86 Å, with Uiso(H) = 1.2Ueq(C,N). H atoms of the water molecule were located in a difference Fourier map and the water molecule geometry was eventually idealized, with O—H = 0.85 Å and Uiso(H) = 1.5Ueq(O).

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

	x	y	z	Uiso*/Ueq
Sn1	1.000000	0.000000	0.000000	0.03672 (7)
Cl1	0.75548 (7)	−0.01363 (7)	0.15744 (5)	0.05267 (13)
Cl2	0.79968 (8)	0.04433 (7)	−0.17040 (5)	0.05363 (13)
Cl3	0.87570 (9)	−0.30370 (6)	−0.08206 (5)	0.05831 (15)
O1W	0.6070 (3)	0.3039 (2)	0.02149 (16)	0.0668 (5)
H1WA	0.488075	0.275909	0.008232	0.100*
H1WB	0.646535	0.225509	−0.021598	0.100*
N1	0.6643 (3)	0.3678 (2)	0.29104 (16)	0.0475 (4)
H1	0.636615	0.323122	0.206756	0.057*
C1	0.7864 (3)	0.5252 (2)	0.32410 (19)	0.0423 (4)
C2	0.8268 (3)	0.5946 (2)	0.4640 (2)	0.0440 (4)
C3	0.7460 (3)	0.5045 (3)	0.55683 (19)	0.0500 (5)
H3	0.773367	0.551264	0.648414	0.060*
C4	0.6218 (3)	0.3417 (3)	0.5144 (2)	0.0485 (5)
C5	0.5824 (3)	0.2753 (3)	0.3814 (2)	0.0504 (5)
H5	0.499435	0.166763	0.352231	0.061*
N2	0.8609 (3)	0.6033 (3)	0.2280 (2)	0.0635 (5)
H2A	0.831417	0.553756	0.144754	0.076*
H2B	0.939027	0.703933	0.248386	0.076*
Cl4	0.97856 (10)	0.79620 (8)	0.51057 (8)	0.0752 (2)
Cl5	0.51633 (12)	0.22629 (11)	0.63144 (8)	0.0814 (2)

Atomic displacement parameters (Ų)

	U11	U22	U33	U12	U13	U23
Sn1	0.04012 (10)	0.03823 (10)	0.02500 (8)	0.00279 (7)	0.00185 (6)	0.00539 (6)
Cl1	0.0505 (3)	0.0630 (3)	0.0385 (2)	0.0095 (2)	0.0146 (2)	0.0090 (2)
Cl2	0.0537 (3)	0.0674 (3)	0.0377 (2)	0.0142 (2)	−0.0065 (2)	0.0131 (2)
Cl3	0.0850 (4)	0.0373 (2)	0.0378 (2)	0.0008 (2)	0.0014 (2)	0.00182 (18)
O1W	0.0687 (10)	0.0721 (11)	0.0450 (8)	0.0080 (8)	−0.0052 (7)	0.0001 (8)
N1	0.0607 (10)	0.0453 (9)	0.0327 (7)	0.0142 (8)	0.0013 (7)	0.0026 (6)
C1	0.0504 (10)	0.0414 (9)	0.0383 (9)	0.0185 (8)	0.0079 (8)	0.0083 (7)
C2	0.0461 (10)	0.0422 (9)	0.0421 (9)	0.0178 (8)	−0.0021 (8)	−0.0014 (8)
C3	0.0571 (12)	0.0667 (13)	0.0328 (8)	0.0331 (10)	−0.0002 (8)	0.0038 (8)
C4	0.0546 (12)	0.0595 (12)	0.0439 (10)	0.0288 (10)	0.0119 (9)	0.0216 (9)
C5	0.0538 (12)	0.0443 (10)	0.0524 (11)	0.0132 (9)	0.0055 (9)	0.0112 (9)
N2	0.0852 (14)	0.0542 (11)	0.0511 (10)	0.0171 (10)	0.0201 (10)	0.0175 (9)
Cl4	0.0688 (4)	0.0496 (3)	0.0897 (5)	0.0096 (3)	−0.0104 (3)	−0.0128 (3)
Cl5	0.0971 (5)	0.1009 (5)	0.0742 (4)	0.0474 (4)	0.0359 (4)	0.0562 (4)

Geometric parameters (Å, º)

Sn1—Cl1	2.4162 (5)	C1—C2	1.417 (3)
Sn1—Cl1i	2.4162 (5)	C1—N2	1.315 (3)
Sn1—Cl2	2.4389 (5)	C2—C3	1.356 (3)
Sn1—Cl2i	2.4389 (5)	C2—Cl4	1.713 (2)
Sn1—Cl3	2.4253 (5)	C3—H3	0.9300
Sn1—Cl3i	2.4253 (5)	C3—C4	1.393 (3)
O1W—H1WA	0.8499	C4—C5	1.348 (3)
O1W—H1WB	0.8496	C4—Cl5	1.726 (2)
N1—H1	0.8600	C5—H5	0.9300
N1—C1	1.345 (3)	N2—H2A	0.8600
N1—C5	1.350 (3)	N2—H2B	0.8600
Cl1—Sn1—Cl1i	180.0	N1—C1—C2	116.00 (18)
Cl1—Sn1—Cl2	90.722 (19)	N2—C1—N1	119.49 (18)
Cl1i—Sn1—Cl2	89.278 (19)	N2—C1—C2	124.50 (19)
Cl1—Sn1—Cl2i	89.277 (19)	C1—C2—Cl4	117.52 (16)
Cl1i—Sn1—Cl2i	90.723 (19)	C3—C2—C1	120.82 (18)
Cl1—Sn1—Cl3	89.906 (19)	C3—C2—Cl4	121.66 (15)
Cl1—Sn1—Cl3i	90.093 (19)	C2—C3—H3	120.1
Cl1i—Sn1—Cl3i	89.907 (19)	C2—C3—C4	119.71 (18)
Cl1i—Sn1—Cl3	90.093 (19)	C4—C3—H3	120.1
Cl2i—Sn1—Cl2	180.0	C3—C4—Cl5	120.22 (16)
Cl3i—Sn1—Cl2	89.81 (2)	C5—C4—C3	119.70 (19)
Cl3i—Sn1—Cl2i	90.19 (2)	C5—C4—Cl5	120.08 (18)
Cl3—Sn1—Cl2	90.19 (2)	N1—C5—H5	120.3
Cl3—Sn1—Cl2i	89.81 (2)	C4—C5—N1	119.4 (2)
Cl3—Sn1—Cl3i	180.0	C4—C5—H5	120.3
H1WA—O1W—H1WB	109.5	C1—N2—H2A	120.0
C1—N1—H1	117.8	C1—N2—H2B	120.0
C1—N1—C5	124.32 (17)	H2A—N2—H2B	120.0
C5—N1—H1	117.8
N1—C1—C2—C3	0.4 (3)	C5—N1—C1—C2	−0.6 (3)
N1—C1—C2—Cl4	−178.93 (15)	C5—N1—C1—N2	178.8 (2)
C1—N1—C5—C4	0.3 (3)	N2—C1—C2—C3	−179.0 (2)
C1—C2—C3—C4	0.0 (3)	N2—C1—C2—Cl4	1.7 (3)
C2—C3—C4—C5	−0.3 (3)	Cl4—C2—C3—C4	179.31 (16)
C2—C3—C4—Cl5	−179.42 (16)	Cl5—C4—C5—N1	179.25 (16)
C3—C4—C5—N1	0.1 (3)

Symmetry code: (i) −x+2, −y, −z.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1···O1W	0.86	1.86	2.685 (2)	160
O1W—H1WA···Cl1ii	0.85	2.67	3.296 (2)	131
O1W—H1WB···Cl2	0.85	2.47	3.301 (2)	168
N2—H2A···Cl3iii	0.86	2.78	3.381 (2)	129
N2—H2A···O1W	0.86	2.38	3.065 (3)	137
N2—H2B···Cl4	0.86	2.61	2.986 (2)	108
N2—H2B···Cl2iv	0.86	2.67	3.435 (2)	149
C3—H3···Cl3v	0.93	2.77	3.695 (2)	177
C5—H5···Cl2ii	0.93	2.80	3.615 (2)	147

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

Funding Statement

Funding for this research was provided by: Unité de recherche de chimie de l’environnement, moléculaire et structurale 113 UR.CHEMS; Direction Générale de la Recherche Scientifique et du Développement Technologique DGRSDT Algérie.