4,4′-Bi­pyridine-1,1′-diium tetra­chloridodi­fluorido­stannate(IV) monohydrate

Kemmouche, A.; Ghallab, R.; Merazig, H.

doi:10.1107/S2414314625005966

metal-organic compounds

IUCrDATA

ISSN: 2414-3146

Volume 10| Part 7| July 2025| x250596

https://doi.org/10.1107/S2414314625005966

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4,4′-Bipyridine-1,1′-diium tetrachloridodifluoridostannate(IV) monohydrate

Amina Kemmouche,^a Rochdi Ghallab ^b ^* and Hocine Merazig ^c

^aEcole Nationale Superieure de Biotechnologie de Constantine, Algeria, ^bLaboratoire de Technologie des Materiaux Avances, Ecole Nationale Polytechnique de Constantine, Algeria, and ^cUnite De Recherche Chimie De L'Environnement Et Moleculaire Structurale, URCHEMS, University of Constantine 1-Mentouri Brothers, Algeria
^*Correspondence e-mail: [email protected]

Edited by W. T. A. Harrison, University of Aberdeen, United Kingdom (Received 5 June 2025; accepted 1 July 2025; online 11 July 2025)

In the title hydrated salt, (C₁₀H₁₀N₂)[SnF₂Cl₄]·H₂O, the dihedral angle between the pyridinium rings in the cation is 40.5 (4)° and the F atoms in the octahedral complex anion have a cis disposition [F—Sn—F = 85.32 (17)°]. In the extended structure, alternating cationic and anionic layers occur, linked by extensive hydrogen bonding, with water molecules inserted between the layers.

Keywords: crystal structure; stannate(IV); bipyridinium; X-ray diffraction.

CCDC reference: 1904712

Structure description

The title compound, (C₁₀H₁₀N₂²⁺)[SnF₂Cl₄]^2–·H₂O, crystallizes in the non-centrosymmetric orthorhombic space group Pna2₁ with one cation, one anion and one water molecule in the asymmetric unit (Fig. 1). The bipyridinium cation exhibits structural parameters indicative of protonation: the inter-ring C—C bond length is 1.476 (7) Å, while the average intra-ring C—C bond length is 1.384 (3) Å, reflecting aromatic conjugation. The C—N bonds measure 1.341 (9) Å or less, which are shorter than those in neutral bipyridine, due to the cationic charge. Angular distortions are observed with C—C—C angles in the range 117.9 (5)°–121.0 (6)° and C—N—C angles of 122.4 (5) and 123.0 (6)°, in agreement with literature data (e.g., Horiacha et al., 2022 ). The dihedral angle between the C1–C5/N1 and C6–C10/N2 pyridinium rings is 40.5 (4)°, which can be attributed to intramolecular (steric) interactions (Gheribi et al., 2022 ). The [SnF₂Cl₄]^2– anion adopts a distorted octahedral coordination sphere around the Sn^IV atom, with Sn—Cl bond lengths ranging from 2.383 (2) to 2.418 (2) Å and Sn—F bonds of 2.030 (4) and 2.096 (4) Å. The bond angles deviate somewhat from ideal octahedral values, with notable examples being 87.98 (13)° for F1—Sn1—F2 and 93.84 (8)° for Cl2—Sn1—Cl4, consistent with previous reports (Bruhn & Preetz, 1996 ).

Figure 1
The molecular structure of the title compound with displacement ellipsoids drawn at the 50% probability level.

The extended structure reveals alternating layers of cations and anions separated by interstitial water molecules (Fig. 2). Eight hydrogen bonds consolidate the tri-periodic network (Table 1), including one strong (N1—H1⋯F2), two moderate (N2—H2⋯O1W and O1W—H1WA⋯Cl1), and five weak interactions (O1W—H1WB⋯Cl4, O1W—H1WB⋯F2, N2—H2⋯F1, C1—H1A⋯Cl3 and C9—H9⋯F1). Water molecules mediate cyclic motifs in the bc plane via O1W—H⋯Cl/F interactions, generating a supramolecular R₄⁴(12) graph-set motif (Fig. 3). Intralayer cohesion is ensured by weak π–π stacking interactions with centroid–centroid distances of 3.950 (4) Å, while interlayer bridging is provided by a Sn—Cl4⋯Cg(2 − x, 1 − y, − $[{1\over 2}]$ + z) halogen⋯π contact [Cl⋯π = 3.472 (4) Å, Sn—Cl⋯π = 110.42 (9)°] linking the [SnF₂Cl₄]^2– anion to the N2 ring of the bipyridinium cation. The crystal packing is thus supported by directional hydrogen bonds, face-to-face π-stacking within cationic layers, and anion–cation halogen⋯π contacts.

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N1—H1⋯F2ⁱ	0.86	1.79	2.629 (6)	163
N2—H2⋯F1	0.86	2.32	2.989 (6)	134
N2—H2⋯O1Wⁱⁱ	0.86	2.11	2.819 (10)	140
O1W—H1WA⋯Cl1ⁱⁱⁱ	0.85	2.51	3.324 (8)	159
O1W—H1WB⋯Cl4ⁱⁱ	0.85	2.72	3.366 (8)	134
O1W—H1WB⋯F2^iv	0.85	2.32	2.906 (9)	126
C1—H1A⋯Cl3^iv	0.93	2.82	3.473 (6)	128
C9—H9⋯F1ⁱⁱ	0.93	2.44	3.109 (9)	129
Symmetry codes: (i) $[-x+{\script{3\over 2}}, y-{\script{1\over 2}}, z-{\script{1\over 2}}]$ ; (ii) $[-x+1, -y+1, z+{\script{1\over 2}}]$ ; (iii) ; (iv) $[-x+1, -y+1, z-{\script{1\over 2}}]$ .

Figure 2
Projection of the crystal packing on (a) the ab plane and (b) the bc plane.

Figure 3
Sequence of R₄⁴(12) loops in the structure.

Synthesis and crystallization

Tin(II) fluoride (1.56 mmol) was combined with 4,4′-bipyridine (1.56 mmol) in a 1:1 molar ratio. A few drops of hydrochloric acid were added to the mixture in a minimal volume of distilled water to facilitate dissolution. After thorough stirring, the solution was transferred into a Biotage microwave vial (2–5 ml) and heated in an oven at 393 K for three days. Upon gradual cooling to room temperature, prismatic crystals of the title compound formed and were isolated under an optical microscope for further analysis.

Refinement

Crystal data, data collection and structure refinement details are summarized in Table 2. The crystal studied was refined as a two-component inversion twin.

Table 2
Experimental details

Crystal data
Chemical formula	(C₁₀H₁₀N₂)[SnCl₄F₂]·H₂O
M_r	474.71
Crystal system, space group	Orthorhombic, Pna2₁
Temperature (K)	293
a, b, c (Å)	7.5641 (2), 26.5989 (5), 7.9422 (2)
V (Å³)	1597.94 (7)
Z	4
Radiation type	Mo Kα
μ (mm⁻¹)	2.28
Crystal size (mm)	0.08 × 0.08 × 0.07

Data collection
Diffractometer	Bruker SMART APEXII area detector
Absorption correction	Multi-scan (SADABS; Krause et al., 2015 )
T_min, T_max	0.852, 0.852
No. of measured, independent and observed [I > 2σ(I)] reflections	16855, 7535, 6299
R_int	0.030
(sin θ/λ)_max (Å⁻¹)	0.837

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.047, 0.107, 1.04
No. of reflections	7535
No. of parameters	182
No. of restraints	1
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	1.11, −2.00
Absolute structure	Ad
Absolute structure parameter	0.06 (4)
Computer programs: APEX2 and SAINT (Bruker, 2014 ), OLEX2.solve (Bourhis et al., 2015 ), SHELXL2019/3 (Sheldrick, 2015 ) and OLEX2 (Dolomanov et al., 2009 ).

Structural data

CCDC reference: 1904712

Crystal structure: contains datablock I. DOI: https://doi.org/10.1107/S2414314625005966/hb4521sup1.cif

Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S2414314625005966/hb4521Isup2.hkl

checkCIF report

Computing details top

4,4'-Bipyridine-1,1'-diium tetrachloridodifluoridostannate(IV) monohydrate top

Crystal data top

(C₁₀H₁₀N₂)[SnCl₄F₂]·H₂O	D_x = 1.973 Mg m⁻³
M_r = 474.71	Mo Kα radiation, λ = 0.71073 Å
Orthorhombic, Pna2₁	Cell parameters from 6299 reflections
a = 7.5641 (2) Å	θ = 1.5–36.5°
b = 26.5989 (5) Å	µ = 2.28 mm⁻¹
c = 7.9422 (2) Å	T = 293 K
V = 1597.94 (7) Å³	Prism, colourless
Z = 4	0.08 × 0.08 × 0.07 mm
F(000) = 920

Data collection top

Bruker SMART APEXII area detector diffractometer	6299 reflections with I > 2σ(I)
ω and φ scans	R_int = 0.030
Absorption correction: multi-scan (SADABS; Krause et al., 2015)	θ_max = 36.5°, θ_min = 1.5°
T_min = 0.852, T_max = 0.852	h = −11→12
16855 measured reflections	k = −44→20
7535 independent reflections	l = −13→13

Refinement top

Refinement on F²	Hydrogen site location: mixed
Least-squares matrix: full	H-atom parameters constrained
R[F² > 2σ(F²)] = 0.047	w = 1/[σ²(F_o²) + (0.0043P)² + 2.4611P] where P = (F_o² + 2F_c²)/3
wR(F²) = 0.107	(Δ/σ)_max = 0.003
S = 1.04	Δρ_max = 1.11 e Å⁻³
7535 reflections	Δρ_min = −2.00 e Å⁻³
182 parameters	Absolute structure: ad
1 restraint	Absolute structure parameter: 0.06 (4)
Primary atom site location: dual

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. Refined as a 2-component inversion twin. Hydrogen atoms on the aromatic rings were geometrically positioned and refined as riding atoms with U_iso(H) = 1.2U_eq(C).

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

	x	y	z	U_iso*/U_eq
N1	0.5711 (7)	0.22347 (18)	0.5432 (7)	0.0394 (10)
H1	0.567363	0.192734	0.510167	0.047*
N2	0.6786 (8)	0.4709 (2)	0.7922 (10)	0.0567 (16)
H2	0.697543	0.501502	0.822841	0.068*
C1	0.5305 (8)	0.2597 (2)	0.4340 (8)	0.0389 (11)
H1A	0.495469	0.251527	0.325148	0.047*
C2	0.5406 (8)	0.3090 (2)	0.4830 (7)	0.0355 (10)
H2A	0.511969	0.334401	0.407206	0.043*
C3	0.5935 (6)	0.32135 (16)	0.6459 (10)	0.0321 (10)
C4	0.6285 (8)	0.2819 (2)	0.7580 (8)	0.0383 (11)
H4	0.659405	0.288740	0.868982	0.046*
C5	0.6171 (9)	0.2333 (2)	0.7030 (8)	0.0437 (13)
H5	0.641172	0.206937	0.776600	0.052*
C6	0.6192 (7)	0.37422 (19)	0.6967 (7)	0.0337 (11)
C7	0.6957 (9)	0.4080 (2)	0.5833 (9)	0.0449 (13)
H7	0.724699	0.398189	0.474367	0.054*
C8	0.7270 (10)	0.4569 (2)	0.6390 (15)	0.061 (2)
H8	0.782381	0.479812	0.568010	0.073*
C9	0.6021 (9)	0.4396 (3)	0.9022 (11)	0.0561 (19)
H9	0.569590	0.451008	1.008552	0.067*
C10	0.5717 (9)	0.3902 (2)	0.8562 (10)	0.0440 (13)
H10	0.519959	0.367892	0.931787	0.053*
Sn1	0.90313 (4)	0.61887 (2)	0.66064 (6)	0.03161 (8)
Cl1	1.0622 (3)	0.54461 (7)	0.7330 (3)	0.0588 (5)
Cl2	1.16953 (18)	0.66810 (5)	0.6621 (3)	0.0487 (3)
Cl3	0.7297 (2)	0.69369 (5)	0.6093 (2)	0.0436 (3)
Cl4	0.9182 (3)	0.60193 (8)	0.3643 (2)	0.0545 (4)
F1	0.6661 (6)	0.57916 (12)	0.6921 (6)	0.0594 (12)
F2	0.8830 (6)	0.63386 (14)	0.9106 (5)	0.0449 (8)
O1W	0.2936 (11)	0.4547 (3)	0.5435 (9)	0.081 (2)
H1WA	0.259704	0.478305	0.608329	0.122*
H1WB	0.250934	0.426975	0.577499	0.122*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
N1	0.045 (3)	0.028 (2)	0.045 (3)	0.0004 (17)	−0.001 (2)	−0.0094 (18)
N2	0.052 (3)	0.037 (3)	0.081 (5)	−0.008 (2)	0.002 (3)	−0.024 (3)
C1	0.044 (3)	0.037 (3)	0.036 (3)	−0.001 (2)	−0.002 (2)	−0.009 (2)
C2	0.040 (2)	0.034 (2)	0.032 (2)	0.001 (2)	−0.005 (2)	−0.0021 (19)
C3	0.0323 (17)	0.0280 (16)	0.036 (3)	−0.0013 (14)	0.005 (2)	−0.005 (2)
C4	0.046 (3)	0.035 (2)	0.034 (3)	0.001 (2)	−0.005 (2)	−0.001 (2)
C5	0.055 (3)	0.033 (2)	0.043 (4)	0.001 (2)	−0.001 (2)	0.003 (2)
C6	0.033 (2)	0.031 (2)	0.037 (3)	−0.0004 (15)	−0.0019 (17)	−0.0056 (17)
C7	0.050 (3)	0.033 (2)	0.052 (4)	−0.006 (2)	0.003 (3)	−0.005 (2)
C8	0.059 (4)	0.039 (3)	0.085 (7)	−0.018 (3)	0.011 (4)	−0.003 (4)
C9	0.052 (4)	0.049 (4)	0.068 (5)	−0.001 (3)	0.009 (3)	−0.028 (3)
C10	0.047 (3)	0.037 (3)	0.049 (3)	−0.004 (2)	0.001 (3)	−0.013 (2)
Sn1	0.03949 (14)	0.02310 (11)	0.03226 (13)	−0.00219 (10)	−0.00508 (19)	−0.00433 (15)
Cl1	0.0618 (10)	0.0384 (7)	0.0760 (12)	0.0042 (7)	−0.0140 (8)	−0.0060 (7)
Cl2	0.0445 (6)	0.0452 (6)	0.0565 (8)	−0.0130 (5)	0.0003 (10)	−0.0090 (10)
Cl3	0.0535 (8)	0.0351 (6)	0.0422 (7)	0.0112 (5)	0.0033 (6)	−0.0005 (5)
Cl4	0.0669 (10)	0.0578 (9)	0.0387 (8)	0.0074 (8)	−0.0084 (7)	−0.0199 (7)
F1	0.095 (3)	0.0278 (13)	0.055 (3)	−0.0150 (16)	−0.033 (2)	0.0077 (15)
F2	0.071 (2)	0.0327 (15)	0.0306 (16)	−0.0019 (16)	0.0021 (16)	−0.0019 (13)
O1W	0.102 (5)	0.074 (4)	0.067 (4)	−0.022 (4)	−0.009 (4)	0.025 (3)

Geometric parameters (Å, º) top

N1—H1	0.8593	C6—C10	1.384 (9)
N1—C1	1.332 (8)	C7—H7	0.9300
N1—C5	1.341 (9)	C7—C8	1.394 (9)
N2—H2	0.8611	C8—H8	0.9300
N2—C8	1.325 (13)	C9—H9	0.9300
N2—C9	1.338 (12)	C9—C10	1.385 (9)
C1—H1A	0.9300	C10—H10	0.9300
C1—C2	1.372 (8)	Sn1—Cl1	2.3831 (18)
C2—H2A	0.9300	Sn1—Cl2	2.4032 (12)
C2—C3	1.393 (9)	Sn1—Cl3	2.4183 (14)
C3—C4	1.401 (8)	Sn1—Cl4	2.3994 (17)
C3—C6	1.476 (7)	Sn1—F1	2.096 (4)
C4—H4	0.9300	Sn1—F2	2.030 (4)
C4—C5	1.368 (9)	O1W—H1WA	0.8512
C5—H5	0.9300	O1W—H1WB	0.8498
C6—C7	1.397 (9)

C1—N1—H1	118.8	C8—C7—H7	121.1
C1—N1—C5	122.4 (5)	N2—C8—C7	120.5 (7)
C5—N1—H1	118.8	N2—C8—H8	119.8
C8—N2—H2	118.7	C7—C8—H8	119.8
C8—N2—C9	123.0 (6)	N2—C9—H9	120.3
C9—N2—H2	118.3	N2—C9—C10	119.3 (7)
N1—C1—H1A	120.2	C10—C9—H9	120.3
N1—C1—C2	119.6 (5)	C6—C10—C9	119.3 (7)
C2—C1—H1A	120.2	C6—C10—H10	120.3
C1—C2—H2A	119.8	C9—C10—H10	120.3
C1—C2—C3	120.3 (5)	Cl1—Sn1—Cl2	91.56 (6)
C3—C2—H2A	119.8	Cl1—Sn1—Cl3	175.29 (7)
C2—C3—C4	117.9 (5)	Cl1—Sn1—Cl4	93.27 (7)
C2—C3—C6	121.0 (5)	Cl2—Sn1—Cl3	90.42 (5)
C4—C3—C6	121.0 (6)	Cl4—Sn1—Cl2	93.84 (8)
C3—C4—H4	120.2	Cl4—Sn1—Cl3	90.87 (6)
C5—C4—C3	119.6 (6)	F1—Sn1—Cl1	89.16 (12)
C5—C4—H4	120.2	F1—Sn1—Cl2	172.46 (14)
N1—C5—C4	120.1 (6)	F1—Sn1—Cl3	88.32 (12)
N1—C5—H5	119.9	F1—Sn1—Cl4	93.60 (14)
C4—C5—H5	119.9	F2—Sn1—Cl1	87.98 (13)
C7—C6—C3	119.4 (5)	F2—Sn1—Cl2	87.21 (13)
C10—C6—C3	120.5 (6)	F2—Sn1—Cl3	87.85 (12)
C10—C6—C7	120.0 (5)	F2—Sn1—Cl4	178.34 (13)
C6—C7—H7	121.1	F2—Sn1—F1	85.32 (17)
C8—C7—C6	117.8 (7)	H1WA—O1W—H1WB	109.4

N1—C1—C2—C3	0.2 (9)	C3—C6—C10—C9	178.1 (6)
N2—C9—C10—C6	−0.8 (11)	C4—C3—C6—C7	138.5 (6)
C1—N1—C5—C4	−1.9 (10)	C4—C3—C6—C10	−40.1 (8)
C1—C2—C3—C4	−2.5 (8)	C5—N1—C1—C2	2.1 (9)
C1—C2—C3—C6	174.9 (5)	C6—C3—C4—C5	−174.8 (5)
C2—C3—C4—C5	2.7 (8)	C6—C7—C8—N2	−2.7 (11)
C2—C3—C6—C7	−38.8 (7)	C7—C6—C10—C9	−0.5 (10)
C2—C3—C6—C10	142.5 (6)	C8—N2—C9—C10	0.2 (12)
C3—C4—C5—N1	−0.6 (9)	C9—N2—C8—C7	1.6 (13)
C3—C6—C7—C8	−176.4 (6)	C10—C6—C7—C8	2.2 (9)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1···F2ⁱ	0.86	1.79	2.629 (6)	163
N2—H2···F1	0.86	2.32	2.989 (6)	134
N2—H2···O1Wⁱⁱ	0.86	2.11	2.819 (10)	140
O1W—H1WA···Cl1ⁱⁱⁱ	0.85	2.51	3.324 (8)	159
O1W—H1WB···Cl4ⁱⁱ	0.85	2.72	3.366 (8)	134
O1W—H1WB···F2^iv	0.85	2.32	2.906 (9)	126
C1—H1A···Cl3^iv	0.93	2.82	3.473 (6)	128
C9—H9···F1ⁱⁱ	0.93	2.44	3.109 (9)	129

Symmetry codes: (i) −x+3/2, y−1/2, z−1/2; (ii) −x+1, −y+1, z+1/2; (iii) x−1, y, z; (iv) −x+1, −y+1, z−1/2.

Acknowledgements

Thanks are due to DRSDT-Algeria.

References

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