The asymmetric unit of the title compound, (C
5H
5BrN)
2[SnBr
6], contains one cation and one half-anion. The [SnBr
6]
2− anion is located on an inversion center and forms a quasi-regular octahedral arrangement. The crystal structure consists of two-dimensional supramolecular layers assembled
via hydrogen-bonding interactions of N—H

Br—Sn [
D
A = 3.375 (13)–3.562 (13) Å and
D—H
A = 127–142°, along with C—Br

Br synthons [3.667 (2) and 3.778 (3) Å]. These layers are parallel to the
bc plane and built up from anions interacting extensively with the six surrounding cations.
Supporting information
CCDC reference: 690802
Key indicators
- Single-crystal X-ray study
- T = 293 K
- Mean
(C-C) = 0.020 Å
- R factor = 0.068
- wR factor = 0.178
- Data-to-parameter ratio = 27.0
checkCIF/PLATON results
No syntax errors found
Alert level B
PLAT201_ALERT_2_B Isotropic non-H Atoms in Main Residue(s) ....... 6
Alert level C
PLAT154_ALERT_1_C The su's on the Cell Angles are Equal (x 10000) 3000 Deg.
PLAT342_ALERT_3_C Low Bond Precision on C-C Bonds (x 1000) Ang ... 20
PLAT480_ALERT_4_C Long H...A H-Bond Reported H1 .. BR1 .. 2.98 Ang.
PLAT790_ALERT_4_C Centre of Gravity not Within Unit Cell: Resd. # 1
C5 H5 Br N
Alert level G
PLAT199_ALERT_1_G Check the Reported _cell_measurement_temperature 293 K
PLAT200_ALERT_1_G Check the Reported _diffrn_ambient_temperature . 293 K
0 ALERT level A = In general: serious problem
1 ALERT level B = Potentially serious problem
4 ALERT level C = Check and explain
2 ALERT level G = General alerts; check
3 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
1 ALERT type 2 Indicator that the structure model may be wrong or deficient
1 ALERT type 3 Indicator that the structure quality may be low
2 ALERT type 4 Improvement, methodology, query or suggestion
0 ALERT type 5 Informative message, check
Warm solution of Sn metal (1.0 mmol) dissolved in absolute ethanol (10 ml) and
HBr (60%, 5 ml), was added dropwise to a stirred hot solution of
2-bromopyridine (2 mmol) dissolved in ethanol (10 ml). The mixture was
then treated with liquid Br2 (2 ml) and refluxed for 3/2 h. The resulting
mixture was then filtered off, and allowed to stand undisturbed at room
temperature. The salt crystallized over 1 d as nice yellow block crystals
(yield: 83%).
H atoms were positioned geometrically, with N—H = 0.86 Å (for NH) and C—H
= 0.93 Å for aromatic H, and constrained to ride on their parent atoms, with
Uiso(H) = 1.2Ueq(C, N).
Data collection: SMART (Bruker, 2006); cell refinement: SAINT-Plus (Bruker, 2006); data reduction: SAINT-Plus (Bruker, 2006); program(s) used to solve structure: XS in SHELXTL (Sheldrick, 2008); program(s) used to refine structure: XL in SHELXTL (Sheldrick, 2008); molecular graphics: XP in SHELXTL (Sheldrick, 2008); software used to prepare material for publication: XCIF in SHELXTL (Sheldrick, 2008).
Bis(2-bromopyridinium) hexabromidostannate(IV)
top
Crystal data top
(C5H5BrN)2[SnBr6] | Z = 1 |
Mr = 916.12 | F(000) = 414 |
Triclinic, P1 | Dx = 2.946 Mg m−3 |
Hall symbol: -P 1 | Mo Kα radiation, λ = 0.71073 Å |
a = 7.4037 (15) Å | Cell parameters from 255 reflections |
b = 8.3393 (17) Å | θ = 2.1–27.7° |
c = 9.4302 (19) Å | µ = 16.71 mm−1 |
α = 73.14 (3)° | T = 293 K |
β = 67.98 (3)° | Block, yellow |
γ = 82.44 (3)° | 0.16 × 0.13 × 0.08 mm |
V = 516.4 (2) Å3 | |
Data collection top
Bruker–Siemens SMART APEX diffractometer | 1807 independent reflections |
Radiation source: fine-focus sealed tube | 1308 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.091 |
Detector resolution: 8.3 pixels mm-1 | θmax = 25.0°, θmin = 2.4° |
ω scans | h = −1→8 |
Absorption correction: multi-scan (SADABS; Bruker, 2007) | k = −9→9 |
Tmin = 0.058, Tmax = 0.261 | l = −10→11 |
2266 measured reflections | |
Refinement top
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)] = 0.068 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.178 | H-atom parameters constrained |
S = 1.02 | w = 1/[σ2(Fo2) + (0.1076P)2 + 1.002P] where P = (Fo2 + 2Fc2)/3 |
1807 reflections | (Δ/σ)max < 0.001 |
67 parameters | Δρmax = 3.31 e Å−3 |
0 restraints | Δρmin = −1.87 e Å−3 |
Crystal data top
(C5H5BrN)2[SnBr6] | γ = 82.44 (3)° |
Mr = 916.12 | V = 516.4 (2) Å3 |
Triclinic, P1 | Z = 1 |
a = 7.4037 (15) Å | Mo Kα radiation |
b = 8.3393 (17) Å | µ = 16.71 mm−1 |
c = 9.4302 (19) Å | T = 293 K |
α = 73.14 (3)° | 0.16 × 0.13 × 0.08 mm |
β = 67.98 (3)° | |
Data collection top
Bruker–Siemens SMART APEX diffractometer | 1807 independent reflections |
Absorption correction: multi-scan (SADABS; Bruker, 2007) | 1308 reflections with I > 2σ(I) |
Tmin = 0.058, Tmax = 0.261 | Rint = 0.091 |
2266 measured reflections | |
Refinement top
R[F2 > 2σ(F2)] = 0.068 | 0 restraints |
wR(F2) = 0.178 | H-atom parameters constrained |
S = 1.02 | Δρmax = 3.31 e Å−3 |
1807 reflections | Δρmin = −1.87 e Å−3 |
67 parameters | |
Special details top
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 (Å2) top | x | y | z | Uiso*/Ueq | |
Sn1 | 0.5000 | 0.5000 | 0.0000 | 0.0271 (4) | |
Br4 | 0.80819 (19) | 0.51691 (17) | −0.25738 (17) | 0.0365 (4) | |
Br3 | 0.5601 (2) | 0.17999 (16) | 0.09614 (18) | 0.0394 (4) | |
Br1 | 0.2879 (2) | 0.43877 (19) | −0.14375 (19) | 0.0426 (4) | |
Br2 | 0.6761 (3) | 0.2489 (2) | −0.4484 (2) | 0.0674 (6) | |
C2 | 0.7936 (19) | 0.1051 (18) | −0.5793 (18) | 0.038 (3)* | |
N1 | 0.9316 (17) | 0.1687 (17) | −0.7225 (17) | 0.049 (3)* | |
H1 | 0.9575 | 0.2732 | −0.7499 | 0.059* | |
C3 | 0.751 (2) | −0.0578 (18) | −0.5321 (19) | 0.042 (3)* | |
H3 | 0.6604 | −0.1039 | −0.4324 | 0.051* | |
C4 | 0.845 (2) | −0.155 (2) | −0.6371 (19) | 0.047 (4)* | |
H4 | 0.8119 | −0.2665 | −0.6094 | 0.057* | |
C5 | 0.990 (2) | −0.090 (2) | −0.784 (2) | 0.051 (4)* | |
H5 | 1.0572 | −0.1560 | −0.8526 | 0.061* | |
C6 | 1.028 (3) | 0.077 (2) | −0.822 (2) | 0.060 (5)* | |
H6 | 1.1225 | 0.1254 | −0.9183 | 0.072* | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
Sn1 | 0.0304 (6) | 0.0249 (6) | 0.0213 (7) | 0.0021 (5) | −0.0058 (5) | −0.0048 (5) |
Br4 | 0.0387 (7) | 0.0322 (7) | 0.0294 (8) | −0.0003 (5) | −0.0011 (6) | −0.0094 (6) |
Br3 | 0.0462 (8) | 0.0258 (7) | 0.0340 (9) | 0.0066 (6) | −0.0067 (6) | −0.0034 (6) |
Br1 | 0.0491 (8) | 0.0446 (8) | 0.0391 (9) | −0.0002 (6) | −0.0226 (7) | −0.0094 (7) |
Br2 | 0.1089 (15) | 0.0522 (10) | 0.0491 (11) | 0.0059 (10) | −0.0295 (11) | −0.0268 (9) |
Geometric parameters (Å, º) top
Sn1—Br3 | 2.5939 (15) | N1—C6 | 1.32 (2) |
Sn1—Br3i | 2.5939 (15) | N1—H1 | 0.8600 |
Sn1—Br1 | 2.6027 (15) | C3—C4 | 1.39 (2) |
Sn1—Br1i | 2.6027 (15) | C3—H3 | 0.9300 |
Sn1—Br4i | 2.6174 (17) | C4—C5 | 1.40 (2) |
Sn1—Br4 | 2.6174 (17) | C4—H4 | 0.9300 |
Br2—C2 | 1.870 (15) | C5—C6 | 1.37 (2) |
C2—C3 | 1.34 (2) | C5—H5 | 0.9300 |
C2—N1 | 1.357 (19) | C6—H6 | 0.9300 |
| | | |
Br3—Sn1—Br3i | 180.0 | N1—C2—Br2 | 117.9 (11) |
Br3—Sn1—Br1 | 89.06 (5) | C6—N1—C2 | 122.7 (14) |
Br3i—Sn1—Br1 | 90.94 (5) | C6—N1—H1 | 118.6 |
Br3—Sn1—Br1i | 90.94 (5) | C2—N1—H1 | 118.6 |
Br3i—Sn1—Br1i | 89.06 (5) | C2—C3—C4 | 117.8 (15) |
Br1—Sn1—Br1i | 180.00 (5) | C2—C3—H3 | 121.1 |
Br3—Sn1—Br4i | 89.43 (6) | C4—C3—H3 | 121.1 |
Br3i—Sn1—Br4i | 90.57 (6) | C3—C4—C5 | 121.7 (15) |
Br1—Sn1—Br4i | 90.21 (5) | C3—C4—H4 | 119.1 |
Br1i—Sn1—Br4i | 89.79 (5) | C5—C4—H4 | 119.1 |
Br3—Sn1—Br4 | 90.57 (6) | C6—C5—C4 | 116.8 (17) |
Br3i—Sn1—Br4 | 89.43 (6) | C6—C5—H5 | 121.6 |
Br1—Sn1—Br4 | 89.79 (5) | C4—C5—H5 | 121.6 |
Br1i—Sn1—Br4 | 90.21 (5) | N1—C6—C5 | 120.6 (17) |
Br4i—Sn1—Br4 | 180.0 | N1—C6—H6 | 119.7 |
C3—C2—N1 | 120.3 (15) | C5—C6—H6 | 119.7 |
C3—C2—Br2 | 121.8 (12) | | |
| | | |
C3—C2—N1—C6 | 1 (2) | C2—C3—C4—C5 | 4 (2) |
Br2—C2—N1—C6 | 177.7 (12) | C3—C4—C5—C6 | −3 (2) |
N1—C2—C3—C4 | −3 (2) | C2—N1—C6—C5 | 1 (3) |
Br2—C2—C3—C4 | −179.9 (11) | C4—C5—C6—N1 | 0 (3) |
Symmetry code: (i) −x+1, −y+1, −z. |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1···Br4ii | 0.86 | 2.65 | 3.375 (13) | 142 |
N1—H1···Br1iii | 0.86 | 2.98 | 3.562 (13) | 127 |
Symmetry codes: (ii) −x+2, −y+1, −z−1; (iii) −x+1, −y+1, −z−1. |
Experimental details
Crystal data |
Chemical formula | (C5H5BrN)2[SnBr6] |
Mr | 916.12 |
Crystal system, space group | Triclinic, P1 |
Temperature (K) | 293 |
a, b, c (Å) | 7.4037 (15), 8.3393 (17), 9.4302 (19) |
α, β, γ (°) | 73.14 (3), 67.98 (3), 82.44 (3) |
V (Å3) | 516.4 (2) |
Z | 1 |
Radiation type | Mo Kα |
µ (mm−1) | 16.71 |
Crystal size (mm) | 0.16 × 0.13 × 0.08 |
|
Data collection |
Diffractometer | Bruker–Siemens SMART APEX diffractometer |
Absorption correction | Multi-scan (SADABS; Bruker, 2007) |
Tmin, Tmax | 0.058, 0.261 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 2266, 1807, 1308 |
Rint | 0.091 |
(sin θ/λ)max (Å−1) | 0.595 |
|
Refinement |
R[F2 > 2σ(F2)], wR(F2), S | 0.068, 0.178, 1.02 |
No. of reflections | 1807 |
No. of parameters | 67 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 3.31, −1.87 |
Selected geometric parameters (Å, º) topSn1—Br3 | 2.5939 (15) | Sn1—Br4 | 2.6174 (17) |
Sn1—Br1 | 2.6027 (15) | | |
| | | |
Br3—Sn1—Br1 | 89.06 (5) | Br1—Sn1—Br4i | 90.21 (5) |
Br3i—Sn1—Br1 | 90.94 (5) | Br3—Sn1—Br4 | 90.57 (6) |
Br3—Sn1—Br4i | 89.43 (6) | Br1—Sn1—Br4 | 89.79 (5) |
Symmetry code: (i) −x+1, −y+1, −z. |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1···Br4ii | 0.86 | 2.65 | 3.375 (13) | 142.4 |
N1—H1···Br1iii | 0.86 | 2.98 | 3.562 (13) | 126.5 |
Symmetry codes: (ii) −x+2, −y+1, −z−1; (iii) −x+1, −y+1, −z−1. |
Noncovalent interactions play an important role in organizing structural units in both natural and artificial systems. Hybrid organic-inorganic compounds are of great interest owing to their ionic, electrical, magnetic and optical properties (Hill, 1998; Kagan et al., 1999; Raptopoulou et al., 2002). Tin metal-halo based hybrids are of particular interest as being materials with interesting optical and magnetic properties (Aruta et al., 2005; Knutson et al., 2005; Kagan et al., 1999). We are currently carrying out studies about lattice including different types of intermolecular interactions (aryl···aryl, X···X, X···aryl and X···H). Within our research of hybrid compounds containing tin metal (Al-Far & Ali 2007; Ali, Al-Far & Al-Sou'od, 2007; Ali & Al-Far, 2007; Ali, Al-Far & Ng, 2007), the crystal structure of the title salt, (I), has been investigated.
The asymmetric unit of (I) contains one cation and one-half anion (Fig. 1). The whole (2-Br—C5H5N)2[SnBr6] geometry is generated through an inversion center with tin being lying on the special crystallographic position of (1/2, 1/2, 0). The (SnBr6)2- anion forms a quasi-octahedral geometry (Table 1), with the Sn—Br bond lengths are almost invariant. These lengths are in accordance with tin-bromide distances reported for (SnBr6)2- anion containing compounds (Willey et al.,1998; Tudela & Khan 1991; Al-Far & Ali 2007; Ali, Al-Far & Al-Sou'od, 2007; Ali & Al-Far, 2007; Ali, Al-Far & Ng, 2007). Bond lengths and angles within the cation are as expected (Allen et al., 1987).
The packing of the structure (Fig. 2) can be described as layers of alternating anions and cations parallel to bc plane. In these layers each (SnBr6)2- anion is interacting with six cations via two N—H···Br interactions (Table 2) and the symmetry related ones along with two Br···Br interactions and symmetry related ones [Br2···Br4and Br2···Br1of 3.6666 (23) and 3.7779 (29) Å, respectively; Fig. 2].
The N—H···N interactions along with C—Br···Br synthons are potential building blocks for this stable supramolecular lattice. The stability of this lattice is evident in the isostructurality with the reported Te analogue (Fernandes et al., 2004).