supplementary materials


Acta Cryst. (2009). E65, m583-m584    [ doi:10.1107/S1600536809015189 ]

Bis(2,6-diamino-3,5-dibromopyridinium) hexabromidostannate(IV)

R. H. Al-Far, S. F. Haddad and B. F. Ali

Abstract top

The asymmetric unit of the title compound, (C5H6Br2N3)2[SnBr6], contains one cation and one half-anion in which the Sn atom is located on a crystallographic centre of inversion and is in a quasi-octahedral geometry. The crystal structure is assembled via hydrogen-bonding interactions of two kinds, N(pyridine/amine)-H...Br-Sn, along with C-Br...Br-Sn interactions [3.4925 (19) Å]. The cations are involved in [pi]-[pi] stacking, which adds an extra supramolecularity as it presents a strong case of offset-face-to-face motifs [centroid-centroid distance = 3.577 (3) Å]. The intermolecular hydrogen bonds, short Br...Br interactions and [pi]-[pi] stacking result in the formation of a three-dimensional supramolecular architecture.

Comment top

Non-covalent 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; Al-Far, Ali & Al-Sou'od, 2007; Ali & Al-Far, 2007; Ali, Al-Far & Ng, 2007), we report herein the crystal structure of the title compound.

The asymmetric unit of the title compound contains one cation and one-half anion, in which the Sn atom is located on a crystallographic centre of inversion and is in a quasi-octahedral geometry (Fig. 1 and Table 1). The Sn-Br bonds are in accordance with the corresponding values in similar compounds (Willey et al., 1998; Tudela & Khan 1991; Ali et al., 2008; Al-Far & Ali 2007). The pyridine ring of the starting cation have undergone bromination during the synthesis process (Al-Far & Ali, 2007). In the cation, the bond lengths (Allen et al., 1987) and angles are within normal ranges.

In the crystal structure, weak intermolecular N-H···Br interactions (Table 2) link the molecules into alternating layers of cations and stacks of anions (Fig. 2), in which they may be effective in the stabilization of the structure. The anion stacks are interacting with the cation layers in an extensive hydrogen bonding and Br···Br halogen bonding interactions. Each anion is surrounded by six cations via three H—N—H···Br, one N—H···Br interactions and the symmetry related ones along with one Br···Br interaction [Br2···Br4i = 3.4925 (19) Å, symmetry code (i): 2 - x, 1 - y, -z)] and the symmetry related one. On the other hand, each cation is associated with three anions, through six (Npyridinic, Naminic)—H···Br—Sn hydrogen bonding interactions, and by one C—Br···Br—Sn interaction. It is noteworthy that structural and theoretical results (Awwadi et al. 2007; and references therein), show the significance of linear C—Br···Br synthons in influencing structures of crystalline materials and in use as potential building blocks in crystal engineering via supramolecular synthesis.

Moreover, interactions between cations perpendicular to [101] represent a case of strong offset face-to-face ππ motif. This is evident by the centroids separation distance of 5.059 (3) Å, with the perpendicular distance between planes being 3.577 (3) Å (the sliding angle between planes is 45.0 (3)°).

Related literature top

For general background to hybrid organic-inorganic compounds, see: Aruta et al. (2005); Hill (1998); Kagan et al. (1999); Knutson et al. (2005); Raptopoulou et al. (2002). For related structures, see: Al-Far & Ali (2007); Al-Far, Ali & Al-Sou'od (2007); Ali & Al-Far (2007); Ali et al. (2008); Ali, Al-Far & Ng (2007); Awwadi et al. (2007); Tudela & Khan (1991); Willey et al. (1998). For bond-length data, see: Allen et al. (1987).

Experimental top

For the preparation of the title compound, the warm solution of SnCl2 metal (1.0 mmol) dissolved in absolute ethanol (15 ml) was mixed with a stirred hot solution of 2,6-diaminopyridine (98%; 2 mmol) dissolved in ethanol (20 ml). The mixture was acidified with HBr (48%, 2-3 ml), and then treated with liquid Br2 (2-3 ml). The resulting mixture was stirred for 3 h, and then allowed to evaporate at room temperature. The salt crystallized over 2 d, as nice parallelepiped yellow crystals (yield; 82%).

Refinement top

H atoms were positioned geometrically, with N-H = 0.86 Å (for NH and NH2) and C-H = 0.93 Å for aromatic H, respectively, and constrained to ride on their parent atoms, with Uiso(H) = 1.2Ueq(C,N).

Computing details top

Data collection: XSCANS (Bruker, 1996); cell refinement: XSCANS (Bruker, 1996); data reduction: SHELXTL (Sheldrick, 2008); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

Figures top
[Figure 1] Fig. 1. The molecular structure of the title molecule, with the atom-numbering scheme. Displacement ellipsoids are drawn at the 50% probability level [symmetry code (A): 2 - x, 1 - y, 1 - z].
[Figure 2] Fig. 2. A partial packing diagram of the title compound. Hydrogen bonds and Br···Br interactions are shown as dashed lines.
Bis(2,6-diamino-3,5-dibromopyridinium) hexabromidostannate(IV) top
Crystal data top
(C5H6Br2N3)2[SnBr6]F(000) = 1028
Mr = 1133.97Dx = 3.042 Mg m3
Monoclinic, P21/cMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybcCell parameters from 29 reflections
a = 8.3696 (14) Åθ = 5.7–12.5°
b = 16.720 (2) ŵ = 17.18 mm1
c = 9.5814 (15) ÅT = 295 K
β = 112.556 (12)°Parallelepiped, yellow
V = 1238.3 (3) Å30.30 × 0.30 × 0.20 mm
Z = 2
Data collection top
Bruker P4
diffractometer
1437 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tubeRint = 0.078
graphiteθmax = 25.0°, θmin = 2.4°
ω scansh = 91
Absorption correction: ψ scan
(XSCANS; Bruker, 1996)
k = 191
Tmin = 0.008, Tmax = 0.035l = 1011
2825 measured reflections3 standard reflections every 97 reflections
2162 independent reflections intensity decay: 0.01%
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.059Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.146H-atom parameters constrained
S = 1.00 w = 1/[σ2(Fo2) + (0.0766P)2]
where P = (Fo2 + 2Fc2)/3
2162 reflections(Δ/σ)max < 0.001
124 parametersΔρmax = 0.97 e Å3
0 restraintsΔρmin = 1.62 e Å3
Crystal data top
(C5H6Br2N3)2[SnBr6]V = 1238.3 (3) Å3
Mr = 1133.97Z = 2
Monoclinic, P21/cMo Kα radiation
a = 8.3696 (14) ŵ = 17.18 mm1
b = 16.720 (2) ÅT = 295 K
c = 9.5814 (15) Å0.30 × 0.30 × 0.20 mm
β = 112.556 (12)°
Data collection top
Bruker P4
diffractometer
1437 reflections with I > 2σ(I)
Absorption correction: ψ scan
(XSCANS; Bruker, 1996)
Rint = 0.078
Tmin = 0.008, Tmax = 0.035θmax = 25.0°
2825 measured reflections3 standard reflections every 97 reflections
2162 independent reflections intensity decay: 0.01%
Refinement top
R[F2 > 2σ(F2)] = 0.059H-atom parameters constrained
wR(F2) = 0.146Δρmax = 0.97 e Å3
S = 1.00Δρmin = 1.62 e Å3
2162 reflectionsAbsolute structure: ?
124 parametersFlack parameter: ?
0 restraintsRogers parameter: ?
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
xyzUiso*/Ueq
Sn11.00000.50000.50000.0284 (3)
Br11.06913 (19)0.61962 (8)0.68737 (17)0.0445 (4)
Br21.03622 (19)0.59582 (8)0.30353 (17)0.0447 (4)
Br30.66959 (17)0.53289 (8)0.39554 (18)0.0423 (4)
Br40.7063 (2)0.32003 (9)0.12875 (19)0.0510 (5)
Br50.2397 (2)0.45315 (8)0.10813 (18)0.0483 (4)
N10.3496 (13)0.2261 (5)0.0181 (12)0.032 (3)
H10.31480.17890.02810.039*
N20.5374 (16)0.1644 (6)0.0743 (13)0.047 (3)
H2A0.62000.16630.10660.056*
H2B0.49400.11900.06500.056*
N30.1518 (14)0.2743 (6)0.1119 (13)0.044 (3)
H3A0.12110.22590.11910.053*
H3B0.10290.31340.13860.053*
C10.4759 (17)0.2325 (7)0.0381 (15)0.034 (3)
C20.5364 (17)0.3061 (7)0.0492 (17)0.036 (3)
C30.4653 (17)0.3720 (8)0.0099 (15)0.040 (4)
H30.50470.42270.02120.048*
C40.3354 (18)0.3649 (7)0.0466 (15)0.034 (3)
C50.2745 (17)0.2888 (8)0.0595 (15)0.039 (3)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Sn10.0293 (7)0.0234 (6)0.0365 (8)0.0000 (5)0.0169 (6)0.0002 (5)
Br10.0485 (9)0.0374 (7)0.0537 (10)0.0074 (7)0.0264 (8)0.0159 (7)
Br20.0494 (9)0.0430 (8)0.0499 (10)0.0016 (7)0.0279 (8)0.0093 (7)
Br30.0271 (7)0.0319 (7)0.0677 (10)0.0009 (6)0.0180 (7)0.0014 (7)
Br40.0472 (9)0.0493 (9)0.0706 (11)0.0030 (8)0.0381 (9)0.0045 (8)
Br50.0480 (9)0.0333 (7)0.0680 (11)0.0059 (7)0.0272 (9)0.0091 (7)
N10.037 (6)0.018 (5)0.055 (8)0.003 (5)0.032 (6)0.002 (5)
N20.061 (9)0.029 (6)0.059 (8)0.003 (6)0.032 (7)0.011 (6)
N30.042 (7)0.035 (6)0.069 (9)0.014 (6)0.037 (7)0.017 (6)
C10.035 (8)0.024 (6)0.042 (9)0.007 (6)0.012 (7)0.002 (6)
C20.037 (8)0.016 (6)0.063 (9)0.004 (6)0.028 (7)0.001 (6)
C30.038 (9)0.032 (7)0.048 (9)0.018 (7)0.015 (8)0.007 (6)
C40.049 (9)0.017 (6)0.034 (8)0.002 (6)0.013 (7)0.004 (5)
C50.032 (8)0.046 (8)0.030 (8)0.003 (7)0.004 (6)0.012 (6)
Geometric parameters (Å, °) top
Sn1—Br12.6002 (13)N3—H3A0.8600
Sn1—Br1i2.6002 (13)N3—H3B0.8600
Sn1—Br22.5768 (14)C1—N11.362 (16)
Sn1—Br2i2.5768 (14)C1—N21.349 (15)
Sn1—Br32.6131 (14)C1—C21.350 (17)
Sn1—Br3i2.6131 (14)C2—Br41.868 (12)
N1—C51.357 (15)C2—C31.372 (18)
N1—H10.8600C3—C41.392 (18)
N2—H2A0.8600C3—H30.9300
N2—H2B0.8600C4—Br51.878 (12)
N3—C51.328 (16)C4—C51.394 (18)
Br1—Sn1—Br1i180.0H2A—N2—H2B120.0
Br1i—Sn1—Br388.56 (5)C5—N3—H3A120.0
Br1—Sn1—Br3i88.56 (5)C5—N3—H3B120.0
Br1—Sn1—Br391.44 (5)H3A—N3—H3B120.0
Br1i—Sn1—Br3i91.44 (5)N2—C1—C2123.9 (12)
Br2—Sn1—Br188.21 (5)N2—C1—N1117.8 (11)
Br2i—Sn1—Br1i88.21 (5)C2—C1—N1118.3 (10)
Br2i—Sn1—Br191.79 (5)C1—C2—Br4120.9 (9)
Br2—Sn1—Br1i91.79 (5)C1—C2—C3119.7 (11)
Br2i—Sn1—Br2180.0C3—C2—Br4119.3 (9)
Br2—Sn1—Br389.60 (5)C2—C3—C4121.6 (11)
Br2i—Sn1—Br3i89.61 (5)C2—C3—H3119.2
Br2i—Sn1—Br390.39 (5)C4—C3—H3119.2
Br2—Sn1—Br3i90.39 (5)C3—C4—Br5123.1 (9)
Br3i—Sn1—Br3180.0C3—C4—C5118.6 (11)
C1—N1—H1117.6C5—C4—Br5118.3 (10)
C5—N1—C1124.9 (10)N1—C5—C4116.9 (12)
C5—N1—H1117.6N3—C5—N1118.8 (12)
C1—N2—H2A120.0N3—C5—C4124.2 (12)
C1—N2—H2B120.0
N2—C1—N1—C5179.9 (12)C2—C3—C4—C52(2)
C2—C1—N1—C52(2)C2—C3—C4—Br5177.8 (11)
N2—C1—C2—C3179.9 (14)C1—N1—C5—N3179.6 (13)
N1—C1—C2—C33(2)C1—N1—C5—C42(2)
N2—C1—C2—Br44(2)C3—C4—C5—N3179.8 (13)
N1—C1—C2—Br4178.7 (10)Br5—C4—C5—N30.4 (19)
C1—C2—C3—C42(2)C3—C4—C5—N11.2 (19)
Br4—C2—C3—C4178.5 (11)Br5—C4—C5—N1178.2 (9)
Symmetry codes: (i) −x+2, −y+1, −z+1.
Hydrogen-bond geometry (Å, °) top
D—H···AD—HH···AD···AD—H···A
N1—H1···Br3ii0.862.543.354 (9)159
N2—H2B···Br3ii0.862.883.612 (12)144
N3—H3A···Br2ii0.862.793.608 (10)160
N3—H3B···Br1iii0.862.823.604 (10)153
Symmetry codes: (ii) −x+1, y−1/2, −z+1/2; (iii) −x+1, −y+1, −z+1.
Table 1
Selected geometric parameters (Å, °)
top
Sn1—Br12.6002 (13)Sn1—Br32.6131 (14)
Sn1—Br22.5768 (14)
Br1i—Sn1—Br388.56 (5)Br2i—Sn1—Br191.79 (5)
Br1—Sn1—Br391.44 (5)Br2—Sn1—Br389.60 (5)
Br2—Sn1—Br188.21 (5)Br2i—Sn1—Br390.39 (5)
Symmetry codes: (i) −x+2, −y+1, −z+1.
Table 2
Hydrogen-bond geometry (Å, °)
top
D—H···AD—HH···AD···AD—H···A
N1—H1···Br3ii0.862.543.354 (9)159
N2—H2B···Br3ii0.862.883.612 (12)144
N3—H3A···Br2ii0.862.793.608 (10)160
N3—H3B···Br1iii0.862.823.604 (10)153
Symmetry codes: (ii) −x+1, y−1/2, −z+1/2; (iii) −x+1, −y+1, −z+1.
Acknowledgements top

The University of Jordan, Al-Balqa'a Applied University and Al al-Bayt University are thanked for financial support.

references
References top

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