2-Amino-5-methyl­pyridinium dibromo­iodate

Haddad, S.F.; Ali, B.F.; Al-Far, R.

doi:10.1107/S1600536812036136

organic compounds

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ISSN: 2056-9890

Volume 68| Part 9| September 2012| Page o2786

doi:10.1107/S1600536812036136

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2-Amino-5-methylpyridinium dibromoiodate

Salim F. Haddad,^a Basem F. Ali ^b ^* and Rawhi Al-Far ^c

^aDepartment of Chemistry, The University of Jordan, Amman 11942, Jordan, ^bDepartment of Chemistry, Al al-Bayt University, Mafraq 25113, Jordan, and ^cFaculty of Science and IT, Al-Balqa'a Applied University, Salt, Jordan
^*Correspondence e-mail: bfali@aabu.edu.jo

(Received 14 August 2012; accepted 16 August 2012; online 25 August 2012)

In the title salt, C₆H₉N₂⁺·Br₂I⁻, the cation is essentially planar (r.m.s. deviation = 0.0062 Å for the non-H atoms) while the anion is almost linear with a Br—I—Br angle of 177.67 (2)°. The crystal packing shows two anions and two cations connected via N—H⋯Br and (pyridine)N—H⋯Br hydrogen-bonding interactions, forming centrosymmetric tetramers with R₄⁴(16) ring motifs. Very weak offset aromatic π–π stacking interactions [centroid-centroid separation = 4.038 (4), slippage = 1.773 Å] also occur.

Related literature

For background to this study, see: Al-Far et al. (2012 ); Kochel (2006 ). For comparison bond lengths and angles, see: Gardberg et al. (2002 ); Hemamalini & Fun (2010 ). For graph-set notation, see: Bernstein et al. (1995 ).

Experimental

Crystal data

C₆H₉N₂⁺·Br₂I⁻
M_r = 395.85
Triclinic, $[P \overline 1]$
a = 8.3648 (13) Å
b = 8.4233 (16) Å
c = 9.2321 (16) Å
α = 105.107 (16)°
β = 115.371 (16)°
γ = 98.241 (15)°
V = 542.7 (2) Å³
Z = 2
Mo Kα radiation
μ = 10.26 mm⁻¹
T = 293 K
0.54 × 0.39 × 0.30 mm

Data collection

Agilent Xcalibur Eos diffractometer
Absorption correction: multi-scan (CrysAlis PRO; Agilent, 2011 ) T_min = 0.011, T_max = 0.045
4283 measured reflections
2465 independent reflections
1777 reflections with I > 2σ(I)
R_int = 0.029

Refinement

R[F² > 2σ(F²)] = 0.040
wR(F²) = 0.096
S = 1.01
2465 reflections
102 parameters
H-atom parameters constrained
Δρ_max = 1.17 e Å⁻³
Δρ_min = −0.85 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N1—H1A⋯Br2	0.86	2.73	3.499 (5)	150
N2—H2B⋯Br1ⁱ	0.86	2.70	3.545 (6)	168
Symmetry code: (i) -x+1, -y, -z+1.

Data collection: CrysAlis PRO (Agilent, 2011); cell refinement: CrysAlis PRO; data reduction: CrysAlis PRO; 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.

Supporting information

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536812036136/pv2581sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536812036136/pv2581Isup2.hkl

checkCIF report

Comment top

Polyhalides display a variety of structures. Various compounds with interesting structures were found when protonated aromatic nitrogen bases were combined with polyhalides (Kochel, 2006). Continuing our research in this area (Al-Far et al., 2012), we now report the crystal structure of the title compound in this article. The cystals of the title compound were found as an unexpected product from a reaction mixture of CdI₂, HBr, 2-amino-5-methylpyridine and Br₂ upon attempting to synthesize [(C₇H₁₀N)]₂ [CdBr₄] complex of 2-amino-5-methylpyrinium.

In the title compound (Fig. 1), the cation, 2-amino-5-methylpyridinium, is essentially planar (r.m.s.d = 0.0062 Å). The IBr₂^- anion is symmetrical and almost linear, Br1—I—Br2 angle of 177.67 (2) °, with I—Br distances 2.6836 (10) and 2.7119 (10) Å. These values are in agreement with the values reported in the literature (Gardberg et al., 2002). The molecular dimensions of the cation are also as expected (Hemamalini & Fun, 2010).

The crystal structure (Fig. 2), shows stacks of anions separated by layers of cations. The anions and cations are connected via H–N–H···Br and pyN–H···Br hydrogen bonding (Table 1), forming centrosymmetric tetramers (two cation and two anions). These tetramers form sixteen membered rings in graph set motif R₄⁴(16) (Bernstein et al., 1995). The rings are further connected via π···π interactions between the cations with separation betweeen the ring centroids [C_g···C_g (2 - x, -y, 1 - z)] being 4.038 (4) Å. Both hydrogen bonding and π···π interactions consolidate a three dimensional network.

Related literature top

For background to this study, see: Al-Far et al. (2012); Kochel (2006). For comparison bond lengths and angles, see: Gardberg et al. (2002); Hemamalini & Fun (2010). For graph-set notation, see: Bernstein et al. (1995).

Experimental top

A solution of CdI₂ (0.37 g, 1.0 mmol) dissolved in 95% EtOH (10 ml) and 60% HBr (1 ml) solution was added to a mixture of 2-amino-5-methylpyridine (0.11 g, 1.0 mmol) dissolved in 95% EtOH (10 ml), 60% HBr (1 ml) and molecular bromine (2 ml). The resulting mixture was refluxed for 2.5 hr. On slow evaporation at room temperature yellow plates of the title compound were formed in 4 days (yield 85%).

Computing details top

Data collection: CrysAlis PRO (Agilent, 2011); cell refinement: CrysAlis PRO (Agilent, 2011); data reduction: CrysAlis PRO (Agilent, 2011); 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

Fig. 1. The molecular structure of the title compound with the atom numbering scheme. Displacement ellipsoids are drawn at the 30% probability level. H atoms are presented as small spheres of arbitrary radius.

Fig. 2. A view of the pyN–H···Br and H–N–H···Br hydrogen bonds (dotted lines) in the crystal structure of the title compound. H atoms non-participating in hydrogen-bonding were omitted for clarity.

2-Amino-5-methylpyridinium dibromoiodate top

Crystal data top

C₆H₉N₂⁺·Br₂I⁻	Z = 2
M_r = 395.85	F(000) = 364
Triclinic, P1	D_x = 2.422 Mg m⁻³
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 8.3648 (13) Å	Cell parameters from 1406 reflections
b = 8.4233 (16) Å	θ = 3.2–30.0°
c = 9.2321 (16) Å	µ = 10.26 mm⁻¹
α = 105.107 (16)°	T = 293 K
β = 115.371 (16)°	Plate, yellow
γ = 98.241 (15)°	0.54 × 0.39 × 0.30 mm
V = 542.7 (2) Å³

Data collection top

Agilent Xcalibur Eos diffractometer	2465 independent reflections
Radiation source: Enhance (Mo) X-ray Source	1777 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.029
Detector resolution: 16.0534 pixels mm^-1	θ_max = 29.1°, θ_min = 3.2°
ω scans	h = −11→10
Absorption correction: multi-scan (CrysAlis PRO; Agilent, 2011)	k = −11→11
T_min = 0.011, T_max = 0.045	l = −10→12
4283 measured reflections

Refinement top

Refinement on F²	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F² > 2σ(F²)] = 0.040	H-atom parameters constrained
wR(F²) = 0.096	w = 1/[σ²(F_o²) + (0.035P)²] where P = (F_o² + 2F_c²)/3
S = 1.01	(Δ/σ)_max < 0.001
2465 reflections	Δρ_max = 1.17 e Å⁻³
102 parameters	Δρ_min = −0.85 e Å⁻³
0 restraints	Extinction correction: SHELXL97 (Sheldrick, 2008), Fc^*=kFc[1+0.001xFc²λ³/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.0292 (12)

Crystal data top

C₆H₉N₂⁺·Br₂I⁻	γ = 98.241 (15)°
M_r = 395.85	V = 542.7 (2) Å³
Triclinic, P1	Z = 2
a = 8.3648 (13) Å	Mo Kα radiation
b = 8.4233 (16) Å	µ = 10.26 mm⁻¹
c = 9.2321 (16) Å	T = 293 K
α = 105.107 (16)°	0.54 × 0.39 × 0.30 mm
β = 115.371 (16)°

Data collection top

Agilent Xcalibur Eos diffractometer	2465 independent reflections
Absorption correction: multi-scan (CrysAlis PRO; Agilent, 2011)	1777 reflections with I > 2σ(I)
T_min = 0.011, T_max = 0.045	R_int = 0.029
4283 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.040	0 restraints
wR(F²) = 0.096	H-atom parameters constrained
S = 1.01	Δρ_max = 1.17 e Å⁻³
2465 reflections	Δρ_min = −0.85 e Å⁻³
102 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	U_iso*/U_eq
N1	1.0416 (7)	0.3049 (7)	0.7106 (6)	0.0606 (15)
H1A	1.0387	0.3331	0.8057	0.073*
I1	0.70649 (5)	−0.04784 (5)	0.90281 (5)	0.04214 (17)
Br1	0.55742 (10)	−0.38624 (9)	0.80942 (10)	0.0661 (2)
N2	0.7745 (7)	0.3836 (7)	0.5894 (7)	0.0699 (17)
H2A	0.7751	0.4121	0.6862	0.084*
H2B	0.6882	0.3947	0.5021	0.084*
C2	0.9069 (8)	0.3223 (8)	0.5748 (8)	0.0509 (16)
Br2	0.85761 (10)	0.29148 (9)	0.98508 (9)	0.0589 (2)
C3	0.9133 (8)	0.2686 (8)	0.4207 (8)	0.0500 (15)
H3A	0.8224	0.2749	0.3211	0.060*
C4	1.0533 (8)	0.2076 (9)	0.4194 (8)	0.0551 (17)
H4A	1.0562	0.1728	0.3166	0.066*
C5	1.1936 (8)	0.1936 (8)	0.5625 (7)	0.0438 (14)
C6	1.1819 (9)	0.2455 (9)	0.7061 (9)	0.0591 (18)
H6A	1.2732	0.2406	0.8064	0.071*
C7	1.3488 (8)	0.1264 (9)	0.5598 (9)	0.0647 (19)
H7A	1.4329	0.1335	0.6734	0.097*
H7B	1.4130	0.1938	0.5211	0.097*
H7C	1.2999	0.0087	0.4830	0.097*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
N1	0.077 (4)	0.061 (4)	0.032 (3)	0.007 (3)	0.025 (3)	0.008 (3)
I1	0.0468 (3)	0.0479 (3)	0.0301 (2)	0.01598 (19)	0.01656 (19)	0.01427 (19)
Br1	0.0739 (5)	0.0464 (4)	0.0580 (5)	0.0088 (4)	0.0210 (4)	0.0132 (4)
N2	0.076 (4)	0.076 (5)	0.060 (4)	0.019 (3)	0.039 (3)	0.019 (4)
C2	0.052 (3)	0.050 (4)	0.046 (4)	0.002 (3)	0.023 (3)	0.018 (3)
Br2	0.0794 (5)	0.0461 (4)	0.0465 (4)	0.0117 (4)	0.0284 (4)	0.0173 (4)
C3	0.054 (4)	0.054 (4)	0.038 (4)	0.011 (3)	0.023 (3)	0.014 (3)
C4	0.062 (4)	0.058 (4)	0.041 (4)	0.008 (3)	0.026 (3)	0.014 (3)
C5	0.049 (3)	0.042 (4)	0.031 (3)	0.005 (3)	0.013 (3)	0.015 (3)
C6	0.060 (4)	0.064 (5)	0.040 (4)	0.013 (4)	0.016 (3)	0.016 (4)
C7	0.063 (4)	0.069 (5)	0.057 (5)	0.022 (4)	0.023 (4)	0.025 (4)

Geometric parameters (Å, º) top

N1—C2	1.340 (7)	C3—H3A	0.9300
N1—C6	1.352 (8)	C4—C5	1.389 (8)
N1—H1A	0.8600	C4—H4A	0.9300
I1—Br1	2.6836 (10)	C5—C6	1.334 (8)
I1—Br2	2.7119 (10)	C5—C7	1.496 (8)
N2—C2	1.330 (7)	C6—H6A	0.9300
N2—H2A	0.8600	C7—H7A	0.9600
N2—H2B	0.8600	C7—H7B	0.9600
C2—C3	1.402 (8)	C7—H7C	0.9600
C3—C4	1.348 (8)

C2—N1—C6	123.5 (5)	C3—C4—H4A	118.0
C2—N1—H1A	118.3	C5—C4—H4A	118.0
C6—N1—H1A	118.3	C6—C5—C4	115.2 (6)
Br1—I1—Br2	177.67 (2)	C6—C5—C7	121.3 (6)
C2—N2—H2A	120.0	C4—C5—C7	123.5 (5)
C2—N2—H2B	120.0	C5—C6—N1	122.1 (6)
H2A—N2—H2B	120.0	C5—C6—H6A	118.9
N2—C2—N1	120.1 (6)	N1—C6—H6A	118.9
N2—C2—C3	123.6 (6)	C5—C7—H7A	109.5
N1—C2—C3	116.3 (6)	C5—C7—H7B	109.5
C4—C3—C2	118.9 (6)	H7A—C7—H7B	109.5
C4—C3—H3A	120.5	C5—C7—H7C	109.5
C2—C3—H3A	120.5	H7A—C7—H7C	109.5
C3—C4—C5	123.9 (6)	H7B—C7—H7C	109.5

C6—N1—C2—N2	−179.2 (6)	C3—C4—C5—C6	0.0 (10)
C6—N1—C2—C3	2.4 (9)	C3—C4—C5—C7	−179.7 (6)
N2—C2—C3—C4	−179.7 (6)	C4—C5—C6—N1	1.0 (10)
N1—C2—C3—C4	−1.4 (9)	C7—C5—C6—N1	−179.3 (6)
C2—C3—C4—C5	0.3 (10)	C2—N1—C6—C5	−2.3 (10)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1A···Br2	0.86	2.73	3.499 (5)	150
N2—H2B···Br1ⁱ	0.86	2.70	3.545 (6)	168

Symmetry code: (i) −x+1, −y, −z+1.

Experimental details

Crystal data
Chemical formula	C₆H₉N₂⁺·Br₂I⁻
M_r	395.85
Crystal system, space group	Triclinic, P1
Temperature (K)	293
a, b, c (Å)	8.3648 (13), 8.4233 (16), 9.2321 (16)
α, β, γ (°)	105.107 (16), 115.371 (16), 98.241 (15)
V (Å³)	542.7 (2)
Z	2
Radiation type	Mo Kα
µ (mm⁻¹)	10.26
Crystal size (mm)	0.54 × 0.39 × 0.30

Data collection
Diffractometer	Agilent Xcalibur Eos diffractometer
Absorption correction	Multi-scan (CrysAlis PRO; Agilent, 2011)
T_min, T_max	0.011, 0.045
No. of measured, independent and observed [I > 2σ(I)] reflections	4283, 2465, 1777
R_int	0.029
(sin θ/λ)_max (Å⁻¹)	0.683

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.040, 0.096, 1.01
No. of reflections	2465
No. of parameters	102
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	1.17, −0.85

Computer programs: CrysAlis PRO (Agilent, 2011), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), SHELXTL (Sheldrick, 2008).

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1A···Br2	0.86	2.73	3.499 (5)	149.5
N2—H2B···Br1ⁱ	0.86	2.70	3.545 (6)	168.0

Symmetry code: (i) −x+1, −y, −z+1.

Acknowledgements

The structure was determined at the Hamdi Mango Center for Scientific Research at the University of Jordan.

References

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