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organic compounds\(\def\hfill{\hskip 5em}\def\hfil{\hskip 3em}\def\eqno#1{\hfil {#1}}\)

Journal logoCRYSTALLOGRAPHIC
COMMUNICATIONS
ISSN: 2056-9890
Volume 67| Part 10| October 2011| Page o2572
https://doi.org/10.1107/S1600536811035100

2-Amino-4,6-di­methyl­pyridinium chloride dihydrate

Mohammad T. M. Al-Dajani,a Jamal Talaat,b Abdusalam Salhin,c Madhukar Hemamalinid and Hoong-Kun Fund*‡

aSchool of Pharmaceutical Sciences, Universiti Sains Malaysia, 11800 USM, Penang, Malaysia, bVirginia Commonwealth University, Chemistry School, USA, cSchool of Chemical Sciences, Universiti Sains Malaysia, 11800 USM, Penang, Malaysia, and dX-ray Crystallography Unit, School of Physics, Universiti Sains Malaysia, 11800 USM, Penang, Malaysia
*Correspondence e-mail: hkfun@usm.my

(Received 24 August 2011; accepted 27 August 2011; online 14 September 2011)

In the title hydrated mol­ecular salt, C7H11N2+·Cl−·2H2O, the pyridine N atom of the 2-amino-4,6-dimethyl­pyridine mol­ecule is protonated. The cation is essentially planar, with a maximum deviation of 0.006 (2) Å. In the crystal, the components are linked by N—H⋯O, N—H⋯Cl and O—H⋯Cl hydrogen bonds, thereby forming sheets lying parallel to (100). The crystal structure is further stabilized by aromatic π–π stacking inter­actions between the pyridinium rings [centroid–centroid distance = 3.4789 (9) Å].

Related literature

For details of 2-amino­pyridine and its derivatives, see: Katritzky et al. (1996[Katritzky, A. R., Rees, C. W. & Scriven, E. F. V. (1996). In Comprehensive Heterocyclic Chemistry II. Oxford: Pergamon Press.]). For pyridine derivatives as templating agents, see: Matsumoto (2003[Matsumoto, A. (2003). Polym. J. 35, 93-121.]); Desiraju (2001[Desiraju, G. R. (2001). Curr. Sci. 81, 1038-1055.]); Bond & Parsons (2002[Bond, A. D. & Parsons, S. (2002). Acta Cryst. E58, o550-o552.]).

[Scheme 1]

Experimental

Crystal data

  • C7H11N2+·Cl−·2H2O

  • Mr = 194.66

  • Monoclinic, P 21 /c

  • a = 7.5811 (6) Å

  • b = 13.8149 (11) Å

  • c = 10.6657 (8) Å

  • β = 109.261 (2)°

  • V = 1054.52 (14) Å3

  • Z = 4

  • Mo Kα radiation

  • μ = 0.33 mm−1

  • T = 296 K

  • 0.44 × 0.18 × 0.05 mm
Data collection

  • Bruker APEXII DUO CCD diffractometer

  • Absorption correction: multi-scan (SADABS; Bruker, 2009[Bruker (2009). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]) Tmin = 0.868, Tmax = 0.982

  • 16733 measured reflections

  • 3109 independent reflections

  • 2020 reflections with I > 2σ(I)

  • Rint = 0.029
Refinement

  • R[F2 > 2σ(F2)] = 0.038

  • wR(F2) = 0.126

  • S = 1.04

  • 3109 reflections

  • 127 parameters

  • H atoms treated by a mixture of independent and constrained refinement

  • Δρmax = 0.16 e Å−3

  • Δρmin = −0.25 e Å−3

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A D⋯A D—H⋯A
O2W—H1WA⋯Cl1 0.84 (3) 2.37 (3) 3.2076 (17) 179 (3)
O2W—H2WA⋯Cl1i 0.83 (3) 2.39 (3) 3.1689 (16) 157 (3)
O1W—H1WB⋯Cl1ii 0.84 (3) 2.36 (3) 3.2019 (15) 179 (3)
O1W—H2WB⋯Cl1iii 0.79 (2) 2.41 (2) 3.1916 (16) 172.4 (18)
N1—H1N1⋯O2W 0.86 1.93 2.7852 (18) 174
N2—H2N1⋯Cl1i 0.86 2.53 3.3177 (12) 153
N2—H2N2⋯O1Wiv 0.86 2.00 2.8543 (17) 175
Symmetry codes: (i) [x, -y+{\script{1\over 2}}, z-{\script{1\over 2}}]; (ii) x+1, y, z-1; (iii) -x+1, -y+1, -z+1; (iv) x-1, y, z.

Data collection: APEX2 (Bruker, 2009[Bruker (2009). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]); cell refinement: SAINT (Bruker, 2009[Bruker (2009). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL and PLATON (Spek, 2009[Spek, A. L. (2009). Acta Cryst. D65, 148-155.]).

Supporting information

Crystal structure: contains datablocks global, I. DOI: https://doi.org/10.1107/S1600536811035100/hb6390sup1.cif

Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S1600536811035100/hb6390Isup2.hkl

Supporting information file. DOI: https://doi.org/10.1107/S1600536811035100/hb6390Isup3.cml

checkCIF report


Comment top

2-Aminopyridine and its derivatives play an important role in heterocyclic chemistry (Katritzky et al., 1996). The use of pyridine derivatives as templating agents for the self-assembly of organic–inorganic supramolecular materials has been widely studied (Matsumoto, 2003; Desiraju, 2001; Bond & Parsons, 2002). In order to further study hydrogen bonding interactions in these systems, the synthesis and structure of the title salt (I) is presented here.

The asymmetric unit of the title compound, (I), contains a 2-amino-4,6- dimethylpyridinium cation, a chloride anion and two water molecules as shown in Fig. 1. The cation (N1/C1–C5) is essentially planar, with a maximum deviation of 0.006 (2) Å for atom C5. In the 2-amino-4,6- dimethylpyridinium cation, a wider than normal angle [123.22 (12)°] is subtended at the protonated N1 atom.

In the crystal structure, (Fig. 2), the ion pais and water molecules are linked via O2W—H1WA···Cl1, O2W—H2WA···Cl1, O1W—H1WA···Cl1, O1W—H2WA···Cl1, N1—H1N1···O2W, N2—H2N1···Cl1 and N2—H2N2···O1W hydrogen bonds (Table 1) forming two-dimensional networks parallel to the (100)-plane. The crystal structure is further stabilized by π–π- interactions between the pyridinium (Cg1; N1/C1–C5) rings [Cg1···Cg1 = 3.4789 (9) Å; 1-x, 1-y, 1-z].

Related literature top

For details of 2-aminopyridine and its derivatives, see: Katritzky et al. (1996). For pyridine derivatives as templating agents, see: Matsumoto (2003); Desiraju (2001); Bond & Parsons (2002).

Experimental top

In a round bottom flask, 25ml of tetrahydrofuran (THF) was mixed with 2-amino-4,6-dimethylpyridine (0.01 mol, 1.3 g) with stirring. Drops of benzoyl chloride (0.01 mol, 1.0 g) dissolved in THF was then added. The reaction mixture was refluxed for 30 min. The precipitate formed was washed with THF. The precipitate was then dissolved in methanol at room temperature. After few days, colorless plates of (I) were formed by slow evaporation.

Refinement top

Atoms H1WA, H2WA, H1WB and H2WB were located from a difference Fourier maps and refined freely [O–H = 0.78 (2)–0.84 (3) Å]. The remaining H atoms were positioned geometrically [N–H = 0.86 Å and C–H = 0.96 Å] and were refined using a riding model, with Uiso(H) = 1.2 or 1.5 Ueq(C). A rotating group model was applied to the methyl groups.

Structure description top

2-Aminopyridine and its derivatives play an important role in heterocyclic chemistry (Katritzky et al., 1996). The use of pyridine derivatives as templating agents for the self-assembly of organic–inorganic supramolecular materials has been widely studied (Matsumoto, 2003; Desiraju, 2001; Bond & Parsons, 2002). In order to further study hydrogen bonding interactions in these systems, the synthesis and structure of the title salt (I) is presented here.

The asymmetric unit of the title compound, (I), contains a 2-amino-4,6- dimethylpyridinium cation, a chloride anion and two water molecules as shown in Fig. 1. The cation (N1/C1–C5) is essentially planar, with a maximum deviation of 0.006 (2) Å for atom C5. In the 2-amino-4,6- dimethylpyridinium cation, a wider than normal angle [123.22 (12)°] is subtended at the protonated N1 atom.

In the crystal structure, (Fig. 2), the ion pais and water molecules are linked via O2W—H1WA···Cl1, O2W—H2WA···Cl1, O1W—H1WA···Cl1, O1W—H2WA···Cl1, N1—H1N1···O2W, N2—H2N1···Cl1 and N2—H2N2···O1W hydrogen bonds (Table 1) forming two-dimensional networks parallel to the (100)-plane. The crystal structure is further stabilized by π–π- interactions between the pyridinium (Cg1; N1/C1–C5) rings [Cg1···Cg1 = 3.4789 (9) Å; 1-x, 1-y, 1-z].

For details of 2-aminopyridine and its derivatives, see: Katritzky et al. (1996). For pyridine derivatives as templating agents, see: Matsumoto (2003); Desiraju (2001); Bond & Parsons (2002).

Computing details top

Data collection: APEX2 (Bruker, 2009); cell refinement: SAINT (Bruker, 2009); data reduction: SAINT (Bruker, 2009); program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008) and PLATON (Spek, 2009).

Figures top
[Figure 1] Fig. 1. The asymmetric unit of the title compound, showing 50% probability displacement ellipsoids. The hydrogen bonds are shown by dashed lines.
[Figure 2] Fig. 2. The crystal packing of title compound, (I), looking down the a-axis.
2-Amino-4,6-dimethylpyridinium chloride dihydrate top
Crystal data top
C7H11N2+·Cl−·2H2OF(000) = 416
Mr = 194.66Dx = 1.226 Mg m−3
Monoclinic, P21/cMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybcCell parameters from 3933 reflections
a = 7.5811 (6) Åθ = 2.5–26.6°
b = 13.8149 (11) ŵ = 0.33 mm−1
c = 10.6657 (8) ÅT = 296 K
β = 109.261 (2)°Plate, colourless
V = 1054.52 (14) Å30.44 × 0.18 × 0.05 mm
Z = 4
Data collection top
Bruker APEXII DUO CCD
diffractometer		3109 independent reflections
Radiation source: fine-focus sealed tube2020 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.029
φ and ω scansθmax = 30.2°, θmin = 2.5°
Absorption correction: multi-scan
(SADABS; Bruker, 2009)		h = −10→10
Tmin = 0.868, Tmax = 0.982k = −19→19
16733 measured reflectionsl = −15→15
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)] = 0.038Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.126H atoms treated by a mixture of independent and constrained refinement
S = 1.04 w = 1/[σ2(Fo2) + (0.0598P)2 + 0.1086P]
where P = (Fo2 + 2Fc2)/3
3109 reflections(Δ/σ)max < 0.001
127 parametersΔρmax = 0.16 e Å−3
0 restraintsΔρmin = −0.25 e Å−3
Crystal data top
C7H11N2+·Cl−·2H2OV = 1054.52 (14) Å3
Mr = 194.66Z = 4
Monoclinic, P21/cMo Kα radiation
a = 7.5811 (6) ŵ = 0.33 mm−1
b = 13.8149 (11) ÅT = 296 K
c = 10.6657 (8) Å0.44 × 0.18 × 0.05 mm
β = 109.261 (2)°
Data collection top
Bruker APEXII DUO CCD
diffractometer		3109 independent reflections
Absorption correction: multi-scan
(SADABS; Bruker, 2009)		2020 reflections with I > 2σ(I)
Tmin = 0.868, Tmax = 0.982Rint = 0.029
16733 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0380 restraints
wR(F2) = 0.126H atoms treated by a mixture of independent and constrained refinement
S = 1.04Δρmax = 0.16 e Å−3
3109 reflectionsΔρmin = −0.25 e Å−3
127 parameters
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. 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 > 2sigma(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
O2W0.2219 (2)0.29451 (10)0.70681 (15)0.0690 (3)
H1WA0.175 (3)0.3025 (18)0.767 (3)0.114 (9)*
H2WA0.167 (3)0.2532 (18)0.652 (3)0.099 (8)*
O1W0.9019 (2)0.45839 (11)0.12748 (12)0.0714 (4)
H1WB0.940 (4)0.422 (2)0.079 (3)0.134 (11)*
H2WB0.907 (3)0.5121 (17)0.105 (2)0.081 (7)*
Cl10.04165 (8)0.32061 (3)0.93781 (4)0.0800 (2)
C40.4433 (2)0.61916 (12)0.62946 (16)0.0601 (4)
H4A0.52280.66490.68330.072*
C50.4204 (2)0.53267 (12)0.68093 (15)0.0551 (4)
C60.3769 (3)0.73643 (12)0.4383 (2)0.0802 (5)
H6A0.31300.73660.34420.120*
H6B0.50800.74680.45550.120*
H6C0.32810.78720.47880.120*
C70.5173 (3)0.50077 (17)0.82075 (17)0.0811 (5)
H7A0.58600.44240.82050.122*
H7B0.42640.48880.86380.122*
H7C0.60170.55050.86770.122*
C10.20566 (17)0.48350 (9)0.47123 (12)0.0431 (3)
C30.3482 (2)0.64080 (10)0.49498 (16)0.0543 (3)
C20.2309 (2)0.57277 (10)0.41758 (14)0.0490 (3)
H2A0.16730.58600.32860.059*
N10.30065 (15)0.46692 (8)0.60065 (11)0.0474 (3)
H1N10.28510.41230.63430.057*
N20.09263 (17)0.41503 (8)0.40042 (11)0.0521 (3)
H2N10.08090.36110.43730.063*
H2N20.03130.42470.31780.063*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O2W0.0867 (9)0.0645 (7)0.0593 (8)0.0020 (6)0.0287 (7)0.0074 (6)
O1W0.1032 (10)0.0577 (7)0.0561 (7)0.0001 (7)0.0301 (7)0.0029 (5)
Cl10.1373 (5)0.0461 (2)0.0693 (3)0.0112 (2)0.0511 (3)0.00246 (16)
C40.0540 (8)0.0599 (9)0.0679 (10)−0.0043 (7)0.0221 (7)−0.0188 (7)
C50.0485 (7)0.0656 (9)0.0511 (8)0.0060 (7)0.0163 (6)−0.0097 (6)
C60.0912 (12)0.0466 (9)0.1132 (16)−0.0066 (8)0.0478 (11)0.0025 (9)
C70.0712 (11)0.1110 (16)0.0514 (10)0.0050 (11)0.0073 (8)−0.0053 (9)
C10.0456 (7)0.0424 (6)0.0445 (7)0.0055 (5)0.0192 (6)0.0002 (5)
C30.0556 (8)0.0432 (7)0.0729 (10)0.0015 (6)0.0332 (7)−0.0040 (6)
C20.0560 (8)0.0438 (7)0.0522 (8)0.0054 (6)0.0247 (6)0.0031 (5)
N10.0502 (6)0.0481 (6)0.0454 (6)0.0066 (5)0.0179 (5)0.0030 (4)
N20.0621 (7)0.0436 (6)0.0478 (6)−0.0038 (5)0.0143 (5)0.0023 (5)
Geometric parameters (Å, º) top
O2W—H1WA0.84 (3)C6—H6C0.9600
O2W—H2WA0.83 (3)C7—H7A0.9600
O1W—H1WB0.84 (3)C7—H7B0.9600
O1W—H2WB0.78 (2)C7—H7C0.9600
C4—C51.350 (2)C1—N21.3314 (17)
C4—C31.409 (2)C1—N11.3493 (17)
C4—H4A0.9300C1—C21.3989 (18)
C5—N11.3673 (18)C3—C21.368 (2)
C5—C71.495 (2)C2—H2A0.9300
C6—C31.498 (2)N1—H1N10.8600
C6—H6A0.9600N2—H2N10.8600
C6—H6B0.9600N2—H2N20.8600
H1WA—O2W—H2WA113 (2)H7A—C7—H7C109.5
H1WB—O1W—H2WB108 (2)H7B—C7—H7C109.5
C5—C4—C3120.70 (14)N2—C1—N1119.09 (12)
C5—C4—H4A119.7N2—C1—C2122.92 (12)
C3—C4—H4A119.7N1—C1—C2117.99 (12)
C4—C5—N1118.78 (14)C2—C3—C4118.76 (14)
C4—C5—C7125.43 (15)C2—C3—C6120.95 (15)
N1—C5—C7115.79 (15)C4—C3—C6120.28 (15)
C3—C6—H6A109.5C3—C2—C1120.54 (13)
C3—C6—H6B109.5C3—C2—H2A119.7
H6A—C6—H6B109.5C1—C2—H2A119.7
C3—C6—H6C109.5C1—N1—C5123.22 (12)
H6A—C6—H6C109.5C1—N1—H1N1118.4
H6B—C6—H6C109.5C5—N1—H1N1118.4
C5—C7—H7A109.5C1—N2—H2N1120.0
C5—C7—H7B109.5C1—N2—H2N2120.0
H7A—C7—H7B109.5H2N1—N2—H2N2120.0
C5—C7—H7C109.5
C3—C4—C5—N1−1.0 (2)N2—C1—C2—C3179.71 (12)
C3—C4—C5—C7178.37 (15)N1—C1—C2—C3−0.19 (19)
C5—C4—C3—C20.5 (2)N2—C1—N1—C5179.69 (12)
C5—C4—C3—C6−179.05 (14)C2—C1—N1—C5−0.40 (18)
C4—C3—C2—C10.2 (2)C4—C5—N1—C11.01 (19)
C6—C3—C2—C1179.67 (13)C7—C5—N1—C1−178.43 (13)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O2W—H1WA···Cl10.84 (3)2.37 (3)3.2076 (17)179 (3)
O2W—H2WA···Cl1i0.83 (3)2.39 (3)3.1689 (16)157 (3)
O1W—H1WB···Cl1ii0.84 (3)2.36 (3)3.2019 (15)179 (3)
O1W—H2WB···Cl1iii0.79 (2)2.41 (2)3.1916 (16)172.4 (18)
N1—H1N1···O2W0.861.932.7852 (18)174
N2—H2N1···Cl1i0.862.533.3177 (12)153
N2—H2N2···O1Wiv0.862.002.8543 (17)175
Symmetry codes: (i) x, −y+1/2, z−1/2; (ii) x+1, y, z−1; (iii) −x+1, −y+1, −z+1; (iv) x−1, y, z.

Experimental details

Crystal data
Chemical formulaC7H11N2+·Cl−·2H2O
Mr194.66
Crystal system, space groupMonoclinic, P21/c
Temperature (K)296
a, b, c (Å)7.5811 (6), 13.8149 (11), 10.6657 (8)
β (°) 109.261 (2)
V (Å3)1054.52 (14)
Z4
Radiation typeMo Kα
µ (mm−1)0.33
Crystal size (mm)0.44 × 0.18 × 0.05
Data collection
DiffractometerBruker APEXII DUO CCD
Absorption correctionMulti-scan
(SADABS; Bruker, 2009)
Tmin, Tmax0.868, 0.982
No. of measured, independent and
observed [I > 2σ(I)] reflections		16733, 3109, 2020
Rint0.029
(sin θ/λ)max (Å−1)0.707
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.038, 0.126, 1.04
No. of reflections3109
No. of parameters127
H-atom treatmentH atoms treated by a mixture of independent and constrained refinement
Δρmax, Δρmin (e Å−3)0.16, −0.25

Computer programs: APEX2 (Bruker, 2009), SAINT (Bruker, 2009), SHELXTL (Sheldrick, 2008) and PLATON (Spek, 2009).

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O2W—H1WA···Cl10.84 (3)2.37 (3)3.2076 (17)179 (3)
O2W—H2WA···Cl1i0.83 (3)2.39 (3)3.1689 (16)157 (3)
O1W—H1WB···Cl1ii0.84 (3)2.36 (3)3.2019 (15)179 (3)
O1W—H2WB···Cl1iii0.79 (2)2.41 (2)3.1916 (16)172.4 (18)
N1—H1N1···O2W0.861.932.7852 (18)174
N2—H2N1···Cl1i0.862.533.3177 (12)153
N2—H2N2···O1Wiv0.862.002.8543 (17)175
Symmetry codes: (i) x, −y+1/2, z−1/2; (ii) x+1, y, z−1; (iii) −x+1, −y+1, −z+1; (iv) x−1, y, z.
 

Footnotes

‡Thomson Reuters ResearcherID: A-3561-2009.

Acknowledgements

AS gratefully acknowledges funding from Universiti Sains Malaysia (USM) under the University Research Grant (No. 1001/PKIMIA/811055). HKF and MH thank the Malaysian Government and USM for the Research University Grant No. 1001/PFIZIK/811160. MH also thanks USM for a post-doctoral research fellowship.

References

First citationBond, A. D. & Parsons, S. (2002). Acta Cryst. E58, o550–o552.  Web of Science CSD CrossRef IUCr Journals Google Scholar
 First citationBruker (2009). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.  Google Scholar
 First citationDesiraju, G. R. (2001). Curr. Sci. 81, 1038–1055.  CAS Google Scholar
 First citationKatritzky, A. R., Rees, C. W. & Scriven, E. F. V. (1996). In Comprehensive Heterocyclic Chemistry II. Oxford: Pergamon Press.  Google Scholar
 First citationMatsumoto, A. (2003). Polym. J. 35, 93–121.  Web of Science CrossRef CAS Google Scholar
 First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals Google Scholar
 First citationSpek, A. L. (2009). Acta Cryst. D65, 148–155.  Web of Science CrossRef CAS IUCr Journals Google Scholar

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COMMUNICATIONS
ISSN: 2056-9890
Volume 67| Part 10| October 2011| Page o2572
https://doi.org/10.1107/S1600536811035100
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