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Crystal structure of bis­­(2-amino-5-chloro­pyridinium) tetra­chlorido­cobaltate(II)

aLaboratoire de Matériaux et Cristallochimie, Faculté des Sciences de Tunis, Université de Tunis El Manar, 2092 Manar II Tunis, Tunisia
*Correspondence e-mail: habib.boughzala@ipein.rnu.tn

Edited by M. Weil, Vienna University of Technology, Austria (Received 11 April 2015; accepted 19 April 2015; online 25 April 2015)

The title salt, (C5H6ClN2)2[CoCl4], was synthesized by slow evaporation of an aqueous solution at room temperature. The asymmetric unit consists of two essentially planar (C5H6ClN2)+ cations [maximum deviations = 0.010 (3) and 0.014 (3) Å] that are nearly perpendicular to each other [dihedral angle = 84.12 (7)°]. They are bonded through N—H⋯Cl hydrogen bonds to distorted [CoCl4]2− tetra­hedra, leading to the formation of undulating layers parallel to (100). The structure is isotypic with the Zn analogue [Kefi et. al (2011). Acta Cryst. E67, m355–m356.]

1. Chemical context

Organic–inorganic hybrid compounds frequently exhibit self-organized structures and can combine organic and inorganic characteristics (Parent et al., 2007[Parent, A. R., Landee, C. P. & Turnbull, M. M. (2007). Inorg. Chim. Acta, 360, 1943-1953.]; Zheng et al., 2010[Zheng, Y., Han, S., Zhou, D. D., Liu, X. P., Zhou, J. R., Yang, L. M., Ni, C. L. & Hu, X. L. (2010). Nano Met. Chem. 40, 772-778.]; Chang et al., 2011[Chang, J., Ho, W. Y., Sun, I. W., Chou, Y. K., Hsieh, H. H. & Wu, T. Y. (2011). Polyhedron, 30, 497-507.]). In particular, anionic cobalt halides associated with organic counter-cations have some inter­esting physical properties, such as luminescence, in which we are inter­ested. In this communication, we report the synthesis and crystal structure of the new organic–inorganic hybrid compound bis­(2-amino-5-chloro­pyridinium) tetra­chlorido­cobaltate(II), (C5H6ClN2)2[CoCl4].

[Scheme 1]

2. Structural commentary

The asymmetric unit of the title compound consists of two 2-amino-5-chloro­pyridinium cations (cat1 consists of ring C1–C5/N2 and cat2 consists of ring C9–C10/N3) and one isolated [CoCl4]2− anion (Fig. 1[link]).

[Figure 1]
Figure 1
The mol­ecular entities of (C5H6ClN2)2[CoCl4], showing the atom-numbering scheme. Displacement ellipsoids are drawn at the 50% probability level.

The organic cations are nearly planar exhibiting small maximum deviations of 0.010 (3) and 0.014 (3) Å for atoms N2 and C6, respectively. The two least-squares planes of the two cations are nearly perpendicular to each other [84.12 (7)°]. The bond angles C4—N2—C5 [123.6 (3)°] and C9—N3—C10 [123.3 (3)°] in the rings of cat1 and cat2, respectively, confirm the presence of pyridinium cations. Previous studies (Jin et al., 2001[Jin, Z.-M., Pan, Y. J., Hu, M. L. & Liang, S. (2001). J. Chem. Crystallogr. 31, 1074-1542.]) showed that a pyridinium cation possesses an expanded C—N(H)—C angle in comparison with the parent pyridine (117°). This geometrical characteristic is in agreement with an imine–enamine resonance (Jin et al., 2005[Jin, Z.-M., Shun, N., Lü, Y.-P., Hu, M.-L. & Shen, L. (2005). Acta Cryst. C61, m43-m45.]) and contributes to the structural stability.

In the [CoCl4]2− anion, the Co—Cl bond lengths range from 2.2645 (12) to 2.2934 (12) Å and the Cl—Co—Cl angles range from 104.84 (5) to 118.58 (5)°, revealing considerable distortions from the ideal tetra­hedral geometry. These values are in agreement with those observed in similar compounds (Dhieb et al., 2014[Dhieb, A. C., Janzen, D. E., Rzaigui, M. & Smirani Sta, W. (2014). Acta Cryst. E70, m139.]; Mghandef & Boughzala, 2014[Mghandef, M. & Boughzala, H. (2014). Acta Cryst. E70, m75.]; Oh et al., 2011[Oh, I.-H., Kim, D., Huh, Y.-D., Park, Y., Park, J. M. S. & Park, S.-H. (2011). Acta Cryst. E67, m522-m523.]). The different Co—Cl bond lengths in the [CoCl4]2− anion are related to the number of hydrogen bonds accepted by the Cl atoms. The Co—Cl1 and Co—Cl4 bonds are longer than the Co—Cl2 and Co—Cl3 bonds because atoms Cl1 and Cl4 are each acceptors of two hydrogen bonds from cat2 and cat1, respectively.

3. Supra­molecular features

Each CoCl4 tetra­hedron is linked to four cations (two cat1 and two cat2) by hydrogen bonds (Fig. 2[link] and Table 1[link]). Atom Cl1 is doubly linked to one cat2 cation by N3—HN3⋯Cl1 and N4—H4A⋯Cl1, and atom Cl2 establishes one hydrogen bond with a symmetry-related cat2 cation via N4—H4B⋯Cl2. Atom Cl3 is linked to cation cat1 by N1—H1B⋯Cl3 and atom Cl4 again shares two hydrogen bonds (N1—H1A⋯Cl4 and N2—HN2⋯Cl4) with a second symmetry-related cat1 cation. The hydrogen-bonding environments of the two cations are similar. Both are linked to two CoCl4 tetra­hedra by three hydrogen bonds (Fig. 3[link])

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA D—H⋯A
N1—H1A⋯Cl4i 0.86 2.64 3.400 (4) 148
N1—H1B⋯Cl3ii 0.86 2.47 3.317 (3) 169
N2—HN2⋯Cl4i 0.86 2.42 3.238 (3) 160
N3—HN3⋯Cl1iii 0.86 2.42 3.251 (3) 164
N4—H4A⋯Cl1iii 0.86 2.77 3.519 (4) 147
N4—H4B⋯Cl2iv 0.86 2.80 3.541 (4) 145
Symmetry codes: (i) -x+2, -y+1, -z+1; (ii) [x, -y+{\script{3\over 2}}, z+{\script{1\over 2}}]; (iii) [-x+1, y+{\script{1\over 2}}, -z+{\script{1\over 2}}]; (iv) -x+1, -y+1, -z+1.
[Figure 2]
Figure 2
The environment of the CoCl4 tetra­hedron.
[Figure 3]
Figure 3
The environment around the cations (cat1 or cat2).

The crystal packing can be described by an alternate stacking of cations and anions with a –cat1–[CoCl4]–cat2–[CoCl4]– sequence along [100], as shown in Fig. 4[link]. Between anti­parallel aligned cat2 cations, ππ inter­actions are also present [centroid-to-centroid separation = 3.900 (2) Å]. The stacked cations and anions are linked through N—H⋯Cl hydrogen bonds into zigzag layers parallel to (100) (Fig. 5[link]).

[Figure 4]
Figure 4
Projection of the crystal structure along [010] showing the –cat1–[CoCl4]–cat2–[CoCl4]– sequence stacked along [100].
[Figure 5]
Figure 5
Projection of the crystal structure along [001] showing the layered character of the hydrogen-bonded components.

4. Database survey

A systematic search procedure in the Cambridge Structural Database (Groom & Allen, 2014[Groom, C. R. & Allen, F. H. (2014). Angew. Chem. Int. Ed. 53, 662-671.]) indicates a total of 32 hits for the 2-amino-5-chloro­pyridinium cation with various counter-anions. For tetra­halogenidometalate anions, the following structures have been reported: (C5H6ClN2)2[ZnCl4]·H2O (Coomer et al., 2007[Coomer, F., Harrison, A. & Parsons, S. (2007). Private communication (deposition No. 660778). CCDC, Cambridge, England.]); (C5H6ClN2)2[ZnCl4] (Kefi et al., 2011a[Kefi, R., Jeanneau, E., Lefebvre, F. & Ben Nasr, C. (2011a). Acta Cryst. E67, m355-m356.]); (C5H6ClN2)2[CdCl4]·H2O (Kefi et al., 2011b[Kefi, R., Maher, E. G., Zeller, M., Lefebvre, F. & Ben Nasr, C. (2011b). Private communication (deposition No. 850225). CCDC, Cambridge, England.]); (C5H6ClN2)2[CuCl4] (Parsons et al., 2006[Parsons, S., Jagaln, V. B., Harrison, A., Davidson, J. & Johnstone, R. (2006). Private communication (deposition No. 610403). CCDC, Cambridge, England.]); (C5H6ClN2)2[CuBr4] (Woodward et al., 2002[Woodward, F. M., Albrecht, A. S., Wynn, C. M., Landee, C. P. & Turnbull, M. M. (2002). Phys. Rev. B Condens. Matter, 65, 144412.]). The title compound is isotypic with the Zn analogue (C5H6ClN2)2[ZnCl4] (Kefi et al., 2011a[Kefi, R., Jeanneau, E., Lefebvre, F. & Ben Nasr, C. (2011a). Acta Cryst. E67, m355-m356.]).

5. Synthesis and crystallization

A mixture of cobalt(II) chloride and 2-amino-5-chloro­pyridine (molar ratio 1:1) was dissolved in an aqueous solution of hydro­chloric acid with 5 ml of ethanol. The mixture was stirred and then kept at room temperature. Blue crystals of the title compound were obtained after two weeks.

6. Refinement

Crystal data, data collection and structure refinement details are summarized in Table 2[link]. H atoms were placed geometrically and included as riding contributions, with N—H = 0.86 Å and C—H = 0.93 Å and with Uiso(H) = 1.2Ueq(N,C).

Table 2
Experimental details

Crystal data
Chemical formula (C5H6ClN2)2[CoCl4]
Mr 459.87
Crystal system, space group Monoclinic, P21/c
Temperature (K) 298
a, b, c (Å) 13.519 (2), 14.945 (3), 8.725 (2)
β (°) 92.858 (3)
V3) 1760.6 (6)
Z 4
Radiation type Mo Kα
μ (mm−1) 1.88
Crystal size (mm) 0.5 × 0.3 × 0.2
 
Data collection
Diffractometer Enraf–Nonius CAD-4
Absorption correction ψ scan (North et al., 1968[North, A. C. T., Phillips, D. C. & Mathews, F. S. (1968). Acta Cryst. A24, 351-359.])
Tmin, Tmax 0.423, 0.649
No. of measured, independent and observed [I > 2σ(I)] reflections 6241, 3707, 2121
Rint 0.039
(sin θ/λ)max−1) 0.638
 
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.041, 0.109, 0.99
No. of reflections 3707
No. of parameters 190
H-atom treatment H-atom parameters not refined
Δρmax, Δρmin (e Å−3) 0.52, −0.34
Computer programs: CAD-4 EXPRESS (Enraf–Nonius, 1994[Enraf-Nonius (1994). CAD-4 EXPRESS. Enraf-Nonius, Delft, The Netherlands.]), XCAD4 (Harms & Wocadlo, 1995[Harms, K. & Wocadlo, S. (1995). XCAD4. University of Marburg, Germany.]), SHELXS97 and SHELXL97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]), DIAMOND (Brandenburg, 2008[Brandenburg, K. (2008). DIAMOND. Crystal Impact GbR, Bonn, Germany.]) and publCIF (Westrip, 2010[Westrip, S. P. (2010). J. Appl. Cryst. 43, 920-925.]).

Supporting information


Computing details top

Data collection: CAD-4 EXPRESS (Enraf–Nonius, 1994); cell refinement: CAD-4 EXPRESS (Enraf–Nonius, 1994); data reduction: XCAD4 (Harms & Wocadlo, 1995); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: DIAMOND (Brandenburg, 2008); software used to prepare material for publication: publCIF (Westrip, 2010).

Bis(2-amino-5-chloropyridinium) tetrachloridocobaltate(II) top
Crystal data top
(C5H6ClN2)2[CoCl4]F(000) = 916
Mr = 459.87Dx = 1.735 Mg m3
Monoclinic, P21/cMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybcCell parameters from 25 reflections
a = 13.519 (2) Åθ = 10–15°
b = 14.945 (3) ŵ = 1.88 mm1
c = 8.725 (2) ÅT = 298 K
β = 92.858 (3)°Prism, blue
V = 1760.6 (6) Å30.5 × 0.3 × 0.2 mm
Z = 4
Data collection top
Enraf–Nonius CAD-4
diffractometer
2121 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tubeRint = 0.039
Graphite monochromatorθmax = 27.0°, θmin = 2.0°
non–profiled ω/2τ scansh = 1717
Absorption correction: ψ scan
(North et al., 1968)
k = 191
Tmin = 0.423, Tmax = 0.649l = 115
6241 measured reflections2 standard reflections every 120 min
3707 independent reflections intensity decay: 6%
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)] = 0.041Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.109H-atom parameters not refined
S = 0.99 w = 1/[σ2(Fo2) + (0.0443P)2]
where P = (Fo2 + 2Fc2)/3
3707 reflections(Δ/σ)max < 0.001
190 parametersΔρmax = 0.52 e Å3
0 restraintsΔρmin = 0.34 e Å3
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
Co0.75262 (3)0.48488 (3)0.01742 (6)0.03927 (16)
Cl10.66040 (7)0.47789 (7)0.20888 (12)0.0475 (3)
Cl20.64020 (8)0.48540 (8)0.20135 (13)0.0580 (3)
Cl30.85951 (8)0.60044 (7)0.05556 (14)0.0580 (3)
Cl40.84305 (8)0.35504 (7)0.03059 (15)0.0690 (4)
Cl50.83772 (8)0.37281 (8)0.53616 (14)0.0646 (3)
Cl60.68358 (8)0.75291 (9)0.29194 (14)0.0672 (4)
N10.9792 (2)0.7278 (2)0.7188 (4)0.0616 (11)
H1A1.02470.73060.79120.074*
H1B0.95650.77620.67680.074*
N20.9798 (2)0.5740 (2)0.7372 (4)0.0430 (8)
HN21.02610.57900.80780.052*
N30.4647 (2)0.8197 (2)0.5514 (4)0.0444 (8)
HN30.43940.86860.58340.053*
N40.3491 (2)0.7428 (2)0.6902 (4)0.0557 (9)
H4A0.32640.79310.72100.067*
H4B0.32330.69350.71950.067*
C10.8770 (3)0.4802 (3)0.5868 (5)0.0427 (9)
C20.8694 (3)0.6385 (3)0.5537 (5)0.0498 (11)
H20.84250.68870.50450.060*
C30.8370 (3)0.5557 (3)0.5125 (5)0.0503 (11)
H30.78800.54920.43460.060*
C40.9472 (3)0.4907 (2)0.6989 (5)0.0458 (10)
H40.97360.44110.75040.055*
C50.9440 (3)0.6484 (2)0.6714 (5)0.0418 (9)
C60.5837 (3)0.7483 (3)0.4092 (4)0.0451 (10)
C70.5437 (3)0.6658 (3)0.4521 (5)0.0550 (11)
H70.57070.61290.41680.066*
C80.4669 (3)0.6625 (3)0.5436 (5)0.0536 (11)
H80.44130.60750.57200.064*
C90.4253 (3)0.7413 (3)0.5959 (4)0.0444 (10)
C100.5418 (3)0.8250 (3)0.4591 (4)0.0433 (9)
H100.56590.88040.43010.052*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Co0.0394 (3)0.0288 (3)0.0492 (4)0.0023 (2)0.0018 (2)0.0013 (3)
Cl10.0502 (5)0.0460 (6)0.0459 (6)0.0005 (5)0.0002 (4)0.0005 (5)
Cl20.0679 (6)0.0542 (7)0.0534 (7)0.0144 (5)0.0158 (5)0.0045 (6)
Cl30.0587 (6)0.0409 (6)0.0740 (8)0.0159 (5)0.0008 (5)0.0049 (6)
Cl40.0673 (7)0.0336 (6)0.1025 (10)0.0110 (5)0.0328 (7)0.0098 (6)
Cl50.0688 (7)0.0414 (6)0.0842 (9)0.0114 (5)0.0087 (6)0.0175 (6)
Cl60.0545 (6)0.0911 (10)0.0556 (7)0.0035 (6)0.0007 (5)0.0019 (7)
N10.072 (2)0.031 (2)0.079 (3)0.0005 (17)0.020 (2)0.0032 (19)
N20.0468 (17)0.0315 (18)0.050 (2)0.0029 (14)0.0070 (15)0.0019 (16)
N30.058 (2)0.0224 (16)0.052 (2)0.0068 (15)0.0028 (17)0.0015 (16)
N40.060 (2)0.048 (2)0.058 (2)0.0021 (17)0.0021 (19)0.0081 (19)
C10.046 (2)0.035 (2)0.048 (2)0.0022 (18)0.0102 (18)0.008 (2)
C20.049 (2)0.041 (2)0.058 (3)0.0069 (19)0.009 (2)0.010 (2)
C30.044 (2)0.050 (3)0.055 (3)0.0022 (19)0.0083 (19)0.002 (2)
C40.054 (2)0.025 (2)0.058 (3)0.0077 (17)0.005 (2)0.003 (2)
C50.044 (2)0.031 (2)0.051 (3)0.0023 (17)0.0027 (18)0.006 (2)
C60.049 (2)0.048 (3)0.038 (2)0.0016 (19)0.0102 (18)0.001 (2)
C70.082 (3)0.035 (2)0.048 (3)0.007 (2)0.002 (2)0.001 (2)
C80.080 (3)0.032 (2)0.049 (3)0.006 (2)0.003 (2)0.005 (2)
C90.050 (2)0.037 (2)0.045 (2)0.0010 (18)0.0099 (19)0.006 (2)
C100.049 (2)0.037 (2)0.043 (2)0.0078 (18)0.0065 (19)0.0046 (19)
Geometric parameters (Å, º) top
Co—Cl22.2645 (12)N4—H4A0.8600
Co—Cl32.2657 (11)N4—H4B0.8600
Co—Cl12.2843 (12)C1—C41.337 (5)
Co—Cl42.2934 (12)C1—C31.397 (6)
Cl5—C11.741 (4)C2—C31.355 (6)
Cl6—C61.735 (4)C2—C51.410 (5)
N1—C51.337 (5)C2—H20.9300
N1—H1A0.8600C3—H30.9300
N1—H1B0.8600C4—H40.9300
N2—C51.331 (4)C6—C101.360 (5)
N2—C41.357 (5)C6—C71.405 (6)
N2—HN20.8600C7—C81.342 (6)
N3—C101.351 (5)C7—H70.9300
N3—C91.352 (5)C8—C91.392 (6)
N3—HN30.8600C8—H80.9300
N4—C91.351 (5)C10—H100.9300
Cl2—Co—Cl3109.81 (5)C2—C3—C1120.1 (4)
Cl2—Co—Cl1104.84 (5)C2—C3—H3119.9
Cl3—Co—Cl1118.58 (5)C1—C3—H3119.9
Cl2—Co—Cl4110.02 (5)C1—C4—N2119.9 (4)
Cl3—Co—Cl4107.65 (5)C1—C4—H4120.1
Cl1—Co—Cl4105.73 (4)N2—C4—H4120.1
C5—N1—H1A120.0N2—C5—N1119.5 (3)
C5—N1—H1B120.0N2—C5—C2117.2 (3)
H1A—N1—H1B120.0N1—C5—C2123.3 (3)
C5—N2—C4123.6 (3)C10—C6—C7118.8 (4)
C5—N2—HN2118.2C10—C6—Cl6120.2 (3)
C4—N2—HN2118.2C7—C6—Cl6120.9 (3)
C10—N3—C9123.3 (3)C8—C7—C6120.7 (4)
C10—N3—HN3118.4C8—C7—H7119.7
C9—N3—HN3118.4C6—C7—H7119.7
C9—N4—H4A120.0C7—C8—C9120.1 (4)
C9—N4—H4B120.0C7—C8—H8120.0
H4A—N4—H4B120.0C9—C8—H8120.0
C4—C1—C3119.2 (4)N4—C9—N3118.9 (4)
C4—C1—Cl5119.4 (3)N4—C9—C8123.1 (4)
C3—C1—Cl5121.4 (3)N3—C9—C8117.9 (4)
C3—C2—C5119.9 (4)N3—C10—C6119.2 (4)
C3—C2—H2120.0N3—C10—H10120.4
C5—C2—H2120.0C6—C10—H10120.4
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1—H1A···Cl4i0.862.643.400 (4)148
N1—H1B···Cl3ii0.862.473.317 (3)169
N2—HN2···Cl4i0.862.423.238 (3)160
N3—HN3···Cl1iii0.862.423.251 (3)164
N4—H4A···Cl1iii0.862.773.519 (4)147
N4—H4B···Cl2iv0.862.803.541 (4)145
Symmetry codes: (i) x+2, y+1, z+1; (ii) x, y+3/2, z+1/2; (iii) x+1, y+1/2, z+1/2; (iv) x+1, y+1, z+1.
 

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