supplementary materials


zl2105 scheme

Acta Cryst. (2008). E64, m777-m778    [ doi:10.1107/S1600536808007745 ]

2-(2-Pyridylamino)pyridinium tetrachloridozincate(II)

D. Venegas-Yazigi, C. Castillo, V. Paredes-García, A. Vega and E. Spodine

Abstract top

The structure of the title compound, (C10H10N3)2[ZnCl4], is composed of C10H9N3H+ (DPAH+) cations and [ZnCl4]2- anions. The two pyridyl rings of DPAH+ are approximately coplanar, with a dihedral angle of 7.2 (2)° between their corresponding least-squares planes. The proton is disordered in a one-to-one ratio over the two chemically equivalent pyridyl N atoms. An intramolecular hydrogen bond is formed between the pyridinium H atom and the pyridyl N atom of the other pyridyl ring. The Zn atom lies on a twofold rotation axis. There are also some weak N-H...Cl hydrogen bonds. These interactions lead to the formation of an alternating zigzag chain in the solid state. The results clearly show that reducing agents normally used in hydrothermal syntheses, such as metallic zinc employed here, are also active in terms of coordination chemistry.

Comment top

Core to the crystal engineering of supramolecular compounds are the different strategies that are used to control the molecular aggregation processes. For example, the selection of metal ions that promote the formation of extended arrays, and organic molecules capable of forming hydrogen bonding or close packed structures are fundamental to control the molecular aggregation (Guillon et al., 2000, Rice et al., 2002). Therefore, the strategies adopted in the preparation of crystal structures involve two main concepts. One of them is related with the use of the shape-controlled close packing of molecules, and the second one with the use of the specific interactions to control aggregation of molecular species (Guillon et al., 2000).

2,2-Dipyridylamine (DPA) is used as an organic linker presenting different coordination modes ranging from monodentate to chelating bidentate or bridging tridentate. Furthermore, this organic ligand contains the amino group and aromatic rings that may induce intermolecular hydrogen bonding and π-π stacking interactions that may lead to different structures. (Camus, et al. 2000, Bose et al., 2004, Rahaman et al.2005, Chowdhury et al., 2005, Youmgme et al., 2005, Marinescu et al., 2005).

In this work we inform on the synthesis of a novel crystal structure with a tetrachlorozincate anion obtained by hydrothermal synthesis. The reaction conditions described in the experimental section lead to the oxidation of the metallic zinc used as the reducing agent and, to the formation of a crystalline tetrahalide species, which is present together with the cationic counterion, DPAH+.

The organic cation (DPAH+) exhibits two pyridinium rings in a highly planar arrangement with a dihedral angle between them of only 7.2 (2)°. This is consistent with the value observed for the isostructural cobalt derivative (DPAH+)2[CoCl4]2- of the title compound (Visser et al., 1997); both compounds being isostructural. The pyridinium nitrogen atoms on the cation are in a "face to face" (or U) arrangement, allowing the existence of an intramolecular hydrogen bond (see hydrogen bonding table), also observed for other 2-(pyridin-2-ylamino)pyridinium salts such as the Cl-, squarate (C4O4H)-, tetraphenylborate (B(C6H5)4)- (Bock et al., 1998) or NO3- (Du & Zhao, 2004) compounds. The parameters for this interaction within these salts are basically identical. A different situation is observed for (DPAH2+)[CuCl4]2- (Willett, 1995) and (DPAH2+)(CF3SO3)- (Bock et al., 1998) where the molecule is diprotonated, leading to an S-like conformation which precludes intramolecular hydrogen bonding.

As expected, the tetrachlorozincate anion, with the zinc atom lying on the twofold axis, displays an almost perfect tetrahedral coordination environment. The [ZnCl4]2-anion interacts with the cations through weak hydrogen bonds between Cl1 and Cl2 with the DPAH+ cations, as summarized in the hydrogen bonding table and depicted in Figure 1. Each tetrachlorozincate anion is bonded in this way to four cations. This differs from what is observed in (DPAH2+)[CuCl4]2-, where the values N(amine)···Cl = 2.133 Å, N(pyridinium)···Cl = 2.307, 2.470 Å) suggest stronger interactions. The rather strong distortion from square planar geometry in this latter molecule has been addressed to the hydrogen bonding interactions (Willett, 1995).

As can be seen in Figure 1, there are two pairs of strictly parallel cations, which are separated by approximately 3.3 Å, a value that is in the range for π-π interactions (Marinescu et al., 2005), but somewhat shorter than the 3.534 (5) Å reported for (DPAH+)NO3-(Du & Zhao, 2004). Each pair of DPAH+cations is in connected with a neighboring pair in a "head to tail" fashion (see Figure 1), thus leading to a packing arrangement with a zigzag chain with alternating organic cations and tetrachlorozincate anions as seen in Figure 2. These chains interact in the solid by means of π-π contacts.

Related literature top

For related literature, see: Bock et al. (1998); Bose et al. (2004); Camus et al. (2000); Chowdhury et al. (2005); Du & Zhao (2004); Gillon et al. (2000); Marinescu et al. (2005); Rahaman et al. (2005); Rice et al. (2002); Visser et al. (1997); Willett (1995); Youmgme et al. (2005).

Experimental top

The compound was obtained by hydrothermal synthesis employing the following reagents: CrCl3.6H2O, DPA, V2O5, Zn, H3PO4 (85%) and H2O (all Aldrich, used without further purification) in the following quantities: 0.1523 g, 0.28 g, 0.1438 g, 0.1054 g, 0.58 ml and 5 ml respectively. This mixture was sealed in a 23 ml PTFE-lined stainless steel autoclave, and heated to 393 K (120°C) for 72 h. The yield of the studied compound was approximately 10%, and X-ray quality crystals were directly selected from the bulk mixture of products.

Refinement top

The hydrogen atoms positions were calculated after each cycle of refinement with SHELXL (Bruker,1999) using a riding model with C—H distance equal to 0.96 Å. Uiso(H) values were set equal to 1.2Ueq of the parent carbon atom. At the final stages of refinement, the hydrogen bonded to the nitrogen atoms becomes evident in the Fourier Difference Map, with some disorder. This was modeled considering two half-occupied hydrogen sites, one on each pyridyl nitrogen atom. These N—H hydrogen atoms were then refined using a riding model with C—N—H angles idealized for amide H atoms, but the the N—H distances were allowed to refine freely.

Computing details top

Data collection: SMART-NT (Bruker, 2001); cell refinement: SAINT-NT (Bruker, 1999); data reduction: SAINT-NT (Bruker, 1999); program(s) used to solve structure: SHELXTL-NT (Sheldrick, 2008); program(s) used to refine structure: SHELXTL-NT (Sheldrick, 2008); molecular graphics: SHELXTL-NT (Sheldrick, 2008); software used to prepare material for publication: SHELXTL-NT (Sheldrick, 2008).

Figures top
[Figure 1] Fig. 1. Molecular drawing for I showing hydrogen bonding between [ZnCl4]2-and the organic cation. Atom numbering scheme is included. Displacement ellipsoids at 20%. The second hydrogen position H3N is not included in the diagram for clarity. Symmetry codes: A: x, 1 - y, 1/2 + z; B: 1 - x,1 - y,1 - z; C 1-x. y,3/2 - z.
[Figure 2] Fig. 2. Packing diagram showing the zigzag chains defined by weak intermolecular interactions in the solid state.
2-(2-Pyridylamino)pyridinium tetrachloridozincate(II) top
Crystal data top
(C10H10N3)2[ZnCl4]F000 = 1120
Mr = 551.61Dx = 1.536 Mg m3
Monoclinic, C2/cMo Kα radiation
λ = 0.71073 Å
Hall symbol: -C 2ycCell parameters from 12557 reflections
a = 14.620 (3) Åθ = 2.9–27.5º
b = 11.260 (2) ŵ = 1.50 mm1
c = 14.765 (3) ÅT = 150 (2) K
β = 101.13 (3)ºPrism, yellow
V = 2384.9 (8) Å30.1 × 0.1 × 0.1 mm
Z = 4
Data collection top
Siemens SMART CCD area-detector
diffractometer
2718 independent reflections
Radiation source: fine-focus sealed tube2063 reflections with I > 2σ(I)
Monochromator: graphiteRint = 0.029
T = 298(2) Kθmax = 27.5º
phi and ω scansθmin = 3.6º
Absorption correction: multi-scan
(SADABS in SAINT-NT; Bruker, 1999)
h = 18→18
Tmin = 0.861, Tmax = 0.861k = 14→14
8907 measured reflectionsl = 18→19
Refinement top
Refinement on F2Secondary atom site location: difference Fourier map
Least-squares matrix: fullHydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.031H atoms treated by a mixture of
independent and constrained refinement
wR(F2) = 0.079  w = 1/[σ2(Fo2) + (0.0297P)2 + 1.3722P]
where P = (Fo2 + 2Fc2)/3
S = 1.17(Δ/σ)max = 0.001
2718 reflectionsΔρmax = 0.53 e Å3
145 parametersΔρmin = 0.31 e Å3
Primary atom site location: structure-invariant direct methodsExtinction correction: none
Crystal data top
(C10H10N3)2[ZnCl4]V = 2384.9 (8) Å3
Mr = 551.61Z = 4
Monoclinic, C2/cMo Kα
a = 14.620 (3) ŵ = 1.50 mm1
b = 11.260 (2) ÅT = 150 (2) K
c = 14.765 (3) Å0.1 × 0.1 × 0.1 mm
β = 101.13 (3)º
Data collection top
Siemens SMART CCD area-detector
diffractometer
2718 independent reflections
Absorption correction: multi-scan
(SADABS in SAINT-NT; Bruker, 1999)
2063 reflections with I > 2σ(I)
Tmin = 0.861, Tmax = 0.861Rint = 0.029
8907 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.031145 parameters
wR(F2) = 0.079H atoms treated by a mixture of
independent and constrained refinement
S = 1.17Δρmax = 0.53 e Å3
2718 reflectionsΔρmin = 0.31 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.

Least-squares planes (x,y,z in crystal coordinates) and deviations from them (* indicates atom used to define plane)

- 7.5257 (0.0143) x - 6.4929 (0.0111) y + 10.6583 (0.0124) z = 0.0740 (0.0091)

* -0.0004 (0.0017) N3 * 0.0057 (0.0017) C6 * -0.0049 (0.0019) C7 * -0.0009 (0.0021) C8 * 0.0062 (0.0022) C9 * -0.0057 (0.0021) C10

Rms deviation of fitted atoms = 0.0046

- 8.0734 (0.0131) x - 5.2989 (0.0109) y + 11.5436 (0.0110) z = 0.7176 (0.0115)

Angle to previous plane (with approximate e.s.d.) = 7.15 (0.16)

* 0.0093 (0.0015) N1 * 0.0017 (0.0017) C1 * -0.0085 (0.0019) C2 * 0.0045 (0.0020) C3 * 0.0061 (0.0019) C4 * -0.0132 (0.0016) C5

Rms deviation of fitted atoms = 0.0081

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*/UeqOcc. (<1)
Zn0.50000.81308 (3)0.75000.03912 (11)
Cl10.42368 (4)0.92732 (5)0.84063 (4)0.05165 (16)
Cl20.39576 (4)0.69311 (5)0.65703 (4)0.05397 (16)
N10.49641 (13)0.42148 (17)0.60363 (12)0.0447 (4)
H1N0.437 (3)0.478 (3)0.5901 (7)0.054*0.50
C10.57114 (16)0.4524 (2)0.66942 (15)0.0479 (5)
H10.56990.52340.70130.057*
C20.64808 (18)0.3812 (3)0.68967 (17)0.0575 (6)
H20.69920.40340.73430.069*
C30.64815 (19)0.2743 (3)0.64175 (18)0.0645 (7)
H30.69950.22410.65520.077*
C40.57324 (19)0.2427 (2)0.57501 (17)0.0568 (6)
H40.57320.17120.54340.068*
C50.49701 (15)0.3193 (2)0.55522 (15)0.0428 (5)
N20.42142 (14)0.29509 (19)0.48707 (14)0.0515 (5)
H2N0.4271 (2)0.228 (2)0.4519 (12)0.062*
C60.33748 (15)0.3559 (2)0.46259 (15)0.0435 (5)
C70.26855 (17)0.3177 (2)0.38963 (17)0.0533 (6)
H70.27800.25140.35500.064*
C80.18643 (18)0.3801 (3)0.37007 (18)0.0602 (7)
H80.13930.35590.32190.072*
C90.17357 (19)0.4798 (3)0.42241 (19)0.0640 (7)
H90.11800.52240.41030.077*
C100.24470 (17)0.5133 (3)0.49185 (19)0.0612 (7)
H100.23700.58050.52620.073*
N30.32622 (14)0.45227 (19)0.51276 (14)0.0508 (5)
H3N0.378 (3)0.4795 (17)0.566 (3)0.061*0.50
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Zn0.0415 (2)0.03647 (19)0.03747 (19)0.0000.00295 (13)0.000
Cl10.0604 (4)0.0447 (3)0.0527 (3)0.0036 (3)0.0181 (3)0.0025 (3)
Cl20.0527 (3)0.0485 (3)0.0531 (3)0.0037 (3)0.0089 (3)0.0057 (3)
N10.0472 (10)0.0473 (11)0.0400 (10)0.0084 (9)0.0093 (8)0.0012 (8)
C10.0519 (13)0.0508 (13)0.0397 (12)0.0013 (11)0.0059 (10)0.0005 (10)
C20.0503 (14)0.0758 (18)0.0438 (13)0.0054 (13)0.0025 (10)0.0067 (13)
C30.0570 (15)0.0811 (19)0.0537 (15)0.0292 (14)0.0068 (12)0.0073 (14)
C40.0635 (16)0.0573 (15)0.0494 (14)0.0217 (13)0.0103 (12)0.0014 (12)
C50.0450 (11)0.0492 (12)0.0357 (10)0.0077 (10)0.0114 (9)0.0059 (10)
N20.0539 (12)0.0482 (12)0.0517 (12)0.0065 (9)0.0089 (9)0.0097 (9)
C60.0437 (12)0.0453 (12)0.0427 (12)0.0040 (10)0.0111 (9)0.0040 (10)
C70.0550 (14)0.0547 (14)0.0486 (13)0.0022 (12)0.0062 (11)0.0063 (12)
C80.0507 (14)0.0729 (18)0.0527 (14)0.0006 (13)0.0006 (11)0.0021 (13)
C90.0477 (14)0.0779 (19)0.0627 (16)0.0164 (13)0.0016 (12)0.0026 (14)
C100.0524 (14)0.0685 (17)0.0607 (16)0.0195 (13)0.0061 (12)0.0118 (14)
N30.0457 (11)0.0574 (12)0.0478 (11)0.0096 (9)0.0050 (9)0.0066 (10)
Geometric parameters (Å, °) top
Zn—Cl22.2856 (8)C5—N21.371 (3)
Zn—Cl2i2.2856 (8)N2—C61.391 (3)
Zn—Cl1i2.2949 (7)N2—H2N0.9333
Zn—Cl12.2949 (7)C6—N31.342 (3)
N1—C51.355 (3)C6—C71.394 (3)
N1—C11.360 (3)C7—C81.373 (4)
N1—H1N1.0584C7—H70.9300
C1—C21.366 (3)C8—C91.396 (4)
C1—H10.9300C8—H80.9300
C2—C31.397 (4)C9—C101.365 (4)
C2—H20.9300C9—H90.9300
C3—C41.371 (4)C10—N31.359 (3)
C3—H30.9300C10—H100.9300
C4—C51.395 (3)N3—H3N1.0328
C4—H40.9300
Cl2—Zn—Cl2i107.54 (4)N2—C5—C4121.9 (2)
Cl2—Zn—Cl1i108.90 (3)C5—N2—C6129.7 (2)
Cl2i—Zn—Cl1i109.79 (3)C5—N2—H2N115.2
Cl2—Zn—Cl1109.79 (3)C6—N2—H2N115.2
Cl2i—Zn—Cl1108.90 (3)N3—C6—N2116.8 (2)
Cl1i—Zn—Cl1111.82 (4)N3—C6—C7121.9 (2)
C5—N1—C1120.5 (2)N2—C6—C7121.3 (2)
C5—N1—H1N119.7C8—C7—C6118.5 (2)
C1—N1—H1N119.7C8—C7—H7120.8
N1—C1—C2121.4 (2)C6—C7—H7120.8
N1—C1—H1119.3C7—C8—C9120.1 (2)
C2—C1—H1119.3C7—C8—H8120.0
C1—C2—C3118.4 (2)C9—C8—H8120.0
C1—C2—H2120.8C10—C9—C8118.2 (2)
C3—C2—H2120.8C10—C9—H9120.9
C4—C3—C2120.6 (2)C8—C9—H9120.9
C4—C3—H3119.7N3—C10—C9122.6 (2)
C2—C3—H3119.7N3—C10—H10118.7
C3—C4—C5119.0 (2)C9—C10—H10118.7
C3—C4—H4120.5C6—N3—C10118.6 (2)
C5—C4—H4120.5C6—N3—H3N120.7
N1—C5—N2118.03 (19)C10—N3—H3N120.7
N1—C5—C4120.1 (2)
C5—N1—C1—C21.0 (3)C5—N2—C6—N31.0 (4)
N1—C1—C2—C30.7 (4)C5—N2—C6—C7179.3 (2)
C1—C2—C3—C41.0 (4)N3—C6—C7—C81.0 (4)
C2—C3—C4—C50.4 (4)N2—C6—C7—C8178.7 (2)
C1—N1—C5—N2177.3 (2)C6—C7—C8—C90.4 (4)
C1—N1—C5—C42.4 (3)C7—C8—C9—C100.7 (4)
C3—C4—C5—N12.1 (4)C8—C9—C10—N31.2 (5)
C3—C4—C5—N2177.6 (2)N2—C6—N3—C10179.1 (2)
N1—C5—N2—C65.5 (4)C7—C6—N3—C100.6 (4)
C4—C5—N2—C6174.7 (2)C9—C10—N3—C60.6 (4)
Symmetry codes: (i) −x+1, y, −z+3/2.
Hydrogen-bond geometry (Å, °) top
D—H···AD—HH···AD···AD—H···A
N1—H1N···N31.061.822.612 (3)129
N3—H3N···N11.031.832.612 (3)130
N1—H1N···Cl21.062.733.548 (2)134
N3—H3N···Cl21.032.743.477 (3)129
N2—H2N···Cl1ii0.932.393.313 (3)170
Symmetry codes: (ii) x, −y+1, z−1/2.
Table 1
Hydrogen-bond geometry (Å, °)
top
D—H···AD—HH···AD···AD—H···A
N1—H1N···N31.061.822.612 (3)129
N3—H3N···N11.031.832.612 (3)130
N1—H1N···Cl21.062.733.548 (2)134
N3—H3N···Cl21.032.743.477 (3)129
N2—H2N···Cl1i0.932.393.313 (3)170
Symmetry codes: (i) x, −y+1, z−1/2.
Acknowledgements top

The authors thank the X-ray Laboratory of the University of Chile for the data collection. The authors acknowledge FONDAP (grant No. 11980002) for financial support.

references
References top

Bock, H., Schodel, H., Van, T. T. H., Dienelt, R. & M.Gluth (1998). J. Prakt. Chem. Chem. Zeitung, 340, 722–732.

Bose, D., Rahaman, S. H., Mostafa, G., Walsh, R. D. B., Zaworotko, M. J. & Ghosh, B. K. (2004). Polyhedron, 23, 545–552.

Bruker (1999). SAINT-NT. Bruker AXS Inc., Madison, Wisconsin, USA.

Bruker (2001). SMART-NT, SAINT-NT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.

Camus, A., Marsich, N., Lanfredi, A. M. M., Ugozzoli, F. & Massera, C. (2000). Inorg. Chim. Acta, 309, 1–2.

Chowdhury, H., Ghosh, R., Rahaman, S. H., Rosair, G. M. & Ghosh, B. K. (2005). Indian J. Chem. 44A, 687–692.

Du, M. & Zhao, X.-J. (2004). Acta Cryst. E60, o439–o441.

Gillon, A. L., Lewis, G. R., Orpen, A. G., Rotter, S., Starbuck, J., Wang, X. M., Rodríguez-Martín, Y. & Ruiz-Pérez, C. (2000). J. Chem. Soc. Dalton Trans. pp. 3897–3905. Gillon or Guillon?

Marinescu, G., Andruh, M., Julve, M., Lloret, F., Llusar, R., Uriel, S. & Vaissermann, J. (2005). Crys. Growth Des. 5, 261–267.

Rahaman, S. H., Bose, D., Chowdhury, H., Mostafa, G., Fun, H.-K. & Ghosh, B. K. (2005). Polyhedron, 24, 1837–1844.

Rice, C. R., Onions, S., Vidal, N., Wallis, J. D., Senna, M. C., Pilkington, M. & Stoeckli-Evans, H. (2002). Eur. J. Inorg. Chem. pp. 1985–1997.

Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122.

Visser, H. G., Purcell, W., Basson, S. S. & Claassen, Q. (1997). Polyhedron, 16, 2851–2855.

Willett, R. D. (1995). Acta Cryst. C51, 1517–1519.

Youmgme, S., Chailuecha, C., van Albada, G. A., Pakawatchai, C., Chaichit, N. & Reedijk, J. (2005). Inorg. Chim. Acta, 358, 1068–1078.