Bis(1-benzyl­piperazine-1,4-diium) hexa­chloridocadmate(II) dihydrate

Meher El Glaoui; Matthias Zeller; Erwann Jeanneau; Cherif Ben Nasr

doi:10.1107/S1600536810026073

. 2010 Jul 7;66(Pt 8):m895. doi: 10.1107/S1600536810026073

Bis(1-benzylpiperazine-1,4-diium) hexachloridocadmate(II) dihydrate

Meher El Glaoui ^a, Matthias Zeller ^b, Erwann Jeanneau ^c, Cherif Ben Nasr ^a,^*

PMCID: PMC3007331 PMID: 21588139

Abstract

The asymmetric unit of the title compound, (C₁₁H₁₈N₂)₂[CdCl₆]·2H₂O, consists of one 1-benzylpiperazine-1,4-diium dication, one water molecule and one-half of a [CdCl₆]⁴⁻ anion, located on an inversion centre. The crystal packing is governed by an extensive three-dimensional network of intermolecular O—H⋯Cl, C—H⋯Cl, N—H⋯O and N—H⋯Cl hydrogen bonds, two of them bifurcated.

Related literature

For meta-chlorido complexes, see: El Glaoui, Jeanneau, et al. (2009 ▶); El Glaoui, Kefi et al. (2009 ▶). For the role of C—H⋯Cl hydrogen bonds, see: Janiak & Scharmann (2003 ▶. For a discussion of Cd—Cl distances and Cl—Cd—Cl bond angles, see: Bala et al. (2006 ▶).

Experimental

Crystal data

(C₁₁H₁₈N₂)₂[CdCl₆]·2H₂O
M _r = 717.68
Monoclinic,
a = 12.734 (2) Å
b = 9.1686 (14) Å
c = 13.216 (2) Å
β = 103.249 (3)°
V = 1502.0 (4) Å³
Z = 2
Mo Kα radiation
μ = 1.29 mm⁻¹
T = 100 K
0.55 × 0.45 × 0.25 mm

Data collection

Bruker SMART APEX CCD diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2009 ▶) T _min = 0.622, T _max = 0.746
11244 measured reflections
4446 independent reflections
4123 reflections with I > 2σ(I)
R _int = 0.016

Refinement

R[F ² > 2σ(F ²)] = 0.022
wR(F ²) = 0.057
S = 1.07
4446 reflections
172 parameters
3 restraints
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.51 e Å⁻³
Δρ_min = −0.83 e Å⁻³

Data collection: APEX2 (Bruker, 2009 ▶); cell refinement: SAINT (Bruker, 2009 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXTL; molecular graphics: DIAMOND (Brandenburg, 1998 ▶); software used to prepare material for publication: SHELXTL.

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536810026073/hb5541sup1.cif

e-66-0m895-sup1.cif^{(19KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536810026073/hb5541Isup2.hkl

e-66-0m895-Isup2.hkl^{(217.9KB, hkl)}

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N2—H2A⋯Cl1ⁱ	0.92	2.58	3.3383 (11)	140
N2—H2A⋯Cl2ⁱ	0.92	2.59	3.2672 (11)	131
N2—H2B⋯Cl2ⁱⁱ	0.92	2.47	3.1846 (11)	135
N2—H2B⋯Cl3ⁱⁱ	0.92	2.58	3.2799 (12)	133
N1—H1⋯O1	0.89 (1)	1.92 (1)	2.7945 (16)	170 (2)
O1—H1A⋯Cl1	0.84 (2)	2.39 (2)	3.1678 (11)	155 (2)
O1—H1B⋯Cl3ⁱⁱⁱ	0.83 (2)	2.42 (2)	3.2152 (11)	161 (2)
C9—H9A⋯Cl3ⁱⁱ	0.99	2.83	3.331 (2)	112
C9—H9B⋯Cl3ⁱⁱⁱ	0.99	2.85	3.659 (3)	139
C10—H10A⋯Cl3ⁱⁱⁱ	0.99	2.73	3.565 (2)	143
C10—H10B⋯Cl2ⁱⁱ	0.99	2.84	3.340 (4)	112
C11—H11A⋯Cl1ⁱⁱ	0.99	2.71	3.626 (1)	154
C11—H11B⋯Cl1	0.99	2.72	3.587 (1)	146

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Symmetry codes: (i) Inline graphic ; (ii) ; (iii) .

Acknowledgments

We would like to acknowledge the support provided by the Secretary of State for Scientific Research and Technology of Tunisia. The diffractometer was funded by NSF grant 0087210, by Ohio Board of Regents grant CAP-491, and by YSU.

supplementary crystallographic information

Comment

As a part of our ongoing investigations in molecular salts containing meta-chlorido complexes (El Glaoui, Jeanneau, et al., 2009; El Glaoui, Kefi et al., 2009), we present here the crystal structure of one such compound, (C₁₁H₁₈N₂)₂CdCl₆.2H₂O, (Fig. 1). The asymmetric unit of its structure consists of one 1-benzylpiperazine-1,4-diium dication doubly protonated at the N1 and N2 nitrogen atoms, one water molecule and one-half of a CdCl₆^4- anion (located on a crystallographic inversion centre) (Fig. 1). The atomic arrangement of (C₁₁H₁₈N₂)₂CdCl₆.2H₂O can be described as built up by inorganic chains of CdCl₆ octahedra and water molecules extending along the b direction held together by O—H···Cl hydrogen bonds (Fig. 2, Table 1). Two such chains cross the unit cell at z = 0, z = 1/2 and x = 1/2 (Fig. 3). The organic groups are located between these chains and connect to them through N—H···Cl, C—H···Cl and N—H···O hydrogen bonds to form a three dimensional infinite network (Fig. 3, Table 1). All the chloride ions are involved in hydrogen bonding. It should be pointed out at this point that the C—H···Cl hydrogen bonds do usually not play a large role in stabilizing a structure (Janiak & Scharmann, 2003), but due to the large number of these interactions in the title compound they seem to substantially contribute to the choice of packing observed in the structure of the title compound. Among all the hydrogen bonds, two are bifurcated: N2—H2A···(Cl1, Cl2) and N2—H2B···(Cl2, Cl3). The H1 hydrogen atom attached to the N1 nitrogen atom is bonded only to the water molecule, via the N1—H1···O1 hydrogen bond, and not to the CdCl₆^4- anion.

The Cd II ion is in an octahedral coordination environment composed of six chloride anions as to form an hexachlorocadmate (II) ion. In this kind of anion, the Cd—Cl bond lengths and Cl—Cd—Cl bond angles are generally not equal to one another but vary with the environment around the Cl atoms (Bala et al., 2006). In the title compound, the values of the Cd—Cl bond lengths vary between 2.5528 (5) and 2.7055 (4) Å. The Cl—Cd—Cl angles range from 87.354 (11) to 92.646 (11)°. These geometrical parameters agree with those found in [Co(NH₃)₆]₄ [CdCl₆] [CdCl₄(SCN)(H₂O)]₂Cl₂.2H₂O where the Cd—Cl distances are between 2.5937 (9) and 2.691 (1) Å and the Cl—Cd—Cl angles ranging from 89.23 (3) to 95.50 (3)° (Bala et al., 2006). Owing to the obvious differences of Cd—Cl distances and Cl—Cd—Cl angles in (C₁₁H₁₈N₂)₂CdCl₆.2H₂O, the coordination geometry of the Cd atom could be regarded as a slightly distorted octahedron which is in full agreement with the literature data (Bala, et al., 2006).

Experimental

1-Benzypyperazine (2 mmol, 0.352 g) and CdCl₂ (1 mmol, 0.183 g), were dissolved in dilute HCl (10 ml, 1 M) and the resultant solution was slowly evaporated at room temperature. A crystal of the title compound, which remained stable under normal conditions of temperature and humidity, was isolated after several days and subjected to X-ray diffraction analysis (yield 55%).