Crystal structure of di-μ₂-chlorido-bis­[(1-aza-4-azoniabi­cyclo­[2.2.2]octane-κN ¹)di­chlorido­dicadmium]

Abstract

In the structure of the binuclear title compound, [Cd₂(C₆H₁₃N₂)₂Cl₆], two Cd^II atoms are bridged by two Cl⁻ ligands, defining a centrosymmetric Cd₂Cl₂ motif. Each metal cation is additionally coordinated by two Cl⁻ ligands and the N atom of a protonated 1,4-di­aza­bicyclo­[2.2.2]octane (H-DABCO)⁺ ligand, leading to an overall trigonal–bipyramidal coordination environment with one of the bridging Cl⁻ ligands and the N atom at the apical sites. In the crystal, the neutral dimers are linked via N—H⋯Cl hydrogen bonds, forming a two-dimensional network expanding parallel to (100).

Related literature  

For a study on phase transition of related Cd₂(DABCO-CH₂Cl)₂(μ-Cl₂), see: Chen et al. (2014 ▸). Mononuclear and dinuclear bromide-nitrite cadmium complexes with DABCO derivatives were reported by Cai (2011 ▸).

Experimental  

Crystal data  

• [Cd₂(C₆H₁₃N₂)₂Cl₆]

• M _r = 663.86

• Orthorhombic,

• a = 12.317 (2) Å

• b = 12.289 (2) Å

• c = 14.440 (2) Å

• V = 2185.7 (6) ų

• Z = 4

• Mo Kα radiation

• μ = 2.68 mm⁻¹

• T = 296 K

• 0.3 × 0.2 × 0.2 mm

Data collection  

• Bruker APEXII CCD diffractometer

• Absorption correction: multi-scan (SADABS; Bruker, 2004 ▸) T _min = 0.500, T _max = 0.616

• 14939 measured reflections

• 1924 independent reflections

• 1752 reflections with I > 2σ(I)

• R _int = 0.025

Refinement  

• R[F ² > 2σ(F ²)] = 0.054

• wR(F ²) = 0.183

• S = 1.12

• 1924 reflections

• 109 parameters

• 30 restraints

• H-atom parameters constrained

• Δρ_max = 1.98 e Å⁻³

• Δρ_min = −1.65 e Å⁻³

Data collection: APEX2 (Bruker, 2004 ▸); cell refinement: SAINT (Bruker, 2004 ▸); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▸); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▸); molecular graphics: DIAMOND (Brandenburg, 2006 ▸); software used to prepare material for publication: OLEX2 (Dolomanov et al., 2009 ▸).

Supplementary Material

CCDC reference: 1440782

Additional supporting information: 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—H2⋯Cl3i	0.91	2.33	3.205 (3)	162

Symmetry code: (i) .

supplementary crystallographic information

S1. Synthesis and crystallization

CdCl₂·2.5H₂O (2.28 g, 10 mmol) and 1,4-di­aza­bicyclo [2.2.2]o­ctan (1.12 g, 10 mmol) were mixed in water (20 ml). After being stirred for 30 min, the reaction mixture was filtered and evaporated slowly at room temperature for 3 days. Colourless block-like crystals were obtained.

S2. Refinement

C-bound H atoms were placed in geometrically idealized positions and constrained to ride on their parent atoms, with C—H = 0.97 Å and U_iso(H) = 1.2U_eq(C). The H atom of the protonated N2 atom was discernible from a difference map. It was modelled with N—H = 0.91 Å and U_iso(H) = 1.2U_eq(N). The maximum and minimum electron density peaks are found 0.20 Å from atom Cl3 and 0.27 Å from atom Cd1, respectively.

Figures

Fig. 1.

The molecular structure of the dinuclear complex in the title compound. Displacement ellipsoids are drawn at the 30% probability level. The left part of the binuclear complex is generated by symmetry code −x + 1, −y, −z + 1.

Fig. 2.

View onto a layer of complexes in the title compound with N—H···Cl hydrogen bonds drawn as dashed lines.

Crystal data

[Cd2(C6H13N2)2Cl6]	Dx = 2.017 Mg m−3
Mr = 663.86	Mo Kα radiation, λ = 0.71073 Å
Orthorhombic, Pbca	Cell parameters from 6044 reflections
a = 12.317 (2) Å	θ = 2.7–27.4°
b = 12.289 (2) Å	µ = 2.68 mm−1
c = 14.440 (2) Å	T = 296 K
V = 2185.7 (6) Å3	Block, colorless
Z = 4	0.3 × 0.2 × 0.2 mm
F(000) = 1296

Data collection

Bruker APEXII CCD diffractometer	1924 independent reflections
Radiation source: fine-focus sealed tube	1752 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.025
phi and ω scans	θmax = 25.0°, θmin = 2.7°
Absorption correction: multi-scan (SADABS; Bruker, 2004)	h = −13→14
Tmin = 0.500, Tmax = 0.616	k = −14→14
14939 measured reflections	l = −17→16

Refinement

Refinement on F2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.054	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.183	H-atom parameters constrained
S = 1.12	w = 1/[σ2(Fo2) + (0.1089P)2 + 19.3777P] where P = (Fo2 + 2Fc2)/3
1924 reflections	(Δ/σ)max = 0.006
109 parameters	Δρmax = 1.98 e Å−3
30 restraints	Δρmin = −1.65 e Å−3

Special details

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 (Ų)

	x	y	z	Uiso*/Ueq
Cd1	0.42960 (2)	0.138551 (19)	0.535783 (17)	0.03153 (7)
Cl2	0.37788 (6)	0.25484 (6)	0.40100 (5)	0.02553 (17)
Cl3	0.28196 (6)	0.11273 (6)	0.65621 (5)	0.02369 (17)
Cl4	0.61656 (7)	0.05552 (8)	0.54294 (8)	0.0606 (3)
C1	0.4234 (3)	0.3697 (3)	0.6469 (3)	0.0453 (12)
H1A	0.3732	0.3344	0.6890	0.054*
H1B	0.3833	0.3921	0.5923	0.054*
C3	0.5670 (3)	0.2551 (3)	0.7038 (2)	0.0401 (9)
H3A	0.6263	0.2078	0.6853	0.048*
H3B	0.5177	0.2128	0.7418	0.048*
N1	0.5090 (2)	0.2930 (2)	0.62028 (18)	0.0284 (7)
C4	0.5890 (3)	0.3502 (3)	0.5617 (3)	0.0418 (10)
H4A	0.5526	0.3799	0.5078	0.050*
H4B	0.6432	0.2987	0.5404	0.050*
C2	0.4742 (3)	0.4710 (3)	0.6946 (3)	0.0512 (12)
H2A	0.4624	0.5352	0.6568	0.061*
H2B	0.4403	0.4829	0.7544	0.061*
N2	0.5912 (3)	0.4521 (3)	0.7064 (2)	0.0429 (8)
H2	0.6208	0.5096	0.7370	0.051*
C5	0.6446 (4)	0.4414 (3)	0.6140 (3)	0.0553 (12)
H5A	0.7211	0.4251	0.6218	0.066*
H5B	0.6381	0.5091	0.5799	0.066*
C6	0.6123 (4)	0.3495 (3)	0.7611 (3)	0.0537 (10)
H6A	0.5763	0.3531	0.8208	0.064*
H6B	0.6895	0.3400	0.7713	0.064*

Atomic displacement parameters (Ų)

	U11	U22	U33	U12	U13	U23
Cd1	0.03132 (14)	0.02795 (13)	0.03533 (14)	0.00383 (9)	−0.00315 (9)	−0.00071 (9)
Cl2	0.0293 (3)	0.0249 (3)	0.0224 (3)	0.0010 (3)	−0.0047 (3)	0.0066 (3)
Cl3	0.0201 (3)	0.0231 (3)	0.0278 (3)	0.0002 (3)	0.0055 (3)	0.0068 (3)
Cl4	0.0362 (4)	0.0375 (4)	0.1082 (7)	0.0139 (4)	−0.0311 (4)	−0.0347 (4)
C1	0.0315 (19)	0.042 (2)	0.062 (2)	0.0035 (15)	0.0005 (17)	−0.0087 (17)
C3	0.0468 (17)	0.0325 (15)	0.0408 (16)	0.0022 (13)	−0.0054 (14)	0.0003 (14)
N1	0.0269 (12)	0.0237 (12)	0.0346 (13)	−0.0007 (10)	0.0030 (11)	0.0011 (11)
C4	0.0393 (18)	0.0414 (19)	0.0448 (19)	−0.0063 (16)	0.0128 (17)	0.0046 (16)
C2	0.041 (2)	0.0406 (19)	0.072 (2)	0.0050 (17)	0.003 (2)	−0.0175 (19)
N2	0.0411 (14)	0.0361 (14)	0.0515 (15)	−0.0060 (12)	−0.0063 (13)	−0.0092 (12)
C5	0.054 (2)	0.0381 (19)	0.074 (3)	−0.0152 (17)	0.024 (2)	0.0006 (19)
C6	0.0584 (17)	0.0475 (16)	0.0551 (17)	−0.0017 (15)	−0.0138 (16)	−0.0050 (15)

Geometric parameters (Å, º)

Cd1—Cl2	2.4972 (8)	N1—C4	1.477 (5)
Cd1—Cl3	2.5361 (8)	C4—H4A	0.9700
Cd1—Cl4i	2.7025 (11)	C4—H4B	0.9700
Cd1—Cl4	2.5207 (10)	C4—C5	1.515 (6)
Cd1—N1	2.460 (3)	C2—H2A	0.9700
Cl4—Cd1i	2.7025 (11)	C2—H2B	0.9700
C1—H1A	0.9700	C2—N2	1.470 (5)
C1—H1B	0.9700	N2—H2	0.9100
C1—N1	1.465 (5)	N2—C5	1.493 (5)
C1—C2	1.555 (6)	N2—C6	1.510 (5)
C3—H3A	0.9700	C5—H5A	0.9700
C3—H3B	0.9700	C5—H5B	0.9700
C3—N1	1.477 (4)	C6—H6A	0.9700
C3—C6	1.530 (6)	C6—H6B	0.9700
Cl2—Cd1—Cl3	115.03 (3)	N1—C4—H4B	109.3
Cl2—Cd1—Cl4	119.78 (3)	N1—C4—C5	111.6 (3)
Cl2—Cd1—Cl4i	97.09 (3)	H4A—C4—H4B	108.0
Cl3—Cd1—Cl4i	91.56 (3)	C5—C4—H4A	109.3
Cl4—Cd1—Cl3	125.19 (3)	C5—C4—H4B	109.3
Cl4—Cd1—Cl4i	81.50 (3)	C1—C2—H2A	110.0
N1—Cd1—Cl2	92.66 (6)	C1—C2—H2B	110.0
N1—Cd1—Cl3	92.39 (6)	H2A—C2—H2B	108.3
N1—Cd1—Cl4	85.91 (7)	N2—C2—C1	108.6 (3)
N1—Cd1—Cl4i	166.77 (6)	N2—C2—H2A	110.0
Cd1—Cl4—Cd1i	98.50 (3)	N2—C2—H2B	110.0
H1A—C1—H1B	108.2	C2—N2—H2	109.0
N1—C1—H1A	109.7	C2—N2—C5	110.0 (3)
N1—C1—H1B	109.7	C2—N2—C6	111.2 (3)
N1—C1—C2	110.0 (3)	C5—N2—H2	109.0
C2—C1—H1A	109.7	C5—N2—C6	108.5 (3)
C2—C1—H1B	109.7	C6—N2—H2	109.0
H3A—C3—H3B	107.9	C4—C5—H5A	110.1
N1—C3—H3A	109.2	C4—C5—H5B	110.1
N1—C3—H3B	109.2	N2—C5—C4	108.2 (3)
N1—C3—C6	112.2 (3)	N2—C5—H5A	110.1
C6—C3—H3A	109.2	N2—C5—H5B	110.1
C6—C3—H3B	109.2	H5A—C5—H5B	108.4
C1—N1—Cd1	109.9 (2)	C3—C6—H6A	110.4
C1—N1—C3	109.7 (3)	C3—C6—H6B	110.4
C1—N1—C4	108.9 (3)	N2—C6—C3	106.7 (3)
C3—N1—Cd1	110.70 (19)	N2—C6—H6A	110.4
C4—N1—Cd1	110.4 (2)	N2—C6—H6B	110.4
C4—N1—C3	107.2 (3)	H6A—C6—H6B	108.6
N1—C4—H4A	109.3
Cd1—N1—C4—C5	−176.4 (2)	C1—C2—N2—C5	63.5 (4)
Cl2—Cd1—Cl4—Cd1i	−93.35 (4)	C1—C2—N2—C6	−56.8 (4)
Cl2—Cd1—N1—C1	67.3 (2)	C3—N1—C4—C5	−55.7 (4)
Cl2—Cd1—N1—C3	−171.4 (2)	N1—Cd1—Cl4—Cd1i	175.92 (7)
Cl2—Cd1—N1—C4	−52.9 (2)	N1—C1—C2—N2	−5.9 (5)
Cl3—Cd1—Cl4—Cd1i	85.88 (4)	N1—C3—C6—N2	−5.6 (4)
Cl3—Cd1—N1—C1	−47.9 (2)	N1—C4—C5—N2	−6.1 (4)
Cl3—Cd1—N1—C3	73.4 (2)	C2—C1—N1—Cd1	−176.3 (3)
Cl3—Cd1—N1—C4	−168.1 (2)	C2—C1—N1—C3	61.8 (4)
Cl4i—Cd1—Cl4—Cd1i	0.0	C2—C1—N1—C4	−55.2 (4)
Cl4—Cd1—N1—C1	−173.0 (2)	C2—N2—C5—C4	−56.7 (4)
Cl4i—Cd1—N1—C1	−155.2 (3)	C2—N2—C6—C3	63.1 (4)
Cl4—Cd1—N1—C3	−51.7 (2)	C5—N2—C6—C3	−58.0 (4)
Cl4i—Cd1—N1—C3	−33.9 (4)	C6—C3—N1—Cd1	−176.8 (3)
Cl4—Cd1—N1—C4	66.8 (2)	C6—C3—N1—C1	−55.5 (4)
Cl4i—Cd1—N1—C4	84.7 (4)	C6—C3—N1—C4	62.7 (4)
C1—N1—C4—C5	62.9 (4)	C6—N2—C5—C4	65.1 (4)

Symmetry code: (i) −x+1, −y, −z+1.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N2—H2···Cl3ii	0.91	2.33	3.205 (3)	162

Symmetry code: (ii) −x+1, y+1/2, −z+3/2.