Poly[di-μ₂-chlorido-μ₄-hexa­methyl­ene­tetra­mine-bis­[chlorido(methanol-κO)­cadmium(II)]]

In the title complex, [Cd₂Cl₄(C₆H₁₂N₄)(CH₃OH)₂]_n, the hexa­methyl­enetetra­mine (hmta) ligand is located on a twofold rotation axis and bridges four Cd^II ions through its four N atoms. Each Cd^II atom is coordinated, with a distorted octa­hedral geometry, by two N atoms from hmta ligands, two μ₂-chloride anions, one terminal chloride anion and one methanol mol­ecule. The μ₂-chloride anions and hmta mol­ecules link the Cd^II cations to form the three-dimensional polymeric structure. O—H...Cl hydrogen bonding between the methanol ligands and the terminal chloride anions is observed in the three-dimensional polymeric structure.

Key indicators

• Single-crystal X-ray study
• T = 130 K
• Mean [sigma](N-C) = 0.008 Å
• R factor = 0.052
• wR factor = 0.097
• Data-to-parameter ratio = 18.0

checkCIF/PLATON results

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Alert level C
PLAT041_ALERT_1_C Calc. and Rep. SumFormula Strings    Differ ....          ?
PLAT042_ALERT_1_C Calc. and Rep. MoietyFormula Strings Differ ....          ?
PLAT045_ALERT_1_C Calculated and Reported Z Differ by ............       2.00 Ratio
PLAT764_ALERT_4_C Overcomplete CIF Bond List Detected (Rep/Expd) .       1.31 Ratio

Alert level G
PLAT793_ALERT_1_G Check the Absolute Configuration of N1     = ...          S
PLAT793_ALERT_1_G Check the Absolute Configuration of N2     = ...          R
PLAT794_ALERT_5_G Check Predicted Bond Valency for Cd1         (2)       1.91
PLAT860_ALERT_3_G Note: Number of Least-Squares Restraints .......          1

   0 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
   4 ALERT level C = Check and explain
   4 ALERT level G = General alerts; check

   5 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   0 ALERT type 2 Indicator that the structure model may be wrong or deficient
   1 ALERT type 3 Indicator that the structure quality may be low
   1 ALERT type 4 Improvement, methodology, query or suggestion
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S1. Comment

Hexamethylenetetramine (hmta) as a potential polydentate ligand has been of interest in recent years. The combination of the hmta ligand with metal ions has produced several complexes with diverse structural topologies (Cheng et al., 2005; Tong et al., 2000; Wang et al., 2006). The compounds of hmta are easier to exhibit high-dimensional structure because of the abundant coordination atoms. The methanol solution of hmta diffuse into the aqua solution of CdCl₂ producing the title compound. We present its structure here.

The asymmetric unit consists of one Cd ion, two Cl anions, one methanol molecule, and a half of hmta molecule. The hmta ligand is located on a twofold rotation axis, which passes through atom C2 and C3, and bridges four cadmium ions through its four N atoms. As depicted in Fig. 1, the Cd atom is coordinated by two µ₂Cl atoms, one terminal Cl atom, one oxygen atom from methanol ligand and two N atoms from hmta ligands with a distorted octahedral geometry; the CdCl₃N₂O octahedron is seriously distorted (Table 1). The bond lengths involving the Cd atom are normal and are comparable to the values found in a related Cd^II complex (Batten et al., 1998). Two types of Cl anions occur in the structure; one is the bridging and the other is the terminal. Four µ₂Cl atoms bridge four Cd atoms to form a 8-membered ring, as shown in Fig. 2. Each hmta ligand bridges four Cd atoms through its four N atoms (Fig. 1). The 8-membered rings are further bridge by the hmta ligands through Cd—N bonds to generate a three-dimensional framework, as shown in Fig. 3. The O—H···Cl hydrogen bond between the methanol molecule and the terminal Cl anion is observed within the three-dimensional structure (Table 2).

Related literature

For general background, see: Cheng et al. (2005); Tong et al. (2000); Wang et al. (2006). For a related structure, see: Batten et al. (1998). For related literature, see: Fang et al. (2004).

S2. Experimental

Orange block-shaped crystals of the title compound were obtained from a diffusion reaction in a U-tube with H₂O as diffusion mediate. A methanol solution (6 ml) of hmta (0.014 g, 0.10 mmol) was carefully added to one side of the diffusion tube, and a aqua solution (7 ml) of CdCl₂.2.5H₂O (0.0456 g, 0.20 mmol) was added to the other side. The tube was located at room temperature for about two weeks, and well shaped crystals were obtained.

S3. Refinement

The H atoms bonded to C atoms were placed in calculated positions and treated using a riding-model approximation (C—H = 0.96 Å and U_iso(H) = 1.5U_eq(C) for methyl group; C—H = 0.97 Å and U_iso(H) = 1.2U_eq(C) for methylene group). H atoms bonded to O atoms were located in a difference map and were refined with a restraint of O—H = 0.90 (1) Å and with U_iso(H) = 1.5U_eq(O). The highest peak in the final difference Fourier map is 1.78 Å apart from H4B atom.

Computing details

Data collection: CrystalClear (Rigaku, 2000); cell refinement: CrystalClear (Rigaku, 2000); data reduction: CrystalClear (Rigaku, 2000); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997a); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997a); molecular graphics: SHELXTL (Sheldrick, 1997b); software used to prepare material for publication: SHELXTL (Sheldrick, 1997b).

Figures

	Fig. 1. The structure of (I), showing the atom-numbering scheme. Displacement ellipsoids are drawn at the 60% probability level and H atoms are shown as small spheres of arbitrary radii. H atoms of hmta ligands are omitted for clarity. [Symmetry codes: (i) -x + 1, -y + 1/2, z; (ii) -x + 3/4, y - 1/4, z - 1/4; (iii) x + 1/4, -y + 1/4, -z + 1/4; (iv) -x + 1/4, y - 1/4, -z + 1/4; (v) x + 1/4, -y + 3/4, z + 1/4; (vi) -x + 1/4, y + 1/4, z + 1/4]
	Fig. 2. A view of the Cd4Cl4 8-membered ring. [Symmetry codes: (iii) x + 1/4, -y + 1/4, -z + 1/4; (iv) -x + 1/4, y - 1/4, -z + 1/4.]
	Fig. 3. A view of the three-dimensional framework of (I) (viewed down the c axis)

Poly[di-µ₂-chlorido-µ₄-hexamethylenetetramine-βis[chlorido(methanol-κO)cadmium(II)]]

Crystal data

[Cd2Cl4(C6H12N4)(CH4O)2]	Dx = 2.386 Mg m^−3
Mr = 568.86	Mo Kα radiation, λ = 0.71073 Å
Tetragonal, I41/a	Cell parameters from 3283 reflections
Hall symbol: -I 4ad	θ = 3.1–27.5°
a = 12.7307 (7) Å	µ = 3.36 mm^−1
c = 19.5433 (18) Å	T = 130 K
V = 3167.4 (4) Å^3	Block, orange
Z = 8	0.11 × 0.10 × 0.10 mm
F(000) = 2192

Data collection

Rigaku Mercury70 (2x2 bin mode) diffractometer	1816 independent reflections
Radiation source: fine-focus sealed tube	1552 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.043
ω scans	θmax = 27.5°, θmin = 3.1°
Absorption correction: multi-scan (CrystalClear; Rigaku, 2000)	h = −15→15
Tmin = 0.712, Tmax = 0.722	k = −6→16
5447 measured reflections	l = −22→25

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.052	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.097	H atoms treated by a mixture of independent and constrained refinement
S = 1.10	w = 1/[σ^2(Fo^2) + (0.0238P)^2 + 61.3128P] where P = (Fo^2 + 2Fc^2)/3
1816 reflections	(Δ/σ)max < 0.001
101 parameters	Δρmax = 1.26 e Å^−3
1 restraint	Δρmin = −0.68 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	Occ. (<1)
Cd1	0.24683 (4)	0.25555 (4)	0.05984 (2)	0.01140 (14)
O1	0.3287 (4)	0.1206 (4)	0.0017 (3)	0.0194 (10)
H6	0.329 (7)	0.0504 (11)	0.006 (4)	0.029*
Cl1	0.15990 (12)	0.09779 (12)	0.12298 (8)	0.0147 (3)
Cl2	0.34179 (13)	0.38436 (13)	−0.01275 (9)	0.0183 (3)
N1	0.4031 (4)	0.2487 (4)	0.1398 (3)	0.0104 (11)
N2	0.4993 (4)	0.3459 (4)	0.2283 (3)	0.0098 (10)
C1	0.3784 (6)	0.1214 (6)	−0.0629 (4)	0.0255 (17)
H1A	0.4051	0.0525	−0.0729	0.038*
H1B	0.4353	0.1708	−0.0624	0.038*
H1C	0.3285	0.1413	−0.0974	0.038*
C2	0.5000	0.2500	0.0967 (5)	0.0111 (17)
H2	0.5008	0.1884	0.0678	0.013*	0.50
C3	0.5000	0.2500	0.2704 (5)	0.0109 (17)
H3	0.4384	0.2495	0.2993	0.013*	0.50
C4	0.4035 (5)	0.3443 (5)	0.1837 (3)	0.0114 (12)
H4A	0.3410	0.3451	0.2121	0.014*
H4B	0.4025	0.4066	0.1551	0.014*
C5	0.4069 (5)	0.1547 (5)	0.1839 (3)	0.0126 (12)
H5A	0.4073	0.0924	0.1554	0.015*
H5B	0.3444	0.1525	0.2121	0.015*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cd1	0.0110 (2)	0.0118 (2)	0.0114 (2)	−0.00013 (17)	0.00009 (17)	0.00014 (17)
O1	0.025 (3)	0.014 (2)	0.019 (3)	−0.001 (2)	0.004 (2)	−0.001 (2)
Cl1	0.0126 (7)	0.0143 (7)	0.0173 (8)	−0.0015 (6)	0.0020 (6)	0.0028 (6)
Cl2	0.0172 (8)	0.0166 (8)	0.0210 (8)	−0.0009 (6)	−0.0007 (7)	0.0061 (6)
N1	0.011 (3)	0.008 (2)	0.012 (3)	0.0010 (19)	0.003 (2)	−0.001 (2)
N2	0.010 (3)	0.008 (2)	0.011 (3)	−0.0018 (19)	−0.001 (2)	−0.003 (2)
C1	0.031 (4)	0.029 (4)	0.017 (4)	0.004 (3)	0.007 (3)	−0.003 (3)
C2	0.009 (4)	0.012 (4)	0.012 (4)	−0.004 (3)	0.000	0.000
C3	0.016 (4)	0.004 (4)	0.013 (4)	0.001 (3)	0.000	0.000
C4	0.011 (3)	0.010 (3)	0.014 (3)	0.000 (2)	0.000 (2)	−0.002 (2)
C5	0.012 (3)	0.013 (3)	0.013 (3)	−0.003 (2)	0.000 (3)	0.000 (3)

Geometric parameters (Å, º)

Cd1—Cl1	2.6041 (16)	N2—Cd1^iv	2.498 (5)
Cd1—Cl1^i	2.6526 (16)	C1—H1A	0.9600
Cd1—Cl2	2.4825 (17)	C1—H1B	0.9600
Cd1—O1	2.308 (5)	C1—H1C	0.9600
Cd1—N1	2.531 (5)	C2—N1^iii	1.493 (7)
Cd1—N2^ii	2.498 (5)	C2—H2	0.9700
O1—C1	1.413 (8)	C3—N2^iii	1.473 (7)
O1—H6	0.897 (10)	C3—H3	0.9700
N1—C5	1.475 (8)	C4—H4A	0.9700
N1—C4	1.490 (8)	C4—H4B	0.9700
N1—C2	1.493 (7)	C5—N2^iii	1.476 (8)
N2—C3	1.473 (7)	C5—H5A	0.9700
N2—C5^iii	1.476 (8)	C5—H5B	0.9700
N2—C4	1.498 (8)
O1—Cd1—Cl2	89.46 (13)	C3—N2—Cd1^iv	106.3 (4)
O1—Cd1—N2^ii	90.87 (18)	C5^iii—N2—Cd1^iv	113.5 (3)
Cl2—Cd1—N2^ii	91.50 (13)	C4—N2—Cd1^iv	111.2 (4)
O1—Cd1—N1	85.60 (17)	O1—C1—H1A	109.5
Cl2—Cd1—N1	89.58 (12)	O1—C1—H1B	109.5
N2^ii—Cd1—N1	176.29 (17)	H1A—C1—H1B	109.5
O1—Cd1—Cl1	81.44 (13)	O1—C1—H1C	109.5
Cl2—Cd1—Cl1	170.82 (6)	H1A—C1—H1C	109.5
N2^ii—Cd1—Cl1	87.50 (12)	H1B—C1—H1C	109.5
N1—Cd1—Cl1	90.87 (12)	N1^iii—C2—N1	111.4 (7)
O1—Cd1—Cl1^i	179.70 (14)	N1^iii—C2—H2	109.2
Cl2—Cd1—Cl1^i	90.84 (5)	N1—C2—H2	109.2
N2^ii—Cd1—Cl1^i	89.13 (12)	N2—C3—N2^iii	112.0 (7)
N1—Cd1—Cl1^i	94.41 (12)	N2—C3—H3	109.1
Cl1—Cd1—Cl1^i	98.26 (6)	N2^iii—C3—H3	109.1
C1—O1—Cd1	129.6 (4)	N1—C4—N2	110.4 (5)
C1—O1—H6	95 (6)	N1—C4—H4A	109.6
Cd1—O1—H6	134 (6)	N2—C4—H4A	109.6
Cd1—Cl1—Cd1^v	154.11 (7)	N1—C4—H4B	109.6
C5—N1—C4	109.0 (5)	N2—C4—H4B	109.6
C5—N1—C2	108.1 (4)	H4A—C4—H4B	108.1
C4—N1—C2	108.2 (4)	N1—C5—N2^iii	112.0 (5)
C5—N1—Cd1	114.5 (4)	N1—C5—H5A	109.2
C4—N1—Cd1	109.3 (3)	N2^iii—C5—H5A	109.2
C2—N1—Cd1	107.5 (4)	N1—C5—H5B	109.2
C3—N2—C5^iii	108.6 (4)	N2^iii—C5—H5B	109.2
C3—N2—C4	108.6 (4)	H5A—C5—H5B	107.9
C5^iii—N2—C4	108.4 (5)
Cl2—Cd1—O1—C1	−19.3 (6)	Cl1—Cd1—N1—C2	130.7 (2)
N2^ii—Cd1—O1—C1	72.2 (6)	Cl1^i—Cd1—N1—C2	−130.9 (2)
N1—Cd1—O1—C1	−108.9 (6)	C5—N1—C2—N1^iii	−58.6 (4)
Cl1—Cd1—O1—C1	159.5 (6)	C4—N1—C2—N1^iii	59.3 (4)
O1—Cd1—Cl1—Cd1^v	−150.0 (2)	Cd1—N1—C2—N1^iii	177.3 (3)
N2^ii—Cd1—Cl1—Cd1^v	−58.79 (19)	C5^iii—N2—C3—N2^iii	−58.6 (4)
N1—Cd1—Cl1—Cd1^v	124.54 (19)	C4—N2—C3—N2^iii	59.2 (4)
Cl1^i—Cd1—Cl1—Cd1^v	29.97 (13)	Cd1^iv—N2—C3—N2^iii	178.9 (3)
O1—Cd1—N1—C5	−70.7 (4)	C5—N1—C4—N2	58.0 (6)
Cl2—Cd1—N1—C5	−160.2 (4)	C2—N1—C4—N2	−59.3 (6)
Cl1—Cd1—N1—C5	10.6 (4)	Cd1—N1—C4—N2	−176.2 (4)
Cl1^i—Cd1—N1—C5	109.0 (4)	C3—N2—C4—N1	−58.4 (6)
O1—Cd1—N1—C4	166.7 (4)	C5^iii—N2—C4—N1	59.5 (6)
Cl2—Cd1—N1—C4	77.2 (4)	Cd1^iv—N2—C4—N1	−175.0 (4)
Cl1—Cd1—N1—C4	−112.0 (4)	C4—N1—C5—N2^iii	−58.4 (6)
Cl1^i—Cd1—N1—C4	−13.6 (4)	C2—N1—C5—N2^iii	59.1 (6)
O1—Cd1—N1—C2	49.4 (3)	Cd1—N1—C5—N2^iii	178.9 (4)
Cl2—Cd1—N1—C2	−40.1 (2)

Symmetry codes: (i) −y+1/4, x+1/4, −z+1/4; (ii) y−1/4, −x+3/4, z−1/4; (iii) −x+1, −y+1/2, z; (iv) −y+3/4, x+1/4, z+1/4; (v) y−1/4, −x+1/4, −z+1/4.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O1—H6···Cl2^vi	0.90 (1)	2.12 (1)	3.020 (5)	176 (8)

Symmetry code: (vi) x, y−1/2, −z.