catena-Poly[ammonium (cadmium-tri-μ-thio­cyanato-κ⁴S:N;κ²N:S)–1,4,10,13,16-hexa­oxa­cyclo­octa­decane (1/1)]

In the title compound, {(NH₄)[Cd(NCS)₃]·C₁₂H₂₄O₆}_n, the Cd²⁺ ion, the ammonium cation, one of the SCN⁻ ligands and the macrocycle are located on mirror planes. The thiocyanate anions act as bridging ligands between the Cd^II ions, leading to a polymeric chain arrangement extending along [001] around a twofold screw axis. The ammonium ions are contained within the bowl of the macrocycle via extensive N—H...O hydrogen bonding.

Key indicators

• Single-crystal X-ray study
• T = 293 K
• Mean [sigma](C-C) = 0.004 Å
• R factor = 0.013
• wR factor = 0.034
• Data-to-parameter ratio = 16.1

checkCIF/PLATON results

No syntax errors found



Alert level A
PLAT900_ALERT_1_A No Matching Reflection File Found ..............          !

Alert level C
PLAT042_ALERT_1_C Calc. and Reported MoietyFormula Strings  Differ          ?
PLAT230_ALERT_2_C Hirshfeld Test Diff for    S1     --  C1      ..        5.5 su
PLAT230_ALERT_2_C Hirshfeld Test Diff for    S2     --  C2      ..        6.9 su
PLAT242_ALERT_2_C Check Low       Ueq as Compared to Neighbors for         O2
PLAT242_ALERT_2_C Check Low       Ueq as Compared to Neighbors for         O3
PLAT420_ALERT_2_C D-H Without Acceptor       N3     -   H3C    ...          ?

Alert level G
FORMU01_ALERT_1_G  There is a discrepancy between the atom counts in the
            _chemical_formula_sum and _chemical_formula_moiety. This is
            usually due to the moiety formula being in the wrong format.
            Atom count from _chemical_formula_sum:   C15 H28 Cd1 N4 O6 S3
            Atom count from _chemical_formula_moiety:C15 H28 Cd1 N3 O6 S3
REFLT03_ALERT_4_G Please check that the estimate of the number of Friedel pairs is
            correct. If it is not, please give the correct count in the
            _publ_section_exptl_refinement section of the submitted CIF.
           From the CIF: _diffrn_reflns_theta_max           25.99
           From the CIF: _reflns_number_total               2483
           Count of symmetry unique reflns         1315
           Completeness (_total/calc)            188.82%
           TEST3: Check Friedels for noncentro structure
           Estimate of Friedel pairs measured      1168
           Fraction of Friedel pairs measured     0.888
           Are heavy atom types Z>Si present        yes
PLAT002_ALERT_2_G Number of Distance or Angle Restraints on AtSite          4
PLAT003_ALERT_2_G Number of Uiso or Uij Restrained Atom Sites ....          2
PLAT004_ALERT_5_G Info: Polymeric Structure Found with Dimension .          1
PLAT005_ALERT_5_G No _iucr_refine_instructions_details in CIF ....          ?
PLAT199_ALERT_1_G Check the Reported _cell_measurement_temperature        293 K
PLAT200_ALERT_1_G Check the Reported   _diffrn_ambient_temperature        293 K
PLAT232_ALERT_2_G Hirshfeld Test Diff (M-X)  Cd1    --  S2      ..        9.0 su
PLAT860_ALERT_3_G Note: Number of Least-Squares Restraints .......          5

   1 ALERT level A = Most likely a serious problem - resolve or explain
   0 ALERT level B = A potentially serious problem, consider carefully
   6 ALERT level C = Check. Ensure it is not caused by an omission or oversight
  10 ALERT level G = General information/check it is not something unexpected

   5 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   8 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
   2 ALERT type 5 Informative message, check

---

S1. Comment

Thiocyanate anion is known to bind the cadmium ion in different modes: terminal N-bound, terminal S-bound (Nfor et al. 2006) or N:S-bridging ligand. As a bridging ligand, it may give rise to a singly bridged (Bose et al. 2004), doubly bridged or triply bridged (Chen et al. 2002) cadmium complex. Cadmium(II) complexes with thiones possess a variety of structures ranging from four- to six-coordinate species with tetrahedral and octahedral environments for the CdII atom, respectively. In some cases, these units further aggregate to form polymeric structures (Lobana et al., 2008). The interest in cadmium compounds was provoked by their luminescent properties (Zheng et al., 2004), magnetic and catalytic properties (Gu et al., 2011) and non-linear optical properties (Rajesh et al., 2004). Herein, we report the synthesis and crystal structure of cadmium complex, the title compound, (I), coordinated by nitrogen and sulfur.

A perspective view of compound (I) with the atom-numbering scheme is shown in Fig. 1. The Cd^II ions are bridged by a pair of thiocyanate N:S-bridging ligands around a twofold screw axis. Two trans-N:S-bridging thiocyanates complete the N3S3 donor set around the Cd atom. The thiocyanate anions function as bridging ligands between the Cd^II centres, leading to a chain-like arrangement expanding along [001]. The thiocyanate ligands are almost linear.

The Cd—S bond lengths are 2.747 (4) and 2.728 (4) Å. These are in agreement with those reported for related compounds (Nawaz et al., 2010). The bond distances of N-bonded NCS groups [Cd—N(NCS) 2.347 (4) and 2.375 (4) Å]. These values agree well with those observed in [Cd(NCS)₂(1-vinylimidazole)₄] (Gu et al., 2011). The values of the bond angles around cadmium are close to those expected for a regular octahedral geometry, the largest angular deviation being observed for the N2 –Cd1- N1 angle [93.34 (5)°].

The parameters of hydrogen bonds are given in the Table 1. The thiocyanate anions function as bridging ligands between the CdII centres, leading to a chain-like arrangement are parallel to one another and expanding along [001]. The ammonium molecules also participate in extensive N—H···O hydrogen bonding, as shown in Fig. 2.

Related literature

For a singly bridged cadmium thiocyanate complex, see: Bose et al. (2004). For a triply bridged cadmium thiocyanate complex, see: Chen et al. (2002). For an S-bound terminal thiocyanate cadmium complex, see: Nfor et al. (2006). For polymeric structures of complexes, see: Lobana et al. (2008). For the structures and properties of cadmium compounds, see: Gu et al. (2011); Zheng et al. (2004); Rajesh et al. (2004). For bond distances and angles, see: Nawaz et al. (2010).

S2. Experimental

The mixture of 18-crown-6 (C₁₂H₂₄O₆), CdCl₂ and NH₄SCN (molar ratio 1:1:3) were thoroughly dissolved in double distilled water and stirred for 5 h to obtain a homogeneous mixture. The colorless single crystals were obtained after the filtrate had been allowed to stand at room temperature for three weeks.

S3. Refinement

Carbon H atoms were placed geometrically (C—H = 0.97 Å) and treated as riding with U_iso(H) = 1.2U_eq(C). Water H atoms were located in calculated positions and treated in the subsequent refinement as riding atoms, with N—H = 0.89 Å and U_iso(H) = 1.5U_eq(O).

Computing details

Data collection: APEX2 (Bruker, 2004); cell refinement: APEX2 and SAINT (Bruker, 2004); data reduction: SAINT and XPREP (Bruker, 2004); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 (Farrugia, 1997) and Mercury (Macrae et al., 2006); software used to prepare material for publication: WinGX (Farrugia, 1999), PLATON (Spek, 2009) and publCIF (Westrip, 2010)..

Figures

	Fig. 1. The molecular structure of the title compound with the atom numbering scheme and 50% probability displacement ellipsoids. H atoms are presented as a small spheres of arbitrary radius.
	Fig. 2. Molecular packing, viewed down c axis.

catena-Poly[ammonium (cadmium-tri-µ-thiocyanato-κ⁴S:N;κ²N:S)– 1,4,10,13,16-hexaoxacyclooctadecane (1/1)]

Crystal data

(NH4)[Cd(NCS)3]·C12H24O6	F(000) = 1160
Mr = 568.99	Dx = 1.559 Mg m^−3
Orthorhombic, Cmc21	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: C 2c -2	Cell parameters from 5280 reflections
a = 14.7568 (6) Å	θ = 2.6–26.7°
b = 15.4378 (6) Å	µ = 1.20 mm^−1
c = 10.6383 (5) Å	T = 293 K
V = 2423.54 (18) Å^3	Block, colourless
Z = 4	0.30 × 0.25 × 0.20 mm

Data collection

Bruker Kappa APEXII CCD diffractometer	2483 independent reflections
Radiation source: fine-focus sealed tube	2445 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.019
ω and ϕ scan	θmax = 26.0°, θmin = 2.6°
Absorption correction: multi-scan (SADABS; Sheldrick, 2004)	h = −18→18
Tmin = 0.716, Tmax = 0.796	k = −19→19
11323 measured reflections	l = −13→13

Refinement

Refinement on F^2	Hydrogen site location: inferred from neighbouring sites
Least-squares matrix: full	H atoms treated by a mixture of independent and constrained refinement
R[F^2 > 2σ(F^2)] = 0.013	w = 1/[σ^2(Fo^2) + (0.020P)^2 + 0.1189P] where P = (Fo^2 + 2Fc^2)/3
wR(F^2) = 0.034	(Δ/σ)max = 0.003
S = 1.09	Δρmax = 0.20 e Å^−3
2483 reflections	Δρmin = −0.36 e Å^−3
154 parameters	Extinction correction: SHELXL97 (Sheldrick, 2008), Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
5 restraints	Extinction coefficient: 0.0058 (2)
Primary atom site location: structure-invariant direct methods	Absolute structure: Flack (1983), 7607 Friedel pairs
Secondary atom site location: difference Fourier map	Absolute structure parameter: 0.005 (15)

Special details

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds 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 > 2sigma(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
C1	0.61632 (10)	1.06679 (10)	0.72484 (14)	0.0337 (3)
C2	0.5000	0.87710 (13)	0.7689 (2)	0.0339 (4)
C3	0.9203 (2)	0.92459 (19)	1.0905 (3)	0.0905 (9)
H3A	0.9205	0.9648	1.1606	0.109*
H3B	0.9177	0.8662	1.1240	0.109*
C4	0.83962 (17)	0.94095 (17)	1.0097 (4)	0.0885 (10)
H4A	0.7851	0.9382	1.0604	0.106*
H4B	0.8436	0.9985	0.9736	0.106*
C5	0.76317 (15)	0.89705 (16)	0.8297 (3)	0.0811 (8)
H5A	0.7709	0.9545	0.7945	0.097*
H5B	0.7062	0.8959	0.8751	0.097*
C6	0.76078 (16)	0.83248 (19)	0.7272 (3)	0.0845 (9)
H6A	0.7596	0.7745	0.7621	0.101*
H6B	0.7065	0.8405	0.6770	0.101*
C7	0.8399 (2)	0.78484 (18)	0.5498 (3)	0.0923 (10)
H7A	0.7847	0.7908	0.5010	0.111*
H7B	0.8430	0.7259	0.5811	0.111*
C8	0.9199 (2)	0.80317 (17)	0.4690 (2)	0.0921 (10)
H8A	0.9185	0.7664	0.3952	0.110*
H8B	0.9186	0.8631	0.4415	0.110*
N1	0.60575 (11)	1.03455 (9)	0.62874 (16)	0.0496 (4)
N2	0.5000	0.91401 (12)	0.86273 (19)	0.0454 (5)
O1	1.0000	0.93509 (16)	1.0190 (3)	0.0776 (8)
O2	0.83461 (10)	0.87912 (10)	0.91271 (18)	0.0692 (4)
O3	0.83851 (11)	0.84297 (10)	0.65100 (18)	0.0703 (4)
O4	1.0000	0.78737 (15)	0.5382 (2)	0.0742 (7)
N3	1.0000	0.80499 (15)	0.8089 (2)	0.0476 (5)
Cd1	0.5000	0.971763 (8)	0.494929 (17)	0.03587 (6)
S1	0.63319 (3)	1.11267 (3)	0.86256 (4)	0.04216 (10)
S2	0.5000	0.82400 (4)	0.63561 (5)	0.04418 (14)
H3E	0.9497 (12)	0.8303 (18)	0.836 (3)	0.096 (10)*
H3C	1.0000	0.7522 (12)	0.844 (3)	0.076 (11)*
H3D	1.0000	0.817 (4)	0.7264 (16)	0.13 (2)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.0298 (7)	0.0389 (8)	0.0324 (7)	−0.0048 (6)	0.0026 (5)	0.0036 (6)
C2	0.0389 (11)	0.0289 (9)	0.0339 (12)	0.000	0.000	0.0067 (9)
C3	0.094 (2)	0.0801 (18)	0.097 (2)	0.0021 (14)	0.0308 (17)	−0.0239 (16)
C4	0.0702 (14)	0.0716 (13)	0.124 (3)	0.0100 (11)	0.035 (2)	−0.025 (2)
C5	0.0397 (11)	0.0731 (14)	0.130 (3)	0.0164 (10)	0.0147 (13)	0.0227 (16)
C6	0.0411 (11)	0.0820 (16)	0.130 (3)	−0.0007 (11)	−0.0205 (13)	0.0190 (17)
C7	0.097 (2)	0.0739 (16)	0.106 (2)	0.0214 (15)	−0.0549 (19)	−0.0204 (15)
C8	0.149 (3)	0.0678 (14)	0.0592 (19)	0.0343 (17)	−0.0297 (17)	−0.0138 (11)
N1	0.0539 (9)	0.0612 (9)	0.0337 (8)	−0.0148 (6)	0.0025 (7)	−0.0026 (7)
N2	0.0682 (13)	0.0370 (9)	0.0309 (9)	0.000	0.000	0.0015 (9)
O1	0.0683 (13)	0.0780 (14)	0.086 (2)	0.000	0.000	−0.0160 (14)
O2	0.0498 (8)	0.0570 (8)	0.1009 (13)	0.0127 (6)	0.0144 (8)	0.0011 (8)
O3	0.0628 (9)	0.0609 (8)	0.0872 (12)	0.0032 (7)	−0.0184 (8)	0.0017 (8)
O4	0.0963 (18)	0.0630 (13)	0.0632 (14)	0.000	0.000	−0.0012 (10)
N3	0.0385 (12)	0.0456 (12)	0.0587 (15)	0.000	0.000	0.0006 (10)
Cd1	0.04531 (9)	0.03708 (8)	0.02522 (8)	0.000	0.000	−0.00054 (7)
S1	0.0465 (2)	0.0454 (2)	0.0346 (2)	−0.00946 (16)	0.00023 (17)	−0.00481 (17)
S2	0.0649 (4)	0.0355 (3)	0.0322 (3)	0.000	0.000	−0.0024 (2)

Geometric parameters (Å, º)

C1—N1	1.148 (2)	C7—C8	1.488 (4)
C1—S1	1.6463 (15)	C7—H7A	0.9700
C2—N2	1.149 (3)	C7—H7B	0.9700
C2—S2	1.638 (2)	C8—O4	1.413 (3)
C3—O1	1.410 (3)	C8—H8A	0.9700
C3—C4	1.490 (5)	C8—H8B	0.9700
C3—H3A	0.9700	N1—Cd1	2.3241 (16)
C3—H3B	0.9700	N2—Cd1^i	2.256 (2)
C4—O2	1.408 (4)	O1—C3^ii	1.410 (3)
C4—H4A	0.9700	O4—C8^ii	1.413 (3)
C4—H4B	0.9700	N3—H3E	0.888 (10)
C5—O2	1.403 (3)	N3—H3C	0.897 (10)
C5—C6	1.478 (4)	N3—H3D	0.898 (10)
C5—H5A	0.9700	Cd1—N2^iii	2.256 (2)
C5—H5B	0.9700	Cd1—N1^iv	2.3241 (16)
C6—O3	1.414 (3)	Cd1—S2	2.7283 (6)
C6—H6A	0.9700	Cd1—S1^iii	2.7468 (4)
C6—H6B	0.9700	Cd1—S1^v	2.7468 (4)
C7—O3	1.402 (3)	S1—Cd1^i	2.7468 (4)
N1—C1—S1	179.10 (16)	O4—C8—C7	109.28 (19)
N2—C2—S2	179.69 (19)	O4—C8—H8A	109.8
O1—C3—C4	109.6 (3)	C7—C8—H8A	109.8
O1—C3—H3A	109.7	O4—C8—H8B	109.8
C4—C3—H3A	109.7	C7—C8—H8B	109.8
O1—C3—H3B	109.7	H8A—C8—H8B	108.3
C4—C3—H3B	109.7	C1—N1—Cd1	144.86 (14)
H3A—C3—H3B	108.2	C2—N2—Cd1^i	158.30 (17)
O2—C4—C3	110.48 (19)	C3^ii—O1—C3	113.1 (4)
O2—C4—H4A	109.6	C5—O2—C4	111.54 (19)
C3—C4—H4A	109.6	C7—O3—C6	112.2 (2)
O2—C4—H4B	109.6	C8—O4—C8^ii	113.4 (3)
C3—C4—H4B	109.6	H3E—N3—H3C	105 (2)
H4A—C4—H4B	108.1	H3E—N3—H3D	103 (3)
O2—C5—C6	110.46 (18)	H3C—N3—H3D	127 (5)
O2—C5—H5A	109.6	N2^iii—Cd1—N1	93.20 (5)
C6—C5—H5A	109.6	N2^iii—Cd1—N1^iv	93.20 (5)
O2—C5—H5B	109.6	N1—Cd1—N1^iv	84.36 (8)
C6—C5—H5B	109.6	N2^iii—Cd1—S2	174.69 (5)
H5A—C5—H5B	108.1	N1—Cd1—S2	90.73 (4)
O3—C6—C5	109.0 (2)	N1^iv—Cd1—S2	90.73 (4)
O3—C6—H6A	109.9	N2^iii—Cd1—S1^iii	92.94 (4)
C5—C6—H6A	109.9	N1—Cd1—S1^iii	172.93 (4)
O3—C6—H6B	109.9	N1^iv—Cd1—S1^iii	91.80 (4)
C5—C6—H6B	109.9	S2—Cd1—S1^iii	83.363 (12)
H6A—C6—H6B	108.3	N2^iii—Cd1—S1^v	92.94 (4)
O3—C7—C8	109.5 (2)	N1—Cd1—S1^v	91.80 (4)
O3—C7—H7A	109.8	N1^iv—Cd1—S1^v	172.93 (4)
C8—C7—H7A	109.8	S2—Cd1—S1^v	83.363 (12)
O3—C7—H7B	109.8	S1^iii—Cd1—S1^v	91.373 (19)
C8—C7—H7B	109.8	C1—S1—Cd1^i	98.27 (5)
H7A—C7—H7B	108.2	C2—S2—Cd1	93.24 (7)
O1—C3—C4—O2	63.7 (3)	C1—N1—Cd1—N2^iii	107.3 (2)
O2—C5—C6—O3	−67.4 (2)	C1—N1—Cd1—N1^iv	14.4 (2)
O3—C7—C8—O4	64.2 (3)	C1—N1—Cd1—S2	−76.3 (2)
C4—C3—O1—C3^ii	177.23 (15)	C1—N1—Cd1—S1^v	−159.7 (2)
C6—C5—O2—C4	178.6 (2)	N1—Cd1—S2—C2	42.19 (4)
C3—C4—O2—C5	−175.5 (2)	N1^iv—Cd1—S2—C2	−42.19 (4)
C8—C7—O3—C6	176.27 (19)	S1^iii—Cd1—S2—C2	−133.916 (9)
C5—C6—O3—C7	−178.75 (19)	S1^v—Cd1—S2—C2	133.916 (9)
C7—C8—O4—C8^ii	−179.93 (16)

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

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N3—H3E···O2	0.89 (1)	2.03 (1)	2.9130 (19)	174 (3)
N3—H3D···O4	0.90 (1)	2.05 (3)	2.892 (3)	155 (5)