catena-Poly[(E)-4,4′-(ethene-1,2-di­yl)dipyridinium [[bis­(thio­cyanato-κN)ferrate(II)]-di-μ-thio­cyanato-κ²N:S;κ²S:N]]

In the title compound, {(C₁₂H₁₂N₂)[Fe(NCS)₄]}_n, each Fe^II cation is coordinated by four N-bonded and two S-bonded thio­cyanate anions in an octa­hedral coordination mode. The asymmetric unit consists of one Fe^II cation, located on a center of inversion, as well as one protonated (E)-4,4′-(ethene-1,2-di­yl)dipyridinium dication and two thio­cyanate anions in general positions. The crystal structure consists of Fe—(NCS)₂—Fe chains extending along the a axis, in which two further thio­cyanate anions are only terminally bonded via nitro­gen. Non-coordinating (E)-4,4′-(ethene-1,2-di­yl)dipyrid­inium cations are found between the chains.

Key indicators

• Single-crystal X-ray study
• T = 293 K
• Mean [sigma](C-C) = 0.003 Å
• R factor = 0.029
• wR factor = 0.068
• Data-to-parameter ratio = 19.2

checkCIF/PLATON results

No syntax errors found



Alert level B
PLAT230_ALERT_2_B Hirshfeld Test Diff for    S1     --  C1      ..       9.77 su
PLAT230_ALERT_2_B Hirshfeld Test Diff for    S11    --  C11     ..       8.88 su

Alert level C
PLAT094_ALERT_2_C Ratio of Maximum / Minimum Residual Density ....       2.75
PLAT230_ALERT_2_C Hirshfeld Test Diff for    C22    --  C26     ..       5.45 su
PLAT913_ALERT_3_C Missing # of Very Strong Reflections in FCF ....          1
PLAT042_ALERT_1_C Calc. and Reported MoietyFormula Strings  Differ          ?
PLAT912_ALERT_4_C Missing # of FCF Reflections Above STh/L=  0.600          6

Alert level G
PLAT199_ALERT_1_G Check the Reported _cell_measurement_temperature        293 K
PLAT200_ALERT_1_G Check the Reported   _diffrn_ambient_temperature        293 K

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

   3 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   4 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
   0 ALERT type 5 Informative message, check

---

S1. Comment

Recently, we have shown that thermal decomposition reactions are an elegant route for the discovering and preparation of new ligand-deficient coordination polymers with defined magnetic properties (Wriedt & Näther, 2009a, 2009b; Wriedt et al., 2009a, 2009b). In our ongoing investigation on the synthesis, structures and properties of such compounds based on paramagnetic transition metal pseudo-halides and N-donor ligands, we have reacted iron(II) sulfate heptahydrate, potassium thiocyanate and E-1,2-di(4'-pyridyl)-ethene in water. In this reaction single crystals of the title compound were obtained, which were characterized by single crystal X-ray diffraction.

The title compound of composition [Fe(NCS)₄]_n-[E-1,2-di(4'-pyridinium)-ethene]_n (Fig. 1) represents an 1-D coordination polymer, in which each iron(II) cation is connected by four µ-1,3 bridging thiocyanato anions into chains that elongate in the direction of the crystallographic a-axis (Fig. 3). The octahedral coordination of each Fe cation is completed by two N-bonded thiocyanato anions. It must be noted that according to a search in the CCDC database (ConQuest Ver. 1.12 2010) such chains with transition metals are unknown (Allen, 2002).

Between the chains noncoordinating protonated (E)-4,4'-(ethene-1,2-diyl)dipyridinium cations are found, which are stacked in the direction of the crystallographic a-axis involving weak π-π-stacking interactions (Fig. 2). The FeN₄S₂ octahedron is slightly distorted with two long Fe—SCN distances of 2.6375 (5) Å and short Fe—NCS distances of 2.109 (2) and 2.116 (2) Å. The angles arround the metal atoms range between 87.23 (5) to 92.77 (5) and 180° (Tab. 1). The shortest intramolecular Fe···Fe distance amounts to 5.7360 (2) Å and the shortest intermolecular Fe···Fe distance amounts to 9.4919 (3) Å.

Related literature

For general background, see: Wriedt & Näther (2009a,b); Wriedt et al. (2009a,b). For a description of the Cambridge Structural Database, see: Allen (2002).

S2. Experimental

FeSO₄ × 7 H₂O and 1,2-di(4'-pyridyl)-ethene were obtained from Sigma Aldrich. KNCS was obtained from Alfa Aesar. 0.6 mmol (168.8 mg) FeSO₄ × 7 H₂O, 1.2 mmol (118.5 mg) KNCS and 0.15 mmol (28.2 mg) 1,2-di(4'-pyridyl)-ethene were reacted with 1 mL H₂O in a closed test-tube at 120°C for three days. On cooling green block-shaped single crystals of the title compound were obtained in a mixture with unknown phases.

S3. Refinement

All H atoms were located in difference map but were positioned with idealized geometry and were refined isotropic with U_eq(H) = 1.2 U_eq(C,N) of the parent atom using a riding model with C—H = 0.93 Å and N—H = 0.86 Å.

Computing details

Data collection: X-AREA (Stoe & Cie, 2008); cell refinement: X-AREA (Stoe & Cie, 2008); data reduction: X-AREA (Stoe & Cie, 2008); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: XP in SHELXTL (Sheldrick, 2008) and DIAMOND (Brandenburg, 1999); software used to prepare material for publication: XCIF in SHELXTL (Sheldrick, 2008).

Figures

	Fig. 1. : Crystal structure of the title compound with labelling and displacement ellipsoids drawn at the 30% probability level. Symmetry codes: i = -x + 1, -y + 1, -z + 1; ii = -x+1, -y, -z+1; iii = +x+1, +y, +z; iv = -x+2, -y+1, -z+1.
	Fig. 2. : Packing arrangement of the title compound with view approximately along the crystallographic a-axis.
	Fig. 3. : Packing arrangement of the title compound with view on the inorganic part Fe(NCS)2–(NCS)2–Fe(NCS)2 approximately along the crystallographic b-axis. The non-coordinated organic cations were omitted for clearity.

catena-Poly[(E)-4,4'-(ethene-1,2-diyl)dipyridinium [[bis(thiocyanato-κN)ferrate(II)]-di-µ-thiocyanato- κ²N:S;κ²S:N]]

Crystal data

(C12H12N2)[Fe(NCS)4]	F(000) = 480
Mr = 472.41	Dx = 1.585 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 16607 reflections
a = 5.7360 (2) Å	θ = 2–28°
b = 11.5093 (4) Å	µ = 1.20 mm^−1
c = 15.0971 (6) Å	T = 293 K
β = 96.562 (3)°	Block, green
V = 990.14 (6) Å^3	0.16 × 0.13 × 0.09 mm
Z = 2

Data collection

Stoe IPDS-2 diffractometer	2379 independent reflections
Radiation source: fine-focus sealed tube	2173 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.029
ω scans	θmax = 28.0°, θmin = 2.2°
Absorption correction: numerical (X-SHAPE and X-RED32; Stoe & Cie, 2008)	h = −7→7
Tmin = 0.826, Tmax = 0.895	k = −15→15
16607 measured reflections	l = −19→19

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)] = 0.029	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.068	H-atom parameters constrained
S = 1.09	w = 1/[σ^2(Fo^2) + (0.0291P)^2 + 0.4228P] where P = (Fo^2 + 2Fc^2)/3
2379 reflections	(Δ/σ)max = 0.001
124 parameters	Δρmax = 0.57 e Å^−3
0 restraints	Δρmin = −0.21 e Å^−3

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
Fe1	1.0000	0.0000	0.5000	0.03128 (10)
N2	0.3720 (3)	0.38242 (17)	0.30355 (13)	0.0541 (4)
H2	0.2544	0.3548	0.2697	0.065*
S1	0.26743 (7)	0.16763 (4)	0.57486 (3)	0.03779 (11)
C1	0.5284 (3)	0.12116 (14)	0.55629 (11)	0.0334 (3)
N1	0.7106 (3)	0.08926 (14)	0.54301 (11)	0.0430 (4)
S11	1.12064 (9)	−0.23939 (5)	0.76873 (3)	0.04587 (13)
C11	1.0730 (3)	−0.15568 (16)	0.68107 (12)	0.0371 (4)
N11	1.0414 (3)	−0.09600 (16)	0.61976 (11)	0.0490 (4)
C21	0.6655 (4)	0.52070 (17)	0.32949 (15)	0.0522 (5)
H21	0.7402	0.5868	0.3113	0.063*
C22	0.7421 (3)	0.46922 (17)	0.41067 (13)	0.0425 (4)
C23	0.6230 (4)	0.3727 (2)	0.43548 (15)	0.0571 (6)
H23	0.6699	0.3361	0.4895	0.069*
C24	0.4368 (4)	0.3310 (2)	0.38090 (17)	0.0620 (6)
H24	0.3550	0.2664	0.3979	0.074*
C25	0.4812 (4)	0.47453 (19)	0.27648 (15)	0.0555 (6)
H25	0.4323	0.5077	0.2213	0.067*
C26	0.9479 (4)	0.52118 (18)	0.46271 (14)	0.0494 (5)
H26	1.0085	0.5891	0.4410	0.059*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Fe1	0.02351 (16)	0.04009 (18)	0.03042 (17)	0.00428 (13)	0.00389 (12)	0.00449 (13)
N2	0.0395 (9)	0.0612 (11)	0.0580 (11)	−0.0001 (8)	−0.0097 (8)	−0.0187 (9)
S1	0.0277 (2)	0.0431 (2)	0.0430 (2)	0.00552 (16)	0.00590 (16)	−0.00552 (18)
C1	0.0305 (8)	0.0355 (8)	0.0338 (8)	−0.0023 (6)	0.0025 (6)	−0.0036 (6)
N1	0.0276 (7)	0.0470 (8)	0.0549 (9)	0.0011 (6)	0.0061 (6)	−0.0103 (7)
S11	0.0449 (3)	0.0521 (3)	0.0399 (2)	0.0004 (2)	0.00183 (19)	0.0133 (2)
C11	0.0297 (8)	0.0441 (9)	0.0372 (9)	−0.0029 (7)	0.0025 (6)	0.0003 (7)
N11	0.0494 (9)	0.0565 (10)	0.0395 (8)	−0.0047 (8)	−0.0020 (7)	0.0121 (7)
C21	0.0602 (13)	0.0386 (10)	0.0549 (12)	−0.0038 (9)	−0.0060 (10)	0.0019 (8)
C22	0.0389 (9)	0.0434 (10)	0.0435 (10)	−0.0004 (7)	−0.0029 (8)	−0.0071 (8)
C23	0.0644 (14)	0.0628 (13)	0.0417 (10)	−0.0140 (11)	−0.0043 (10)	0.0063 (9)
C24	0.0612 (14)	0.0671 (14)	0.0573 (13)	−0.0247 (12)	0.0048 (11)	−0.0017 (11)
C25	0.0639 (14)	0.0466 (11)	0.0510 (12)	0.0118 (10)	−0.0146 (10)	−0.0034 (9)
C26	0.0510 (11)	0.0445 (10)	0.0504 (11)	−0.0050 (8)	−0.0048 (9)	0.0022 (8)

Geometric parameters (Å, º)

Fe1—N11	2.1090 (16)	C11—N11	1.150 (2)
Fe1—N11^i	2.1090 (16)	C21—C25	1.359 (3)
Fe1—N1	2.1165 (15)	C21—C22	1.387 (3)
Fe1—N1^i	2.1165 (15)	C21—H21	0.9300
Fe1—S1^ii	2.6375 (5)	C22—C23	1.378 (3)
Fe1—S1^iii	2.6375 (5)	C22—C26	1.469 (3)
N2—C25	1.320 (3)	C23—C24	1.360 (3)
N2—C24	1.324 (3)	C23—H23	0.9300
N2—H2	0.8600	C24—H24	0.9300
S1—C1	1.6437 (17)	C25—H25	0.9300
S1—Fe1^iv	2.6375 (5)	C26—C26^v	1.307 (4)
C1—N1	1.147 (2)	C26—H26	0.9300
S11—C11	1.6345 (19)
N11—Fe1—N11^i	180.0	N11—C11—S11	179.25 (19)
N11—Fe1—N1	90.39 (7)	C11—N11—Fe1	174.08 (17)
N11^i—Fe1—N1	89.61 (7)	C25—C21—C22	120.0 (2)
N11—Fe1—N1^i	89.61 (7)	C25—C21—H21	120.0
N11^i—Fe1—N1^i	90.39 (7)	C22—C21—H21	120.0
N1—Fe1—N1^i	180.0 (9)	C23—C22—C21	117.88 (18)
N11—Fe1—S1^ii	89.26 (5)	C23—C22—C26	125.17 (19)
N11^i—Fe1—S1^ii	90.74 (5)	C21—C22—C26	116.93 (19)
N1—Fe1—S1^ii	92.77 (4)	C24—C23—C22	120.0 (2)
N1^i—Fe1—S1^ii	87.23 (4)	C24—C23—H23	120.0
N11—Fe1—S1^iii	90.74 (5)	C22—C23—H23	120.0
N11^i—Fe1—S1^iii	89.26 (5)	N2—C24—C23	119.9 (2)
N1—Fe1—S1^iii	87.23 (4)	N2—C24—H24	120.1
N1^i—Fe1—S1^iii	92.77 (4)	C23—C24—H24	120.1
S1^ii—Fe1—S1^iii	180.0	N2—C25—C21	119.8 (2)
C25—N2—C24	122.48 (18)	N2—C25—H25	120.1
C25—N2—H2	118.8	C21—C25—H25	120.1
C24—N2—H2	118.8	C26^v—C26—C22	124.7 (3)
C1—S1—Fe1^iv	100.68 (6)	C26^v—C26—H26	117.6
N1—C1—S1	179.60 (19)	C22—C26—H26	117.6
C1—N1—Fe1	166.29 (15)

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