Poly[1,4-bis­(ammonio­meth­yl)cyclo­hexane [di-μ-iodido-diiodido­plumbate(II)]]

The title compound, {(C₈H₂₀N₂)[PbI₄]}_n, is an inorganic–organic hybrid. The structure is composed of alternate layers of two-dimensional corner-sharing PbI₆ octa­hedra ( symmetry) and 1,4-bis­(ammonio­meth­yl)cyclo­hexane cations ( symmetry) extending parallel to the bc plane. The cations inter­act with the inorganic layer via N—H...I hydrogen bonding in the right-angled halogen sub-type of the terminal halide hydrogen-bonding motif.

Key indicators

• Single-crystal X-ray study
• T = 173 K
• Mean [sigma](C-C) = 0.010 Å
• R factor = 0.033
• wR factor = 0.093
• Data-to-parameter ratio = 32.3

checkCIF/PLATON results

No syntax errors found



Alert level B
PLAT919_ALERT_3_B Reflection(s) # Likely Affected by the Beamstop           1

Alert level C
PLAT232_ALERT_2_C Hirshfeld Test Diff (M-X)  Pb1    --  I1      ..       5.52 su
PLAT342_ALERT_3_C Low Bond Precision on  C-C Bonds (x 1000) Ang ..         10
PLAT972_ALERT_2_C Large Calcd. Non-Metal Negative Residual Density      -1.90 eA-3
PLAT972_ALERT_2_C Large Calcd. Non-Metal Negative Residual Density      -1.73 eA-3
PLAT972_ALERT_2_C Large Calcd. Non-Metal Negative Residual Density      -1.54 eA-3
PLAT480_ALERT_4_C Long H...A H-Bond Reported H1E    ..  I2      ..       3.12 Ang.

Alert level G
PLAT764_ALERT_4_G Overcomplete CIF Bond List Detected (Rep/Expd) .       1.18 Ratio

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

   0 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
   2 ALERT type 3 Indicator that the structure quality may be low
   2 ALERT type 4 Improvement, methodology, query or suggestion
   0 ALERT type 5 Informative message, check

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S1. Comment

The title structure (Fig. 1) is one of three 2-dimensional hybrid structures that we have synthesized encorporating this diammonium cation. The structures differ in terms of their halogen ligands, which include iodide (presented here), the bromide (Rayner & Billing, 2010b) and chloride (Rayner & Billing, 2010a). The bromide and iodide hybrids are isotypic and crystallize in the monoclinic system with space group P2₁/c while the chloride hybrid crystallizes in the orthorhombic, Pnma system.

In the structure of the title compound the lead atoms in the PbI₆ octahedra occupy inversion centers, giving the octahedra 1 symmetry. The PbI₆ octahedra share corners to form layers extending parallel to the bc plane. Octahedra from alternate layers are eclipsed relative to one another (Fig. 2). In all three structures only the trans form of the cation has been observed, giving the cation 1 symmetry (Fig. 3). The ammonium cations interact with the inorganic layer via N—H···X (X = Br, I and Cl) hydrogen bonding in the right-angled halogen subtype of the terminal halide hydrogen bonding motif (Mitzi, 1999). Billing & Lemmerer (2006) reported a series of inorganic-organic hybrids encorpoating cyclic ammonium cations, however no diammonium cations were synthesized.

Related literature

For other examples of inorganic–organic hybrid structures encorporating cyclic ammonium cations, see: Billing & Lemmerer (2006). For hydrogen-bonding nomenclature for inorganic–organic hybrids, see: Mitzi (1999). For the related chloridoplumbate(II), see: Rayner & Billing (2010a) and for the isotypic bromidoplumbate(II), see: Rayner & Billing (2010b).

S2. Experimental

A mixture of 0.050 g (0.11 mmol) PbI₂ and 0.017 g (0.17 mmol) 1,4-bis-(aminomethyl)-cyclohexane (mixture of isomers) was dissolved in 5 ml HI at 383 K and slow cooled at a rate of 0.069 K/min to yield yellow, plate-shaped single crystals suitable for X-ray analysis.

S3. Refinement

The H atoms on the diammonium cation were refined using a riding-model, with C—H = 0.99 Å, N—H = 0.91 Å and with U_iso(H)=1.2U_eq(C) or 1.5U_eq(N). The highest residual electron density peak (1.76 e Å-3) was 0.955Å from Pb1.

Computing details

Data collection: APEX2 (Bruker, 2005); cell refinement: SAINT (Bruker, 2005); data reduction: SAINT (Bruker, 2005); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997) and DIAMOND (Brandenburg, 1999); software used to prepare material for publication: WinGX (Farrugia, 1999) and PLATON (Spek, 2009).

Figures

	Fig. 1. The extended asymmetric unit of the title compound with atom labels. Displacement ellipsoids were drawn at the 50% probability level. Symmetry codes: (a) -x, -1/2+y, 3/2-z (b) -x, 1-y, 1-z (c) x, 3/2-y, -1/2+z (d) 1-x, 1-y, -z.
	Fig. 2. Packing diagram viewed along the a axis. Hydrogen bonds are drawn as dashed red lines.
	Fig. 3. Packing diagram viewed along the b axis. Hydrogen bonds are drawn as dashed red lines.

Poly[1,4-bis(ammoniomethyl)cyclohexane [di-µ-iodido-diiodidoplumbate(II)]]

Crystal data

(C8H20N2)[PbI4]	F(000) = 752
Mr = 859.05	Dx = 3.043 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 6011 reflections
a = 12.2793 (17) Å	θ = 3.0–28.2°
b = 8.7413 (12) Å	µ = 15.56 mm^−1
c = 8.7829 (13) Å	T = 173 K
β = 95.922 (3)°	Plate, orange
V = 937.7 (2) Å^3	0.36 × 0.26 × 0.08 mm
Z = 2

Data collection

Bruker APEXII CCD area-detector diffractometer	2264 independent reflections
Radiation source: fine-focus sealed tube	2085 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.080
φ and ω scans	θmax = 28.0°, θmin = 1.7°
Absorption correction: integration (XPREP; Bruker, 2005)	h = −16→16
Tmin = 0.043, Tmax = 0.288	k = −11→10
5435 measured reflections	l = −9→11

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)] = 0.033	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.093	H-atom parameters constrained
S = 1.08	w = 1/[σ^2(Fo^2) + (0.0511P)^2 + 1.0393P] where P = (Fo^2 + 2Fc^2)/3
2264 reflections	(Δ/σ)max = 0.009
70 parameters	Δρmax = 1.76 e Å^−3
0 restraints	Δρmin = −2.79 e Å^−3

Special details

Experimental. Numerical intergration absorption corrections based on indexed crystal faces were applied using the XPREP routine (Bruker, 2005)

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 > 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
C1	0.2676 (6)	0.0434 (9)	−0.4667 (9)	0.0333 (15)
H1A	0.2773	0.1355	−0.4011	0.040*
H1B	0.2216	0.0719	−0.5617	0.040*
C2	0.3794 (6)	−0.0123 (8)	−0.5065 (8)	0.0273 (15)
H2	0.3672	−0.0991	−0.5804	0.033*
C3	0.4366 (6)	0.1194 (9)	−0.5867 (8)	0.0306 (14)
H3A	0.3890	0.1529	−0.6785	0.037*
H3B	0.4475	0.2077	−0.5162	0.037*
C4	0.4542 (6)	−0.0685 (9)	−0.3667 (8)	0.0299 (14)
H4A	0.4654	0.0151	−0.2906	0.036*
H4B	0.4187	−0.1550	−0.3183	0.036*
N1	0.2111 (5)	−0.0797 (7)	−0.3841 (6)	0.0274 (12)
H1C	0.1450	−0.0448	−0.3610	0.041*
H1D	0.2531	−0.1050	−0.2962	0.041*
H1E	0.2012	−0.1637	−0.4451	0.041*
I1	−0.26315 (4)	0.02539 (5)	−0.02301 (5)	0.02714 (13)
I2	0.00031 (4)	0.18981 (5)	−0.30914 (4)	0.02605 (14)
Pb1	0.0000	0.0000	0.0000	0.01915 (11)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.036 (4)	0.026 (3)	0.039 (4)	0.002 (3)	0.005 (3)	0.004 (3)
C2	0.027 (4)	0.027 (4)	0.028 (3)	−0.003 (3)	0.003 (3)	−0.001 (2)
C3	0.028 (3)	0.030 (3)	0.034 (3)	0.000 (3)	0.001 (3)	0.010 (3)
C4	0.023 (3)	0.035 (4)	0.031 (3)	−0.003 (3)	0.002 (3)	0.008 (3)
N1	0.025 (3)	0.031 (3)	0.026 (3)	−0.004 (2)	0.003 (2)	−0.001 (2)
I1	0.0262 (2)	0.0257 (2)	0.0288 (2)	−0.00327 (17)	−0.00048 (18)	−0.00028 (16)
I2	0.0356 (2)	0.0218 (2)	0.0212 (2)	0.00569 (16)	0.00513 (16)	0.00779 (14)
Pb1	0.02537 (19)	0.01599 (17)	0.01602 (16)	0.00087 (11)	0.00182 (12)	0.00032 (10)

Geometric parameters (Å, º)

C1—N1	1.507 (9)	C4—H4B	0.9900
C1—C2	1.530 (10)	N1—H1C	0.9100
C1—H1A	0.9900	N1—H1D	0.9100
C1—H1B	0.9900	N1—H1E	0.9100
C2—C4	1.536 (10)	I1—Pb1	3.2243 (6)
C2—C3	1.554 (9)	I2—Pb1	3.1824 (5)
C2—H2	1.0000	I2—Pb1^ii	3.1875 (5)
C3—C4^i	1.510 (10)	Pb1—I2^iii	3.1824 (5)
C3—H3A	0.9900	Pb1—I2^iv	3.1875 (5)
C3—H3B	0.9900	Pb1—I2^v	3.1875 (5)
C4—C3^i	1.510 (10)	Pb1—I1^iii	3.2243 (6)
C4—H4A	0.9900
N1—C1—C2	110.5 (6)	H4A—C4—H4B	108.1
N1—C1—H1A	109.5	C1—N1—H1C	109.5
C2—C1—H1A	109.5	C1—N1—H1D	109.5
N1—C1—H1B	109.5	H1C—N1—H1D	109.5
C2—C1—H1B	109.5	C1—N1—H1E	109.5
H1A—C1—H1B	108.1	H1C—N1—H1E	109.5
C4—C2—C1	113.3 (6)	H1D—N1—H1E	109.5
C4—C2—C3	109.8 (6)	Pb1—I2—Pb1^ii	153.144 (15)
C1—C2—C3	109.0 (6)	I2—Pb1—I2^iii	180.00 (2)
C4—C2—H2	108.2	I2—Pb1—I2^iv	90.294 (11)
C1—C2—H2	108.2	I2^iii—Pb1—I2^iv	89.706 (11)
C3—C2—H2	108.2	I2—Pb1—I2^v	89.706 (11)
C4^i—C3—C2	111.1 (6)	I2^iii—Pb1—I2^v	90.294 (11)
C4^i—C3—H3A	109.4	I2^iv—Pb1—I2^v	180.0
C2—C3—H3A	109.4	I2—Pb1—I1^iii	89.999 (12)
C4^i—C3—H3B	109.4	I2^iii—Pb1—I1^iii	90.001 (12)
C2—C3—H3B	109.4	I2^iv—Pb1—I1^iii	94.518 (12)
H3A—C3—H3B	108.0	I2^v—Pb1—I1^iii	85.482 (12)
C3^i—C4—C2	110.6 (6)	I2—Pb1—I1	90.001 (12)
C3^i—C4—H4A	109.5	I2^iii—Pb1—I1	89.999 (12)
C2—C4—H4A	109.5	I2^iv—Pb1—I1	85.482 (12)
C3^i—C4—H4B	109.5	I2^v—Pb1—I1	94.518 (12)
C2—C4—H4B	109.5	I1^iii—Pb1—I1	180.0
N1—C1—C2—C4	−55.7 (8)	C3—C2—C4—C3^i	−57.0 (9)
N1—C1—C2—C3	−178.2 (6)	Pb1^ii—I2—Pb1—I2^iv	−0.35 (4)
C4—C2—C3—C4^i	57.3 (8)	Pb1^ii—I2—Pb1—I2^v	179.65 (4)
C1—C2—C3—C4^i	−178.1 (6)	Pb1^ii—I2—Pb1—I1^iii	−94.87 (4)
C1—C2—C4—C3^i	−179.1 (6)	Pb1^ii—I2—Pb1—I1	85.13 (4)

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

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1D···I1^iii	0.91	2.88	3.598 (5)	137
N1—H1E···I1^v	0.91	2.84	3.619 (6)	144
N1—H1E···I2^vi	0.91	3.12	3.672 (6)	121
N1—H1C···I2	0.91	2.78	3.611 (6)	152

Symmetry codes: (iii) −x, −y, −z; (v) −x, y−1/2, −z−1/2; (vi) −x, −y, −z−1.