Bis­(pentane-1,5-di­ammonium) deca­iodo­triplumbate(II)

The title compound, {(NH₃C₅H₁₀NH₃)₂[Pb₃I₁₀]}_n, crystallizes as an organic–inorganic hybrid. As such, the structure consists of extended chains of [Pb₃I₁₀]_n⁴ⁿ⁻ ions extending along [111]. The asymmetric unit contains two independent Pb atoms: one is in a general position and the other is on an inversion centre. Each Pb atom is octahedrally coordinated by six iodide ions and exhibits both face- and edge-sharing with adjacent atoms in the inorganic chain. The organic counter-ion, viz. pentane-1,5-di­ammonium, lies in channels formed by the chains and interacts with these chains via N—H...I hydrogen bonding.

S1. Comment

In recent years, a significant number of organic–inorganic hybrid materials based on metal halide units have been prepared and studied [for reviews see Papavassiliou (1997) and Mitzi (1999)]. Haloplumbates, in particular, have demonstrated a propensity for forming a great variety of crystaline structures by self-assembling from suitable solution mixtures. It has been shown that these structures can vary considerably, ranging from systems based on isolated molecules, to those containing infinite chains, as in [Me₄N][PbI₃] (Contreras et al., 1983), right up to two- or three-dimensional networks (Mitzi, 1999). The lead iodide octahedra can be connected in one of three ways, viz. face-sharing between two equatorial and one axial halide, edge-sharing between two equatorial halides, or corner-sharing through a single halide. It is also possible to have combinations of the various types of sharing in one chain, as in [Na(dmf)₃]₄[Pb₆I₁₆] and [PrN(C₂H₄)₃NPr][Pb₂I₆], where the octahedra simultaneously share common faces, edges and vertices (Krautscheid et al., 2001). The chains formed by the octahedra can be described by the shorthand notation (f_me)_n for m adjacent face-sharing octahedra, f, connected by octahedra sharing an edge, denoted e. Structures with m = 3 have been synthesized for lead iodide (Maxcy et al., 2003; Krautscheid & Vielsack, 1997) and tin iodide (Lode & Krautscheid, 2001) octahedra. The case with m = 1 has PbI₆ octahedra that share a face with PbI₅ square pyramids, which in turn share an edge.

Pentadiamine has previously been incorporated into the layered perovskite structure type. For example, single-crystal structures of [NH₃C₅H₁₀NH₃]CuX₄ (X = Cl and Br; Garland et al., 1990) have been determined. In general, the hybrid perovskite family displays structural phase transitions resulting from conformational changes within the amines between the layers, as well as the slipping of layers with respect to each other. The temperatures at which the phase changes occur are dependent on the length of the chain, as can be seen for [NH₃(CH₂)_nNH₃]CdCl₄ (n = 3, 4 and 5; Kind et al., 1981).

We present here an m = 3 case, which has [Pb₃I₁₀]_n^4n- chains approximately extending along [111] with the pentadiammonium ion as counter-cation (Fig. 1). The asymmetric unit contains two crystallographically independent Pb atoms, viz. Pb1 and Pb2. Each face-sharing monomer unit consists of two Pb2 octahedra and one Pb1 octahedron, where the central Pb1 octahedron is connected to the Pb2 octahedra by shared faces. The Pb2 octahedra are linked via edge-sharing at both ends to adjacent monomers. The overall repeat pattern can be represented as (f₂e)₃ (Fig. 2).

Atom Pb1 is located on a centre of inversion, chosen for convenience as that at the centre of the unit cell, and is bonded to three unique halide atoms, viz. I1, I2 and I3, which then complete the full octahedron through the inversion centre. At the centre of a quadrilateral formed by atoms Pb2, I4, Pb2a and I4a [Pb2a and I4a are at the equivalent position (-x,-y,-z); (Fig. 1)] is a second inversion centre, chosen for convenience as the cell origin. Atom Pb2 is bonded to four unique halides, the extra halide, I4, is responsible for the edge-sharing between the Pb2 octahedra. This second inversion centre then generates the second I4 halide involved in the edge-sharing. The metal–halide bond distances are very similiar, possibly because of the lower strain imposed by the simpler sharing. Atoms I1, I2 and I3 are the three halides that partake in the face-sharing between the Pb1 and Pb2 octahedra. Axial atom I5 is the only halide not involved in any bonding to adjacent octahedra and has the shortest Pb—I distance [3.1221 (12) Å].

Atom Pb1 has a more regular coordination geometry, as it lies on an inversion centre, which ensures that all trans angles are exactly 180°, and shares trans faces with the two adjacent Pb2 octahedra. Atom Pb2, in contrast, has a more distorted environment, with all cis and trans angles different (Table 2).

One unique inorganic chain runs through the unit cell along the body, diagonally from (0,0,0) to (1,1,1). The Pb1 octahedra are located at the centre of the the unit cell, with the two Pb2 octahedra located along the body diagonal and related by the inversion centres at (0,0,0) and (1,1,1). In the crystal structure, the cations occupy channels that run parallel to the anion chains. Each diammonium cation is hydrogen bonded to three different chains in a pseudo-trigonal pattern. One anion chain lies along the body diagonal and the other two run through the corners of the unit cell in a pseudo-hexagonal pattern (Fig. 3).

Both ammonium groups on the cation form three hydrogen bonds to I atoms of the anion chains (details are in Table 2). Ammonium atom N1 connects three chains, atom I5 being a bifurcated acceptor. The ammonium group containing atom N2 bonds to two chains. It connects via a short and a long hydrogen bond to atoms I2 and I4, respectively, and to a second chain via the N2—H2B···I1^iv interaction.

The pentadiamine ion exhibits two types of conformational arrangement between the four possible torsion angles. There are antiperiplanar C1—C2—C3—C4 and C3—C4—C5—N5 angles of 174.0 (15) and −179.2 (14)°, and synclinal (gauche) C2—C3—C4—C5 and N1—C1—C2—C3 angles of 59 (2) and −71 (2)°.

S2. Experimental

PbI₂ (0.125 g, 0.271 mmol) and C₅H₁₆N₂ (0.031 g, 0.507 mmol) were added to HI (3 ml) and the mixture was heated until all the components dissolved. The solution was allowed to cool to room temperature, whereupon yellow plate-like crystals formed. A crystal suitable for X-ray diffraction analysis was selected and studied. Analysis calculated for C₁₀H₃₂N₄Pb₃I₁₀: C 5.72, H 1.54, N 2.67%; found: C 5.74, H 1.63, N 2.73%.

S3. Refinement

All H atoms were allowed for in idealized positions in the riding-model approximation [C—H = 0.97 Å, N—H = 0.89 Å and U_iso(H) = 1.2U_eq(C,N)].

Computing details

Data collection: SMART-NT (Bruker, 1998); cell refinement: SAINT-Plus (Bruker, 1999); data reduction: XPREP (Bruker, 1999); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); 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, 2003).

Figures

	Fig. 1. The asymmetric unit of (I) and some adjacent atoms, with the atomic numbering scheme. Displacement ellipsoids are shown at the 50% probability level. Atoms labeled with the suffixes A, B and C are at the symmetry positions (-x,-y,-z), (1 − x,1 − y,1 − z) and (1 + x,1 + y,1 + z), respectively.
	Fig. 2. An illustration of the (PB3I10)n^4n- chain.
	Fig. 3. The crystal packing of (I), viewed along [111], showing the pseudo-hexagonal packing and the N—H···I hydrogen bonding.

Bis(pentane-1,5-diammonium) decaiodotriplumbate(II)

Crystal data

(C5H16N2)2[Pb3I10]	Z = 1
Mr = 2098.97	F(000) = 896
Triclinic, P1	Dx = 3.742 Mg m^−3
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 8.8543 (15) Å	Cell parameters from 849 reflections
b = 11.1457 (19) Å	θ = 2.6–25°
c = 11.5725 (19) Å	µ = 21.82 mm^−1
α = 109.624 (3)°	T = 293 K
β = 106.173 (3)°	Plate, yellow
γ = 107.339 (3)°	0.30 × 0.24 × 0.03 mm
V = 931.4 (3) Å^3

Data collection

Bruker SMART CCD area-detector diffractometer	3257 independent reflections
Radiation source: fine-focus sealed tube	2593 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.052
ϕ and ω scans	θmax = 25°, θmin = 2.1°
Absorption correction: integration (XPREP in SAINT-Plus; Bruker, 1999)	h = −10→7
Tmin = 0.026, Tmax = 0.643	k = −13→13
5061 measured reflections	l = −11→13

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.036	H-atom parameters constrained
wR(F^2) = 0.104	w = 1/[σ^2(Fo^2) + (0.0464P)^2 + 4.4173P] where P = (Fo^2 + 2Fc^2)/3
S = 1.10	(Δ/σ)max < 0.001
3257 reflections	Δρmax = 1.25 e Å^−3
127 parameters	Δρmin = −1.19 e Å^−3
0 restraints	Extinction correction: SHELXL97, Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.00170 (19)

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
Pb1	0.5000	0.5000	0.5000	0.0392 (2)
Pb2	0.17920 (6)	0.10698 (5)	0.21099 (5)	0.03863 (18)
I1	0.14443 (11)	0.29176 (9)	0.48552 (10)	0.0443 (3)
I2	0.27005 (11)	0.40849 (10)	0.19085 (10)	0.0477 (3)
I3	0.60509 (11)	0.24323 (10)	0.39754 (11)	0.0503 (3)
I4	−0.21829 (10)	0.03520 (9)	0.06001 (9)	0.0426 (2)
I5	0.08075 (13)	−0.14724 (10)	0.27750 (11)	0.0523 (3)
N1	−0.7421 (18)	0.0562 (15)	−0.3538 (16)	0.075 (4)
H1A	−0.7447	−0.0237	−0.3522	0.113*
H1B	−0.8099	0.0372	−0.4366	0.113*
H1C	−0.7807	0.0967	−0.2954	0.113*
N5	−0.0792 (18)	0.4487 (18)	0.2629 (14)	0.082 (5)
H5A	−0.1113	0.5038	0.3167	0.123*
H5B	0.0352	0.4922	0.2887	0.123*
H5C	−0.1052	0.3677	0.2681	0.123*
C1	−0.563 (2)	0.152 (2)	−0.316 (2)	0.088 (7)
H1D	−0.5640	0.2312	−0.3333	0.106*
H1E	−0.5166	0.1028	−0.3724	0.106*
C2	−0.443 (2)	0.2082 (19)	−0.1659 (16)	0.064 (5)
H2A	−0.3229	0.2531	−0.1515	0.077*
H2B	−0.4568	0.1290	−0.1455	0.077*
C3	−0.482 (2)	0.3170 (18)	−0.0656 (18)	0.062 (4)
H3A	−0.4559	0.4018	−0.0775	0.074*
H3B	−0.6051	0.2764	−0.0844	0.074*
C4	−0.370 (2)	0.354 (2)	0.0812 (18)	0.076 (5)
H4A	−0.3959	0.4205	0.1425	0.091*
H4B	−0.4014	0.2694	0.0926	0.091*
C5	−0.174 (2)	0.419 (2)	0.120 (2)	0.071 (5)
H5D	−0.1456	0.3542	0.0595	0.085*
H5E	−0.1395	0.5061	0.1117	0.085*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Pb1	0.0344 (4)	0.0359 (4)	0.0435 (4)	0.0131 (3)	0.0162 (3)	0.0162 (3)
Pb2	0.0381 (3)	0.0398 (3)	0.0365 (3)	0.0161 (2)	0.0156 (2)	0.0164 (2)
I1	0.0439 (5)	0.0441 (5)	0.0451 (5)	0.0152 (4)	0.0257 (4)	0.0183 (4)
I2	0.0477 (5)	0.0574 (6)	0.0494 (6)	0.0240 (4)	0.0249 (4)	0.0321 (5)
I3	0.0456 (5)	0.0488 (5)	0.0621 (6)	0.0288 (4)	0.0223 (4)	0.0242 (5)
I4	0.0402 (4)	0.0487 (5)	0.0421 (5)	0.0211 (4)	0.0194 (4)	0.0209 (4)
I5	0.0645 (6)	0.0468 (6)	0.0547 (6)	0.0253 (5)	0.0310 (5)	0.0271 (5)
N1	0.077 (9)	0.069 (10)	0.071 (10)	0.034 (8)	0.024 (8)	0.027 (8)
N5	0.067 (9)	0.103 (12)	0.053 (9)	0.049 (9)	0.017 (7)	0.007 (9)
C1	0.060 (10)	0.096 (15)	0.084 (14)	0.003 (10)	−0.001 (9)	0.068 (13)
C2	0.057 (9)	0.071 (12)	0.053 (10)	0.024 (8)	0.016 (8)	0.028 (9)
C3	0.069 (10)	0.062 (10)	0.077 (12)	0.042 (8)	0.039 (9)	0.038 (9)
C4	0.078 (12)	0.077 (13)	0.061 (12)	0.037 (10)	0.029 (9)	0.017 (10)
C5	0.061 (10)	0.072 (12)	0.094 (14)	0.037 (9)	0.036 (10)	0.041 (11)

Geometric parameters (Å, º)

Pb1—I2^i	3.1998 (11)	N5—H5A	0.89
Pb1—I2	3.1998 (11)	N5—H5B	0.89
Pb1—I3^i	3.2226 (10)	N5—H5C	0.89
Pb1—I3	3.2226 (10)	C1—C2	1.54 (2)
Pb1—I1^i	3.2275 (10)	C1—H1D	0.97
Pb1—I1	3.2275 (10)	C1—H1E	0.97
Pb2—I5	3.1221 (12)	C2—C3	1.57 (2)
Pb2—I4	3.1680 (10)	C2—H2A	0.97
Pb2—I4^ii	3.1718 (12)	C2—H2B	0.97
Pb2—I1	3.3102 (12)	C3—C4	1.54 (2)
Pb2—I2	3.3187 (12)	C3—H3A	0.97
Pb2—I3	3.3222 (11)	C3—H3B	0.97
N1—C1	1.46 (2)	C4—C5	1.53 (2)
N1—H1A	0.89	C4—H4A	0.97
N1—H1B	0.89	C4—H4B	0.97
N1—H1C	0.89	C5—H5D	0.97
N5—C5	1.50 (2)	C5—H5E	0.97
I2^i—Pb1—I2	180	H1A—N1—H1C	109.5
I2^i—Pb1—I3^i	88.76 (3)	H1B—N1—H1C	109.5
I2—Pb1—I3^i	91.24 (3)	C5—N5—H5A	109.5
I2^i—Pb1—I3	91.24 (3)	C5—N5—H5B	109.5
I2—Pb1—I3	88.76 (3)	H5A—N5—H5B	109.5
I3^i—Pb1—I3	180	C5—N5—H5C	109.5
I2^i—Pb1—I1^i	84.82 (3)	H5A—N5—H5C	109.5
I2—Pb1—I1^i	95.18 (3)	H5B—N5—H5C	109.5
I3^i—Pb1—I1^i	91.17 (3)	N1—C1—C2	112.5 (16)
I3—Pb1—I1^i	88.83 (3)	N1—C1—H1D	109.1
I2^i—Pb1—I1	95.18 (3)	C2—C1—H1D	109.1
I2—Pb1—I1	84.82 (3)	N1—C1—H1E	109.1
I3^i—Pb1—I1	88.83 (3)	C2—C1—H1E	109.1
I3—Pb1—I1	91.17 (3)	H1D—C1—H1E	107.8
I1^i—Pb1—I1	180	C1—C2—C3	113.3 (15)
I5—Pb2—I4	91.83 (3)	C1—C2—H2A	108.9
I5—Pb2—I4^ii	100.21 (3)	C3—C2—H2A	108.9
I4—Pb2—I4^ii	94.16 (3)	C1—C2—H2B	108.9
I5—Pb2—I1	87.33 (3)	C3—C2—H2B	108.9
I4—Pb2—I1	84.54 (3)	H2A—C2—H2B	107.7
I4^ii—Pb2—I1	172.40 (3)	C4—C3—C2	109.3 (12)
I5—Pb2—I2	168.97 (3)	C4—C3—H3A	109.8
I4—Pb2—I2	86.31 (3)	C2—C3—H3A	109.8
I4^ii—Pb2—I2	90.77 (3)	C4—C3—H3B	109.8
I1—Pb2—I2	81.67 (3)	C2—C3—H3B	109.8
I5—Pb2—I3	95.38 (3)	H3A—C3—H3B	108.3
I4—Pb2—I3	169.37 (3)	C5—C4—C3	113.5 (16)
I4^ii—Pb2—I3	92.25 (3)	C5—C4—H4A	108.9
I1—Pb2—I3	88.00 (3)	C3—C4—H4A	108.9
I2—Pb2—I3	85.13 (3)	C5—C4—H4B	108.9
Pb1—I1—Pb2	75.14 (2)	C3—C4—H4B	108.9
Pb1—I2—Pb2	75.38 (2)	H4A—C4—H4B	107.7
Pb1—I3—Pb2	75.04 (2)	N5—C5—C4	108.5 (16)
Pb2—I4—Pb2^ii	85.84 (3)	N5—C5—H5D	110.0
C1—N1—H1A	109.5	C4—C5—H5D	110.0
C1—N1—H1B	109.5	N5—C5—H5E	110.0
H1A—N1—H1B	109.5	C4—C5—H5E	110.0
C1—N1—H1C	109.5	H5D—C5—H5E	108.4
I2^i—Pb1—I1—Pb2	−132.37 (2)	I2^i—Pb1—I3—Pb2	136.08 (2)
I2—Pb1—I1—Pb2	47.63 (2)	I2—Pb1—I3—Pb2	−43.92 (2)
I3^i—Pb1—I1—Pb2	138.97 (2)	I1^i—Pb1—I3—Pb2	−139.13 (3)
I3—Pb1—I1—Pb2	−41.03 (2)	I1—Pb1—I3—Pb2	40.87 (3)
I5—Pb2—I1—Pb1	135.05 (2)	I5—Pb2—I3—Pb1	−126.79 (3)
I4—Pb2—I1—Pb1	−132.86 (3)	I4—Pb2—I3—Pb1	5.68 (18)
I2—Pb2—I1—Pb1	−45.80 (2)	I4^ii—Pb2—I3—Pb1	132.74 (2)
I3—Pb2—I1—Pb1	39.57 (2)	I1—Pb2—I3—Pb1	−39.66 (2)
I3^i—Pb1—I2—Pb2	−136.11 (3)	I2—Pb2—I3—Pb1	42.15 (3)
I3—Pb1—I2—Pb2	43.89 (3)	I5—Pb2—I4—Pb2^ii	−100.38 (3)
I1^i—Pb1—I2—Pb2	132.61 (2)	I1—Pb2—I4—Pb2^ii	172.48 (3)
I1—Pb1—I2—Pb2	−47.39 (2)	I2—Pb2—I4—Pb2^ii	90.51 (3)
I5—Pb2—I2—Pb1	50.68 (15)	I3—Pb2—I4—Pb2^ii	126.92 (17)
I4—Pb2—I2—Pb1	131.26 (2)	N1—C1—C2—C3	−71 (2)
I4^ii—Pb2—I2—Pb1	−134.62 (2)	C1—C2—C3—C4	174.0 (15)
I1—Pb2—I2—Pb1	46.25 (2)	C2—C3—C4—C5	59 (2)
I3—Pb2—I2—Pb1	−42.44 (2)	C3—C4—C5—N5	−179.2 (14)

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

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1A···I3^ii	0.89	3.02	3.806 (15)	149
N1—H1B···I5^iii	0.89	2.93	3.669 (16)	142
N1—H1C···I5^iv	0.89	2.92	3.672 (15)	143
N5—H5A···I1^v	0.89	2.79	3.668 (14)	169
N5—H5B···I2	0.89	2.87	3.531 (14)	132
N5—H5C···I4	0.89	3.31	4.001 (16)	136

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