research communications\(\def\hfill{\hskip 5em}\def\hfil{\hskip 3em}\def\eqno#1{\hfil {#1}}\)

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ISSN: 2056-9890

Synthesis and structural studies of a new complex of catena-poly[p-anisidinium [[di­iodidobismu­thate(III)]-di-μ-iodido] dihydrate]

aLaboratoire de Matériaux et Cristallochimie, Faculté des Sciences de Tunis, Université de Tunis El Manar, 2092 Manar II Tunis, Tunisia, and bLaboratoire de Physique appliquée, Faculté des Sciences de Sfax, 3018 BP 802, Tunisia
*Correspondence e-mail: habib.boughzala@ipein.rnu.tn

Edited by A. Van der Lee, Université de Montpellier II, France (Received 20 September 2015; accepted 14 October 2015; online 24 October 2015)

A new organic–inorganic hybrid material, {(C7H10NO)[BiI4]·2H2O}n, has been synthesized by slow evaporation of an aqueous solution at room temperature. The anionic sublattice of the crystal is built up by [BiI6] octa­hedra sharing edges. The resulting zigzag chains extend along the a-axis direction and are arranged in a distorted hexagonal rod packing. The p-anisidinium cations and the water mol­ecules are located in the voids of the anionic sublattice. The cations are linked to each other through N—H⋯O hydrogen bonds with the water mol­ecules, and also through weaker N—H⋯I inter­actions to the anionic inorganic layers.

1. Chemical context

Previous X-ray structural studies showed that halogenidobismuthate(III) complexes may contain an array of variously self-organized halobismuthate anions since different polynuclear species can be formed through oligomerization by halide bridging (Bowmaker et al., 1998[Bowmaker, G. A., Junk, P. C., Lee, A. M., Skelton, B. W. & White, A. H. (1998). Aust. J. Chem. 51, 293-309.]; Benetollo et al., 1998[Benetollo, F., Bombieri, G., Alonzo, G., Bertazzi, N. & Casella, G. (1998). J. Chem. Crystallogr. 28, 791-796.]; Alonzo et al., 1999[Alonzo, G., Benetollo, F., Bertazzi, N. & Bombieri, G. (1999). J. Chem. Crystallogr. 29, 913-919.]).

In general, the coordination sphere of bis­muth appears to be dominated by an hexa­coordination tendency with polybismuthate species arising from corner-, edge- or face-sharing [BiX6] distorted octa­hedra. If the anionic sublattice dimensionality is clearly determined by the counter-cations, the effects of their most evident properties such as charge, size and shape are not predictable. Organic cations resulting from protonated nitro­gen functionalities may provide a rich family of salts where the factors cited above could be varied rationally. In addition, since the important contribution to the lattice stabilization in the crystalline state is due to hydrogen-bonding inter­actions, it should be possible to influence the bis­muth coordination geometry by changing the number and orientation of the hydrogen-bond donor sites of the cations. In an effort to increase the size of the [BiX6] octahedra, iodine was used in the chemical synthesis.

[Scheme 1]

2. Structural commentary

The principal building blocks of the title compound are octahedral iodidobismuthate [BiI6] units, p-anisidinium cations and two water mol­ecules (Fig. 1[link]). The anionic sublattice of the crystal is built of one-dimensional zigzag chains extending along the a-axis direction and composed of [BiI6] octa­hedra sharing edges as shown in Fig. 2[link]. The one-dimensional secondary building unit (SBU) topology observed in the described structure is one of the most common and stable ones (Billing & Lemmerer, 2006[Billing, D. G. & Lemmerer, A. (2006). Acta Cryst. C62, m269-m271.]) in bis­muth halide hybrids. The shortest Bi—Bi distance [4.590 (1) Å] observed is in agreement with homologous structures having the same one-dimensional topology. The octa­hedral bis­muth coordination is almost regular, proving the stereochemical inactivity of the Bi3+ 6s2 electron lone pair. Furthermore, among the six octa­hedral vertices, two are monocoordinated with short bond lengths (I2 and I3), while the four others (I4, I1 and symmetry-related atoms) are bicoordinated exhibiting long bond lengths (Table 1[link]).

Table 1
Selected bond lengths (Å)

Bi—I2 2.8938 (7) Bi—I1ii 3.1390 (8)
Bi—I3 2.9850 (7) Bi—I1 3.1842 (8)
Bi—I4i 3.0184 (8) Bi—I4 3.3238 (7)
Symmetry codes: (i) -x+1, -y+1, -z+1; (ii) -x+2, -y+1, -z+1.
[Figure 1]
Figure 1
Representation of the structural units of (C7H10NO)[BiI4]·2H2O, with 50% probability displacement ellipsoids. [Symmetry codes: (i) 1 − x, 1 − y, 1 − z; (ii) 2 − x, 1 − y, 1 − z.]
[Figure 2]
Figure 2
View of the anionic framework in the structure of (C7H10NO)[BiI4]·2H2O, showing the zigzag chains running along the a-axis direction.

In Fig. 3[link], it can be seen that each [BiI6] octa­hedron is linked to one p-anisidinium cation and a water mol­ecule OW1 via I3⋯HA—N and I3⋯HW1A—OW1 hydrogen bonds.

[Figure 3]
Figure 3
The environment of the [BiI6] octa­hedron in the structure of (C7H10NO)[BiI4]·2H2O. [Symmetry codes: (i) −x + [{1\over 2}], y − [{1\over 2}], −z + [{1\over 2}]; (ii) −x + [{3\over 2}], y − [{1\over 2}], −z + [{1\over 2}].]

The p-anisidinium cation is adopting a quite planar configuration characterized by a slight r.m.s. deviation of 0.020 (9) Å. Each p-anisidinium cation inter­acts with one [BiI6] octa­hedron via N—HA⋯I3i ([{1\over 2}] − x, −[{1\over 2}] + y, [{1\over 2}] − z) , with two water mol­ecules by N—HB⋯OW1ii ([{3\over 2}] − x, −[{1\over 2}] + y, [{1\over 2}] − z) and N—HC⋯OW2 hydrogen bonds (Table 2[link]), as shown in Fig. 4[link].

Table 2
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA D—H⋯A
N—HA⋯I3iii 0.89 2.77 3.658 (10) 176
N—HB⋯OW1iv 0.89 1.97 2.762 (12) 147
N—HC⋯OW2 0.89 1.88 2.704 (14) 154
OW1—HW1A⋯I3 0.85 2.77 3.604 (7) 167
OW2—HW2A⋯I1i 0.85 3.23 3.817 (10) 129
OW2—HW2A⋯I3 0.85 3.20 3.850 (12) 135
OW2—HW2B⋯OW1v 0.85 2.32 2.925 (13) 129
Symmetry codes: (i) -x+1, -y+1, -z+1; (iii) [-x+{\script{1\over 2}}, y-{\script{1\over 2}}, -z+{\script{1\over 2}}]; (iv) [-x+{\script{3\over 2}}, y-{\script{1\over 2}}, -z+{\script{1\over 2}}]; (v) x-1, y, z.
[Figure 4]
Figure 4
The environment of the p-anisidinium cation in the structure of (C7H10NO)[BiI4]·2H2O. [Symmetry codes: (i) −x + [{1\over 2}], y − [{1\over 2}], −z + [{1\over 2}]; (ii) [{3\over 2}] − x, −[{1\over 2}] + y, [{1\over 2}] − z.]

3. Supra­molecular features

The role of the water mol­ecules is crucial in the crystal cohesion. In fact, OW1 is engaged in three hydrogen bonds to one organic cation, one [BiI6] octa­hedra and one water mol­ecule via OW1⋯HBi—Ni, OW1—HW1A⋯I3 and OW1⋯HW2Bii—OW2ii, respectively, as shown in Fig. 5[link] [symmetry codes: (i) [{3\over 2}] − x, [{1\over 2}] + y, [{1\over 2}] − z; (ii) x + 1, y, z). The second water mol­ecule OW2 is linked to OW1 by OW2—HW2B⋯OW1(−1 + x, y, z) and to the p-anisidinium cation by N—HC⋯OW2 hydrogen bonds as shown in Fig. 6[link]. The role of this water mol­ecule can be seen better in Fig. 7[link] where mol­ecular stacking along the b axis is observed, leaving an empty inter­layer space where OW2 mol­ecules are located, ensuring a strong link between organic and inorganic sheets.

[Figure 5]
Figure 5
The environment of the OW1 water mol­ecule. [Symmetry codes: (i) [{3\over 2}] − x, [{1\over 2}] + y, [{1\over 2}] − z; (ii) x + 1, y, z.]
[Figure 6]
Figure 6
The environment of the OW2 water mol­ecule. [Symmetry code: (i) −1 + x, y, z.]
[Figure 7]
Figure 7
The mol­ecular stacking along the b axis, showing the empty inter­layer space where the OW2 water mol­ecules are located.

There are two types of hydrogen bonds, the first one has nitro­gen as the donor with iodine as an acceptor to form N—H⋯I bonds. The second type has nitro­gen as the donor with oxygen as an acceptor to form N—H⋯O bonds. All these bonds are listed in Table 2[link]. We have to note that HW2A is not involved in hydrogen bonding.

4. Database survey

A systematic search procedure in the Cambridge Structural Database (Version 5.36; Groom & Allen, 2014[Groom, C. R. & Allen, F. H. (2014). Angew. Chem. Int. Ed. 53, 662-671.]) based on the p-anisidinium cation scheme gives a total of 25 hits. Only two are hybrid compounds: (C7H10NO)+4[BiCl6]3−·Cl·H2O (Liu, 2012[Liu, M.-L. (2012). Acta Cryst. E68, m652.]) and (C7H10NO)+2n[Pb3I8]2−n·2nH2O (Prakash et al., 2009[Prakash, G. V., Pradeesh, K., Ratnani, R., Saraswat, K., Light, M. E. & Baumberg, J. J. (2009). J. Appl. Phys. 42, 185405-185412.]).

5. Synthesis and crystallization

The title compound was synthesized by dissolving stoichiometric amounts of bis­muth(III) iodide in p-anisidine in a mixture of water and HI. The resulting solution was stirred well and kept at room temperature. Bright-red prismatic crystals were grown by slow evaporation in a couple of weeks. The purity of the synthesized compound was improved by successive recrystallization processes.

6. Refinement

Crystal data, data collection and structure refinement details are summarized in Table 3[link]. The hydrogen atoms were located in difference Fourier maps. Those attached to carbon were placed in calculated positions (C—H = 0.90–1.00 Å) while those attached to nitro­gen were placed in experimental positions and their coordinates adjusted to give N—H = 0.89 Å. All were included as riding on their parent atoms with isotropic displacement parameters 1.2–1.5 times those of the parent atoms. Hydrogen positions for the water mol­ecules were partly located from a Fourier difference map and partly placed based on geometrical considerations. They are not of sufficient precision to refine the hydrogen-atom positions for the water mol­ecules with angle and distance restraints and they were therefore treated as riding on their parent oxygen atoms.

Table 3
Experimental details

Crystal data
Chemical formula (C7H10NO)[BiI4]·2H2O
Mr 876.77
Crystal system, space group Monoclinic, P21/n
Temperature (K) 293
a, b, c (Å) 7.779 (2), 12.747 (2), 18.252 (3)
β (°) 94.97 (1)
V3) 1803.0 (6)
Z 4
Radiation type Mo Kα
μ (mm−1) 16.62
Crystal size (mm) 0.6 × 0.2 × 0.1
 
Data collection
Diffractometer Enraf–Nonius CAD-4
Absorption correction ψ scan (North et al., 1968[North, A. C. T., Phillips, D. C. & Mathews, F. S. (1968). Acta Cryst. A24, 351-359.])
Tmin, Tmax 0.014, 0.036
No. of measured, independent and observed [I > 2σ(I)] reflections 5050, 3923, 3064
Rint 0.035
(sin θ/λ)max−1) 0.639
 
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.035, 0.080, 1.05
No. of reflections 3923
No. of parameters 147
H-atom treatment H-atom parameters constrained
Δρmax, Δρmin (e Å−3) 1.68, −2.01
Computer programs: CAD-4 EXPRESS (Enraf–Nonius, 1994[Enraf-Nonius (1994). CAD-4 EXPRESS. Enraf-Nonius, Delft, The Netherlands.]), XCAD4 (Harms & Wocadlo, 1995[Harms, K. & Wocadlo, S. (1995). XCAD4. University of Marburg, Germany.]), SHELXS97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]), SHELXL2014 (Sheldrick, 2015[Sheldrick, G. M. (2015). Acta Cryst. C71, 3-8.]), DIAMOND (Brandenburg, 2008[Brandenburg, K. (2008). DIAMOND. Crystal Impact GbR, Bonn, Germany.]) and publCIF (Westrip, 2010[Westrip, S. P. (2010). J. Appl. Cryst. 43, 920-925.]).

Supporting information


Computing details top

Data collection: CAD-4 EXPRESS (Enraf–Nonius, 1994); cell refinement: CAD-4 EXPRESS (Enraf–Nonius, 1994); data reduction: XCAD4 (Harms & Wocadlo, 1995); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL2014 (Sheldrick, 2015); molecular graphics: DIAMOND (Brandenburg, 2008); software used to prepare material for publication: publCIF (Westrip, 2010).

catena-Poly[p-anisidinium [[diiodidobismuthate(III)]-di-µ-iodido]] dihydrate] top
Crystal data top
(C7H10NO)[BiI4]·2H2OF(000) = 1528
Mr = 876.77Dx = 3.230 Mg m3
Monoclinic, P21/nMo Kα radiation, λ = 0.71073 Å
a = 7.779 (2) ÅCell parameters from 25 reflections
b = 12.747 (2) Åθ = 10–15°
c = 18.252 (3) ŵ = 16.62 mm1
β = 94.97 (1)°T = 293 K
V = 1803.0 (6) Å3Prism, red
Z = 40.6 × 0.2 × 0.1 mm
Data collection top
Enraf–Nonius CAD-4
diffractometer
3064 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tubeRint = 0.035
Graphite monochromatorθmax = 27.0°, θmin = 2.2°
ω/2θ scansh = 91
Absorption correction: ψ scan
(North et al., 1968)
k = 116
Tmin = 0.014, Tmax = 0.036l = 2323
5050 measured reflections2 standard reflections every 120 min
3923 independent reflections intensity decay: 1%
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.035Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.080H-atom parameters constrained
S = 1.05 w = 1/[σ2(Fo2) + (0.0317P)2 + 8.0053P]
where P = (Fo2 + 2Fc2)/3
3923 reflections(Δ/σ)max = 0.001
147 parametersΔρmax = 1.68 e Å3
0 restraintsΔρmin = 2.01 e Å3
Special details top

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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
Bi0.73731 (4)0.51922 (2)0.43418 (2)0.02320 (9)
I10.93941 (7)0.62637 (5)0.57383 (3)0.03934 (16)
I20.86930 (9)0.67240 (5)0.33633 (4)0.04831 (18)
I30.56183 (8)0.38519 (5)0.31619 (3)0.04102 (16)
I40.58407 (7)0.35207 (5)0.55223 (3)0.03656 (15)
N0.2818 (12)0.0413 (8)0.2801 (5)0.059 (2)
HA0.19830.00590.25440.071*
HB0.38390.01760.26890.071*
HC0.27260.10920.26900.071*
C10.2662 (13)0.0267 (9)0.3590 (6)0.048 (3)
C20.1996 (13)0.0648 (9)0.3862 (6)0.051 (3)
H20.16220.11790.35360.061*
C30.1880 (13)0.0783 (8)0.4581 (6)0.047 (2)
H30.14000.13960.47500.056*
C40.2466 (12)0.0020 (7)0.5077 (6)0.040 (2)
C50.3162 (13)0.0920 (8)0.4821 (6)0.050 (3)
H50.35460.14460.51480.060*
C60.3261 (13)0.1043 (8)0.4071 (6)0.051 (3)
H60.37340.16510.38920.061*
C70.1791 (15)0.1049 (9)0.6110 (6)0.062 (3)
H7A0.06570.11860.58790.093*
H7B0.17380.09910.66320.093*
H7C0.25500.16130.60060.093*
O0.2425 (9)0.0092 (6)0.5833 (4)0.0522 (18)
OW10.9289 (10)0.4148 (6)0.2103 (4)0.063 (2)
HW1A0.83840.39810.23070.095*
HW1B0.92220.38830.16750.095*
OW20.1501 (15)0.2339 (8)0.2484 (5)0.110 (4)
HW2A0.18890.28550.27450.166*
HW2B0.05020.24990.22910.166*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Bi0.02239 (16)0.02297 (16)0.02394 (14)0.00093 (13)0.00020 (11)0.00034 (12)
I10.0305 (3)0.0385 (3)0.0470 (3)0.0095 (3)0.0082 (2)0.0207 (3)
I20.0548 (4)0.0413 (4)0.0509 (4)0.0060 (3)0.0163 (3)0.0164 (3)
I30.0403 (3)0.0472 (4)0.0342 (3)0.0063 (3)0.0044 (2)0.0136 (3)
I40.0313 (3)0.0287 (3)0.0509 (3)0.0086 (2)0.0110 (3)0.0120 (3)
N0.056 (6)0.059 (6)0.061 (6)0.007 (5)0.001 (5)0.001 (5)
C10.034 (5)0.045 (6)0.066 (7)0.008 (5)0.001 (5)0.001 (5)
C20.050 (6)0.040 (6)0.060 (7)0.002 (5)0.007 (5)0.012 (5)
C30.046 (6)0.025 (5)0.069 (7)0.000 (4)0.005 (5)0.002 (5)
C40.027 (5)0.030 (5)0.063 (6)0.005 (4)0.001 (4)0.005 (4)
C50.045 (6)0.028 (5)0.073 (7)0.001 (5)0.010 (5)0.002 (5)
C60.045 (6)0.034 (6)0.073 (7)0.006 (5)0.005 (5)0.010 (5)
C70.060 (7)0.052 (7)0.071 (8)0.008 (6)0.010 (6)0.018 (6)
O0.051 (4)0.042 (4)0.062 (5)0.007 (3)0.006 (4)0.000 (4)
OW10.063 (5)0.068 (5)0.061 (5)0.007 (4)0.019 (4)0.004 (4)
OW20.135 (9)0.091 (8)0.098 (8)0.041 (7)0.029 (7)0.005 (6)
Geometric parameters (Å, º) top
Bi—I22.8938 (7)C3—C41.379 (14)
Bi—I32.9850 (7)C3—H30.9300
Bi—I4i3.0184 (8)C4—O1.386 (13)
Bi—I1ii3.1390 (8)C4—C51.410 (14)
Bi—I13.1842 (8)C5—C61.387 (15)
Bi—I43.3238 (7)C5—H50.9300
I1—Biii3.1390 (8)C6—H60.9300
I4—Bii3.0184 (8)C7—O1.425 (12)
N—C11.468 (14)C7—H7A0.9600
N—HA0.8900C7—H7B0.9600
N—HB0.8900C7—H7C0.9600
N—HC0.8900OW1—HW1A0.8518
C1—C61.376 (15)OW1—HW1B0.8479
C1—C21.386 (15)OW2—HW2A0.8511
C2—C31.336 (14)OW2—HW2B0.8499
C2—H20.9300
I2—Bi—I396.05 (2)C2—C1—N121.5 (10)
I2—Bi—I4i91.41 (2)C3—C2—C1121.3 (10)
I3—Bi—I4i92.30 (2)C3—C2—H2119.4
I2—Bi—I1ii92.39 (2)C1—C2—H2119.4
I3—Bi—I1ii86.92 (2)C2—C3—C4120.5 (10)
I4i—Bi—I1ii176.18 (2)C2—C3—H3119.8
I2—Bi—I191.58 (2)C4—C3—H3119.8
I3—Bi—I1170.46 (2)C3—C4—O124.8 (9)
I4i—Bi—I193.21 (2)C3—C4—C5119.8 (10)
I1ii—Bi—I187.07 (2)O—C4—C5115.4 (9)
I2—Bi—I4177.35 (2)C6—C5—C4118.6 (10)
I3—Bi—I486.19 (2)C6—C5—H5120.7
I4i—Bi—I487.08 (2)C4—C5—H5120.7
I1ii—Bi—I489.14 (2)C1—C6—C5120.3 (10)
I1—Bi—I486.33 (2)C1—C6—H6119.9
Biii—I1—Bi92.93 (2)C5—C6—H6119.9
Bii—I4—Bi92.92 (2)O—C7—H7A109.5
C1—N—HA109.5O—C7—H7B109.5
C1—N—HB109.5H7A—C7—H7B109.5
HA—N—HB109.5O—C7—H7C109.5
C1—N—HC109.5H7A—C7—H7C109.5
HA—N—HC109.5H7B—C7—H7C109.5
HB—N—HC109.5C4—O—C7116.7 (8)
C6—C1—C2119.6 (11)HW1A—OW1—HW1B108.5
C6—C1—N118.9 (10)HW2A—OW2—HW2B108.4
Symmetry codes: (i) x+1, y+1, z+1; (ii) x+2, y+1, z+1.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N—HA···I3iii0.892.773.658 (10)176
N—HB···OW1iv0.891.972.762 (12)147
N—HC···OW20.891.882.704 (14)154
OW1—HW1A···I30.852.773.604 (7)167
OW2—HW2A···I1i0.853.233.817 (10)129
OW2—HW2A···I30.853.203.850 (12)135
OW2—HW2B···OW1v0.852.322.925 (13)129
Symmetry codes: (i) x+1, y+1, z+1; (iii) x+1/2, y1/2, z+1/2; (iv) x+3/2, y1/2, z+1/2; (v) x1, y, z.
 

Acknowledgements

The authors thank the members of the Laboratory of Applied Physics, Faculty of Sciences of Sfax, for the synthesis of the title compound.

References

First citationAlonzo, G., Benetollo, F., Bertazzi, N. & Bombieri, G. (1999). J. Chem. Crystallogr. 29, 913–919.  CSD CrossRef CAS Google Scholar
First citationBenetollo, F., Bombieri, G., Alonzo, G., Bertazzi, N. & Casella, G. (1998). J. Chem. Crystallogr. 28, 791–796.  CSD CrossRef CAS Google Scholar
First citationBilling, D. G. & Lemmerer, A. (2006). Acta Cryst. C62, m269–m271.  CSD CrossRef CAS IUCr Journals Google Scholar
First citationBowmaker, G. A., Junk, P. C., Lee, A. M., Skelton, B. W. & White, A. H. (1998). Aust. J. Chem. 51, 293–309.  Web of Science CSD CrossRef CAS Google Scholar
First citationBrandenburg, K. (2008). DIAMOND. Crystal Impact GbR, Bonn, Germany.  Google Scholar
First citationEnraf–Nonius (1994). CAD-4 EXPRESS. Enraf–Nonius, Delft, The Netherlands.  Google Scholar
First citationGroom, C. R. & Allen, F. H. (2014). Angew. Chem. Int. Ed. 53, 662–671.  Web of Science CSD CrossRef CAS Google Scholar
First citationHarms, K. & Wocadlo, S. (1995). XCAD4. University of Marburg, Germany.  Google Scholar
First citationLiu, M.-L. (2012). Acta Cryst. E68, m652.  CSD CrossRef IUCr Journals Google Scholar
First citationNorth, A. C. T., Phillips, D. C. & Mathews, F. S. (1968). Acta Cryst. A24, 351–359.  CrossRef IUCr Journals Web of Science Google Scholar
First citationPrakash, G. V., Pradeesh, K., Ratnani, R., Saraswat, K., Light, M. E. & Baumberg, J. J. (2009). J. Appl. Phys. 42, 185405–185412.  Google Scholar
First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationSheldrick, G. M. (2015). Acta Cryst. C71, 3–8.  Web of Science CrossRef IUCr Journals Google Scholar
First citationWestrip, S. P. (2010). J. Appl. Cryst. 43, 920–925.  Web of Science CrossRef CAS IUCr Journals Google Scholar

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