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

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ISSN: 2056-9890

m-Xylylenediaminium sulfate: crystal structure and Hirshfeld surface analysis

CROSSMARK_Color_square_no_text.svg

aLaboratoire de Chimie des Matériaux, Faculté des Sciences de Bizerte, 7021 Zarzouna Bizerte, Université de Carthage, Tunisia, and bCentre de Diffractométrie X, UMR 6226 CNRS, Unité Sciences Chimiques de Rennes, Université de Rennes I, 263 Avenue du, Général Leclerc, 35042 Rennes, France
*Correspondence e-mail: afefguesmi2016@yahoo.fr

Edited by W. T. A. Harrison, University of Aberdeen, Scotland (Received 17 April 2016; accepted 24 April 2016; online 4 May 2016)

The crystal structure of the title salt {systematic name: [1,3-phenyl­enebis(methyl­ene)]bis­(aza­nium) sulfate}, C8H14N22+·SO42−, consists of infinite (100) sheets of alternating organic and inorganic entities The m-xylylenediaminium cations are linked to the sulfate anions by N—H⋯O and asymmetric bifurcated N—H⋯(O,O) hydrogen bonds, generating a three-dimensional network. A weak C—H⋯O inter­action also occurs. The Hirshfeld surface analysis and the two-dimensional fingerprint maps indicate that the packing is dominated by H⋯O/O⋯H and H⋯H contacts.

1. Chemical context

m-Xylylenediaminum compounds have been intensively investigated due to their good anti­microbial activity against various anti­bacterial and anti­fungal species (Murugesan et al., 2015[Murugesan, V., Saravanabhavan, M. & Sekar, M. (2015). J. Photochem. Photobiol. B, 148, 358-365.]). Sequestration of carbon dioxide by m-xylylene­di­amine with formation of a crystalline adduct has been reported (Lee et al., 2013[Lee, S. W., Lim, S. W., Park, S. H., Ha, K., Kim, K. S., Oh, S. M., Lee, J. Y. & Seo, G. (2013). Korean J. Chem. Eng. 30, 2241-2247.]). In addition, polyamides of m-xylylenedi­amine possess dielectric properties (Murata et al., 1999[Murata, Y., Tsunashima, K. & Koizumi, N. (1999). Jpn. J. Appl. Phys. 38, 5148-5153.]). In this work, as part of our studies in this area, we report the synthesis, the structural investigation and the Hirshfeld surface analysis of a new organic sulfate salt, (C8H14N2)SO4, (I)[link].

[Scheme 1]

2. Structural commentary

The asymmetric unit of (I)[link] comprises one m-xylylene­diaminium cation and one sulfate anion (Fig. 1[link]). Both ammonium groups in the m-xylylenediaminium cation adopt a trans conformation with respect to the benzene ring. The same conformation has been observed in C8H14N22+·2Cl (Cheng & Li, 2008[Cheng, H. & Li, H. (2008). Acta Cryst. E64, o2060.]), but in C8H14N22+·2NO3 (Gatfaoui et al., 2014[Gatfaoui, S., Dhaouadi, H., Roisnel, T., Rzaigui, M. & Marouani, H. (2014). Acta Cryst. E70, o398-o399.]) the cis conformation occurs. Thus, the cation conformation is modified when substituting sulfate or chloride anions by nitrates. Examination of the organic cations shows that the bond distances and angles show no significant differences from those in other compounds involving the same organic groups (Cheng & Li, 2008[Cheng, H. & Li, H. (2008). Acta Cryst. E64, o2060.]; Gatfaoui et al., 2014[Gatfaoui, S., Dhaouadi, H., Roisnel, T., Rzaigui, M. & Marouani, H. (2014). Acta Cryst. E70, o398-o399.]). The aromatic ring of the cation is essentially planar with an r.m.s. deviation of 0.0014 Å.

[Figure 1]
Figure 1
A view of (I)[link], with displacement ellipsoids drawn at the 30% probability level. H atoms are represented as small spheres of arbitrary radii. Hydrogen bonds are shown as dotted lines.

In the sulfate anion, the S—O bond lengths range from 1.4673 (12) to 1.4895 (11) Å. Their similar values confirm the absence of a proton in this anion. It is worth noting that the S—O4 distance is the longest because O4 accepts three hydrogen bonds, one of which is considered to be strong (Blessing, 1986[Blessing, R. H. (1986). Acta Cryst. B42, 613-621.]; Brown, 1976[Brown, I. D. (1976). Acta Cryst. A32, 24-31.]). The average values of the S—O distances and O—S—O angles are 1.4799 Å and 109.46°, respectively. Similar geometrical features have also been observed in other crystal structures (Marouani et al., 2011a[Marouani, H., Rzaigui, M. & Al-Deyab, S. S. (2011a). Eur. J. Chem. 8, 1930-1936.],b[Marouani, H., Rzaigui, M. & Al-Deyab, S. S. (2011b). X-ray Struct. Anal. Online, 27, 25-26.]). The calculated average values of the distortion indices (Baur, 1974[Baur, W. H. (1974). Acta Cryst. B30, 1195-1215.]) corresponding to the different angles and distances in the SO4 tetra­hedron [DI(SO) = 0.006, DI(OSO) = 0.008, and DI(OO) = 0.003] show a slight distortion of the OSO angles if compared to the SO and OO distances. Hence, the SO4 group can be considered as a rigid regular arrangement of oxygen atoms, with the sulfur atom slightly displaced from the centre of gravity.

3. Supra­molecular features

The packing of the title salt is dominated by hydrogen bonding, as detailed in Table 1[link]. Ten distinct hydrogen bonds of types N—H⋯O and C—H⋯O involve all of the oxygen atoms of the sulfate anions as acceptors, However, only two of the N—H⋯O hydrogen bonds are considered as strong according to the Blessing and Brown criteria (Blessing, 1986[Blessing, R. H. (1986). Acta Cryst. B42, 613-621.]; Brown, 1976[Brown, I. D. (1976). Acta Cryst. A32, 24-31.]).

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA D—H⋯A
N1—H1N1⋯O4i 0.88 (2) 1.88 (2) 2.7271 (17) 160.1 (19)
N1—H1N1⋯O2i 0.88 (2) 2.54 (2) 3.1461 (18) 126.1 (16)
N1—H2N1⋯O1ii 0.90 (3) 1.85 (3) 2.7191 (17) 162 (2)
N1—H3N1⋯O3iii 0.88 (3) 2.03 (2) 2.8264 (17) 150 (2)
N1—H3N1⋯O2iii 0.88 (3) 2.54 (2) 3.1733 (18) 129.4 (18)
N2—H1N2⋯O4iv 0.84 (2) 1.97 (2) 2.8096 (17) 177 (2)
N2—H2N2⋯O1v 0.80 (3) 2.26 (3) 2.9537 (18) 145 (2)
N2—H3N2⋯O3 1.00 (3) 1.92 (3) 2.9021 (19) 168 (3)
N2—H3N2⋯O4 1.00 (3) 2.52 (3) 3.0502 (18) 113 (2)
C5—H5⋯O3 0.93 2.47 3.3050 (17) 150
Symmetry codes: (i) [-x, y+{\script{1\over 2}}, -z-{\script{3\over 2}}]; (ii) x+1, y, z; (iii) [-x, y-{\script{1\over 2}}, -z-{\script{3\over 2}}]; (iv) -x-1, -y-1, -z-2; (v) -x-1, -y, -z-2.

The packing for (I)[link] generates rings with an R44(12) motif (Fig. 2[link]) and the overall structure of the title compound consists of infinite sheets of organic and inorganic entities propagating parallel to (100). Each organic dication is connected to six different sulfate anions via N—H⋯O and C—H⋯O hydrogen bonds, forming a three-dimensional supra­molecular network (Fig. 3[link]).

[Figure 2]
Figure 2
The 12-membered ring motif R44(12) in (I)[link]. C atoms have been omitted for clarity.
[Figure 3]
Figure 3
Projection of (I)[link] along the b axis. H atoms not involved in hydrogen bonding have been omitted.

The inter-planar distance between nearby benzene rings in the crystal structure is in the vicinity of 4.63 Å, which is much longer than 3.80 Å, value required for the formation of ππ inter­actions (Janiak, 2000[Janiak, J. (2000). J. Chem. Soc. Dalton Trans. pp. 3885-3896.]).

4. Hirshfeld analysis

The three-dimensional Hirshfeld surfaces and two-dimensional fingerprint plots of (I)[link] were prepared using CrystalExplorer (Wolff et al., 2012[Wolff, S. K., Grimwood, D. J., McKinnon, J. J., Turner, M. J., Jayatilaka, D. & Spackman, M. A. (2012). CrystalExplorer. Perth: University of Western Australia.]) and are shown in Fig. 4[link] and Fig. 5[link], respectively.

[Figure 4]
Figure 4
Hirshfeld surface mapped over dnorm showing hydrogen bonds with neighbouring sulfate groups. The surfaces are shown as transparent to allow visualization of the orientation and conformation of the functional groups. N—H⋯O and C—H⋯O hydrogen bonds are represented by red and blue dotted lines, respectively.
[Figure 5]
Figure 5
Fingerprint plots of the major contacts: (a) H⋯O, (b) H⋯H, (c) C⋯H and (d) O⋯O.

The O⋯H/H⋯O contacts, which are attributed to N—H⋯O and C—H⋯O hydrogen-bonding inter­actions, appear as two sharp symmetric spikes in the two-dimensional fingerprint maps with a prominent long spike at de + di = 1.8 Å. They have the most significant contribution to the total Hirshfeld surfaces (51.4%). The H⋯H contacts appear in the middle of the scattered points in the two-dimensional fingerprint maps with a single broad peak at de = di = 1 Å and a percentage contribution of 32.1%. The 15.9% contribution from the C⋯H/H⋯C contacts to the Hirshfeld surface, generally slightly favoured in a sample of CH aromatic mol­ecules, results in a symmetric pair of wings, Fig. 5[link]c. The O⋯O contacts, which represent only 0.2% of the Hirshfeld surface, Fig. 5[link]d, are extremely impoverished in the crystal (enrichment ratio EOO = 0.03) (Jelsch et al. 2014[Jelsch, C., Ejsmont, K. & Huder, L. (2014). IUCrJ, 1, 119-128.]), as the oxygen atoms bound to sulfur and the SO4 group as a whole are electronegative, therefore the O⋯O contacts are electrostatically repulsive.

5. Synthesis and crystallization

Equimolar solutions of m-xylylenedi­amine dissolved in methanol and aqueous sulfuric acid were mixed together and stirred for about 1 h. Crystals of (I)[link] were formed as the solvent evaporated over a few days at room temperature: these were filtered off, dried and repeatedly recrystallized as colourless prisms to enhance the purity of the product.

6. Refinement

Crystal data, data collection and structure refinement details are summarized in Table 2[link]. H atoms bonded to N atoms were located from a difference map and were allowed to refine. The rest of the H atoms were treated as riding, with C—H = 0.93 Å (aromatic) or 0.97 Å (methyl­ene) with Uiso(H) = 1.2Ueq(C).

Table 2
Experimental details

Crystal data
Chemical formula C8H14N22+·SO42−
Mr 234.27
Crystal system, space group Monoclinic, P21/c
Temperature (K) 150
a, b, c (Å) 12.841 (1), 6.0989 (5), 15.9642 (9)
β (°) 125.791 (4)
V3) 1014.15 (13)
Z 4
Radiation type Mo Kα
μ (mm−1) 0.32
Crystal size (mm) 0.56 × 0.44 × 0.30
 
Data collection
Diffractometer Bruker APEXII
Absorption correction Multi-scan (SADABS; Bruker, 2014[Bruker (2014). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.])
Tmin, Tmax 0.735, 0.910
No. of measured, independent and observed [I > 2σ(I)] reflections 10992, 2293, 2131
Rint 0.048
(sin θ/λ)max−1) 0.649
 
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.038, 0.114, 1.14
No. of reflections 2293
No. of parameters 160
H-atom treatment H atoms treated by a mixture of independent and constrained refinement
Δρmax, Δρmin (e Å−3) 0.38, −0.61
Computer programs: APEX2 (Bruker, 2014[Bruker (2014). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]) and SAINT (Bruker, 2014[Bruker (2014). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]), XPREP (Sheldrick, 2015[Sheldrick, G. M. (2015). Acta Cryst. C71, 3-8.]), SIR97 (Altomare et al., 1999[Altomare, A., Burla, M. C., Camalli, M., Cascarano, G. L., Giacovazzo, C., Guagliardi, A., Moliterni, A. G. G., Polidori, G. & Spagna, R. (1999). J. Appl. Cryst. 32, 115-119.]), SHELXL2014/7 (Sheldrick, 2015[Sheldrick, G. M. (2015). Acta Cryst. C71, 3-8.]) and ORTEP-3 for Windows and WinGX publication routines (Farrugia, 2012[Farrugia, L. J. (2012). J. Appl. Cryst. 45, 849-854.]).

Supporting information


Computing details top

Data collection: SAINT (Bruker, 2014) and XPREP (Sheldrick, 2015); cell refinement: APEX2 (Bruker, 2014) and SAINT (Bruker, 2014); data reduction: SAINT (Bruker, 2014) and XPREP (Sheldrick, 2015); program(s) used to solve structure: SIR97 (Altomare et al., 1999); program(s) used to refine structure: SHELXL2014/7 (Sheldrick, 2015); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012); software used to prepare material for publication: WinGX publication routines (Farrugia, 2012).

[1,3-Phenylenebis(methylene)]bis(azanium) sulfate top
Crystal data top
C8H14N22+·SO42F(000) = 496
Mr = 234.27Dx = 1.534 Mg m3
Monoclinic, P21/cMo Kα radiation, λ = 0.71073 Å
a = 12.841 (1) ÅCell parameters from 9927 reflections
b = 6.0989 (5) Åθ = 3.7–27.5°
c = 15.9642 (9) ŵ = 0.32 mm1
β = 125.791 (4)°T = 150 K
V = 1014.15 (13) Å3Prism, colourless
Z = 40.56 × 0.44 × 0.30 mm
Data collection top
APEXII, Bruker-AXS
diffractometer
2293 independent reflections
Radiation source: fine-focus sealed tube2131 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.048
CCD rotation images, thin slices scansθmax = 27.5°, θmin = 3.2°
Absorption correction: multi-scan
(SADABS; Bruker, 2014)
h = 1616
Tmin = 0.735, Tmax = 0.910k = 77
10992 measured reflectionsl = 1717
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)] = 0.038Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.114H atoms treated by a mixture of independent and constrained refinement
S = 1.14 w = 1/[σ2(Fo2) + (0.0639P)2 + 0.4545P]
where P = (Fo2 + 2Fc2)/3
2293 reflections(Δ/σ)max = 0.001
160 parametersΔρmax = 0.38 e Å3
0 restraintsΔρmin = 0.61 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.

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 (Å2) top
xyzUiso*/Ueq
S0.43829 (3)0.22666 (6)0.83072 (3)0.01170 (15)
O10.57682 (10)0.1916 (2)0.88190 (9)0.0190 (3)
O20.36751 (12)0.22945 (19)0.71797 (9)0.0236 (3)
O30.38903 (10)0.04803 (18)0.86220 (9)0.0187 (3)
O40.41947 (10)0.43848 (17)0.86666 (8)0.0155 (2)
N10.29551 (12)0.2271 (2)0.79401 (10)0.0131 (3)
C10.16854 (14)0.1870 (4)0.89148 (12)0.0256 (4)
H1A0.14230.31800.93380.031*
H1B0.17680.06990.92840.031*
C20.06392 (13)0.1263 (3)0.87945 (11)0.0158 (3)
C30.06536 (13)0.0745 (3)0.83697 (10)0.0161 (3)
H30.13570.16740.80890.019*
C40.03879 (13)0.1353 (2)0.83668 (11)0.0147 (3)
H40.03740.26890.80800.018*
C50.14527 (12)0.0016 (2)0.87887 (10)0.0125 (3)
H50.21470.04170.87890.015*
C60.14779 (13)0.2033 (2)0.92106 (11)0.0114 (3)
C70.04235 (14)0.2636 (2)0.92037 (12)0.0150 (3)
H70.04300.39850.94780.018*
C80.25953 (13)0.3597 (2)0.96596 (12)0.0160 (3)
H8A0.25670.46321.01070.019*
H8B0.25110.44210.91030.019*
N20.38513 (12)0.2467 (2)1.02553 (12)0.0175 (3)
H1N10.3194 (19)0.114 (4)0.7518 (16)0.020 (5)*
H2N10.350 (2)0.234 (3)0.8120 (18)0.027 (6)*
H3N10.299 (2)0.352 (4)0.7644 (17)0.029 (6)*
H1N20.445 (2)0.340 (4)1.0567 (16)0.021 (5)*
H2N20.387 (2)0.161 (5)1.064 (2)0.039 (7)*
H3N20.399 (3)0.172 (5)0.977 (2)0.059 (8)*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
S0.0084 (2)0.0123 (2)0.0163 (2)0.00019 (11)0.00831 (17)0.00144 (11)
O10.0099 (5)0.0250 (6)0.0266 (6)0.0029 (4)0.0133 (5)0.0046 (5)
O20.0256 (6)0.0229 (6)0.0167 (6)0.0027 (5)0.0092 (5)0.0022 (4)
O30.0199 (5)0.0146 (5)0.0308 (6)0.0049 (4)0.0201 (5)0.0037 (4)
O40.0148 (5)0.0134 (5)0.0212 (5)0.0007 (4)0.0122 (4)0.0036 (4)
N10.0098 (6)0.0150 (6)0.0167 (6)0.0016 (4)0.0091 (5)0.0017 (5)
C10.0064 (6)0.0557 (12)0.0145 (7)0.0006 (7)0.0061 (6)0.0075 (7)
C20.0066 (6)0.0296 (8)0.0114 (6)0.0004 (5)0.0054 (5)0.0016 (6)
C30.0081 (6)0.0241 (8)0.0137 (6)0.0050 (5)0.0050 (5)0.0007 (5)
C40.0129 (6)0.0159 (7)0.0138 (6)0.0015 (5)0.0070 (5)0.0016 (5)
C50.0092 (6)0.0168 (7)0.0130 (6)0.0012 (5)0.0074 (5)0.0004 (5)
C60.0063 (6)0.0161 (7)0.0122 (6)0.0003 (5)0.0056 (5)0.0004 (5)
C70.0088 (6)0.0209 (7)0.0151 (7)0.0006 (5)0.0069 (6)0.0044 (5)
C80.0079 (6)0.0138 (7)0.0247 (7)0.0008 (5)0.0087 (6)0.0035 (6)
N20.0066 (6)0.0187 (7)0.0211 (7)0.0022 (5)0.0047 (5)0.0051 (5)
Geometric parameters (Å, º) top
S—O21.4673 (12)C3—H30.9300
S—O11.4756 (10)C4—C51.3941 (19)
S—O31.4871 (11)C4—H40.9300
S—O41.4895 (11)C5—C61.393 (2)
N1—C11.4738 (19)C5—H50.9300
N1—H1N10.88 (2)C6—C71.3971 (19)
N1—H2N10.90 (3)C6—C81.5100 (19)
N1—H3N10.88 (3)C7—H70.9300
C1—C21.510 (2)C8—N21.4787 (18)
C1—H1A0.9700C8—H8A0.9700
C1—H1B0.9700C8—H8B0.9700
C2—C31.395 (2)N2—H1N20.84 (2)
C2—C71.395 (2)N2—H2N20.80 (3)
C3—C41.391 (2)N2—H3N21.00 (3)
O2—S—O1111.24 (7)C3—C4—C5120.81 (14)
O2—S—O3110.02 (7)C3—C4—H4119.6
O1—S—O3108.67 (7)C5—C4—H4119.6
O2—S—O4109.80 (6)C6—C5—C4120.08 (13)
O1—S—O4109.08 (7)C6—C5—H5120.0
O3—S—O4107.96 (6)C4—C5—H5120.0
C1—N1—H1N1110.6 (13)C5—C6—C7118.71 (13)
C1—N1—H2N1104.9 (15)C5—C6—C8122.29 (12)
H1N1—N1—H2N1107.1 (19)C7—C6—C8119.00 (13)
C1—N1—H3N1112.8 (15)C2—C7—C6121.56 (14)
H1N1—N1—H3N1112 (2)C2—C7—H7119.2
H2N1—N1—H3N1109 (2)C6—C7—H7119.2
N1—C1—C2115.06 (13)N2—C8—C6112.76 (12)
N1—C1—H1A108.5N2—C8—H8A109.0
C2—C1—H1A108.5C6—C8—H8A109.0
N1—C1—H1B108.5N2—C8—H8B109.0
C2—C1—H1B108.5C6—C8—H8B109.0
H1A—C1—H1B107.5H8A—C8—H8B107.8
C3—C2—C7119.07 (13)C8—N2—H1N2109.8 (15)
C3—C2—C1121.14 (14)C8—N2—H2N2108.8 (18)
C7—C2—C1119.50 (15)H1N2—N2—H2N2112 (2)
C4—C3—C2119.76 (13)C8—N2—H3N2109.3 (18)
C4—C3—H3120.1H1N2—N2—H3N2105 (2)
C2—C3—H3120.1H2N2—N2—H3N2112 (3)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1—H1N1···O4i0.88 (2)1.88 (2)2.7271 (17)160.1 (19)
N1—H1N1···O2i0.88 (2)2.54 (2)3.1461 (18)126.1 (16)
N1—H2N1···O1ii0.90 (3)1.85 (3)2.7191 (17)162 (2)
N1—H3N1···O3iii0.88 (3)2.03 (2)2.8264 (17)150 (2)
N1—H3N1···O2iii0.88 (3)2.54 (2)3.1733 (18)129.4 (18)
N2—H1N2···O4iv0.84 (2)1.97 (2)2.8096 (17)177 (2)
N2—H2N2···O1v0.80 (3)2.26 (3)2.9537 (18)145 (2)
N2—H3N2···O31.00 (3)1.92 (3)2.9021 (19)168 (3)
N2—H3N2···O41.00 (3)2.52 (3)3.0502 (18)113 (2)
C5—H5···O30.932.473.3050 (17)150
Symmetry codes: (i) x, y+1/2, z3/2; (ii) x+1, y, z; (iii) x, y1/2, z3/2; (iv) x1, y1, z2; (v) x1, y, z2.
 

Acknowledgements

This work was supported by the Tunisian Ministry of Higher Education Scientific Research.

References

First citationAltomare, A., Burla, M. C., Camalli, M., Cascarano, G. L., Giacovazzo, C., Guagliardi, A., Moliterni, A. G. G., Polidori, G. & Spagna, R. (1999). J. Appl. Cryst. 32, 115–119.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationBaur, W. H. (1974). Acta Cryst. B30, 1195–1215.  CrossRef CAS IUCr Journals Web of Science Google Scholar
First citationBlessing, R. H. (1986). Acta Cryst. B42, 613–621.  CSD CrossRef CAS Web of Science IUCr Journals Google Scholar
First citationBrown, I. D. (1976). Acta Cryst. A32, 24–31.  CrossRef IUCr Journals Web of Science Google Scholar
First citationBruker (2014). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.  Google Scholar
First citationCheng, H. & Li, H. (2008). Acta Cryst. E64, o2060.  Web of Science CSD CrossRef IUCr Journals Google Scholar
First citationFarrugia, L. J. (2012). J. Appl. Cryst. 45, 849–854.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationGatfaoui, S., Dhaouadi, H., Roisnel, T., Rzaigui, M. & Marouani, H. (2014). Acta Cryst. E70, o398–o399.  CSD CrossRef IUCr Journals Google Scholar
First citationJaniak, J. (2000). J. Chem. Soc. Dalton Trans. pp. 3885–3896.  Web of Science CrossRef Google Scholar
First citationJelsch, C., Ejsmont, K. & Huder, L. (2014). IUCrJ, 1, 119–128.  Web of Science CrossRef CAS PubMed IUCr Journals Google Scholar
First citationLee, S. W., Lim, S. W., Park, S. H., Ha, K., Kim, K. S., Oh, S. M., Lee, J. Y. & Seo, G. (2013). Korean J. Chem. Eng. 30, 2241–2247.  Web of Science CrossRef CAS Google Scholar
First citationMarouani, H., Rzaigui, M. & Al-Deyab, S. S. (2011a). Eur. J. Chem. 8, 1930–1936.  CAS Google Scholar
First citationMarouani, H., Rzaigui, M. & Al-Deyab, S. S. (2011b). X-ray Struct. Anal. Online, 27, 25–26.  CSD CrossRef CAS Google Scholar
First citationMurata, Y., Tsunashima, K. & Koizumi, N. (1999). Jpn. J. Appl. Phys. 38, 5148–5153.  Web of Science CrossRef CAS Google Scholar
First citationMurugesan, V., Saravanabhavan, M. & Sekar, M. (2015). J. Photochem. Photobiol. B, 148, 358–365.  Web of Science CSD CrossRef CAS PubMed Google Scholar
First citationSheldrick, G. M. (2015). Acta Cryst. C71, 3–8.  Web of Science CrossRef IUCr Journals Google Scholar
First citationWolff, S. K., Grimwood, D. J., McKinnon, J. J., Turner, M. J., Jayatilaka, D. & Spackman, M. A. (2012). CrystalExplorer. Perth: University of Western Australia.  Google Scholar

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