Crystal structure of bis­(thio­cyanato-κS)bis­(thio­urea-κS)mercury(II)

Baskaran, A.; Rajarajan, K.; NizamMohideen, M.; Sagayaraj, P.

doi:10.1107/S2056989015000584

metal-organic compounds

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Volume 71| Part 2| February 2015| Pages m28-m29

doi:10.1107/S2056989015000584

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Crystal structure of bis(thiocyanato-κS)bis(thiourea-κS)mercury(II)

A. Baskaran,^a K. Rajarajan,^a ^* M. NizamMohideen ^b ^* and P. Sagayaraj ^c

^aDepartment of Physics, Rajeswari Vedachalam Government Arts College, Chengalpet 603 001, India, ^bDepartment of Physics, The New College (Autonomous), Chennai 600 014, India, and ^cDepartment of Physics, Loyola College (Autonomous), Chennai 600 034, India
^*Correspondence e-mail: drkrr2007@gmail.com, mnizam_new@yahoo.in

Edited by H. Stoeckli-Evans, University of Neuchâtel, Switzerland (Received 6 January 2015; accepted 12 January 2015; online 17 January 2015)

In the title complex, [Hg(NCS)₂(CH₄N₂S)₂], the Hg^II atom is four-coordinated having an irregular four-coordinate geometry composed of four thione S atoms of two thiocyanate groups and two thiourea groups. The S—Hg—S angles are 172.02 (9)° for the trans-thiocyanate S atoms and 90.14 (5)° for the cis-thiourea S atoms. The molecular structure is stabilized by an intramolecular N—H⋯S hydrogen bond, which forms an S(6) ring motif. In the crystal, molecules are linked by a number of N—H⋯N and N—H⋯S hydrogen bonds, forming a three-dimensional framework. The first report of the crystal structure of this compound appeared in 1966 [Korczynski (1966 ). Rocz. Chem. 40, 547–569] with an extremely high R factor of 17.2%, and no mention of how the data were collected.

Keywords: crystal structure; thiourea; thiocyanate; mercury(II); molecular complex; hydrogen bonding.

CCDC reference: 1043131

1. Related literature

For literature on thiourea- and thiocyanate-based metal–organic crystalline materials and their derivatives, see: Ramesh et al. (2012 ); Shihabuddeen Syed et al. (2013 ). For the concept of hard and soft acids and bases, see: Ozutsumi et al. (1989 ); Bell et al. (2001 ). For the crystal structures of similar compounds, see: Nawaz et al. (2010 ); Safari et al. (2009 ); Shihabuddeen Syed et al. (2013). For the first report of the crystal structure of the title compound, see: Korczynski (1966).

2. Experimental

2.1. Crystal data

[Hg(NCS)₂(CH₄N₂S)₂]
M_r = 468.99
Orthorhombic, P b c 2₁
a = 8.5359 (5) Å
b = 9.0337 (5) Å
c = 15.7575 (10) Å
V = 1215.07 (12) Å³
Z = 4
Mo Kα radiation
μ = 13.33 mm⁻¹
T = 293 K
0.20 × 0.20 × 0.15 mm

2.2. Data collection

Bruker Kappa APEXII CCD diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 2004 ) T_min = 0.176, T_max = 0.240
19798 measured reflections
2397 independent reflections
2158 reflections with I > 2σ(I)
R_int = 0.058

2.3. Refinement

R[F² > 2σ(F²)] = 0.029
wR(F²) = 0.075
S = 1.15
2397 reflections
137 parameters
1 restraint
H-atom parameters constrained
Δρ_max = 1.44 e Å⁻³
Δρ_min = −1.03 e Å⁻³
Absolute structure: Flack (1983 ), 1149 Freidel pairs.
Absolute structure parameter: 0.034 (12)

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N3—H3B⋯S1	0.86	2.55	3.404 (7)	174
N3—H3A⋯N2ⁱ	0.86	2.37	3.103 (10)	143
N4—H4A⋯N2ⁱ	0.86	2.17	2.952 (10)	151
N4—H4B⋯N1ⁱⁱ	0.86	2.56	3.085 (11)	121
N5—H5A⋯N1ⁱⁱⁱ	0.86	2.26	3.025 (10)	149
N5—H5A⋯S4^iv	0.86	2.80	3.384 (7)	126
N5—H5B⋯N2^v	0.86	2.21	3.025 (10)	158
N6—H6A⋯N1ⁱⁱⁱ	0.86	2.25	3.019 (10)	149
N6—H6B⋯S2^vi	0.86	2.56	3.419 (8)	172
Symmetry codes: (i) $[-x+1, y-{\script{1\over 2}}, z]$ ; (ii) $[x, -y+{\script{3\over 2}}, z+{\script{1\over 2}}]$ ; (iii) x-1, y, z; (iv) $[-x, -y+2, z-{\script{1\over 2}}]$ ; (v) $[x, -y+{\script{5\over 2}}, z-{\script{1\over 2}}]$ ; (vi) $[-x, y-{\script{1\over 2}}, z]$ .

Data collection: APEX2 (Bruker, 2004 ); cell refinement: APEX2 and SAINT (Bruker, 2004); data reduction: SAINT and XPREP (Bruker, 2004); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 2015 ); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012 ) and PLATON (Spek, 2009 ); software used to prepare material for publication: WinGX (Farrugia, 2012) and PLATON.

Supporting information

CCDC reference: 1043131

Crystal structure: contains datablocks global, I. DOI: 10.1107/S2056989015000584/su5058sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S2056989015000584/su5058Isup2.hkl

checkCIF report

Synthesis and crystallization top

A mixture of thiourea, ammonium thiocyanate and mercury (II) chloride were dissolved in aqueous solution in the molar ratio 2:2:1 and thoroughly mixed for 1 h to obtain a homogeneous mixture. The solution was allowed to evaporate slowly at ambient temperature. Colourless block-like crystals were obtained in a week.

Refinement top

All the H atoms were positioned geometrically with N—H = 0.86 Å and constrained to ride on their parent atoms with U_iso(H) = 1.2U_eq(N).

Comment top

This work is part of a research project concerning the investigation of thiourea (N₂H₄CS) and thiocyanate (SCN) based metal organic crystalline materials and their derivatives (Ramesh et al., 2012; Shihabuddeen Syed et al., 2013). Transition metal thiourea and thiocyanate coordination complexes are candidate materials for device applications including their nonlinear optical properties. As ligands, both thiourea and thiocyanate are interesting due to their potential formation of metal coordination complexes as they exhibit multifunctional coordination modes due to the presence of 'S' and 'N' donor atoms. With reference to the hard and soft acids and bases) concept (Ozutsumi et al., 1989; Bell et al., 2001), the soft cations show a pronounced affinity for coordination with the softer ligands, while hard cations prefer coordination with harder ligands. Several crystallographic reports about mercury(II) complexes usually consist of discrete monomeric molecules with tetrahedral (somewhat distorted) coordination environments around mercury(II) (Nawaz et al., 2010). Herein, we report on the synthesis and crystal structure of the title complex.

The title monomeric complex is composed of two thiocyanate and two thiourea ligands coordinated to the Hg atom via the softer thione S atom (Fig. 1). The four-coordinate mercury atom adopts a severely distorted tetrahedral geometry. The S—Hg—S angles are S3-Hg1-S4 = 172.02 (9) ° for the trans thiocyanate S atoms and S1-Hg1-S2 = 90.14 (5) ° for the trans thiourea S atoms. The bond distances Hg1-S3 and Hg1-S4 are 2.390 (3) and 2.381 (3) Å, respectively, while bond distances Hg1—S1 and Hg1—S2 are 3.064818) and 3.0836 (18) Å, respectively. Bond distances and angles are in agreement with those reported for related compounds (Shihabuddeen Syed et al., 2013; Safari et al., 2009; Nawaz et al., 2010). The SCN moiety is planar [to within 0.007 (1) Å with the C-N and C-S bond lengths corresponding to the values intermediate between single and double bonds. The S2-C2-N2 and S1-C1-N1 units are nearly linear with bond angles of 178.5 (7) and 179.4 (8)°, respectively. The compound is closely related with (thiocyanato-kS)tris(thiourea-kS)mercury(II) chloride (Shihabuddeen Syed et al., 2013). The molecular structure is stabilized by intramolecular an N-H···S hydrogen bond, which forms an S(6) ring motif (Fig. 1 and Table 1).

In the crystal, molecules are connected via N-H···N hydrogen bonds, involving the thiourea NH₂ H atoms and the thiocyanate N atom (Fig. 2 and Table 1). This gives rise to the formation of a three-dimensional framework which is reinforced by N-H···S hydrogen bonds (Fig. 2 and Table 1).

The first report of the crystal structure of the title compound appeared in 1966 (Korczynski, 1966) with an extremely high R factor of 17.2 %, and no mention of how the data were collected.

Related literature top

For literature on thiourea- and thiocyanate-based metal–organic crystalline materials and their derivatives, see: Ramesh et al. (2012); Shihabuddeen Syed et al. (2013). For the concept of hard and soft acids and bases, see: Ozutsumi et al. (1989); Bell et al. (2001). For the crystal structures of similar compounds, see: Nawaz et al. (2010); Safari et al. (2009); Shihabuddeen Syed et al. (2013). For the first report of the crystal structure of the title compound, see: Korczynski (1966).

Computing details top

Data collection: APEX2 (Bruker, 2004); cell refinement: APEX2 and SAINT (Bruker, 2004); data reduction: SAINT and XPREP (Bruker, 2004); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2015); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012) and PLATON (Spek, 2009); software used to prepare material for publication: WinGX (Farrugia, 2012) and PLATON (Spek, 2009).

Figures top

	Fig. 1. A view of the molecular structure of the title complex, with atom labelling. Displacement ellipsoids are drawn at the 50% probability level. The intramolecular N—H···S hydrogen bond is shown as a double dashed line (see Table 1 for details).
	Fig. 2. The crystal packing of the title complex, viewed along the a axis. Hydrogen bonds are shown as dashed lines (see Table 1 for details).

Bis(thiocyanato-κS)bis(thiourea-κS)mercury(II) top

Crystal data top

[Hg(NCS)₂(CH₄N₂S)₂]	F(000) = 872
M_r = 468.99	D_x = 2.564 Mg m⁻³
Orthorhombic, Pbc2₁	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2c -2b	Cell parameters from 2397 reflections
a = 8.5359 (5) Å	θ = 2.4–31.2°
b = 9.0337 (5) Å	µ = 13.33 mm⁻¹
c = 15.7575 (10) Å	T = 293 K
V = 1215.07 (12) Å³	Block, colourless
Z = 4	0.20 × 0.20 × 0.15 mm

Data collection top

Bruker Kappa APEXII CCD diffractometer	2397 independent reflections
Radiation source: fine-focus sealed tube	2158 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.058
ω and ϕ scans	θ_max = 26.0°, θ_min = 2.4°
Absorption correction: multi-scan (SADABS; Sheldrick, 2004)	h = −10→10
T_min = 0.176, T_max = 0.240	k = −11→11
19798 measured reflections	l = −19→19

Refinement top

Refinement on F²	Hydrogen site location: inferred from neighbouring sites
Least-squares matrix: full	H-atom parameters constrained
R[F² > 2σ(F²)] = 0.029	w = 1/[σ²(F_o²) + (0.0237P)² + 4.6956P] where P = (F_o² + 2F_c²)/3
wR(F²) = 0.075	(Δ/σ)_max = 0.001
S = 1.15	Δρ_max = 1.44 e Å⁻³
2397 reflections	Δρ_min = −1.03 e Å⁻³
137 parameters	Extinction correction: SHELXL97 (Sheldrick, 2008), Fc^*=kFc[1+0.001xFc²λ³/sin(2θ)]^-1/4
1 restraint	Extinction coefficient: 0.0082 (3)
Primary atom site location: structure-invariant direct methods	Absolute structure: Flack (1983), 1149 Freidel pairs.
Secondary atom site location: difference Fourier map	Absolute structure parameter: 0.034 (12)

Crystal data top

[Hg(NCS)₂(CH₄N₂S)₂]	V = 1215.07 (12) Å³
M_r = 468.99	Z = 4
Orthorhombic, Pbc2₁	Mo Kα radiation
a = 8.5359 (5) Å	µ = 13.33 mm⁻¹
b = 9.0337 (5) Å	T = 293 K
c = 15.7575 (10) Å	0.20 × 0.20 × 0.15 mm

Data collection top

Bruker Kappa APEXII CCD diffractometer	2397 independent reflections
Absorption correction: multi-scan (SADABS; Sheldrick, 2004)	2158 reflections with I > 2σ(I)
T_min = 0.176, T_max = 0.240	R_int = 0.058
19798 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.029	H-atom parameters constrained
wR(F²) = 0.075	Δρ_max = 1.44 e Å⁻³
S = 1.15	Δρ_min = −1.03 e Å⁻³
2397 reflections	Absolute structure: Flack (1983), 1149 Freidel pairs.
137 parameters	Absolute structure parameter: 0.034 (12)
1 restraint

Special details top

Geometry. Bond distances, angles etc. have been calculated using the rounded fractional coordinates. All su's are estimated from the variances of the (full) variance-covariance matrix. The cell esds are taken into account in the estimation of distances, angles and torsion angles

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 (Å²) top

	x	y	z	U_iso*/U_eq
Hg1	0.25569 (4)	0.89378 (3)	0.72851 (8)	0.0374 (1)
S1	0.4564 (2)	1.1691 (2)	0.69569 (13)	0.0336 (6)
S2	−0.0283 (2)	1.0924 (2)	0.76929 (13)	0.0334 (6)
S3	0.2017 (3)	0.8900 (3)	0.57967 (14)	0.0329 (7)
S4	0.3068 (3)	0.8610 (3)	0.87589 (15)	0.0353 (7)
N1	0.6053 (9)	1.0000 (9)	0.5700 (5)	0.041 (3)
N2	0.0984 (9)	1.2628 (8)	0.9017 (5)	0.037 (3)
N3	0.6051 (8)	0.9346 (7)	0.8444 (5)	0.034 (2)
N4	0.5630 (8)	0.7508 (9)	0.9391 (4)	0.039 (2)
N5	−0.0507 (8)	1.0248 (7)	0.5262 (4)	0.031 (2)
N6	−0.0982 (7)	0.8404 (8)	0.6204 (5)	0.032 (2)
C1	0.5444 (9)	1.0700 (9)	0.6213 (5)	0.026 (2)
C2	0.0478 (9)	1.1927 (9)	0.8463 (5)	0.025 (2)
C3	0.5073 (8)	0.8485 (9)	0.8853 (5)	0.026 (2)
C4	0.0009 (9)	0.9200 (8)	0.5772 (4)	0.022 (2)
H3A	0.70430	0.92670	0.85300	0.0410*
H3B	0.57020	0.99910	0.80900	0.0410*
H4A	0.66240	0.74400	0.94710	0.0460*
H4B	0.50010	0.69370	0.96640	0.0460*
H5A	−0.14960	1.04050	0.52150	0.0370*
H5B	0.01460	1.07740	0.49760	0.0370*
H6A	−0.19710	0.85630	0.61570	0.0380*
H6B	−0.06470	0.77190	0.65370	0.0380*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Hg1	0.0319 (2)	0.0600 (2)	0.0205 (2)	−0.0029 (1)	−0.0073 (2)	0.0032 (3)
S1	0.0359 (11)	0.0344 (10)	0.0304 (10)	−0.0005 (9)	−0.0003 (8)	−0.0009 (9)
S2	0.0319 (11)	0.0370 (10)	0.0314 (11)	0.0017 (9)	0.0016 (9)	−0.0026 (9)
S3	0.0231 (10)	0.0548 (14)	0.0209 (11)	0.0038 (9)	−0.0006 (9)	−0.0002 (9)
S4	0.0243 (11)	0.0616 (14)	0.0200 (11)	0.0005 (10)	0.0013 (9)	−0.0005 (10)
N1	0.035 (4)	0.051 (5)	0.038 (4)	0.000 (4)	0.003 (4)	−0.005 (4)
N2	0.039 (4)	0.035 (4)	0.037 (5)	0.002 (3)	−0.002 (3)	0.002 (3)
N3	0.026 (4)	0.033 (4)	0.044 (4)	−0.001 (3)	−0.005 (3)	0.011 (3)
N4	0.041 (4)	0.044 (4)	0.031 (4)	0.010 (3)	−0.005 (3)	0.009 (3)
N5	0.031 (4)	0.031 (4)	0.030 (4)	0.000 (3)	−0.003 (3)	0.006 (3)
N6	0.026 (3)	0.036 (4)	0.033 (4)	−0.001 (3)	−0.007 (3)	0.007 (3)
C1	0.024 (4)	0.032 (4)	0.022 (4)	−0.004 (3)	−0.004 (3)	0.008 (3)
C2	0.025 (4)	0.036 (4)	0.015 (4)	0.003 (3)	0.005 (3)	0.011 (3)
C3	0.028 (4)	0.031 (4)	0.019 (4)	0.008 (3)	−0.002 (3)	−0.010 (3)
C4	0.028 (4)	0.026 (4)	0.012 (4)	0.001 (3)	−0.005 (3)	−0.001 (3)

Geometric parameters (Å, º) top

Hg1—S1	3.0641 (18)	N4—C3	1.313 (11)
Hg1—S2	3.0836 (18)	N5—C4	1.318 (9)
Hg1—S3	2.390 (3)	N6—C4	1.302 (10)
Hg1—S4	2.381 (3)	N3—H3A	0.8600
S1—C1	1.655 (8)	N3—H3B	0.8600
S2—C2	1.648 (8)	N4—H4A	0.8600
S3—C4	1.736 (8)	N4—H4B	0.8600
S4—C3	1.722 (7)	N5—H5A	0.8600
N1—C1	1.151 (11)	N5—H5B	0.8600
N2—C2	1.162 (11)	N6—H6A	0.8600
N3—C3	1.310 (10)	N6—H6B	0.8600

S1—Hg1—S2	90.14 (5)	C3—N3—H3A	120.00
S1—Hg1—S3	87.35 (8)	C3—N3—H3B	120.00
S1—Hg1—S4	99.39 (8)	H3A—N3—H3B	120.00
S2—Hg1—S3	93.51 (8)	S3—C4—N5	117.1 (6)
S2—Hg1—S4	90.75 (8)	S3—C4—N6	122.9 (6)
S3—Hg1—S4	172.02 (9)	N5—C4—N6	119.9 (7)
Hg1—S1—C1	86.2 (3)	C3—N4—H4A	120.00
Hg1—S2—C2	99.4 (3)	C3—N4—H4B	120.00
Hg1—S3—C4	102.1 (2)	H4A—N4—H4B	120.00
Hg1—S4—C3	105.9 (3)	C4—N5—H5A	120.00
S1—C1—N1	179.4 (8)	C4—N5—H5B	120.00
S2—C2—N2	178.4 (8)	H5A—N5—H5B	120.00
S4—C3—N3	123.5 (6)	C4—N6—H6A	120.00
S4—C3—N4	117.4 (6)	C4—N6—H6B	120.00
N3—C3—N4	119.1 (7)	H6A—N6—H6B	120.00

S2—Hg1—S1—C1	−145.2 (3)	S2—Hg1—S3—C4	−26.2 (3)
S3—Hg1—S1—C1	−51.7 (3)	S1—Hg1—S4—C3	−55.8 (3)
S4—Hg1—S1—C1	124.0 (3)	S2—Hg1—S4—C3	−146.1 (3)
S1—Hg1—S2—C2	−56.6 (3)	Hg1—S3—C4—N6	−53.0 (7)
S3—Hg1—S2—C2	−144.0 (3)	Hg1—S3—C4—N5	129.8 (5)
S4—Hg1—S2—C2	42.8 (3)	Hg1—S4—C3—N4	−139.9 (6)
S1—Hg1—S3—C4	−116.2 (3)	Hg1—S4—C3—N3	42.8 (8)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N3—H3B···S1	0.86	2.55	3.404 (7)	174
N3—H3A···N2ⁱ	0.86	2.37	3.103 (10)	143
N4—H4A···N2ⁱ	0.86	2.17	2.952 (10)	151
N4—H4B···N1ⁱⁱ	0.86	2.56	3.085 (11)	121
N5—H5A···N1ⁱⁱⁱ	0.86	2.26	3.025 (10)	149
N5—H5A···S4^iv	0.86	2.80	3.384 (7)	126
N5—H5B···N2^v	0.86	2.21	3.025 (10)	158
N6—H6A···N1ⁱⁱⁱ	0.86	2.25	3.019 (10)	149
N6—H6B···S2^vi	0.86	2.56	3.419 (8)	172

Symmetry codes: (i) −x+1, y−1/2, z; (ii) x, −y+3/2, z+1/2; (iii) x−1, y, z; (iv) −x, −y+2, z−1/2; (v) x, −y+5/2, z−1/2; (vi) −x, y−1/2, z.

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N3—H3B···S1	0.86	2.55	3.404 (7)	174
N3—H3A···N2ⁱ	0.86	2.37	3.103 (10)	143
N4—H4A···N2ⁱ	0.86	2.17	2.952 (10)	151
N4—H4B···N1ⁱⁱ	0.86	2.56	3.085 (11)	121
N5—H5A···N1ⁱⁱⁱ	0.86	2.26	3.025 (10)	149
N5—H5A···S4^iv	0.86	2.80	3.384 (7)	126
N5—H5B···N2^v	0.86	2.21	3.025 (10)	158
N6—H6A···N1ⁱⁱⁱ	0.86	2.25	3.019 (10)	149
N6—H6B···S2^vi	0.86	2.56	3.419 (8)	172

Symmetry codes: (i) −x+1, y−1/2, z; (ii) x, −y+3/2, z+1/2; (iii) x−1, y, z; (iv) −x, −y+2, z−1/2; (v) x, −y+5/2, z−1/2; (vi) −x, y−1/2, z.

Acknowledgements

The authors are grateful to the SAIF, IIT, Madras, India, for the data collection. KR thanks the University Grants Commission, Government of India, for financial support granted under a Major Research Project [F. No. 41–1008/2012 (SR)].

References

Bell, N. A., Branston, T. N., Clegg, W., Parker, L., Raper, E. S., Sammon, C. & Constable, C. P. (2001). Inorg. Chim. Acta, 319, 130–136. Web of Science CSD CrossRef CAS Google Scholar
Bruker (2004). APEX2, SAINT and XPREP. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Farrugia, L. J. (2012). J. Appl. Cryst. 45, 849–854. Web of Science CrossRef CAS IUCr Journals Google Scholar
Flack, H. D. (1983). Acta Cryst. A39, 876–881. CrossRef CAS Web of Science IUCr Journals Google Scholar
Korczynski, A. (1966). Rocz. Chem. 40, 547–569. Google Scholar
Nawaz, S., Sadaf, H., Fettouhi, M., Fazal, A. & Ahmad, S. (2010). Acta Cryst. E66, m952. Web of Science CSD CrossRef IUCr Journals Google Scholar
Ozutsumi, K., Takamuku, T., Ishiguro, S. & Ohtaki, H. (1989). Bull. Chem. Soc. Jpn, 62, 1875–1879. Google Scholar
Ramesh, V., Rajarajan, K., Kumar, K. S., Subashini, A. & NizamMohideen, M. (2012). Acta Cryst. E68, m335–m336. CSD CrossRef CAS IUCr Journals Google Scholar
Safari, N., Amani, V., Abedi, A., Notash, B. & Ng, S. W. (2009). Acta Cryst. E65, m372. Web of Science CSD CrossRef IUCr Journals Google Scholar
Sheldrick, G. M. (2004). SADABS. University of Göttingen, Germany. Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Sheldrick, G. M. (2015). Acta Cryst. C71, 3–8. Web of Science CrossRef IUCr Journals Google Scholar
Shihabuddeen Syed, A., Rajarajan, K. & NizamMohideen, M. (2013). Acta Cryst. E69, i33. CrossRef IUCr Journals Google Scholar
Spek, A. L. (2009). Acta Cryst. D65, 148–155. Web of Science CrossRef CAS IUCr Journals Google Scholar

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ISSN: 2056-9890

Volume 71| Part 2| February 2015| Pages m28-m29

doi:10.1107/S2056989015000584

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