1H,3H-Imidazolium (R,S)-camphor-10-sulfonate

Abdul Rahman, M.B.; Omar, E.M.; Ng, S.L.; Kia, R.; Fun, H.-K.

doi:10.1107/S1600536808043742

organic compounds

CRYSTALLOGRAPHIC
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ISSN: 2056-9890

Volume 65| Part 2| February 2009| Pages o224-o225

doi:10.1107/S1600536808043742

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1H,3H-Imidazolium (R,S)-camphor-10-sulfonate

Mohd Basyaruddin Abdul Rahman,^a ‡ Emmy Maryati Omar,^a Shie Ling Ng,^b Reza Kia ^c and Hoong-Kun Fun ^c ^*

^aDepartment of Chemistry, Faculty of Science, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia, ^bQueen's University Ionic Liquid Laboratory (QUILL), David Keir Building, Stransmillis Road, BT9 5AG Belfast, Northern Ireland, United Kingdom, and ^cX-ray Crystallography Unit, School of Physics, Universiti Sains Malaysia, 11800 USM, Penang, Malaysia
^*Correspondence e-mail: hkfun@usm.my

(Received 4 December 2008; accepted 23 December 2008; online 8 January 2009)

The title compound, C₃H₅N₂⁺·C₁₀H₁₅O₄S⁻, comprises two crystallographically independent ion pairs (A and B) in the asymmetric unit with slightly different conformations due to the disordered methyl groups in the anion of molecule A. Two intramolecular C—H⋯O hydrogen bonds generate S(6) ring motifs. In molecule A, the methyl groups are disordered over two sets of positions with a site-ocuppancy ratio of 0.547 (9):0.453 (9). Extensive intermolecular N—H⋯O and C—H⋯O hydrogen-bonding interactions occur in the crystal structure which link the molecules into a two-dimensional network parallel to the (100) plane.

Related literature

For hydrogen-bond motifs, see: Bernstein et al. (1995 ). For bond-length data, see: Allen et al. (1987 ). For general background, see: Fukumoto et al. (2005 ); Jeremić et al. (2008 ).

Experimental

Crystal data

C₃H₅N₂⁺·C₁₀H₁₅O₄S⁻
M_r = 300.37
Monoclinic, P 2₁
a = 9.1362 (2) Å
b = 12.0126 (2) Å
c = 13.2526 (3) Å
β = 90.757 (1)°
V = 1454.34 (5) Å³
Z = 4
Mo Kα radiation
μ = 0.24 mm⁻¹
T = 100.0 (1) K
0.46 × 0.45 × 0.19 mm

Data collection

Bruker SMART APEXII CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2005 ) T_min = 0.900, T_max = 0.956
25973 measured reflections
9954 independent reflections
9652 reflections with I > 2σ(I)
R_int = 0.022

Refinement

R[F² > 2σ(F²)] = 0.031
wR(F²) = 0.083
S = 1.07
9954 reflections
355 parameters
1 restraint
H-atom parameters constrained
Δρ_max = 0.53 e Å⁻³
Δρ_min = −0.34 e Å⁻³
Absolute structure: Flack (1983 ), 4199 Friedel pairs
Flack parameter: 0.01 (3)

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N1A—H1AC⋯O2Bⁱ	0.86	2.46	2.9479 (14)	116
N1A—H1AC⋯O3Aⁱⁱ	0.86	2.00	2.8293 (14)	161
N2A—H2AA⋯O1Bⁱⁱⁱ	0.86	1.89	2.7235 (14)	164
N1B—H1BC⋯O1Aⁱ	0.86	1.88	2.7231 (14)	165
N2B—H2BA⋯O2Bⁱⁱⁱ	0.86	1.97	2.7412 (14)	148
N2B—H2BA⋯O3A^iv	0.86	2.43	3.0111 (14)	125
C7A—H7AB⋯O1A	0.97	2.53	3.0257 (19)	111
C11A—H11A⋯O2Bⁱ	0.93	2.49	2.9716 (16)	113
C11A—H11A⋯O3Bⁱ	0.93	2.35	3.2648 (15)	170
C11B—H11B⋯O2A^iv	0.93	2.33	3.2103 (16)	159
C9A—H9AC⋯O2Aⁱ	0.96	2.59	3.469 (3)	152
C12B—H12B⋯O3Bⁱ	0.93	2.39	2.9950 (15)	122
C12B—H12B⋯O4Aⁱ	0.93	2.49	3.0155 (16)	116
C13A—H13A⋯O2Aⁱⁱⁱ	0.93	2.44	3.0167 (16)	120
C13A—H13A⋯O4Aⁱⁱⁱ	0.93	2.39	3.2591 (17)	155
C13B—H13B⋯O1Bⁱⁱⁱ	0.93	2.58	3.2720 (16)	131
C7B—H7BA⋯O2B	0.97	2.47	3.0613 (16)	119
C5A—H5AA⋯Cg1	0.98	2.83	3.5459 (5)	131
Symmetry codes: (i) x-1, y, z; (ii) x-1, y, z+1; (iii) $[-x+2, y-{\script{1\over 2}}, -z+1]$ ; (iv) $[-x+2, y-{\script{1\over 2}}, -z]$ .

Data collection: APEX2 (Bruker, 2005); cell refinement: SAINT (Bruker, 2005); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2008 ); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL and PLATON (Spek, 2003 ).

Supporting information

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536808043742/ww2136sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536808043742/ww2136Isup2.hkl

checkCIF report

Comment top

The title compound, (I, Fig. 1), is based on alkyl-imidazole with plant acid as anion (halogen-free). Crystallization of the 1,3-dihydrogenimidazolium camphor-10 -sulfonate having a sulfonate ion as a counter-ion was achieved by a slow evaporation of methanol at ambient temperature. Camphorsulfonate anion was selected due to their low toxicity for biocatalysis applications (Jeremić et al., 2008). The title compound has strong ion-ion interactions between cations and anions, which was attributed to an increase in the van der Waals attraction between the alkyl groups (Fukumoto et al., 2005).

In the title compound (I, Fig. 1), the bond lengths (Allen et al., 1987) and angles are within the normal ranges. There are two intramolecular C—H···O interactions generating six-membered rings with S(6) ring motifs (Bernstein et al., 1995). In the molecule A, the methyl groups are disordered over two positions and refined isotropically with site-ocuppancy ratio of 0.547 (9)/0.453 (9). In the crystal structure, molecules are linked together into 1-D infinite chains along the b axis, and are also linked into 1-D infinite chains along the c axis, thus forming a 2-D network which is parallel to the (100)-plane. The crystal structure is stabilized by intermolecular N—H···O (x 6) and C—H···O (x 9) hydrogen bonds, and weak intermlecular C—H···π interactions (Cg1 is the centroid of the N1B/C11B/N2B/C13B/C12B ring).

Related literature top

For hydrogen-bond motifs, see: Bernstein et al. (1995). For bond-length data, see: Allen et al. (1987). For general background, see: Fukumoto et al. (2005); Jeremić et al. (2008).

Experimental top

(R)-(-)-Camphor-10-sulfonic acid (0.05 mol, 7.504 g) was added to imidazole (0.05 mol, 3.404 g) which was first dissolved in 20 ml of methanol. The mixture was stirred (150 rpm) for 2 h at room temperature and the excess methanol was removed in vacuo at 343 K. The final product was obtained as a white solid with 97% yield. It was then dried under high vacuum for 2 days. m.p. 559.77 K. Single Crystals suitable for X-ray analysis was obtained from methanol. Anal. Calc.: C, 51.98; H, 6.71; N, 9.33; O, 21.31; S, 10.67. Found: C, 51.97; H, 6.77; N, 9.11; O, 21.38; S, 10.77%.

Computing details top

Data collection: APEX2 (Bruker, 2005); cell refinement: SAINT (Bruker, 2005); data reduction: SAINT (Bruker, 2005); program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008) and PLATON (Spek, 2003).

Figures top

	Fig. 1. The molecular structure of (I) with atom labels and 30% probability ellipsoids for non-H atoms. Intramolecular interactions are shown as dashed lines. Open bonds show the minor component.
	Fig. 2. The crystal packing of (I), viewed down the a-axis showing infinite 1-D chains along the b and c-axes of the unit cell. Intermolecular interactions are shown as dashed lines. Only the major component of molecule A is shown.

1H,3H-Imidazolium (2R,5S)-camphor-10-sulfonate top

Crystal data top

C₃H₅N₂⁺·C₁₀H₁₅O₄S⁻	F(000) = 640
M_r = 300.37	D_x = 1.372 Mg m⁻³
Monoclinic, P2₁	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2yb	Cell parameters from 9809 reflections
a = 9.1362 (2) Å	θ = 2.3–38.9°
b = 12.0126 (2) Å	µ = 0.24 mm⁻¹
c = 13.2526 (3) Å	T = 100 K
β = 90.757 (1)°	Block, colourless
V = 1454.34 (5) Å³	0.46 × 0.45 × 0.19 mm
Z = 4

Data collection top

Bruker SMART APEXII CCD area-detector diffractometer	9954 independent reflections
Radiation source: fine-focus sealed tube	9652 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.022
ϕ and ω scans	θ_max = 32.5°, θ_min = 1.5°
Absorption correction: multi-scan (SADABS; Bruker, 2005)	h = −13→13
T_min = 0.900, T_max = 0.956	k = −17→18
25973 measured reflections	l = −17→20

Refinement top

Refinement on F²	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F² > 2σ(F²)] = 0.031	H-atom parameters constrained
wR(F²) = 0.083	w = 1/[σ²(F_o²) + (0.047P)² + 0.3247P] where P = (F_o² + 2F_c²)/3
S = 1.07	(Δ/σ)_max = 0.002
9954 reflections	Δρ_max = 0.53 e Å⁻³
355 parameters	Δρ_min = −0.34 e Å⁻³
1 restraint	Absolute structure: Flack (1983), 4199 Friedel pairs
Primary atom site location: structure-invariant direct methods	Absolute structure parameter: 0.01 (3)

Crystal data top

C₃H₅N₂⁺·C₁₀H₁₅O₄S⁻	V = 1454.34 (5) Å³
M_r = 300.37	Z = 4
Monoclinic, P2₁	Mo Kα radiation
a = 9.1362 (2) Å	µ = 0.24 mm⁻¹
b = 12.0126 (2) Å	T = 100 K
c = 13.2526 (3) Å	0.46 × 0.45 × 0.19 mm
β = 90.757 (1)°

Data collection top

Bruker SMART APEXII CCD area-detector diffractometer	9954 independent reflections
Absorption correction: multi-scan (SADABS; Bruker, 2005)	9652 reflections with I > 2σ(I)
T_min = 0.900, T_max = 0.956	R_int = 0.022
25973 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.031	H-atom parameters constrained
wR(F²) = 0.083	Δρ_max = 0.53 e Å⁻³
S = 1.07	Δρ_min = −0.34 e Å⁻³
9954 reflections	Absolute structure: Flack (1983), 4199 Friedel pairs
355 parameters	Absolute structure parameter: 0.01 (3)
1 restraint

Special details top

Experimental. The low-temperature data was collected with the Oxford Cyrosystem Cobra low-temperature attachment.

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 (Å²) top

	x	y	z	U_iso*/U_eq	Occ. (<1)
S1A	1.27663 (3)	0.30766 (2)	−0.033021 (19)	0.01112 (5)
O1A	1.29170 (10)	0.19188 (8)	0.00012 (7)	0.01629 (16)
O2A	1.37452 (10)	0.38323 (9)	0.02074 (7)	0.01975 (18)
O3A	1.28934 (9)	0.31774 (8)	−0.14282 (6)	0.01632 (16)
O4A	1.17524 (10)	0.29350 (10)	0.20717 (7)	0.0227 (2)
C1A	1.09258 (13)	0.35344 (13)	−0.00674 (10)	0.0230 (3)
H1AA	1.0990	0.4290	0.0189	0.028*
H1AB	1.0396	0.3569	−0.0706	0.028*
C2A	1.00007 (12)	0.28760 (11)	0.06562 (9)	0.0161 (2)
C3A	1.05299 (13)	0.27735 (10)	0.17433 (9)	0.0146 (2)
C4A	0.91989 (14)	0.24497 (12)	0.23603 (10)	0.0206 (2)
H4AA	0.8990	0.3005	0.2870	0.025*
H4AB	0.9338	0.1733	0.2684	0.025*
C5A	0.79837 (14)	0.24006 (14)	0.15568 (11)	0.0238 (3)
H5AA	0.6991	0.2465	0.1822	0.029*
C6A	0.8249 (2)	0.13498 (19)	0.09277 (16)	0.0449 (5)
H6AA	0.7441	0.1211	0.0463	0.054*
H6AB	0.8390	0.0703	0.1356	0.054*
C7A	0.96719 (18)	0.16430 (16)	0.03538 (13)	0.0334 (4)
H7AA	0.9522	0.1576	−0.0370	0.040*
H7AB	1.0470	0.1158	0.0560	0.040*
C8A	0.84295 (13)	0.33538 (17)	0.08391 (10)	0.0290 (3)
C9A	0.7508 (3)	0.3652 (4)	−0.0072 (2)	0.0259 (7)*	0.547 (9)
H9AA	0.7369	0.3004	−0.0486	0.039*	0.547 (9)
H9AB	0.7993	0.4219	−0.0452	0.039*	0.547 (9)
H9AC	0.6574	0.3923	0.0143	0.039*	0.547 (9)
C9C	0.7443 (3)	0.3212 (4)	−0.0153 (2)	0.0206 (8)*	0.453 (9)
H9CA	0.7518	0.2461	−0.0395	0.031*	0.453 (9)
H9CB	0.7775	0.3717	−0.0663	0.031*	0.453 (9)
H9CC	0.6441	0.3374	0.0001	0.031*	0.453 (9)
C10A	0.8557 (3)	0.4563 (2)	0.1473 (2)	0.0172 (6)*	0.547 (9)
H10A	0.9196	0.4470	0.2047	0.026*	0.547 (9)
H10B	0.7604	0.4783	0.1694	0.026*	0.547 (9)
H10C	0.8945	0.5127	0.1038	0.026*	0.547 (9)
C10C	0.8303 (4)	0.4391 (3)	0.1224 (3)	0.0212 (8)*	0.453 (9)
H10D	0.7510	0.4773	0.0890	0.032*	0.453 (9)
H10E	0.9197	0.4793	0.1123	0.032*	0.453 (9)
H10F	0.8110	0.4344	0.1934	0.032*	0.453 (9)
N1A	0.44499 (11)	0.14307 (9)	0.76374 (8)	0.01573 (18)*
H1AC	0.3885	0.1977	0.7787	0.019*
N2A	0.56872 (12)	0.02395 (9)	0.67786 (8)	0.01563 (18)
H2AA	0.6054	−0.0114	0.6278	0.019*
C11A	0.47931 (13)	0.11135 (11)	0.67088 (9)	0.0155 (2)
H11A	0.4466	0.1445	0.6113	0.019*
C12A	0.51470 (14)	0.07405 (12)	0.83219 (9)	0.0176 (2)
H12A	0.5091	0.0780	0.9021	0.021*
C13A	0.59299 (14)	−0.00070 (11)	0.77835 (10)	0.0177 (2)
H13A	0.6516	−0.0575	0.8042	0.021*
S1B	1.29554 (3)	0.33636 (2)	0.532398 (19)	0.01117 (5)
O1B	1.30840 (10)	0.45125 (8)	0.49628 (7)	0.01658 (16)
O2B	1.32660 (9)	0.32743 (8)	0.64062 (6)	0.01474 (15)
O3B	1.37993 (10)	0.25718 (8)	0.47370 (7)	0.01687 (17)
O4B	0.95635 (13)	0.47418 (10)	0.40752 (8)	0.0267 (2)
C1B	1.10979 (12)	0.29462 (11)	0.51462 (9)	0.0165 (2)
H1BA	1.0902	0.2916	0.4426	0.020*
H1BB	1.1005	0.2193	0.5402	0.020*
C2B	0.98994 (12)	0.36491 (10)	0.56233 (9)	0.0141 (2)
C3B	0.91119 (14)	0.44242 (11)	0.48786 (10)	0.0186 (2)
C4B	0.76277 (16)	0.46991 (13)	0.53347 (11)	0.0233 (3)
H4BA	0.6828	0.4448	0.4903	0.028*
H4BB	0.7526	0.5491	0.5456	0.028*
C5B	0.76907 (13)	0.40436 (11)	0.63263 (10)	0.0185 (2)
H5BA	0.6734	0.3897	0.6625	0.022*
C6B	0.87688 (15)	0.46647 (12)	0.70195 (11)	0.0217 (2)
H6BA	0.8732	0.4381	0.7704	0.026*
H6BB	0.8563	0.5457	0.7026	0.026*
C7B	1.02824 (14)	0.44215 (12)	0.65360 (11)	0.0199 (2)
H7BA	1.0933	0.4049	0.7012	0.024*
H7BB	1.0743	0.5104	0.6311	0.024*
C8B	0.85559 (12)	0.29851 (11)	0.60317 (9)	0.0154 (2)
C9B	0.89102 (17)	0.22292 (13)	0.69361 (11)	0.0244 (3)
H9BA	0.8036	0.1854	0.7143	0.037*
H9BB	0.9285	0.2672	0.7485	0.037*
H9BC	0.9631	0.1690	0.6746	0.037*
C10B	0.78064 (14)	0.22785 (12)	0.52073 (11)	0.0207 (2)
H10G	0.6992	0.1888	0.5490	0.031*
H10H	0.8494	0.1752	0.4945	0.031*
H10I	0.7465	0.2755	0.4672	0.031*
N1B	0.42936 (11)	0.12226 (9)	0.17235 (8)	0.01373 (17)
H1BC	0.3802	0.1537	0.1244	0.016*
N2B	0.56682 (11)	0.00652 (9)	0.25337 (9)	0.01636 (19)
H2BA	0.6221	−0.0496	0.2668	0.020*
C11B	0.50552 (13)	0.02832 (11)	0.16403 (9)	0.0153 (2)
H11B	0.5143	−0.0145	0.1060	0.018*
C12B	0.44173 (13)	0.16124 (11)	0.27007 (9)	0.0154 (2)
H12B	0.3992	0.2253	0.2960	0.018*
C13B	0.52797 (14)	0.08788 (11)	0.32086 (9)	0.0171 (2)
H13B	0.5556	0.0918	0.3886	0.021*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
S1A	0.01090 (10)	0.01332 (11)	0.00917 (10)	0.00054 (8)	0.00172 (8)	0.00011 (8)
O1A	0.0197 (4)	0.0149 (4)	0.0142 (4)	0.0028 (3)	−0.0013 (3)	0.0028 (3)
O2A	0.0213 (4)	0.0211 (5)	0.0168 (4)	−0.0046 (3)	−0.0011 (3)	−0.0040 (3)
O3A	0.0219 (4)	0.0171 (4)	0.0101 (3)	0.0017 (3)	0.0030 (3)	0.0002 (3)
O4A	0.0188 (4)	0.0302 (6)	0.0189 (4)	0.0012 (4)	−0.0020 (3)	−0.0005 (4)
C1A	0.0152 (5)	0.0307 (7)	0.0232 (6)	0.0082 (5)	0.0075 (4)	0.0153 (5)
C2A	0.0115 (4)	0.0247 (6)	0.0120 (5)	0.0004 (4)	0.0019 (3)	0.0015 (4)
C3A	0.0164 (5)	0.0129 (5)	0.0146 (5)	0.0023 (4)	0.0019 (4)	0.0019 (4)
C4A	0.0213 (5)	0.0236 (6)	0.0171 (5)	0.0022 (5)	0.0067 (4)	0.0062 (5)
C5A	0.0161 (5)	0.0345 (8)	0.0211 (6)	−0.0054 (5)	0.0068 (4)	−0.0012 (5)
C6A	0.0342 (8)	0.0530 (12)	0.0480 (10)	−0.0286 (8)	0.0241 (8)	−0.0278 (9)
C7A	0.0280 (7)	0.0392 (9)	0.0333 (8)	−0.0180 (6)	0.0153 (6)	−0.0200 (7)
C8A	0.0121 (5)	0.0538 (10)	0.0212 (6)	0.0088 (6)	0.0043 (4)	0.0164 (6)
N2A	0.0192 (4)	0.0139 (5)	0.0138 (4)	0.0027 (3)	0.0020 (3)	0.0009 (3)
C11A	0.0179 (5)	0.0141 (5)	0.0146 (5)	0.0019 (4)	0.0010 (4)	0.0013 (4)
C12A	0.0200 (5)	0.0203 (6)	0.0124 (5)	0.0010 (4)	0.0012 (4)	0.0017 (4)
C13A	0.0195 (5)	0.0186 (6)	0.0151 (5)	0.0032 (4)	0.0009 (4)	0.0034 (4)
S1B	0.01270 (10)	0.01178 (11)	0.00904 (10)	0.00008 (8)	0.00085 (8)	−0.00100 (8)
O1B	0.0207 (4)	0.0140 (4)	0.0151 (4)	−0.0021 (3)	0.0020 (3)	0.0028 (3)
O2B	0.0204 (4)	0.0147 (4)	0.0091 (3)	0.0010 (3)	−0.0011 (3)	−0.0004 (3)
O3B	0.0161 (4)	0.0197 (4)	0.0148 (4)	0.0036 (3)	0.0019 (3)	−0.0045 (3)
O4B	0.0345 (5)	0.0241 (5)	0.0217 (5)	−0.0021 (4)	0.0052 (4)	0.0054 (4)
C1B	0.0143 (4)	0.0160 (5)	0.0192 (5)	−0.0007 (4)	0.0007 (4)	−0.0069 (4)
C2B	0.0132 (4)	0.0127 (5)	0.0164 (5)	−0.0005 (3)	0.0020 (4)	−0.0034 (4)
C3B	0.0216 (5)	0.0129 (5)	0.0213 (6)	−0.0010 (4)	0.0023 (4)	−0.0001 (4)
C4B	0.0219 (6)	0.0204 (6)	0.0277 (7)	0.0068 (5)	0.0021 (5)	0.0034 (5)
C5B	0.0154 (5)	0.0174 (6)	0.0230 (6)	0.0023 (4)	0.0050 (4)	−0.0003 (4)
C6B	0.0206 (5)	0.0207 (6)	0.0239 (6)	0.0017 (4)	0.0057 (5)	−0.0081 (5)
C7B	0.0170 (5)	0.0200 (6)	0.0227 (6)	−0.0009 (4)	0.0038 (4)	−0.0099 (5)
C8B	0.0155 (4)	0.0143 (5)	0.0165 (5)	−0.0011 (4)	0.0031 (4)	0.0005 (4)
C9B	0.0316 (7)	0.0209 (7)	0.0208 (6)	0.0027 (5)	0.0048 (5)	0.0050 (5)
C10B	0.0185 (5)	0.0195 (6)	0.0243 (6)	−0.0061 (4)	0.0019 (4)	−0.0039 (5)
N1B	0.0142 (4)	0.0156 (5)	0.0114 (4)	0.0014 (3)	−0.0004 (3)	0.0017 (3)
N2B	0.0139 (4)	0.0138 (5)	0.0214 (5)	0.0016 (3)	0.0000 (4)	0.0036 (4)
C11B	0.0145 (5)	0.0149 (5)	0.0165 (5)	0.0000 (4)	0.0026 (4)	−0.0016 (4)
C12B	0.0167 (5)	0.0162 (5)	0.0132 (5)	0.0013 (4)	0.0020 (4)	−0.0015 (4)
C13B	0.0184 (5)	0.0193 (6)	0.0136 (5)	−0.0026 (4)	−0.0007 (4)	0.0029 (4)

Geometric parameters (Å, º) top

S1A—O2A	1.4542 (10)	C11A—H11A	0.9300
S1A—O1A	1.4645 (9)	C12A—C13A	1.3566 (18)
S1A—O3A	1.4663 (8)	C12A—H12A	0.9300
S1A—C1A	1.8074 (12)	C13A—H13A	0.9300
O4A—C3A	1.2090 (15)	S1B—O3B	1.4560 (9)
C1A—C2A	1.5102 (17)	S1B—O2B	1.4622 (8)
C1A—H1AA	0.9700	S1B—O1B	1.4661 (9)
C1A—H1AB	0.9700	S1B—C1B	1.7822 (12)
C2A—C3A	1.5185 (16)	O4B—C3B	1.2088 (17)
C2A—C7A	1.563 (2)	C1B—C2B	1.5264 (16)
C2A—C8A	1.5678 (17)	C1B—H1BA	0.9700
C3A—C4A	1.5248 (17)	C1B—H1BB	0.9700
C4A—C5A	1.529 (2)	C2B—C3B	1.5297 (18)
C4A—H4AA	0.9700	C2B—C7B	1.5606 (18)
C4A—H4AB	0.9700	C2B—C8B	1.5663 (16)
C5A—C6A	1.534 (2)	C3B—C4B	1.5280 (19)
C5A—C8A	1.547 (2)	C4B—C5B	1.532 (2)
C5A—H5AA	0.9800	C4B—H4BA	0.9700
C6A—C7A	1.555 (2)	C4B—H4BB	0.9700
C6A—H6AA	0.9700	C5B—C6B	1.532 (2)
C6A—H6AB	0.9700	C5B—C8B	1.5499 (18)
C7A—H7AA	0.9700	C5B—H5BA	0.9800
C7A—H7AB	0.9700	C6B—C7B	1.5593 (18)
C8A—C10C	1.352 (5)	C6B—H6BA	0.9700
C8A—C9A	1.506 (3)	C6B—H6BB	0.9700
C8A—C9C	1.594 (3)	C7B—H7BA	0.9700
C8A—C10A	1.681 (4)	C7B—H7BB	0.9700
C9A—H9AA	0.9600	C8B—C9B	1.5347 (19)
C9A—H9AB	0.9600	C8B—C10B	1.5374 (18)
C9A—H9AC	0.9600	C9B—H9BA	0.9600
C9C—H9CA	0.9600	C9B—H9BB	0.9600
C9C—H9CB	0.9600	C9B—H9BC	0.9600
C9C—H9CC	0.9600	C10B—H10G	0.9600
C10A—H10A	0.9600	C10B—H10H	0.9600
C10A—H10B	0.9600	C10B—H10I	0.9600
C10A—H10C	0.9600	N1B—C11B	1.3311 (16)
C10C—H10D	0.9600	N1B—C12B	1.3803 (15)
C10C—H10E	0.9600	N1B—H1BC	0.8600
C10C—H10F	0.9600	N2B—C11B	1.3291 (16)
N1A—C11A	1.3297 (16)	N2B—C13B	1.3747 (17)
N1A—C12A	1.3786 (17)	N2B—H2BA	0.8600
N1A—H1AC	0.8600	C11B—H11B	0.9300
N2A—C11A	1.3327 (16)	C12B—C13B	1.3552 (18)
N2A—C13A	1.3793 (16)	C12B—H12B	0.9300
N2A—H2AA	0.8600	C13B—H13B	0.9300

O2A—S1A—O1A	113.02 (6)	C13A—N2A—H2AA	125.5
O2A—S1A—O3A	112.24 (6)	N1A—C11A—N2A	108.26 (11)
O1A—S1A—O3A	111.57 (5)	N1A—C11A—H11A	125.9
O2A—S1A—C1A	106.46 (7)	N2A—C11A—H11A	125.9
O1A—S1A—C1A	108.37 (6)	C13A—C12A—N1A	107.11 (11)
O3A—S1A—C1A	104.61 (6)	C13A—C12A—H12A	126.4
C2A—C1A—S1A	119.53 (9)	N1A—C12A—H12A	126.4
C2A—C1A—H1AA	107.4	C12A—C13A—N2A	106.65 (11)
S1A—C1A—H1AA	107.4	C12A—C13A—H13A	126.7
C2A—C1A—H1AB	107.4	N2A—C13A—H13A	126.7
S1A—C1A—H1AB	107.4	O3B—S1B—O2B	112.27 (5)
H1AA—C1A—H1AB	107.0	O3B—S1B—O1B	113.28 (6)
C1A—C2A—C3A	118.10 (11)	O2B—S1B—O1B	111.96 (5)
C1A—C2A—C7A	116.16 (11)	O3B—S1B—C1B	104.81 (5)
C3A—C2A—C7A	102.95 (11)	O2B—S1B—C1B	106.33 (5)
C1A—C2A—C8A	115.32 (11)	O1B—S1B—C1B	107.57 (6)
C3A—C2A—C8A	99.42 (9)	C2B—C1B—S1B	118.47 (8)
C7A—C2A—C8A	102.31 (12)	C2B—C1B—H1BA	107.7
O4A—C3A—C2A	127.55 (11)	S1B—C1B—H1BA	107.7
O4A—C3A—C4A	125.97 (11)	C2B—C1B—H1BB	107.7
C2A—C3A—C4A	106.46 (10)	S1B—C1B—H1BB	107.7
C3A—C4A—C5A	102.31 (10)	H1BA—C1B—H1BB	107.1
C3A—C4A—H4AA	111.3	C1B—C2B—C3B	113.79 (10)
C5A—C4A—H4AA	111.3	C1B—C2B—C7B	119.69 (10)
C3A—C4A—H4AB	111.3	C3B—C2B—C7B	103.70 (10)
C5A—C4A—H4AB	111.3	C1B—C2B—C8B	115.55 (10)
H4AA—C4A—H4AB	109.2	C3B—C2B—C8B	99.72 (9)
C4A—C5A—C6A	106.96 (14)	C7B—C2B—C8B	101.75 (9)
C4A—C5A—C8A	101.83 (11)	O4B—C3B—C4B	126.53 (13)
C6A—C5A—C8A	103.31 (13)	O4B—C3B—C2B	126.68 (12)
C4A—C5A—H5AA	114.5	C4B—C3B—C2B	106.78 (10)
C6A—C5A—H5AA	114.5	C3B—C4B—C5B	101.81 (10)
C8A—C5A—H5AA	114.5	C3B—C4B—H4BA	111.4
C5A—C6A—C7A	102.63 (13)	C5B—C4B—H4BA	111.4
C5A—C6A—H6AA	111.2	C3B—C4B—H4BB	111.4
C7A—C6A—H6AA	111.2	C5B—C4B—H4BB	111.4
C5A—C6A—H6AB	111.2	H4BA—C4B—H4BB	109.3
C7A—C6A—H6AB	111.2	C6B—C5B—C4B	106.29 (12)
H6AA—C6A—H6AB	109.2	C6B—C5B—C8B	102.98 (10)
C6A—C7A—C2A	104.38 (13)	C4B—C5B—C8B	102.65 (10)
C6A—C7A—H7AA	110.9	C6B—C5B—H5BA	114.5
C2A—C7A—H7AA	110.9	C4B—C5B—H5BA	114.5
C6A—C7A—H7AB	110.9	C8B—C5B—H5BA	114.5
C2A—C7A—H7AB	110.9	C5B—C6B—C7B	103.23 (10)
H7AA—C7A—H7AB	108.9	C5B—C6B—H6BA	111.1
C10C—C8A—C9A	91.9 (2)	C7B—C6B—H6BA	111.1
C10C—C8A—C5A	115.18 (19)	C5B—C6B—H6BB	111.1
C9A—C8A—C5A	121.34 (19)	C7B—C6B—H6BB	111.1
C10C—C8A—C2A	118.6 (2)	H6BA—C6B—H6BB	109.1
C9A—C8A—C2A	117.82 (16)	C6B—C7B—C2B	103.83 (10)
C5A—C8A—C2A	94.20 (11)	C6B—C7B—H7BA	111.0
C10C—C8A—C9C	111.1 (2)	C2B—C7B—H7BA	111.0
C9A—C8A—C9C	19.89 (13)	C6B—C7B—H7BB	111.0
C5A—C8A—C9C	106.14 (19)	C2B—C7B—H7BB	111.0
C2A—C8A—C9C	110.03 (16)	H7BA—C7B—H7BB	109.0
C10C—C8A—C10A	11.72 (18)	C9B—C8B—C10B	108.40 (11)
C9A—C8A—C10A	103.2 (2)	C9B—C8B—C5B	113.06 (11)
C5A—C8A—C10A	110.47 (13)	C10B—C8B—C5B	114.08 (10)
C2A—C8A—C10A	109.62 (14)	C9B—C8B—C2B	114.39 (10)
C9C—C8A—C10A	122.6 (2)	C10B—C8B—C2B	112.29 (10)
C8A—C9A—H9AA	109.5	C5B—C8B—C2B	94.24 (9)
C8A—C9A—H9AB	109.5	C8B—C9B—H9BA	109.5
H9AA—C9A—H9AB	109.5	C8B—C9B—H9BB	109.5
C8A—C9A—H9AC	109.5	H9BA—C9B—H9BB	109.5
H9AA—C9A—H9AC	109.5	C8B—C9B—H9BC	109.5
H9AB—C9A—H9AC	109.5	H9BA—C9B—H9BC	109.5
C8A—C9C—H9CA	109.5	H9BB—C9B—H9BC	109.5
C8A—C9C—H9CB	109.5	C8B—C10B—H10G	109.5
H9CA—C9C—H9CB	109.5	C8B—C10B—H10H	109.5
C8A—C9C—H9CC	109.5	H10G—C10B—H10H	109.5
H9CA—C9C—H9CC	109.5	C8B—C10B—H10I	109.5
H9CB—C9C—H9CC	109.5	H10G—C10B—H10I	109.5
C8A—C10A—H10A	109.5	H10H—C10B—H10I	109.5
C8A—C10A—H10B	109.5	C11B—N1B—C12B	109.21 (10)
H10A—C10A—H10B	109.5	C11B—N1B—H1BC	125.4
C8A—C10A—H10C	109.5	C12B—N1B—H1BC	125.4
H10A—C10A—H10C	109.5	C11B—N2B—C13B	109.28 (11)
H10B—C10A—H10C	109.5	C11B—N2B—H2BA	125.4
C8A—C10C—H10D	109.5	C13B—N2B—H2BA	125.4
C8A—C10C—H10E	109.5	N2B—C11B—N1B	107.93 (11)
H10D—C10C—H10E	109.5	N2B—C11B—H11B	126.0
C8A—C10C—H10F	109.5	N1B—C11B—H11B	126.0
H10D—C10C—H10F	109.5	C13B—C12B—N1B	106.57 (11)
H10E—C10C—H10F	109.5	C13B—C12B—H12B	126.7
C11A—N1A—C12A	108.91 (11)	N1B—C12B—H12B	126.7
C11A—N1A—H1AC	125.5	C12B—C13B—N2B	107.01 (11)
C12A—N1A—H1AC	125.5	C12B—C13B—H13B	126.5
C11A—N2A—C13A	109.07 (11)	N2B—C13B—H13B	126.5
C11A—N2A—H2AA	125.5

O2A—S1A—C1A—C2A	−105.42 (12)	C12A—N1A—C11A—N2A	0.11 (14)
O1A—S1A—C1A—C2A	16.45 (14)	C13A—N2A—C11A—N1A	−0.31 (14)
O3A—S1A—C1A—C2A	135.58 (11)	C11A—N1A—C12A—C13A	0.14 (15)
S1A—C1A—C2A—C3A	62.08 (16)	N1A—C12A—C13A—N2A	−0.32 (15)
S1A—C1A—C2A—C7A	−60.97 (16)	C11A—N2A—C13A—C12A	0.40 (15)
S1A—C1A—C2A—C8A	179.34 (11)	O3B—S1B—C1B—C2B	−176.85 (9)
C1A—C2A—C3A—O4A	−18.12 (19)	O2B—S1B—C1B—C2B	64.08 (11)
C7A—C2A—C3A—O4A	111.36 (15)	O1B—S1B—C1B—C2B	−56.02 (11)
C8A—C2A—C3A—O4A	−143.57 (14)	S1B—C1B—C2B—C3B	101.52 (11)
C1A—C2A—C3A—C4A	160.54 (11)	S1B—C1B—C2B—C7B	−21.79 (16)
C7A—C2A—C3A—C4A	−69.99 (12)	S1B—C1B—C2B—C8B	−143.94 (9)
C8A—C2A—C3A—C4A	35.08 (13)	C1B—C2B—C3B—O4B	−20.75 (19)
O4A—C3A—C4A—C5A	178.27 (13)	C7B—C2B—C3B—O4B	110.90 (15)
C2A—C3A—C4A—C5A	−0.41 (13)	C8B—C2B—C3B—O4B	−144.36 (14)
C3A—C4A—C5A—C6A	72.78 (14)	C1B—C2B—C3B—C4B	157.98 (11)
C3A—C4A—C5A—C8A	−35.27 (14)	C7B—C2B—C3B—C4B	−70.38 (12)
C4A—C5A—C6A—C7A	−68.92 (19)	C8B—C2B—C3B—C4B	34.36 (12)
C8A—C5A—C6A—C7A	38.09 (18)	O4B—C3B—C4B—C5B	178.76 (14)
C5A—C6A—C7A—C2A	−4.3 (2)	C2B—C3B—C4B—C5B	0.04 (14)
C1A—C2A—C7A—C6A	−156.62 (14)	C3B—C4B—C5B—C6B	72.54 (13)
C3A—C2A—C7A—C6A	72.72 (16)	C3B—C4B—C5B—C8B	−35.24 (13)
C8A—C2A—C7A—C6A	−30.11 (17)	C4B—C5B—C6B—C7B	−71.47 (13)
C4A—C5A—C8A—C10C	−68.8 (2)	C8B—C5B—C6B—C7B	36.08 (13)
C6A—C5A—C8A—C10C	−179.6 (2)	C5B—C6B—C7B—C2B	−1.55 (14)
C4A—C5A—C8A—C9A	−178.0 (2)	C1B—C2B—C7B—C6B	−161.59 (11)
C6A—C5A—C8A—C9A	71.1 (2)	C3B—C2B—C7B—C6B	70.33 (12)
C4A—C5A—C8A—C2A	55.64 (13)	C8B—C2B—C7B—C6B	−32.87 (13)
C6A—C5A—C8A—C2A	−55.21 (14)	C6B—C5B—C8B—C9B	63.83 (13)
C4A—C5A—C8A—C9C	167.90 (17)	C4B—C5B—C8B—C9B	174.13 (11)
C6A—C5A—C8A—C9C	57.05 (19)	C6B—C5B—C8B—C10B	−171.69 (11)
C4A—C5A—C8A—C10A	−57.12 (16)	C4B—C5B—C8B—C10B	−61.40 (13)
C6A—C5A—C8A—C10A	−167.96 (15)	C6B—C5B—C8B—C2B	−54.96 (11)
C1A—C2A—C8A—C10C	−60.1 (2)	C4B—C5B—C8B—C2B	55.33 (11)
C3A—C2A—C8A—C10C	67.3 (2)	C1B—C2B—C8B—C9B	66.55 (14)
C7A—C2A—C8A—C10C	172.9 (2)	C3B—C2B—C8B—C9B	−171.07 (11)
C1A—C2A—C8A—C9A	49.3 (3)	C7B—C2B—C8B—C9B	−64.75 (13)
C3A—C2A—C8A—C9A	176.6 (2)	C1B—C2B—C8B—C10B	−57.54 (14)
C7A—C2A—C8A—C9A	−77.8 (3)	C3B—C2B—C8B—C10B	64.84 (12)
C1A—C2A—C8A—C5A	178.22 (12)	C7B—C2B—C8B—C10B	171.16 (11)
C3A—C2A—C8A—C5A	−54.43 (12)	C1B—C2B—C8B—C5B	−175.74 (10)
C7A—C2A—C8A—C5A	51.17 (13)	C3B—C2B—C8B—C5B	−53.37 (10)
C1A—C2A—C8A—C9C	69.4 (2)	C7B—C2B—C8B—C5B	52.95 (11)
C3A—C2A—C8A—C9C	−163.3 (2)	C13B—N2B—C11B—N1B	0.55 (14)
C7A—C2A—C8A—C9C	−57.7 (2)	C12B—N1B—C11B—N2B	−0.35 (14)
C1A—C2A—C8A—C10A	−68.30 (16)	C11B—N1B—C12B—C13B	0.01 (14)
C3A—C2A—C8A—C10A	59.06 (15)	N1B—C12B—C13B—N2B	0.32 (13)
C7A—C2A—C8A—C10A	164.65 (14)	C11B—N2B—C13B—C12B	−0.54 (14)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N1A—H1AC···O2Bⁱ	0.86	2.46	2.9479 (14)	116
N1A—H1AC···O3Aⁱⁱ	0.86	2.00	2.8293 (14)	161
N2A—H2AA···O1Bⁱⁱⁱ	0.86	1.89	2.7235 (14)	164
N1B—H1BC···O1Aⁱ	0.86	1.88	2.7231 (14)	165
N2B—H2BA···O2Bⁱⁱⁱ	0.86	1.97	2.7412 (14)	148
N2B—H2BA···O3A^iv	0.86	2.43	3.0111 (14)	125
C7A—H7AB···O1A	0.97	2.53	3.0257 (19)	111
C11A—H11A···O2Bⁱ	0.93	2.49	2.9716 (16)	113
C11A—H11A···O3Bⁱ	0.93	2.35	3.2648 (15)	170
C11B—H11B···O2A^iv	0.93	2.33	3.2103 (16)	159
C9A—H9AC···O2Aⁱ	0.96	2.59	3.469 (3)	152
C12B—H12B···O3Bⁱ	0.93	2.39	2.9950 (15)	122
C12B—H12B···O4Aⁱ	0.93	2.49	3.0155 (16)	116
C13A—H13A···O2Aⁱⁱⁱ	0.93	2.44	3.0167 (16)	120
C13A—H13A···O4Aⁱⁱⁱ	0.93	2.39	3.2591 (17)	155
C13B—H13B···O1Bⁱⁱⁱ	0.93	2.58	3.2720 (16)	131
C7B—H7BA···O2B	0.97	2.47	3.0613 (16)	119
C5A—H5AA···Cg1	0.98	2.83	3.5459 (5)	131

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

Experimental details

Crystal data
Chemical formula	C₃H₅N₂⁺·C₁₀H₁₅O₄S⁻
M_r	300.37
Crystal system, space group	Monoclinic, P2₁
Temperature (K)	100
a, b, c (Å)	9.1362 (2), 12.0126 (2), 13.2526 (3)
β (°)	90.757 (1)
V (Å³)	1454.34 (5)
Z	4
Radiation type	Mo Kα
µ (mm⁻¹)	0.24
Crystal size (mm)	0.46 × 0.45 × 0.19

Data collection
Diffractometer	Bruker SMART APEXII CCD area-detector diffractometer
Absorption correction	Multi-scan (SADABS; Bruker, 2005)
T_min, T_max	0.900, 0.956
No. of measured, independent and observed [I > 2σ(I)] reflections	25973, 9954, 9652
R_int	0.022
(sin θ/λ)_max (Å⁻¹)	0.756

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.031, 0.083, 1.07
No. of reflections	9954
No. of parameters	355
No. of restraints	1
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.53, −0.34
Absolute structure	Flack (1983), 4199 Friedel pairs
Absolute structure parameter	0.01 (3)

Computer programs: APEX2 (Bruker, 2005), SAINT (Bruker, 2005), SHELXTL (Sheldrick, 2008) and PLATON (Spek, 2003).

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N1A—H1AC···O2Bⁱ	0.8600	2.4600	2.9479 (14)	116.00
N1A—H1AC···O3Aⁱⁱ	0.8600	2.0000	2.8293 (14)	161.00
N2A—H2AA···O1Bⁱⁱⁱ	0.8600	1.8900	2.7235 (14)	164.00
N1B—H1BC···O1Aⁱ	0.8600	1.8800	2.7231 (14)	165.00
N2B—H2BA···O2Bⁱⁱⁱ	0.8600	1.9700	2.7412 (14)	148.00
N2B—H2BA···O3A^iv	0.8600	2.4300	3.0111 (14)	125.00
C7A—H7AB···O1A	0.9700	2.5300	3.0257 (19)	111.00
C11A—H11A···O2Bⁱ	0.9300	2.4900	2.9716 (16)	113.00
C11A—H11A···O3Bⁱ	0.9300	2.3500	3.2648 (15)	170.00
C11B—H11B···O2A^iv	0.9300	2.3300	3.2103 (16)	159.00
C9A—H9AC···O2Aⁱ	0.9600	2.5900	3.469 (3)	152.00
C12B—H12B···O3Bⁱ	0.9300	2.3900	2.9950 (15)	122.00
C12B—H12B···O4Aⁱ	0.9300	2.4900	3.0155 (16)	116.00
C13A—H13A···O2Aⁱⁱⁱ	0.9300	2.4400	3.0167 (16)	120.00
C13A—H13A···O4Aⁱⁱⁱ	0.9300	2.3900	3.2591 (17)	155.00
C13B—H13B···O1Bⁱⁱⁱ	0.9300	2.5800	3.2720 (16)	131.00
C7B—H7BA···O2B	0.9700	2.4700	3.0613 (16)	119.00
C5A—H5AA···Cg1	0.9800	2.8300	3.5459 (5)	131.00

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

Footnotes

‡Additional correspondence author, e-mail: basya@science.upm.edu.my.

Acknowledgements

MBAR, EMO and NSL thank the Malaysian Government and Universiti Putra Malaysia for the Research Universiti Grant Scheme (RUGS 2007) grant No. 91183. MBAR would like to thank Professor Kenneth R. Seddon for the opportunity to conduct this research by SLN at QUILL. HKF and RK thank the Malaysian Government and Universiti Sains Malaysia for the Science Fund grant No. 305/PFIZIK/613312. RK thanks Universiti Sains Malaysia for a post-doctoral research fellowship. HKF also thanks Universiti Sains Malaysia for the Research University Golden Goose grant No. 1001/PFIZIK/811012.

References

Allen, F. H., Kennard, O., Watson, D. G., Brammer, L., Orpen, A. G. & Taylor, R. (1987). J. Chem. Soc. Perkin Trans. 2, pp. S1–19. CrossRef Web of Science Google Scholar
Bernstein, J., Davis, R. E., Shimoni, L. & Chang, N.-L. (1995). Angew. Chem. Int. Ed. Engl. 34, 1555–1573. CrossRef CAS Web of Science Google Scholar
Bruker (2005). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Flack, H. D. (1983). Acta Cryst. A39, 876–881. CrossRef CAS Web of Science IUCr Journals Google Scholar
Fukumoto, K., Yoshizawa, M. & Ohno, H. (2005). J. Am. Chem. Soc. 127, 2398–2399. Web of Science CrossRef PubMed CAS Google Scholar
Jeremić, D., Kaluderović, G. N., Brčeski, I., Gómez-Ruiz, S. & Andelković, K. K. (2008). Acta Cryst. E64, m952. Web of Science CrossRef IUCr Journals Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Spek, A. L. (2003). J. Appl. Cryst. 36, 7–13. Web of Science CrossRef CAS IUCr Journals Google Scholar