2-(1H-Indol-3-yl)acetohydrazide

Sidra, L.R.; Khan, I.U.; Yar, M.; Simpson, J.

doi:10.1107/S1600536812041694

organic compounds

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ISSN: 2056-9890

Volume 68| Part 11| November 2012| Pages o3140-o3141

doi:10.1107/S1600536812041694

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2-(1H-Indol-3-yl)acetohydrazide

Lala Rukh Sidra,^a Islam Ullah Khan,^a ^* Muhammad Yar ^b and Jim Simpson ^c

^aMaterials Chemistry Laboratory, Department of Chemistry, GC University, Lahore 54000, Pakistan, ^bInterdisciplinary Research Center in Biomedical Materials, COMSATS Institute of Information Technology, Lahore 54000, Pakistan, and ^cDepartment of Chemistry, University of Otago, PO Box 56, Dunedin, New Zealand
^*Correspondence e-mail: iuklodhi@yahoo.com

(Received 24 September 2012; accepted 5 October 2012; online 20 October 2012)

In the title compound C₁₀H₁₁N₃O, the mean plane of the indole ring system (r.m.s. deviation 0.0131 Å) subtends a dihedral angle of 87.27 (5)° to the almost planar acetohydrazide substituent (r.m.s. deviation 0.0291 Å). In the crystal, bifurcated N—H⋯(O,N) and N—H⋯N hydrogen bonds involving the pyrrole N–H grouping combine to form zigzag chains along a. Additional N—H⋯O contacts from the hydrazide N–H group augmented by C—H⋯π interactions link the molecules into chains along the a axis. The overall effect of these contacts is a three-dimensional network structure with molecules stacked along the b-axis direction.

Related literature

For the use of hydrazides in the synthesis of heterocyclic compounds, see: Narayana et al. (2005a ,b ) and in the production of pharmaceuticals, see: Liu et al. (2006 ). For related structures, see: Butcher et al. (2007 ); Hou (2009 ); Li & Ban (2009 ); Sarojini et al. (2007a ,b ,c ,d ).

Experimental

Crystal data

C₁₀H₁₁N₃O
M_r = 189.22
Orthorhombic, P b c a
a = 12.1599 (7) Å
b = 9.6153 (4) Å
c = 16.2345 (8) Å
V = 1898.16 (16) Å³
Z = 8
Mo Kα radiation
μ = 0.09 mm⁻¹
T = 296 K
0.17 × 0.14 × 0.11 mm

Data collection

Bruker APEXII CCD area detector diffractometer
8600 measured reflections
2329 independent reflections
1294 reflections with I > 2σ(I)
R_int = 0.039

Refinement

R[F² > 2σ(F²)] = 0.046
wR(F²) = 0.122
S = 1.00
2329 reflections
139 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.16 e Å⁻³
Δρ_min = −0.16 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

Cg2 is the centroid of the C1–C6 benzene ring.

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N1—H1N⋯O10ⁱ	0.80 (2)	2.21 (2)	2.927 (2)	149.4 (19)
N1—H1N⋯N3ⁱ	0.80 (2)	2.50 (2)	3.126 (2)	136.6 (19)
N2—H2N⋯O10ⁱⁱ	0.89 (2)	2.20 (2)	3.0799 (19)	166.3 (17)
C9—H9A⋯Cg2ⁱⁱⁱ	0.97	2.73	3.644 (2)	157
Symmetry codes: (i) $[x+{\script{1\over 2}}, -y+{\script{1\over 2}}, -z+1]$ ; (ii) $[-x+{\script{1\over 2}}, y-{\script{1\over 2}}, z]$ ; (iii) $[x, -y-{\script{3\over 2}}, z-{\script{1\over 2}}]$ .

Data collection: APEX2 (Bruker 2005 ); cell refinement: APEX2 and SAINT (Bruker 2005); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 (Farrugia, 1997 ) and Mercury (Macrae et al., 2008 ); software used to prepare material for publication: SHELXL97, enCIFer (Allen et al., 2004 ), PLATON (Spek, 2009 ), publCIF (Westrip 2010 ).

Supporting information

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536812041694/hg5253sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536812041694/hg5253Isup2.hkl

Supporting information file. DOI: 10.1107/S1600536812041694/hg5253Isup3.cml

checkCIF report

Comment top

Hydrazides are useful precursors in the synthesis of several heterocyclic compounds. (Narayana et al., 2005a,b). They are also intermediates in the production of many pharmaceutically important compounds (Liu et al., 2006). The structures of a number of hydrazides and their derivatives have also been reported (Butcher et al., 2007; Hou, 2009; Li & Ban, 2009; Sarojini et al., 2007a,b,c,d).

In the title hydrazide compound, the indole ring system is planar (r.m.s. deviation 0.0131 Å) and subtends an angle of 87.27 (5)° to the C9, C10, O10, N2, N3 acetohydrazide substituent which is also planar (r.m.s. deviation 0.0291 Å). In the crystal structure, bifurcated N1–H1N···O10 and N1–H1N···N6 hydrogen bonds together form zigzag chains along a, Table 1, Fig 2. Additional N2–H2N···O10 contacts augmented by C9–H9A···π interactions link the molecules into rows along b, Fig 3. The overall effect of these contacts is a three dimensional network structure with molecules stacked along the b axis, Fig 4.

Related literature top

For the use of hydrazides in the synthesis of heterocyclic compounds, see: Narayana et al. (2005a,b) and in the production of pharmaceuticals, see: Liu et al. (2006). For related structures, see: Butcher et al. (2007); Hou (2009); Li & Ban (2009); Sarojini et al. (2007a,b,c,d).

Experimental top

Indole 3-methyl ester (500 mg, 2.6 mmole, 1eq) was added to hydrazine hydrate (80%, 4eq) in ethanol. The reaction mixture was refluxed for 2–3 h, allowed to cool and poured into 100 ml of chilled water. The resulting solid was filtered, dried and re-crystallized from ethanol to obtain the product (300 mg, 60%), mp: 143°C. The purity of the compound was confirmed using thin layer chromatography Rf: 0.18, (n-hexane: ethyl acetate). Crystals of the title compound suitable for X-ray analysis were grown from a solution in ethanol at room temperature.

Computing details top

Data collection: APEX2 (Bruker 2005); cell refinement: APEX2 and SAINT (Bruker 2005); data reduction: SAINT (Bruker 2005); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 (Farrugia, 1997) and Mercury (Macrae et al., 2008); software used to prepare material for publication: SHELXL97, enCIFer (Allen et al., 2004), PLATON (Spek, 2009), publCIF (Westrip 2010).

Figures top

	Fig. 1. The structure of the title compound showing the atom numbering scheme with displacement ellipsoids drawn at the 50% probability level
	Fig. 2. Zigzag chains along a with hydrogen bonds drawn as dashed lines.
	Fig. 3. Molecules linked into rows along the b by N–H···O hydrogen bonds (dashed lines) and C–H···π contacts (dotted lines).
	Fig. 4. A three dimensional network structure of molecules stacked along the b axis with hydrogen bonds drawn as dashed lines.

2-(1H-Indol-3-yl)acetohydrazide top

Crystal data top

C₁₀H₁₁N₃O	F(000) = 800
M_r = 189.22	D_x = 1.324 Mg m⁻³
Orthorhombic, Pbca	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ac 2ab	Cell parameters from 1251 reflections
a = 12.1599 (7) Å	θ = 3.0–22.1°
b = 9.6153 (4) Å	µ = 0.09 mm⁻¹
c = 16.2345 (8) Å	T = 296 K
V = 1898.16 (16) Å³	Prism, colorless
Z = 8	0.17 × 0.14 × 0.11 mm

Data collection top

Bruker APEXII CCD area detector diffractometer	1294 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	R_int = 0.039
Graphite monochromator	θ_max = 28.3°, θ_min = 3.0°
ϕ and ω scans	h = −16→14
8600 measured reflections	k = −12→12
2329 independent reflections	l = −20→21

Refinement top

Refinement on F²	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F² > 2σ(F²)] = 0.046	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.122	H atoms treated by a mixture of independent and constrained refinement
S = 1.00	w = 1/[σ²(F_o²) + (0.0512P)² + 0.1536P] where P = (F_o² + 2F_c²)/3
2329 reflections	(Δ/σ)_max < 0.001
139 parameters	Δρ_max = 0.16 e Å⁻³
0 restraints	Δρ_min = −0.16 e Å⁻³

Crystal data top

C₁₀H₁₁N₃O	V = 1898.16 (16) Å³
M_r = 189.22	Z = 8
Orthorhombic, Pbca	Mo Kα radiation
a = 12.1599 (7) Å	µ = 0.09 mm⁻¹
b = 9.6153 (4) Å	T = 296 K
c = 16.2345 (8) Å	0.17 × 0.14 × 0.11 mm

Data collection top

Bruker APEXII CCD area detector diffractometer	1294 reflections with I > 2σ(I)
8600 measured reflections	R_int = 0.039
2329 independent reflections

Refinement top

R[F² > 2σ(F²)] = 0.046	0 restraints
wR(F²) = 0.122	H atoms treated by a mixture of independent and constrained refinement
S = 1.00	Δρ_max = 0.16 e Å⁻³
2329 reflections	Δρ_min = −0.16 e Å⁻³
139 parameters

Special details top

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
N1	0.51122 (13)	0.27482 (16)	0.60889 (11)	0.0549 (5)
H1N	0.5591 (17)	0.321 (2)	0.5893 (12)	0.066*
C1	0.45025 (15)	0.30809 (17)	0.67668 (12)	0.0463 (5)
C2	0.46525 (18)	0.4106 (2)	0.73576 (14)	0.0615 (6)
H2	0.5251	0.4707	0.7335	0.074*
C3	0.3892 (2)	0.4202 (2)	0.79725 (14)	0.0683 (6)
H3	0.3980	0.4878	0.8377	0.082*
C4	0.29916 (19)	0.3318 (2)	0.80094 (13)	0.0664 (6)
H4	0.2479	0.3428	0.8430	0.080*
C5	0.28434 (16)	0.22822 (19)	0.74347 (12)	0.0542 (5)
H5	0.2242	0.1687	0.7466	0.065*
C6	0.36154 (14)	0.21440 (16)	0.68030 (11)	0.0418 (4)
C7	0.37296 (14)	0.12255 (16)	0.61199 (11)	0.0437 (4)
C8	0.46342 (15)	0.16439 (18)	0.57039 (12)	0.0512 (5)
H8	0.4894	0.1235	0.5222	0.061*
C9	0.29943 (16)	0.00197 (17)	0.59225 (12)	0.0526 (5)
H9A	0.2600	−0.0243	0.6418	0.063*
H9B	0.3448	−0.0764	0.5762	0.063*
C10	0.21718 (14)	0.02925 (16)	0.52500 (11)	0.0404 (4)
O10	0.18296 (11)	0.14649 (11)	0.50855 (8)	0.0575 (4)
N2	0.18364 (13)	−0.08386 (15)	0.48613 (10)	0.0505 (4)
H2N	0.2143 (16)	−0.165 (2)	0.4996 (11)	0.061*
N3	0.09921 (17)	−0.07433 (16)	0.42677 (12)	0.0631 (5)
H3N1	0.1226 (17)	−0.128 (2)	0.3824 (13)	0.076*
H3N2	0.0381 (19)	−0.125 (2)	0.4406 (14)	0.076*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
N1	0.0422 (9)	0.0513 (10)	0.0711 (12)	−0.0088 (7)	0.0042 (9)	0.0060 (9)
C1	0.0431 (10)	0.0411 (9)	0.0548 (11)	−0.0031 (7)	−0.0091 (9)	0.0057 (9)
C2	0.0620 (14)	0.0526 (11)	0.0699 (15)	−0.0112 (10)	−0.0161 (12)	−0.0005 (10)
C3	0.0867 (17)	0.0570 (13)	0.0612 (14)	0.0031 (12)	−0.0161 (13)	−0.0101 (11)
C4	0.0741 (15)	0.0708 (14)	0.0542 (13)	0.0138 (12)	0.0036 (11)	0.0026 (11)
C5	0.0498 (11)	0.0527 (11)	0.0600 (12)	−0.0022 (9)	0.0011 (10)	0.0136 (10)
C6	0.0415 (9)	0.0341 (8)	0.0497 (10)	0.0006 (7)	−0.0065 (8)	0.0085 (8)
C7	0.0442 (10)	0.0335 (8)	0.0534 (11)	0.0010 (7)	−0.0056 (9)	0.0087 (8)
C8	0.0537 (11)	0.0422 (10)	0.0577 (12)	0.0064 (8)	0.0021 (10)	0.0009 (9)
C9	0.0625 (12)	0.0328 (9)	0.0624 (12)	−0.0039 (8)	−0.0095 (10)	0.0070 (8)
C10	0.0444 (10)	0.0282 (8)	0.0485 (10)	−0.0012 (7)	0.0029 (8)	0.0015 (7)
O10	0.0671 (9)	0.0300 (6)	0.0752 (9)	0.0049 (6)	−0.0198 (7)	−0.0020 (6)
N2	0.0627 (10)	0.0292 (8)	0.0594 (10)	0.0020 (7)	−0.0114 (9)	−0.0020 (7)
N3	0.0782 (13)	0.0455 (10)	0.0656 (12)	−0.0004 (8)	−0.0177 (11)	−0.0082 (8)

Geometric parameters (Å, º) top

N1—C8	1.362 (2)	C6—C7	1.425 (2)
N1—C1	1.365 (3)	C7—C8	1.352 (2)
N1—H1N	0.80 (2)	C7—C9	1.499 (2)
C1—C2	1.387 (3)	C8—H8	0.9300
C1—C6	1.407 (2)	C9—C10	1.504 (2)
C2—C3	1.364 (3)	C9—H9A	0.9700
C2—H2	0.9300	C9—H9B	0.9700
C3—C4	1.388 (3)	C10—O10	1.2310 (18)
C3—H3	0.9300	C10—N2	1.322 (2)
C4—C5	1.377 (3)	N2—N3	1.411 (2)
C4—H4	0.9300	N2—H2N	0.89 (2)
C5—C6	1.397 (2)	N3—H3N1	0.93 (2)
C5—H5	0.9300	N3—H3N2	0.92 (2)

C8—N1—C1	108.72 (15)	C8—C7—C6	106.48 (15)
C8—N1—H1N	124.2 (15)	C8—C7—C9	127.50 (18)
C1—N1—H1N	125.9 (15)	C6—C7—C9	126.01 (16)
N1—C1—C2	130.74 (18)	C7—C8—N1	110.48 (17)
N1—C1—C6	107.46 (16)	C7—C8—H8	124.8
C2—C1—C6	121.79 (18)	N1—C8—H8	124.8
C3—C2—C1	117.75 (19)	C7—C9—C10	114.65 (14)
C3—C2—H2	121.1	C7—C9—H9A	108.6
C1—C2—H2	121.1	C10—C9—H9A	108.6
C2—C3—C4	121.66 (19)	C7—C9—H9B	108.6
C2—C3—H3	119.2	C10—C9—H9B	108.6
C4—C3—H3	119.2	H9A—C9—H9B	107.6
C5—C4—C3	121.2 (2)	O10—C10—N2	123.07 (16)
C5—C4—H4	119.4	O10—C10—C9	122.82 (15)
C3—C4—H4	119.4	N2—C10—C9	114.10 (14)
C4—C5—C6	118.58 (18)	C10—N2—N3	119.81 (15)
C4—C5—H5	120.7	C10—N2—H2N	118.4 (12)
C6—C5—H5	120.7	N3—N2—H2N	121.8 (12)
C5—C6—C1	119.03 (17)	N2—N3—H3N1	105.6 (13)
C5—C6—C7	134.12 (16)	N2—N3—H3N2	112.8 (15)
C1—C6—C7	106.84 (16)	H3N1—N3—H3N2	97.9 (18)

C8—N1—C1—C2	179.29 (19)	C5—C6—C7—C8	177.68 (18)
C8—N1—C1—C6	0.1 (2)	C1—C6—C7—C8	−1.15 (18)
N1—C1—C2—C3	179.47 (19)	C5—C6—C7—C9	−3.4 (3)
C6—C1—C2—C3	−1.5 (3)	C1—C6—C7—C9	177.72 (16)
C1—C2—C3—C4	−0.5 (3)	C6—C7—C8—N1	1.3 (2)
C2—C3—C4—C5	1.6 (3)	C9—C7—C8—N1	−177.58 (16)
C3—C4—C5—C6	−0.7 (3)	C1—N1—C8—C7	−0.9 (2)
C4—C5—C6—C1	−1.2 (2)	C8—C7—C9—C10	−79.8 (2)
C4—C5—C6—C7	−179.92 (18)	C6—C7—C9—C10	101.5 (2)
N1—C1—C6—C5	−178.42 (15)	C7—C9—C10—O10	−26.0 (3)
C2—C1—C6—C5	2.3 (3)	C7—C9—C10—N2	155.06 (17)
N1—C1—C6—C7	0.62 (18)	O10—C10—N2—N3	−4.6 (3)
C2—C1—C6—C7	−178.61 (16)	C9—C10—N2—N3	174.30 (17)

Hydrogen-bond geometry (Å, º) top

Cg2 is the centroid of the C1–C6 benzene ring.

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1N···O10ⁱ	0.80 (2)	2.21 (2)	2.927 (2)	149.4 (19)
N1—H1N···N3ⁱ	0.80 (2)	2.50 (2)	3.126 (2)	136.6 (19)
N2—H2N···O10ⁱⁱ	0.89 (2)	2.20 (2)	3.0799 (19)	166.3 (17)
C9—H9A···Cg2ⁱⁱⁱ	0.97	2.73	3.644 (2)	157

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

Experimental details

Crystal data
Chemical formula	C₁₀H₁₁N₃O
M_r	189.22
Crystal system, space group	Orthorhombic, Pbca
Temperature (K)	296
a, b, c (Å)	12.1599 (7), 9.6153 (4), 16.2345 (8)
V (Å³)	1898.16 (16)
Z	8
Radiation type	Mo Kα
µ (mm⁻¹)	0.09
Crystal size (mm)	0.17 × 0.14 × 0.11

Data collection
Diffractometer	Bruker APEXII CCD area detector diffractometer
Absorption correction	–
No. of measured, independent and observed [I > 2σ(I)] reflections	8600, 2329, 1294
R_int	0.039
(sin θ/λ)_max (Å⁻¹)	0.668

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.046, 0.122, 1.00
No. of reflections	2329
No. of parameters	139
H-atom treatment	H atoms treated by a mixture of independent and constrained refinement
Δρ_max, Δρ_min (e Å⁻³)	0.16, −0.16

Computer programs: APEX2 (Bruker 2005), APEX2 and SAINT (Bruker 2005), SAINT (Bruker 2005), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), ORTEP-3 (Farrugia, 1997) and Mercury (Macrae et al., 2008), SHELXL97, enCIFer (Allen et al., 2004), PLATON (Spek, 2009), publCIF (Westrip 2010).

Hydrogen-bond geometry (Å, º) top

Cg2 is the centroid of the C1–C6 benzene ring.

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1N···O10ⁱ	0.80 (2)	2.21 (2)	2.927 (2)	149.4 (19)
N1—H1N···N3ⁱ	0.80 (2)	2.50 (2)	3.126 (2)	136.6 (19)
N2—H2N···O10ⁱⁱ	0.89 (2)	2.20 (2)	3.0799 (19)	166.3 (17)
C9—H9A···Cg2ⁱⁱⁱ	0.97	2.73	3.644 (2)	157

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

Acknowledgements

The authors acknowledge the Higher Education Commission of Pakistan for the purchase of the diffractometer.

References

Allen, F. H., Johnson, O., Shields, G. P., Smith, B. R. & Towler, M. (2004). J. Appl. Cryst. 37, 335–338. Web of Science CrossRef CAS IUCr Journals Google Scholar
Bruker (2005). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Butcher, R. J., Jasinski, J. P., Narayana, B., Sunil, K. & Yathirajan, H. S. (2007). Acta Cryst. E63, o3652. Web of Science CSD CrossRef IUCr Journals Google Scholar
Farrugia, L. J. (1997). J. Appl. Cryst. 30, 565. CrossRef IUCr Journals Google Scholar
Hou, J.-L. (2009). Acta Cryst. E65, o851. Web of Science CSD CrossRef IUCr Journals Google Scholar
Li, C.-M. & Ban, H.-Y. (2009). Acta Cryst. E65, o883. Web of Science CSD CrossRef IUCr Journals Google Scholar
Liu, F., Stephen, A. G., Adainson, C. S., Gousset, K., Aman, M. J., Freed, E. O., Fisher, R. J. & Burke, T. R. Jr (2006). Org. Lett. 8, 5165–5168. Web of Science CrossRef PubMed CAS Google Scholar
Macrae, C. F., Bruno, I. J., Chisholm, J. A., Edgington, P. R., McCabe, P., Pidcock, E., Rodriguez-Monge, L., Taylor, R., van de Streek, J. & Wood, P. A. (2008). J. Appl. Cryst. 41, 466–470. Web of Science CrossRef CAS IUCr Journals Google Scholar
Narayana, B., Ashalatha, B. V., Vijayaraj, K. K., Fernandes, J. & Sarojini, B. K. (2005a). Bioorg. Med. Chem. 13, 4638–4644. Web of Science CrossRef PubMed CAS Google Scholar
Narayana, B., Vijayaraj, K. K., Ashalatha, B. V. & Suchetha Kumari, N. (2005b). Pharmazie, 338, 373–377. Web of Science CrossRef CAS Google Scholar
Sarojini, B. K., Mustafa, K., Narayana, B., Yathirajan, H. S. & Bolte, M. (2007d). Acta Cryst. E63, o4419. Web of Science CSD CrossRef IUCr Journals Google Scholar
Sarojini, B. K., Narayana, B., Sunil, K., Yathirajan, H. S. & Bolte, M. (2007b). Acta Cryst. E63, o3551. Web of Science CSD CrossRef IUCr Journals Google Scholar
Sarojini, B. K., Narayana, B., Sunil, K., Yathirajan, H. S. & Bolte, M. (2007c). Acta Cryst. E63, o3862–o3863. Web of Science CSD CrossRef IUCr Journals Google Scholar
Sarojini, B. K., Yathirajan, H. S., Sunil, K., Narayana, B. & Bolte, M. (2007a). Acta Cryst. E63, o3487. Web of Science CSD 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. (2009). Acta Cryst. D65, 148–155. Web of Science CrossRef CAS IUCr Journals Google Scholar
Westrip, S. P. (2010). J. Appl. Cryst. 43, 920–925. Web of Science CrossRef CAS IUCr Journals Google Scholar

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Volume 68| Part 11| November 2012| Pages o3140-o3141

doi:10.1107/S1600536812041694

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