4-tert-Butyl­pyridinium picrate

Ramesh, P.; Akalya, R.; Chandramohan, A.; Ponnuswamy, M.N.

doi:10.1107/S1600536810011037

organic compounds

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ISSN: 2056-9890

Volume 66| Part 4| April 2010| Page o999

doi:10.1107/S1600536810011037

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4-tert-Butylpyridinium picrate

P. Ramesh,^a R. Akalya,^b A. Chandramohan ^b and M. N. Ponnuswamy ^a ^*

^aCentre of Advanced Study in Crystallography and Biophysics, University of Madras, Guindy Campus, Chennai 600 025, India, and ^bDepartment of Chemistry, Sri Ramakrishna Mission Vidyalaya Arts and Science College, Coimbatore 641 020, India
^*Correspondence e-mail: mnpsy2004@yahoo.com

(Received 12 March 2010; accepted 24 March 2010; online 31 March 2010)

In the title compound, C₉H₁₄N⁺·C₆H₂N₃O₇⁻, the three nitro groups of the picrate anion are twisted out of the plane of the attached benzene ring; the dihedral angles are 32.8 (2), 10.5 (4) and 12.3 (4)°. The pyridinium cations and picrate anions are linked via bifurcated N—H⋯(O,O) hydrogen bonds. The ionic pairs are linked into a ribbon-like structure along [101] by C—H⋯O hydrogen bonds.

Related literature

For general background to picrate complexes, see: In et al. (1997 ); Zaderenko et al. (1997 ); Ashwell et al. (1995 ); Owen & White (1976 ); Shakir et al. (2009 ).

Experimental

Crystal data

C₉H₁₄N⁺·C₆H₂N₃O₇⁻
M_r = 364.32
Monoclinic, P 2₁ /n
a = 5.7669 (12) Å
b = 26.798 (6) Å
c = 11.195 (3) Å
β = 97.335 (6)°
V = 1715.9 (7) Å³
Z = 4
Mo Kα radiation
μ = 0.11 mm⁻¹
T = 293 K
0.21 × 0.19 × 0.16 mm

Data collection

Bruker SMART APEXII area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2008 ) T_min = 0.976, T_max = 0.982
16875 measured reflections
4318 independent reflections
2677 reflections with I > 2σ(I)
R_int = 0.027

Refinement

R[F² > 2σ(F²)] = 0.055
wR(F²) = 0.178
S = 1.05
4318 reflections
242 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.48 e Å⁻³
Δρ_min = −0.18 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N1—H1⋯O1ⁱ	0.91 (3)	1.85 (3)	2.659 (2)	148 (2)
N1—H1⋯O7ⁱ	0.91 (3)	2.38 (3)	3.085 (3)	135 (2)
C2—H2⋯O4ⁱⁱ	0.93	2.45	3.131 (3)	130
C6—H6⋯O1ⁱⁱⁱ	0.93	2.42	3.137 (3)	133
Symmetry codes: (i) $[-x+{\script{1\over 2}}, y+{\script{1\over 2}}, -z+{\script{1\over 2}}]$ ; (ii) $[x-{\script{1\over 2}}, -y+{\script{1\over 2}}, z-{\script{1\over 2}}]$ ; (iii) $[x+{\script{1\over 2}}, -y+{\script{1\over 2}}, z+{\script{1\over 2}}]$ .

Data collection: APEX2 (Bruker, 2008); cell refinement: SAINT (Bruker, 2008); 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 ); software used to prepare material for publication: SHELXL97 and PLATON (Spek, 2009 ).

Supporting information

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536810011037/ci5056sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536810011037/ci5056Isup2.hkl

checkCIF report

Comment top

It is well known that picric acid forms charge transfer molecular complexes with a number of aromatic compounds such as aromatic hydrocarbons and amines, through electrostatic or hydrogen bonding interactions (In et al., 1997; Zaderenko et al., 1997). The bonding of donor-acceptor picric acid complexes strongly depends on the nature of partners. Some of the picric acid complexes crystallize in centrosymmetric space group owing to non-linear optical properties (NLO) (Shakir et al., 2009). This is due to the aggregation of the donor-acceptor molecules in a non-centrosymmetric manner which contributes to the bulk susceptibility from intermolecular charge transfer (Ashwell et al.,1995; Owen & White, 1976). We report here the crystal structure of the title salt.

The pyridinium ring of the cation (Fig.1) is planar (r.m.s. deviation 0.019 Å). In the picrate anion, the keto O atom deviates from the benzene plane by 0.139 (3) Å. The C11—O1 bond [1.245 (2) Å] assumes a partial double bond character. The C11—C12 [1.452 (3) Å] and C11—C16 [1.436 (3) Å] bond distances are longer than the other C—C bond lengths of the benzene ring. The three nitro groups are twisted out of the attached benzene ring by 32.8 (2)° [N17/O2/O3], 10.5 (4)° [N18/O4/O5] and 12.3 (4)° [N19/O6/O7].

In the crystal, the cations and anions are linked via N—H···O hydrogen bonds involving the phenolate O atom and one of the nitro O atoms. The ionic pairs are linked into a ribbon-like structure along the [101] by C—H···O hydrogen bonds (Fig.2).

Related literature top

For general background to picrate complexes, see: In et al. (1997); Zaderenko et al. (1997); Ashwell et al. (1995); Owen & White (1976); Shakir et al. (2009).

Experimental top

Equimolar solutions of 4-tertiarybutyl pyridine in methanol and picric acid in methanol were mixed together and the solution was stirred well for 1 h and the precipitated salt was filtered off. The salt was repeatedly recrystallised from methanol to get single crystals suitable for X-ray analysis.

Computing details top

Data collection: APEX2 (Bruker, 2008); cell refinement: SAINT (Bruker, 2008); data reduction: SAINT (Bruker, 2008); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 (Farrugia, 1997); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008) and PLATON (Spek, 2009).

Figures top

	Fig. 1. The asymmetric unit of the title compound. Displacement ellipsoids are drawn at the 50% probability level.
	Fig. 2. The crystal packing of the title compound, viewed down the a axis. H atoms not involved in hydrogen bonding (dashed lines) have been omitted for clarity.

4-tert-Butylpyridinium picrate top

Crystal data top

C₉H₁₄N⁺·C₆H₂N₃O₇⁻	F(000) = 760
M_r = 364.32	D_x = 1.410 Mg m⁻³
Monoclinic, P2₁/n	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2yn	Cell parameters from 2565 reflections
a = 5.7669 (12) Å	θ = 1.5–28.5°
b = 26.798 (6) Å	µ = 0.11 mm⁻¹
c = 11.195 (3) Å	T = 293 K
β = 97.335 (6)°	Block, colourless
V = 1715.9 (7) Å³	0.21 × 0.19 × 0.16 mm
Z = 4

Data collection top

Bruker SMART APEXII area-detector diffractometer	4318 independent reflections
Radiation source: fine-focus sealed tube	2677 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.027
ω and ϕ scans	θ_max = 28.5°, θ_min = 1.5°
Absorption correction: multi-scan (SADABS; Bruker, 2008)	h = −7→7
T_min = 0.976, T_max = 0.982	k = −34→35
16875 measured reflections	l = −14→15

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)] = 0.055	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.178	H atoms treated by a mixture of independent and constrained refinement
S = 1.05	w = 1/[σ²(F_o²) + (0.0841P)² + 0.3243P] where P = (F_o² + 2F_c²)/3
4318 reflections	(Δ/σ)_max = 0.001
242 parameters	Δρ_max = 0.48 e Å⁻³
0 restraints	Δρ_min = −0.18 e Å⁻³

Crystal data top

C₉H₁₄N⁺·C₆H₂N₃O₇⁻	V = 1715.9 (7) Å³
M_r = 364.32	Z = 4
Monoclinic, P2₁/n	Mo Kα radiation
a = 5.7669 (12) Å	µ = 0.11 mm⁻¹
b = 26.798 (6) Å	T = 293 K
c = 11.195 (3) Å	0.21 × 0.19 × 0.16 mm
β = 97.335 (6)°

Data collection top

Bruker SMART APEXII area-detector diffractometer	4318 independent reflections
Absorption correction: multi-scan (SADABS; Bruker, 2008)	2677 reflections with I > 2σ(I)
T_min = 0.976, T_max = 0.982	R_int = 0.027
16875 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.055	0 restraints
wR(F²) = 0.178	H atoms treated by a mixture of independent and constrained refinement
S = 1.05	Δρ_max = 0.48 e Å⁻³
4318 reflections	Δρ_min = −0.18 e Å⁻³
242 parameters

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 > 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
O1	0.2606 (3)	0.00115 (5)	0.17613 (13)	0.0663 (4)
O2	0.5627 (3)	−0.05436 (6)	0.32430 (15)	0.0744 (4)
O3	0.8672 (3)	−0.00990 (7)	0.37736 (16)	0.0800 (5)
O4	0.7078 (4)	0.14493 (6)	0.57283 (18)	0.0991 (7)
O5	0.3706 (4)	0.17951 (7)	0.5339 (2)	0.1081 (7)
O6	−0.1374 (4)	0.12612 (8)	0.1958 (3)	0.1319 (10)
O7	−0.1413 (3)	0.05113 (7)	0.13505 (15)	0.0829 (5)
N1	0.5892 (3)	0.43662 (7)	0.37124 (16)	0.0627 (4)
H1	0.516 (5)	0.4666 (11)	0.362 (3)	0.097 (9)*
C2	0.5004 (4)	0.39966 (9)	0.3030 (2)	0.0669 (6)
H2	0.3705	0.4053	0.2463	0.080*
C3	0.5967 (4)	0.35326 (8)	0.31436 (19)	0.0631 (5)
H3	0.5356	0.3277	0.2637	0.076*
C4	0.7843 (3)	0.34401 (7)	0.40070 (18)	0.0545 (5)
C5	0.8766 (4)	0.38456 (8)	0.46659 (19)	0.0667 (6)
H5	1.0077	0.3803	0.5233	0.080*
C6	0.7790 (4)	0.43054 (9)	0.45000 (19)	0.0715 (6)
H6	0.8451	0.4577	0.4937	0.086*
C7	0.8842 (4)	0.29206 (8)	0.4249 (2)	0.0732 (6)
C8	0.7573 (6)	0.25297 (11)	0.3428 (4)	0.1142 (11)
H8A	0.7858	0.2589	0.2613	0.171*
H8B	0.5925	0.2549	0.3475	0.171*
H8C	0.8134	0.2204	0.3677	0.171*
C9	0.8433 (7)	0.27804 (12)	0.5529 (3)	0.1227 (12)
H9A	0.8943	0.2444	0.5696	0.184*
H9B	0.6797	0.2807	0.5603	0.184*
H9C	0.9302	0.3002	0.6092	0.184*
C10	1.1361 (5)	0.29230 (13)	0.4139 (6)	0.179 (3)
H10A	1.1620	0.3094	0.3415	0.268*
H10B	1.1913	0.2586	0.4110	0.268*
H10C	1.2193	0.3090	0.4822	0.268*
C11	0.3052 (3)	0.03289 (7)	0.25697 (16)	0.0529 (4)
C12	0.5135 (3)	0.03034 (7)	0.34450 (16)	0.0508 (4)
C13	0.5836 (3)	0.06717 (7)	0.42427 (17)	0.0545 (5)
H13	0.7245	0.0645	0.4745	0.065*
C14	0.4436 (4)	0.10853 (7)	0.42986 (18)	0.0594 (5)
C15	0.2372 (4)	0.11350 (7)	0.35493 (19)	0.0615 (5)
H15	0.1429	0.1413	0.3608	0.074*
C16	0.1713 (3)	0.07717 (7)	0.27149 (17)	0.0568 (5)
N17	0.6573 (3)	−0.01424 (6)	0.34792 (14)	0.0580 (4)
N18	0.5107 (4)	0.14682 (7)	0.51824 (18)	0.0770 (6)
N19	−0.0483 (3)	0.08495 (8)	0.19498 (17)	0.0707 (5)

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
O1	0.0751 (9)	0.0638 (9)	0.0581 (8)	−0.0153 (7)	0.0019 (7)	−0.0106 (7)
O2	0.0854 (10)	0.0527 (9)	0.0874 (11)	−0.0013 (7)	0.0194 (8)	−0.0060 (8)
O3	0.0656 (10)	0.0859 (12)	0.0845 (11)	0.0082 (8)	−0.0058 (8)	−0.0085 (9)
O4	0.1186 (14)	0.0598 (10)	0.1032 (13)	−0.0103 (9)	−0.0463 (12)	−0.0089 (9)
O5	0.1340 (17)	0.0605 (11)	0.1192 (16)	0.0156 (11)	−0.0245 (13)	−0.0300 (10)
O6	0.1079 (15)	0.0853 (15)	0.181 (2)	0.0249 (12)	−0.0669 (16)	−0.0217 (14)
O7	0.0782 (10)	0.0846 (11)	0.0774 (10)	−0.0123 (9)	−0.0226 (8)	−0.0048 (9)
N1	0.0751 (11)	0.0559 (10)	0.0575 (9)	0.0129 (9)	0.0101 (8)	0.0106 (8)
C2	0.0577 (11)	0.0668 (13)	0.0720 (13)	0.0010 (10)	−0.0075 (9)	0.0177 (11)
C3	0.0625 (12)	0.0542 (12)	0.0683 (12)	−0.0073 (9)	−0.0087 (9)	0.0063 (9)
C4	0.0507 (10)	0.0532 (10)	0.0587 (11)	0.0022 (8)	0.0038 (8)	0.0099 (8)
C5	0.0692 (13)	0.0670 (13)	0.0579 (11)	0.0038 (10)	−0.0148 (9)	0.0055 (10)
C6	0.0972 (16)	0.0614 (13)	0.0527 (11)	0.0015 (11)	−0.0024 (11)	−0.0025 (9)
C7	0.0648 (12)	0.0551 (12)	0.0963 (17)	0.0080 (10)	−0.0022 (11)	0.0165 (11)
C8	0.122 (3)	0.0661 (17)	0.150 (3)	0.0173 (16)	0.000 (2)	−0.0063 (18)
C9	0.161 (3)	0.084 (2)	0.114 (2)	0.001 (2)	−0.014 (2)	0.0452 (18)
C10	0.0698 (19)	0.087 (2)	0.386 (8)	0.0310 (16)	0.058 (3)	0.059 (3)
C11	0.0595 (11)	0.0507 (10)	0.0481 (9)	−0.0149 (8)	0.0051 (8)	0.0020 (8)
C12	0.0559 (10)	0.0482 (10)	0.0483 (9)	−0.0056 (8)	0.0069 (8)	0.0042 (8)
C13	0.0596 (10)	0.0497 (10)	0.0516 (10)	−0.0089 (8)	−0.0024 (8)	0.0057 (8)
C14	0.0733 (12)	0.0422 (10)	0.0590 (11)	−0.0101 (9)	−0.0054 (9)	0.0005 (8)
C15	0.0681 (12)	0.0457 (10)	0.0678 (12)	−0.0029 (9)	−0.0026 (9)	0.0033 (9)
C16	0.0572 (10)	0.0544 (11)	0.0560 (10)	−0.0081 (9)	−0.0042 (8)	0.0057 (9)
N17	0.0661 (11)	0.0581 (10)	0.0504 (9)	−0.0002 (8)	0.0096 (7)	−0.0010 (7)
N18	0.1021 (15)	0.0435 (10)	0.0770 (12)	−0.0075 (9)	−0.0203 (11)	−0.0017 (8)
N19	0.0655 (11)	0.0675 (12)	0.0741 (12)	−0.0054 (9)	−0.0102 (9)	0.0049 (9)

Geometric parameters (Å, º) top

O1—C11	1.245 (2)	C7—C9	1.529 (4)
O2—N17	1.219 (2)	C8—H8A	0.96
O3—N17	1.219 (2)	C8—H8B	0.96
O4—N18	1.221 (3)	C8—H8C	0.96
O5—N18	1.219 (3)	C9—H9A	0.96
O6—N19	1.218 (3)	C9—H9B	0.96
O7—N19	1.211 (2)	C9—H9C	0.96
N1—C2	1.314 (3)	C10—H10A	0.96
N1—C6	1.325 (3)	C10—H10B	0.96
N1—H1	0.91 (3)	C10—H10C	0.96
C2—C3	1.361 (3)	C11—C16	1.436 (3)
C2—H2	0.93	C11—C12	1.452 (3)
C3—C4	1.378 (3)	C12—C13	1.357 (3)
C3—H3	0.93	C12—N17	1.452 (3)
C4—C5	1.381 (3)	C13—C14	1.377 (3)
C4—C7	1.518 (3)	C13—H13	0.93
C5—C6	1.357 (3)	C14—C15	1.372 (3)
C5—H5	0.93	C14—N18	1.444 (3)
C6—H6	0.93	C15—C16	1.369 (3)
C7—C10	1.473 (4)	C15—H15	0.93
C7—C8	1.519 (4)	C16—N19	1.451 (3)

C2—N1—C6	121.45 (19)	H9B—C9—H9C	109.5
C2—N1—H1	117.2 (18)	C7—C10—H10A	109.5
C6—N1—H1	121.3 (18)	C7—C10—H10B	109.5
N1—C2—C3	120.67 (18)	H10A—C10—H10B	109.5
N1—C2—H2	119.7	C7—C10—H10C	109.5
C3—C2—H2	119.7	H10A—C10—H10C	109.5
C2—C3—C4	120.3 (2)	H10B—C10—H10C	109.5
C2—C3—H3	119.9	O1—C11—C16	125.64 (17)
C4—C3—H3	119.9	O1—C11—C12	122.35 (18)
C3—C4—C5	116.58 (18)	C16—C11—C12	111.90 (16)
C3—C4—C7	122.42 (19)	C13—C12—C11	124.14 (17)
C5—C4—C7	120.99 (18)	C13—C12—N17	117.36 (16)
C6—C5—C4	121.09 (18)	C11—C12—N17	118.50 (16)
C6—C5—H5	119.5	C12—C13—C14	119.20 (17)
C4—C5—H5	119.5	C12—C13—H13	120.4
N1—C6—C5	119.7 (2)	C14—C13—H13	120.4
N1—C6—H6	120.2	C15—C14—C13	121.19 (18)
C5—C6—H6	120.2	C15—C14—N18	119.05 (19)
C10—C7—C4	109.7 (2)	C13—C14—N18	119.73 (18)
C10—C7—C8	110.9 (3)	C16—C15—C14	119.45 (19)
C4—C7—C8	112.5 (2)	C16—C15—H15	120.3
C10—C7—C9	110.5 (3)	C14—C15—H15	120.3
C4—C7—C9	107.0 (2)	C15—C16—C11	123.94 (17)
C8—C7—C9	106.1 (2)	C15—C16—N19	116.49 (18)
C7—C8—H8A	109.5	C11—C16—N19	119.57 (17)
C7—C8—H8B	109.5	O3—N17—O2	122.98 (18)
H8A—C8—H8B	109.5	O3—N17—C12	118.23 (17)
C7—C8—H8C	109.5	O2—N17—C12	118.77 (17)
H8A—C8—H8C	109.5	O5—N18—O4	123.3 (2)
H8B—C8—H8C	109.5	O5—N18—C14	119.00 (19)
C7—C9—H9A	109.5	O4—N18—C14	117.7 (2)
C7—C9—H9B	109.5	O7—N19—O6	121.66 (19)
H9A—C9—H9B	109.5	O7—N19—C16	120.72 (19)
C7—C9—H9C	109.5	O6—N19—C16	117.60 (19)
H9A—C9—H9C	109.5

C6—N1—C2—C3	2.4 (3)	C12—C13—C14—N18	177.02 (19)
N1—C2—C3—C4	2.2 (3)	C13—C14—C15—C16	−1.3 (3)
C2—C3—C4—C5	−4.7 (3)	N18—C14—C15—C16	−179.48 (19)
C2—C3—C4—C7	174.3 (2)	C14—C15—C16—C11	0.5 (3)
C3—C4—C5—C6	2.9 (3)	C14—C15—C16—N19	−179.75 (19)
C7—C4—C5—C6	−176.1 (2)	O1—C11—C16—C15	−173.87 (19)
C2—N1—C6—C5	−4.2 (3)	C12—C11—C16—C15	2.3 (3)
C4—C5—C6—N1	1.5 (4)	O1—C11—C16—N19	6.4 (3)
C3—C4—C7—C10	124.9 (3)	C12—C11—C16—N19	−177.37 (16)
C5—C4—C7—C10	−56.2 (4)	C13—C12—N17—O3	−31.6 (2)
C3—C4—C7—C8	0.9 (3)	C11—C12—N17—O3	148.47 (18)
C5—C4—C7—C8	179.9 (2)	C13—C12—N17—O2	146.61 (18)
C3—C4—C7—C9	−115.2 (3)	C11—C12—N17—O2	−33.3 (2)
C5—C4—C7—C9	63.7 (3)	C15—C14—N18—O5	8.6 (3)
O1—C11—C12—C13	171.42 (18)	C13—C14—N18—O5	−169.7 (2)
C16—C11—C12—C13	−4.9 (3)	C15—C14—N18—O4	−170.6 (2)
O1—C11—C12—N17	−8.6 (3)	C13—C14—N18—O4	11.1 (3)
C16—C11—C12—N17	175.02 (16)	C15—C16—N19—O7	−166.1 (2)
C11—C12—C13—C14	4.5 (3)	C11—C16—N19—O7	13.6 (3)
N17—C12—C13—C14	−175.42 (17)	C15—C16—N19—O6	12.1 (3)
C12—C13—C14—C15	−1.2 (3)	C11—C16—N19—O6	−168.2 (2)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1···O1ⁱ	0.91 (3)	1.85 (3)	2.659 (2)	148 (2)
N1—H1···O7ⁱ	0.91 (3)	2.38 (3)	3.085 (3)	135 (2)
C2—H2···O4ⁱⁱ	0.93	2.45	3.131 (3)	130
C6—H6···O1ⁱⁱⁱ	0.93	2.42	3.137 (3)	133

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

Experimental details

Crystal data
Chemical formula	C₉H₁₄N⁺·C₆H₂N₃O₇⁻
M_r	364.32
Crystal system, space group	Monoclinic, P2₁/n
Temperature (K)	293
a, b, c (Å)	5.7669 (12), 26.798 (6), 11.195 (3)
β (°)	97.335 (6)
V (Å³)	1715.9 (7)
Z	4
Radiation type	Mo Kα
µ (mm⁻¹)	0.11
Crystal size (mm)	0.21 × 0.19 × 0.16

Data collection
Diffractometer	Bruker SMART APEXII area-detector diffractometer
Absorption correction	Multi-scan (SADABS; Bruker, 2008)
T_min, T_max	0.976, 0.982
No. of measured, independent and observed [I > 2σ(I)] reflections	16875, 4318, 2677
R_int	0.027
(sin θ/λ)_max (Å⁻¹)	0.672

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.055, 0.178, 1.05
No. of reflections	4318
No. of parameters	242
H-atom treatment	H atoms treated by a mixture of independent and constrained refinement
Δρ_max, Δρ_min (e Å⁻³)	0.48, −0.18

Computer programs: APEX2 (Bruker, 2008), SAINT (Bruker, 2008), SHELXS97 (Sheldrick, 2008), ORTEP-3 (Farrugia, 1997), SHELXL97 (Sheldrick, 2008) and PLATON (Spek, 2009).

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1···O1ⁱ	0.91 (3)	1.85 (3)	2.659 (2)	148 (2)
N1—H1···O7ⁱ	0.91 (3)	2.38 (3)	3.085 (3)	135 (2)
C2—H2···O4ⁱⁱ	0.93	2.45	3.131 (3)	130
C6—H6···O1ⁱⁱⁱ	0.93	2.42	3.137 (3)	133

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

Acknowledgements

The authors wish to thank TBI Consultancy, University of Madras, for the data collection.

References

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