Benzene-1,2,4,5-tetra­carb­oxy­lic acid bis­(1,3,7-trimethyl-2,3,6,7-tetra­hydro-1H-purine-2,6-dione)

Arman, H.D.; Tiekink, E.R.T.

doi:10.1107/S1600536813022563

organic compounds

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ISSN: 2056-9890

Volume 69| Part 9| September 2013| Page o1443

doi:10.1107/S1600536813022563

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Benzene-1,2,4,5-tetracarboxylic acid bis(1,3,7-trimethyl-2,3,6,7-tetrahydro-1H-purine-2,6-dione)

Hadi D. Arman ^a and Edward R. T. Tiekink ^b ^*

^aDepartment of Chemistry, University of Texas at San Antonio, One UTSA Circle, San Antonio, TX 78249-0698, USA, and ^bDepartment of Chemistry, University of Malaya, 50603 Kuala Lumpur, Malaysia
^*Correspondence e-mail: edward.tiekink@gmail.com

(Received 11 August 2013; accepted 11 August 2013; online 17 August 2013)

The asymmetric unit of the title co-crystal, C₁₀H₆O₈·2C₈H₁₀N₄O₂, comprises a centrosymmetric benzene-1,2,4,5-tetracarboxylic acid (LH₄) molecule and a molecule of caffeine in a general position. LH₄ is nonplanar, with the dihedral angles between the ring and pendent carboxylic acid groups being 44.22 (7) and 49.74 (7)°. By contrast, the caffeine molecule is planar (r.m.s. deviation = 0.040 Å). Supramolecular layers parallel to (-1-10) are sustained by carboxylic acid O—H⋯O(carbonyl) and O—H⋯N(imidazole) hydrogen bonds, as well as by methyl–carbonyl C—H⋯O interactions. These stack via π–π interactions between the benzene and imidazole rings [inter-centroid distance = 3.4503 (10) Å].

Related literature

For cocrystallization studies with benzene-1,2,4,5-tetracarboxylic acid, see: Arman & Tiekink (2013 ).

Experimental

Crystal data

C₁₀H₆O₈·2C₈H₁₀N₄O₂
M_r = 642.55
Triclinic, $[P \overline 1]$
a = 7.4570 (15) Å
b = 9.0490 (15) Å
c = 11.782 (2) Å
α = 68.800 (11)°
β = 81.124 (13)°
γ = 73.441 (9)°
V = 709.3 (2) Å³
Z = 1
Mo Kα radiation
μ = 0.12 mm⁻¹
T = 98 K
0.55 × 0.30 × 0.25 mm

Data collection

Rigaku AFC12 Kappa/SATURN724 diffractometer
Absorption correction: multi-scan (ABSCOR; Higashi, 1995 ) T_min = 0.838, T_max = 1
4935 measured reflections
3213 independent reflections
3006 reflections with I > 2σ(I)
R_int = 0.020
Standard reflections: 0

Refinement

R[F² > 2σ(F²)] = 0.044
wR(F²) = 0.120
S = 1.04
3213 reflections
218 parameters
2 restraints
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.37 e Å⁻³
Δρ_min = −0.33 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O2—H1O⋯N3ⁱ	0.86 (1)	1.83 (1)	2.6774 (17)	171 (2)
O4—H2O⋯O5	0.84 (2)	1.84 (2)	2.6571 (15)	162 (2)
C12—H12B⋯O6ⁱⁱ	0.98	2.30	3.239 (2)	159
Symmetry codes: (i) -x, -y+2, -z+1; (ii) -x+2, -y+1, -z+1.

Data collection: CrystalClear (Molecular Structure Corporation & Rigaku, 2005 ); cell refinement: CrystalClear; data reduction: CrystalClear; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEPII (Johnson, 1976 ) and DIAMOND (Brandenburg, 2006 ); software used to prepare material for publication: publCIF (Westrip, 2010 ).

Supporting information

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536813022563/hg5340sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536813022563/hg5340Isup2.hkl

Supporting information file. DOI: 10.1107/S1600536813022563/hg5340Isup3.cml

checkCIF report

Comment top

The title co-crystal was investigated in continuation of recent structural studies of the products obtained from the co-crystallization of benzene-1,2,4,5-tetracarboxylic acid (LH₄) with various pyridyl-containing molecules (Arman & Tiekink, 2013).

The asymmetric unit comprises half a molecule of LH₄, being disposed about a centre of inversion, and a molecule of caffeine in a general position, Fig. 1. Twists are evident in LH₄ as seen in the dihedral angles of 44.22 (7) and 49.74 (7)° formed, respectively, between the O1- and O3-carboxylic acids and the benzene ring to which they are attached. The 14 non-hydrogen atoms of the caffeine molecule are co-planar with an r.m.s. deviation = 0.040 Å.

In the crystal packing, the HL₄ molecule forms two O2—H···O5-carbonyl and two O4—H···N3-imidazole hydrogen bonds to form a supramolecular chain constructed about centrosymmetric 26-membered {···HO—C₄OH···OCNCN}₂ synthons, Table 1. Chains are connected into a layer approximately parallel to (110) by methyl-C12—H···O6(carbonyl) interactions via centrosymmetric and 10-membered {···OCNCH}₂ synthons, Fig. 2. Layers are connected into a three-dimensional architecture by π–π interactions between the benzene and imidazolyl rings [inter-centroid distance = 3.4503 (10) Å, angle of inclination = 9.54 (7)° for symmetry operation x, y, 1 + z], Fig. 3.

Related literature top

For cocrystallization studies with benzene-1,2,4,5-tetracarboxylic acid, see: Arman & Tiekink (2013).

Experimental top

Crystals of (I) were obtained by the co-crystallization of caffeine (Sigma–Aldrich, 0.08 mmol) and benzene-1,2,4,5-tetracarboxylic acid (Sigma–Aldrich, 0.09 mmol) in acetone solution. Crystals were obtained by slow evaporation.

Computing details top

Data collection: CrystalClear (Molecular Structure Corporation & Rigaku, 2005); cell refinement: CrystalClear (Molecular Structure Corporation & Rigaku, 2005); data reduction: CrystalClear (Molecular Structure Corporation & Rigaku, 2005); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEPII (Johnson, 1976) and DIAMOND (Brandenburg, 2006); software used to prepare material for publication: publCIF (Westrip, 2010).

Figures top

	Fig. 1. Molecular structures of the components of (I), showing atom-labelling scheme and displacement ellipsoids at the 50% probability level. The unlabelled atoms of HL₄ (a) are generated by the symmetry operation 1 - x, 2 - y, 2 - z.
	Fig. 2. Views of the supramolecular layer in (I). The O—H···O (orange), O—H···N (blue) and C—H···O (green) interactions are shown as dashed lines.
	Fig. 3. Unit-cell contents in (I) highlighting the stacking of layers shown in Fig. 2.

Benzene-1,2,4,5-tetracarboxylic acid bis(1,3,7-trimethyl-2,3,6,7-tetrahydro-1H-purine-2,6-dione) top

Crystal data top

C₁₀H₆O₈·2C₈H₁₀N₄O₂	Z = 1
M_r = 642.55	F(000) = 334
Triclinic, P1	D_x = 1.504 Mg m⁻³
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 7.4570 (15) Å	Cell parameters from 2842 reflections
b = 9.0490 (15) Å	θ = 3.3–40.4°
c = 11.782 (2) Å	µ = 0.12 mm⁻¹
α = 68.800 (11)°	T = 98 K
β = 81.124 (13)°	Block, colourless
γ = 73.441 (9)°	0.55 × 0.30 × 0.25 mm
V = 709.3 (2) Å³

Data collection top

Rigaku AFC12 Kappa/SATURN724 diffractometer	3213 independent reflections
Radiation source: fine-focus sealed tube	3006 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.020
ω scans	θ_max = 27.5°, θ_min = 1.9°
Absorption correction: multi-scan (ABSCOR; Higashi, 1995)	h = −9→9
T_min = 0.838, T_max = 1	k = −11→11
4935 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)] = 0.044	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.120	H atoms treated by a mixture of independent and constrained refinement
S = 1.04	w = 1/[σ²(F_o²) + (0.0679P)² + 0.3025P] where P = (F_o² + 2F_c²)/3
3213 reflections	(Δ/σ)_max < 0.001
218 parameters	Δρ_max = 0.37 e Å⁻³
2 restraints	Δρ_min = −0.33 e Å⁻³

Crystal data top

C₁₀H₆O₈·2C₈H₁₀N₄O₂	γ = 73.441 (9)°
M_r = 642.55	V = 709.3 (2) Å³
Triclinic, P1	Z = 1
a = 7.4570 (15) Å	Mo Kα radiation
b = 9.0490 (15) Å	µ = 0.12 mm⁻¹
c = 11.782 (2) Å	T = 98 K
α = 68.800 (11)°	0.55 × 0.30 × 0.25 mm
β = 81.124 (13)°

Data collection top

Rigaku AFC12 Kappa/SATURN724 diffractometer	3213 independent reflections
Absorption correction: multi-scan (ABSCOR; Higashi, 1995)	3006 reflections with I > 2σ(I)
T_min = 0.838, T_max = 1	R_int = 0.020
4935 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.044	2 restraints
wR(F²) = 0.120	H atoms treated by a mixture of independent and constrained refinement
S = 1.04	Δρ_max = 0.37 e Å⁻³
3213 reflections	Δρ_min = −0.33 e Å⁻³
218 parameters

Special details top

Geometry. All s.u.'s (except the s.u. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell s.u.'s are taken into account individually in the estimation of s.u.'s in distances, angles and torsion angles; correlations between s.u.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell s.u.'s is used for estimating s.u.'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
O1	0.10476 (13)	0.94888 (12)	0.88177 (9)	0.0215 (2)
O2	0.05750 (13)	1.21613 (12)	0.85531 (9)	0.0216 (2)
H1O	−0.0516 (16)	1.226 (2)	0.8350 (17)	0.032*
O3	0.56478 (16)	0.70162 (12)	0.84529 (9)	0.0283 (3)
O4	0.43724 (14)	0.95115 (12)	0.71641 (8)	0.0202 (2)
H2O	0.430 (3)	0.902 (2)	0.6695 (17)	0.051 (6)*
O5	0.35494 (13)	0.85084 (12)	0.54930 (8)	0.0225 (2)
O6	0.84545 (14)	0.50918 (14)	0.40808 (10)	0.0283 (2)
N1	0.30711 (15)	0.79348 (14)	0.38575 (10)	0.0189 (2)
N2	0.60054 (15)	0.68600 (13)	0.47529 (10)	0.0175 (2)
N3	0.29341 (15)	0.71840 (13)	0.20867 (10)	0.0180 (2)
N4	0.58825 (16)	0.56529 (14)	0.20875 (10)	0.0191 (2)
C1	0.33603 (17)	1.03685 (15)	0.94094 (11)	0.0162 (3)
C2	0.49837 (17)	0.92882 (15)	0.91321 (11)	0.0159 (2)
C3	0.66122 (18)	0.89199 (15)	0.97280 (11)	0.0168 (3)
H3	0.7709	0.8179	0.9544	0.020*
C4	0.15397 (18)	1.06201 (16)	0.88843 (11)	0.0174 (3)
C5	0.50294 (18)	0.84709 (16)	0.82237 (11)	0.0179 (3)
C6	0.41768 (18)	0.78078 (16)	0.47369 (11)	0.0178 (3)
C7	0.68657 (18)	0.59678 (16)	0.39564 (12)	0.0187 (3)
C8	0.56313 (18)	0.62252 (15)	0.30563 (11)	0.0174 (3)
C9	0.38190 (18)	0.71494 (15)	0.30277 (11)	0.0167 (3)
C10	0.42496 (19)	0.62623 (16)	0.15447 (12)	0.0193 (3)
H10	0.4046	0.6060	0.0844	0.023*
C11	0.1111 (2)	0.8869 (2)	0.38356 (14)	0.0312 (3)
H11A	0.0737	0.9370	0.2991	0.047*
H11B	0.0969	0.9727	0.4189	0.047*
H11C	0.0316	0.8135	0.4312	0.047*
C12	0.71544 (19)	0.68114 (17)	0.56767 (12)	0.0217 (3)
H12A	0.7238	0.7922	0.5549	0.033*
H12B	0.8414	0.6118	0.5607	0.033*
H12C	0.6579	0.6362	0.6491	0.033*
C13	0.7597 (2)	0.46116 (18)	0.17183 (13)	0.0251 (3)
H13A	0.7855	0.3524	0.2344	0.038*
H13B	0.8650	0.5102	0.1623	0.038*
H13C	0.7433	0.4514	0.0941	0.038*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
O1	0.0199 (5)	0.0252 (5)	0.0241 (5)	−0.0084 (4)	−0.0032 (4)	−0.0109 (4)
O2	0.0180 (5)	0.0209 (5)	0.0262 (5)	−0.0038 (4)	−0.0101 (4)	−0.0055 (4)
O3	0.0414 (6)	0.0210 (5)	0.0249 (5)	−0.0036 (4)	−0.0113 (4)	−0.0099 (4)
O4	0.0250 (5)	0.0225 (5)	0.0154 (4)	−0.0064 (4)	−0.0052 (3)	−0.0072 (4)
O5	0.0203 (5)	0.0306 (5)	0.0201 (5)	−0.0043 (4)	−0.0040 (4)	−0.0129 (4)
O6	0.0192 (5)	0.0350 (6)	0.0301 (5)	0.0028 (4)	−0.0086 (4)	−0.0147 (4)
N1	0.0148 (5)	0.0249 (6)	0.0188 (5)	−0.0036 (4)	−0.0036 (4)	−0.0093 (4)
N2	0.0159 (5)	0.0215 (5)	0.0163 (5)	−0.0054 (4)	−0.0039 (4)	−0.0059 (4)
N3	0.0194 (5)	0.0191 (5)	0.0172 (5)	−0.0051 (4)	−0.0042 (4)	−0.0065 (4)
N4	0.0196 (5)	0.0205 (5)	0.0193 (5)	−0.0056 (4)	−0.0017 (4)	−0.0083 (4)
C1	0.0166 (6)	0.0174 (6)	0.0148 (5)	−0.0062 (5)	−0.0038 (4)	−0.0030 (4)
C2	0.0186 (6)	0.0170 (5)	0.0140 (5)	−0.0067 (5)	−0.0030 (4)	−0.0048 (4)
C3	0.0173 (6)	0.0175 (5)	0.0163 (5)	−0.0050 (4)	−0.0029 (4)	−0.0049 (4)
C4	0.0167 (6)	0.0227 (6)	0.0139 (5)	−0.0064 (5)	−0.0019 (4)	−0.0060 (5)
C5	0.0184 (6)	0.0206 (6)	0.0174 (6)	−0.0061 (5)	−0.0036 (4)	−0.0075 (5)
C6	0.0175 (6)	0.0205 (6)	0.0163 (6)	−0.0067 (5)	−0.0023 (4)	−0.0050 (5)
C7	0.0180 (6)	0.0203 (6)	0.0180 (6)	−0.0056 (5)	−0.0022 (5)	−0.0057 (5)
C8	0.0178 (6)	0.0187 (6)	0.0161 (6)	−0.0052 (5)	−0.0015 (5)	−0.0056 (5)
C9	0.0163 (6)	0.0183 (6)	0.0164 (5)	−0.0064 (5)	−0.0022 (4)	−0.0046 (4)
C10	0.0228 (6)	0.0189 (6)	0.0176 (6)	−0.0064 (5)	−0.0042 (5)	−0.0058 (5)
C11	0.0177 (7)	0.0470 (9)	0.0312 (7)	0.0037 (6)	−0.0071 (5)	−0.0225 (7)
C12	0.0188 (6)	0.0291 (7)	0.0198 (6)	−0.0061 (5)	−0.0065 (5)	−0.0090 (5)
C13	0.0213 (6)	0.0279 (7)	0.0291 (7)	−0.0035 (5)	−0.0007 (5)	−0.0154 (6)

Geometric parameters (Å, º) top

O1—C4	1.2123 (16)	C1—C3ⁱ	1.3911 (17)
O2—C4	1.3176 (16)	C1—C2	1.4008 (18)
O2—H1O	0.855 (9)	C1—C4	1.5030 (17)
O3—C5	1.2057 (17)	C2—C3	1.3935 (17)
O4—C5	1.3270 (15)	C2—C5	1.4968 (17)
O4—H2O	0.843 (9)	C3—C1ⁱ	1.3911 (17)
O5—C6	1.2349 (16)	C3—H3	0.9500
O6—C7	1.2197 (17)	C7—C8	1.4236 (17)
N1—C9	1.3713 (17)	C8—C9	1.3698 (18)
N1—C6	1.3747 (16)	C10—H10	0.9500
N1—C11	1.4638 (17)	C11—H11A	0.9800
N2—C6	1.3875 (17)	C11—H11B	0.9800
N2—C7	1.4181 (17)	C11—H11C	0.9800
N2—C12	1.4671 (15)	C12—H12A	0.9800
N3—C10	1.3384 (17)	C12—H12B	0.9800
N3—C9	1.3618 (16)	C12—H12C	0.9800
N4—C10	1.3410 (17)	C13—H13A	0.9800
N4—C8	1.3829 (16)	C13—H13B	0.9800
N4—C13	1.4664 (17)	C13—H13C	0.9800

C4—O2—H1O	110.9 (13)	O6—C7—N2	121.91 (12)
C5—O4—H2O	111.5 (16)	O6—C7—C8	126.89 (13)
C9—N1—C6	119.13 (11)	N2—C7—C8	111.20 (11)
C9—N1—C11	121.00 (11)	C9—C8—N4	105.48 (11)
C6—N1—C11	119.85 (11)	C9—C8—C7	123.20 (12)
C6—N2—C7	126.45 (11)	N4—C8—C7	131.32 (12)
C6—N2—C12	116.05 (11)	N3—C9—C8	111.54 (11)
C7—N2—C12	117.50 (11)	N3—C9—N1	126.48 (12)
C10—N3—C9	103.47 (11)	C8—C9—N1	121.97 (11)
C10—N4—C8	106.08 (11)	N3—C10—N4	113.43 (11)
C10—N4—C13	127.01 (11)	N3—C10—H10	123.3
C8—N4—C13	126.90 (11)	N4—C10—H10	123.3
C3ⁱ—C1—C2	119.74 (12)	N1—C11—H11A	109.5
C3ⁱ—C1—C4	119.61 (11)	N1—C11—H11B	109.5
C2—C1—C4	120.31 (11)	H11A—C11—H11B	109.5
C3—C2—C1	119.94 (11)	N1—C11—H11C	109.5
C3—C2—C5	117.97 (11)	H11A—C11—H11C	109.5
C1—C2—C5	122.07 (11)	H11B—C11—H11C	109.5
C1ⁱ—C3—C2	120.31 (12)	N2—C12—H12A	109.5
C1ⁱ—C3—H3	119.8	N2—C12—H12B	109.5
C2—C3—H3	119.8	H12A—C12—H12B	109.5
O1—C4—O2	125.76 (12)	N2—C12—H12C	109.5
O1—C4—C1	121.79 (12)	H12A—C12—H12C	109.5
O2—C4—C1	112.42 (11)	H12B—C12—H12C	109.5
O3—C5—O4	125.01 (12)	N4—C13—H13A	109.5
O3—C5—C2	121.87 (11)	N4—C13—H13B	109.5
O4—C5—C2	113.10 (11)	H13A—C13—H13B	109.5
O5—C6—N1	120.74 (12)	N4—C13—H13C	109.5
O5—C6—N2	121.29 (11)	H13A—C13—H13C	109.5
N1—C6—N2	117.97 (11)	H13B—C13—H13C	109.5

C3ⁱ—C1—C2—C3	0.6 (2)	C6—N2—C7—C8	3.16 (18)
C4—C1—C2—C3	−172.74 (11)	C12—N2—C7—C8	−175.68 (10)
C3ⁱ—C1—C2—C5	179.23 (11)	C10—N4—C8—C9	0.39 (14)
C4—C1—C2—C5	5.92 (18)	C13—N4—C8—C9	179.52 (12)
C1—C2—C3—C1ⁱ	−0.6 (2)	C10—N4—C8—C7	179.29 (13)
C5—C2—C3—C1ⁱ	−179.28 (11)	C13—N4—C8—C7	−1.6 (2)
C3ⁱ—C1—C4—O1	−131.94 (13)	O6—C7—C8—C9	175.61 (13)
C2—C1—C4—O1	41.37 (18)	N2—C7—C8—C9	−3.34 (18)
C3ⁱ—C1—C4—O2	46.39 (15)	O6—C7—C8—N4	−3.1 (2)
C2—C1—C4—O2	−140.30 (12)	N2—C7—C8—N4	177.92 (12)
C3—C2—C5—O3	48.27 (18)	C10—N3—C9—C8	−0.07 (14)
C1—C2—C5—O3	−130.41 (14)	C10—N3—C9—N1	179.02 (12)
C3—C2—C5—O4	−130.22 (12)	N4—C8—C9—N3	−0.20 (14)
C1—C2—C5—O4	51.09 (16)	C7—C8—C9—N3	−179.22 (11)
C9—N1—C6—O5	179.55 (11)	N4—C8—C9—N1	−179.34 (11)
C11—N1—C6—O5	−1.85 (19)	C7—C8—C9—N1	1.6 (2)
C9—N1—C6—N2	−1.00 (18)	C6—N1—C9—N3	−178.25 (12)
C11—N1—C6—N2	177.60 (12)	C11—N1—C9—N3	3.2 (2)
C7—N2—C6—O5	178.31 (12)	C6—N1—C9—C8	0.75 (19)
C12—N2—C6—O5	−2.83 (18)	C11—N1—C9—C8	−177.83 (13)
C7—N2—C6—N1	−1.14 (19)	C9—N3—C10—N4	0.33 (15)
C12—N2—C6—N1	177.72 (11)	C8—N4—C10—N3	−0.47 (15)
C6—N2—C7—O6	−175.85 (12)	C13—N4—C10—N3	−179.60 (12)
C12—N2—C7—O6	5.31 (19)

Symmetry code: (i) −x+1, −y+2, −z+2.

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
O2—H1O···N3ⁱⁱ	0.86 (1)	1.83 (1)	2.6774 (17)	171 (2)
O4—H2O···O5	0.84 (2)	1.84 (2)	2.6571 (15)	162 (2)
C12—H12B···O6ⁱⁱⁱ	0.98	2.30	3.239 (2)	159

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

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
O2—H1O···N3ⁱ	0.855 (14)	1.831 (14)	2.6774 (17)	170.6 (18)
O4—H2O···O5	0.841 (19)	1.84 (2)	2.6571 (15)	162 (2)
C12—H12B···O6ⁱⁱ	0.98	2.30	3.239 (2)	159

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

Acknowledgements

The authors gratefully thank the Ministry of Higher Education (Malaysia) for funding structural studies through the High-Impact Research scheme (grant No. UM.C/HIR-MOHE/SC/03).

References

Arman, H. D. & Tiekink, E. R. T. (2013). Z. Kristallogr. Cryst. Mat. 228, 289–294. Web of Science CSD CrossRef CAS Google Scholar
Brandenburg, K. (2006). DIAMOND. Crystal Impact GbR, Bonn, Germany. Google Scholar
Higashi, T. (1995). ABSCOR. Rigaku Corporation, Tokyo, Japan. Google Scholar
Johnson, C. K. (1976). ORTEPII. Report ORNL-5138. Oak Ridge National Laboratory, Tennessee, USA. Google Scholar
Molecular Structure Corporation & Rigaku (2005). CrystalClear. MSC, The Woodlands, Texas, USA, and Rigaku Corporation, Tokyo, Japan. Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. 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 69| Part 9| September 2013| Page o1443

doi:10.1107/S1600536813022563

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organic compounds\(\def\hfill{\hskip 5em}\def\hfil{\hskip 3em}\def\eqno#1{\hfil {#1}}\)

Benzene-1,2,4,5-tetra­carb­­oxy­lic acid bis­­(1,3,7-tri­methyl-2,3,6,7-tetra­hydro-1H-purine-2,6-dione)

Related literature

Experimental

Crystal data

Data collection

Refinement

Supporting information

Acknowledgements

References

organic compounds

Benzene-1,2,4,5-tetracarboxylic acid bis(1,3,7-trimethyl-2,3,6,7-tetrahydro-1H-purine-2,6-dione)