Theophylline-2,4-dihydroxy­benzoic acid-water (1/1/1)

In the the title cocrystal, C₇H₈N₄O₂·C₇H₆O₄·H₂O, the three mol­ecules form an S(6) and a C₂²(8) ring by intra- and inter­molecular hydrogen bonds, respectively. Finally, these components are organized into an infinite two-dimensional network via hydrogen bonds.

Key indicators

• Single-crystal X-ray study
• T = 298 K
• Mean [sigma](C-C) = 0.003 Å
• R factor = 0.052
• wR factor = 0.138
• Data-to-parameter ratio = 12.4

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT066_ALERT_1_C Predicted and Reported Transmissions Identical .          ?
PLAT250_ALERT_2_C Large U3/U1 Ratio for Average U(i,j) Tensor ....       2.21
PLAT250_ALERT_2_C Large U3/U1 Ratio for Average U(i,j) Tensor ....       2.06
PLAT790_ALERT_4_C Centre of Gravity not Within Unit Cell: Resd.  #          1
              C7 H8 N4 O2

   0 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
   4 ALERT level C = Check and explain
   0 ALERT level G = General alerts; check

   1 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   2 ALERT type 2 Indicator that the structure model may be wrong or deficient
   0 ALERT type 3 Indicator that the structure quality may be low
   1 ALERT type 4 Improvement, methodology, query or suggestion
   0 ALERT type 5 Informative message, check

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Computing details

Data collection: SMART (Bruker, 2001); cell refinement: SMART; data reduction: SAINT-Plus (Bruker, 2001); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: PLATON (Spek, 2003); software used to prepare material for publication: PLATON.

theophylline–2,4-dihydroxybenzoic acid–water (1/1/1)

Crystal data

C7H8N4O2·C7H6O4·H2O	F(000) = 736
Mr = 352.31	Dx = 1.492 Mg m^−3
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2yn	Cell parameters from 2806 reflections
a = 10.1984 (12) Å	θ = 2.3–22.4°
b = 13.4881 (16) Å	µ = 0.12 mm^−1
c = 11.4941 (13) Å	T = 298 K
β = 97.116 (2)°	Plate, colourless
V = 1568.9 (3) Å^3	0.30 × 0.20 × 0.04 mm
Z = 4

Data collection

Bruker SMART APEX CCD area-detector diffractometer	3062 independent reflections
Radiation source: fine-focus sealed tube	2338 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.036
ω scans	θmax = 26.0°, θmin = 2.3°
Absorption correction: multi-scan (SADABS; Sheldrick, 2001)	h = −12→12
Tmin = 0.964, Tmax = 0.995	k = −16→16
13299 measured reflections	l = −14→13

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.052	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.138	H atoms treated by a mixture of independent and constrained refinement
S = 1.07	w = 1/[σ^2(Fo^2) + (0.0654P)^2 + 0.315P] where P = (Fo^2 + 2Fc^2)/3
3062 reflections	(Δ/σ)max = 0.012
246 parameters	Δρmax = 0.23 e Å^−3
7 restraints	Δρmin = −0.19 e Å^−3

Special details

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 (Ų)

	x	y	z	Uiso*/Ueq
N1	−0.22428 (18)	0.16776 (13)	−0.51118 (14)	0.0503 (4)
N2	−0.13020 (19)	0.36817 (13)	−0.30263 (15)	0.0552 (5)
H2	−0.107 (2)	0.3504 (17)	−0.2278 (10)	0.066*
N3	−0.1829 (2)	0.46247 (14)	−0.46031 (17)	0.0639 (5)
N4	−0.24459 (17)	0.32737 (14)	−0.59729 (15)	0.0507 (5)
O1	−0.07291 (17)	0.30364 (11)	−0.07171 (13)	0.0602 (4)
O2	−0.07482 (17)	0.13964 (11)	−0.09058 (13)	0.0590 (4)
H2A	−0.104 (3)	0.152 (2)	−0.1592 (12)	0.089*
O3	−0.00987 (19)	0.38207 (11)	0.13305 (13)	0.0656 (5)
H3A	−0.032 (3)	0.377 (2)	0.0610 (10)	0.098*
O4	0.10158 (18)	0.16448 (12)	0.45115 (14)	0.0663 (5)
H4	0.114 (3)	0.2194 (13)	0.484 (3)	0.100*
O5	−0.14847 (16)	0.14300 (11)	−0.31775 (12)	0.0587 (4)
O6	−0.30014 (19)	0.18905 (13)	−0.70384 (14)	0.0750 (5)
O7	0.15210 (19)	0.33864 (13)	0.55842 (13)	0.0683 (5)
H7A	0.164 (3)	0.3315 (19)	0.6299 (10)	0.102*
H7B	0.165 (3)	0.3965 (10)	0.541 (2)	0.102*
C1	−0.01384 (19)	0.20570 (14)	0.09671 (17)	0.0415 (5)
C2	0.0068 (2)	0.28755 (14)	0.17173 (18)	0.0440 (5)
C3	0.0456 (2)	0.27380 (15)	0.29037 (18)	0.0489 (5)
H3	0.0588	0.3285	0.3397	0.059*
C4	0.0648 (2)	0.17968 (16)	0.33583 (18)	0.0482 (5)
C5	0.0452 (2)	0.09740 (16)	0.2625 (2)	0.0580 (6)
H5	0.0584	0.0337	0.2927	0.070*
C6	0.0065 (2)	0.11140 (15)	0.14537 (19)	0.0520 (5)
H6	−0.0068	0.0563	0.0967	0.062*
C7	−0.05644 (19)	0.22053 (15)	−0.02770 (18)	0.0444 (5)
C8	−0.1998 (2)	0.36555 (15)	−0.48881 (18)	0.0473 (5)
C9	−0.16852 (19)	0.30580 (14)	−0.39442 (17)	0.0436 (5)
C10	−0.1769 (2)	0.20170 (15)	−0.39926 (17)	0.0441 (5)
C11	−0.2584 (2)	0.22668 (18)	−0.61000 (18)	0.0532 (6)
C12	−0.1408 (3)	0.45921 (17)	−0.3462 (2)	0.0700 (7)
H12	−0.1206	0.5157	−0.3011	0.084*
C13	−0.2371 (3)	0.06027 (18)	−0.5279 (2)	0.0794 (8)
H13A	−0.3080	0.0465	−0.5888	0.119*
H13B	−0.2557	0.0299	−0.4562	0.119*
H13C	−0.1561	0.0340	−0.5496	0.119*
C14	−0.2778 (3)	0.3918 (2)	−0.6993 (2)	0.0694 (7)
H14A	−0.2016	0.3997	−0.7398	0.104*
H14B	−0.3052	0.4555	−0.6738	0.104*
H14C	−0.3483	0.3625	−0.7511	0.104*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
N1	0.0692 (11)	0.0446 (10)	0.0343 (10)	0.0043 (8)	−0.0040 (8)	−0.0055 (7)
N2	0.0862 (13)	0.0406 (10)	0.0357 (10)	−0.0059 (9)	−0.0043 (9)	0.0031 (8)
N3	0.0960 (15)	0.0465 (11)	0.0479 (12)	0.0002 (10)	0.0039 (10)	0.0097 (9)
N4	0.0591 (11)	0.0593 (12)	0.0326 (9)	0.0127 (8)	0.0014 (8)	0.0069 (8)
O1	0.0932 (12)	0.0482 (9)	0.0364 (8)	0.0012 (8)	−0.0028 (8)	0.0037 (7)
O2	0.0883 (11)	0.0497 (9)	0.0366 (8)	−0.0017 (8)	−0.0023 (8)	−0.0059 (7)
O3	0.1161 (14)	0.0384 (8)	0.0389 (9)	0.0050 (8)	−0.0039 (9)	0.0032 (7)
O4	0.1005 (12)	0.0539 (10)	0.0397 (9)	−0.0014 (9)	−0.0109 (8)	0.0087 (7)
O5	0.0932 (11)	0.0410 (8)	0.0378 (9)	0.0044 (7)	−0.0080 (8)	−0.0004 (7)
O6	0.0998 (13)	0.0876 (13)	0.0337 (9)	0.0030 (10)	−0.0073 (8)	−0.0113 (8)
O7	0.1026 (13)	0.0630 (10)	0.0354 (9)	−0.0163 (9)	−0.0069 (9)	0.0033 (8)
C1	0.0470 (11)	0.0407 (11)	0.0366 (11)	−0.0003 (8)	0.0046 (8)	0.0004 (8)
C2	0.0557 (12)	0.0375 (11)	0.0381 (11)	0.0018 (8)	0.0026 (9)	0.0026 (8)
C3	0.0660 (13)	0.0416 (11)	0.0379 (12)	−0.0031 (9)	0.0013 (10)	−0.0040 (9)
C4	0.0581 (12)	0.0473 (12)	0.0374 (12)	−0.0009 (9)	−0.0014 (9)	0.0057 (9)
C5	0.0835 (16)	0.0381 (11)	0.0496 (14)	0.0018 (10)	−0.0034 (11)	0.0063 (10)
C6	0.0718 (14)	0.0391 (11)	0.0432 (13)	−0.0010 (10)	−0.0005 (10)	−0.0035 (9)
C7	0.0492 (11)	0.0451 (12)	0.0388 (11)	−0.0015 (8)	0.0047 (9)	−0.0019 (9)
C8	0.0533 (12)	0.0489 (12)	0.0395 (12)	0.0050 (9)	0.0051 (9)	0.0042 (9)
C9	0.0521 (11)	0.0431 (11)	0.0340 (11)	0.0010 (8)	−0.0011 (9)	−0.0007 (8)
C10	0.0530 (12)	0.0440 (11)	0.0334 (11)	0.0049 (9)	−0.0016 (9)	−0.0004 (9)
C11	0.0584 (13)	0.0663 (15)	0.0336 (12)	0.0082 (10)	0.0006 (10)	−0.0031 (10)
C12	0.116 (2)	0.0441 (13)	0.0477 (15)	−0.0095 (13)	0.0014 (13)	0.0021 (11)
C13	0.125 (2)	0.0537 (15)	0.0550 (15)	0.0011 (14)	−0.0072 (15)	−0.0154 (12)
C14	0.0830 (17)	0.0831 (18)	0.0410 (13)	0.0200 (14)	0.0036 (12)	0.0175 (12)

Geometric parameters (Å, º)

N1—C10	1.394 (2)	O7—H7B	0.820 (10)
N1—C11	1.395 (3)	C1—C6	1.395 (3)
N1—C13	1.466 (3)	C1—C2	1.401 (3)
N2—C12	1.326 (3)	C1—C7	1.456 (3)
N2—C9	1.368 (3)	C2—C3	1.385 (3)
N2—H2	0.896 (10)	C3—C4	1.378 (3)
N3—C12	1.329 (3)	C3—H3	0.9300
N3—C8	1.354 (3)	C4—C5	1.393 (3)
N4—C11	1.371 (3)	C5—C6	1.368 (3)
N4—C8	1.374 (3)	C5—H5	0.9300
N4—C14	1.465 (3)	C6—H6	0.9300
O1—C7	1.233 (2)	C8—C9	1.357 (3)
O2—C7	1.309 (2)	C9—C10	1.407 (3)
O2—H2A	0.827 (10)	C12—H12	0.9300
O3—C2	1.354 (2)	C13—H13A	0.9600
O3—H3A	0.834 (10)	C13—H13B	0.9600
O4—C4	1.348 (2)	C13—H13C	0.9600
O4—H4	0.832 (10)	C14—H14A	0.9600
O5—C10	1.234 (2)	C14—H14B	0.9600
O6—C11	1.220 (3)	C14—H14C	0.9600
O7—H7A	0.821 (10)
C10—N1—C11	125.96 (18)	C1—C6—H6	119.0
C10—N1—C13	117.43 (18)	O1—C7—O2	121.89 (19)
C11—N1—C13	116.60 (18)	O1—C7—C1	122.47 (18)
C12—N2—C9	106.03 (18)	O2—C7—C1	115.63 (18)
C12—N2—H2	127.5 (16)	N3—C8—C9	111.71 (19)
C9—N2—H2	126.4 (16)	N3—C8—N4	126.85 (19)
C12—N3—C8	102.87 (18)	C9—C8—N4	121.44 (19)
C11—N4—C8	119.09 (17)	C8—C9—N2	105.53 (17)
C11—N4—C14	119.47 (19)	C8—C9—C10	123.62 (19)
C8—N4—C14	121.4 (2)	N2—C9—C10	130.85 (18)
C7—O2—H2A	111 (2)	O5—C10—N1	120.80 (18)
C2—O3—H3A	105 (2)	O5—C10—C9	127.08 (19)
C4—O4—H4	108 (2)	N1—C10—C9	112.12 (17)
H7A—O7—H7B	110.0 (16)	O6—C11—N4	121.7 (2)
C6—C1—C2	117.94 (19)	O6—C11—N1	120.5 (2)
C6—C1—C7	122.05 (18)	N4—C11—N1	117.75 (18)
C2—C1—C7	120.01 (17)	N2—C12—N3	113.9 (2)
O3—C2—C3	117.29 (18)	N2—C12—H12	123.1
O3—C2—C1	122.48 (18)	N3—C12—H12	123.1
C3—C2—C1	120.24 (18)	N1—C13—H13A	109.5
C4—C3—C2	120.46 (19)	N1—C13—H13B	109.5
C4—C3—H3	119.8	H13A—C13—H13B	109.5
C2—C3—H3	119.8	N1—C13—H13C	109.5
O4—C4—C3	121.5 (2)	H13A—C13—H13C	109.5
O4—C4—C5	118.40 (19)	H13B—C13—H13C	109.5
C3—C4—C5	120.11 (19)	N4—C14—H14A	109.5
C6—C5—C4	119.2 (2)	N4—C14—H14B	109.5
C6—C5—H5	120.4	H14A—C14—H14B	109.5
C4—C5—H5	120.4	N4—C14—H14C	109.5
C5—C6—C1	122.1 (2)	H14A—C14—H14C	109.5
C5—C6—H6	119.0	H14B—C14—H14C	109.5

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N2—H2···O1	0.90 (1)	1.89 (1)	2.786 (2)	174 (2)
O2—H2A···O5	0.83 (1)	1.83 (1)	2.626 (2)	163 (3)
O3—H3A···O1	0.83 (1)	1.83 (2)	2.588 (2)	151 (3)
O4—H4···O7	0.83 (1)	1.84 (1)	2.673 (2)	177 (3)
O7—H7A···O6^i	0.82 (1)	1.92 (1)	2.741 (2)	177 (3)
O7—H7B···N3^ii	0.82 (1)	2.14 (1)	2.942 (2)	168 (3)

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