3,4,5-Trihy-droxy-benzoic acid.

In the title compound, C(7)H(6)O(5), the three hy-droxy groups on the ring are oriented in the same direction. There are two intra-molecular O-H⋯O hydrogen bonds in the ring. In the crystal, there are several inter-molecular O-H⋯O hydrogen bonds and a short contact of 2.7150 (18) Å between the O atoms of the para-OH groups of adjacent mol-ecules.

Related literature

For the biological activity of the title compound, see: Gomes et al. (2003 ▶); Priscilla & Prince (2009 ▶); Lu et al. (2010 ▶). For the structure of gallic acid monohydrate, see: Okabe et al. (2001 ▶); Jiang et al. (2000 ▶); Billes et al. (2007 ▶).

Experimental

Crystal data

C7H6O5

M = 170.12

Monoclinic,

a = 25.629 (2) Å

b = 4.9211 (4) Å

c = 11.2217 (9) Å

β = 106.251 (1)°

V = 1358.77 (19) Å3

Z = 8

Mo Kα radiation

μ = 0.15 mm−1

T = 293 K

0.30 × 0.19 × 0.11 mm

Data collection

Bruker APEX CCD area-detector diffractometer

Absorption correction: multi-scan (SADABS; Bruker, 2003 ▶) T min = 0.916, T max = 1.000

7171 measured reflections

1254 independent reflections

1172 reflections with I > 2s(I)

R int = 0.022

Refinement

R[F 2 > 2σ(F 2)] = 0.032

wR(F 2) = 0.091

S = 1.06

1254 reflections

121 parameters

4 restraints

H atoms treated by a mixture of independent and constrained refinement

Δρmax = 0.16 e Å−3

Δρmin = −0.21 e Å−3

Data collection: SMART (Bruker, 1998 ▶); cell refinement: SAINT (Bruker, 2003 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: SHELXTL (Sheldrick, 2008 ▶) and Mercury (Macrae et al., 2008) ▶; software used to prepare material for publication: SHELXL97 and publCIF (Westrip, 2010 ▶).

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536811007471/fj2397sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536811007471/fj2397Isup2.hkl

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

C7H6O5	F(000) = 704
Mr = 170.12	Dx = 1.663 Mg m−3
Monoclinic, C2/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -C 2yc	Cell parameters from 3476 reflections
a = 25.629 (2) Å	θ = 3.3–28.1°
b = 4.9211 (4) Å	µ = 0.14 mm−1
c = 11.2217 (9) Å	T = 293 K
β = 106.251 (1)°	Hexagon, colourless
V = 1358.77 (19) Å3	0.30 × 0.19 × 0.11 mm
Z = 8

Bruker APEX CCD area-detector diffractometer	1254 independent reflections
Radiation source: fine-focus sealed tube	1172 reflections with I > 2s(I)
graphite	Rint = 0.022
Frames, each covering 0.3 ° in ω scans	θmax = 25.5°, θmin = 1.7°
Absorption correction: multi-scan (SADABS; Bruker, 2003)	h = −30→30
Tmin = 0.916, Tmax = 1.000	k = −5→5
7171 measured reflections	l = −13→13

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)] = 0.032	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.091	H atoms treated by a mixture of independent and constrained refinement
S = 1.06	w = 1/[σ2(Fo2) + (0.054P)2 + 0.7476P] where P = (Fo2 + 2Fc2)/3
1254 reflections	(Δ/σ)max < 0.001
121 parameters	Δρmax = 0.16 e Å−3
4 restraints	Δρmin = −0.21 e Å−3

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 > 2σ(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.

	x	y	z	Uiso*/Ueq
C1	0.40390 (5)	0.4849 (2)	−0.00701 (11)	0.0251 (3)
C2	0.40861 (5)	0.6475 (3)	0.09733 (11)	0.0267 (3)
H2A	0.4380	0.6271	0.1674	0.032*
C3	0.36900 (5)	0.8389 (3)	0.09502 (11)	0.0256 (3)
C4	0.32438 (5)	0.8667 (2)	−0.00919 (11)	0.0249 (3)
C5	0.32041 (5)	0.7058 (2)	−0.11289 (11)	0.0247 (3)
C6	0.36006 (5)	0.5156 (3)	−0.11223 (12)	0.0262 (3)
H6A	0.3575	0.4083	−0.1819	0.031*
C7	0.44558 (5)	0.2786 (2)	−0.00657 (11)	0.0262 (3)
O1	0.36873 (4)	1.0116 (2)	0.18952 (9)	0.0367 (3)
H1	0.3935 (6)	0.969 (4)	0.2539 (15)	0.044*
O2	0.28434 (4)	1.0485 (2)	−0.01206 (10)	0.0352 (3)
H2	0.2920 (6)	1.127 (3)	0.0553 (13)	0.042*
O3	0.27680 (4)	0.7268 (2)	−0.21619 (9)	0.0334 (3)
H3	0.2610 (7)	0.872 (3)	−0.2151 (16)	0.040*
O4	0.48474 (4)	0.2647 (2)	0.09722 (9)	0.0392 (3)
H4	0.5076 (7)	0.143 (3)	0.0928 (17)	0.047*
O5	0.44465 (4)	0.12950 (19)	−0.09537 (8)	0.0314 (3)

	U11	U22	U33	U12	U13	U23
C1	0.0237 (6)	0.0240 (6)	0.0263 (6)	0.0027 (5)	0.0050 (5)	0.0020 (5)
C2	0.0244 (6)	0.0292 (7)	0.0234 (6)	0.0041 (5)	0.0015 (5)	0.0025 (5)
C3	0.0284 (6)	0.0248 (6)	0.0230 (6)	0.0007 (5)	0.0062 (5)	0.0000 (5)
C4	0.0224 (6)	0.0219 (6)	0.0301 (7)	0.0036 (5)	0.0070 (5)	0.0028 (5)
C5	0.0214 (6)	0.0236 (6)	0.0254 (6)	−0.0008 (5)	0.0005 (5)	0.0018 (5)
C6	0.0260 (6)	0.0252 (6)	0.0256 (6)	0.0021 (5)	0.0042 (5)	−0.0027 (5)
C7	0.0238 (6)	0.0264 (7)	0.0263 (6)	0.0028 (5)	0.0037 (5)	0.0014 (5)
O1	0.0420 (6)	0.0387 (6)	0.0251 (5)	0.0130 (4)	0.0020 (4)	−0.0060 (4)
O2	0.0309 (5)	0.0345 (6)	0.0369 (5)	0.0131 (4)	0.0038 (4)	−0.0051 (4)
O3	0.0265 (5)	0.0293 (5)	0.0346 (5)	0.0063 (4)	−0.0074 (4)	−0.0050 (4)
O4	0.0332 (5)	0.0433 (6)	0.0324 (5)	0.0189 (4)	−0.0054 (4)	−0.0078 (4)
O5	0.0292 (5)	0.0322 (5)	0.0289 (5)	0.0101 (4)	0.0019 (4)	−0.0037 (4)

C1—C6	1.3918 (17)	C5—O3	1.3706 (14)
C1—C2	1.3951 (18)	C5—C6	1.3800 (18)
C1—C7	1.4726 (17)	C6—H6A	0.9300
C2—C3	1.3796 (18)	C7—O5	1.2325 (15)
C2—H2A	0.9300	C7—O4	1.3093 (15)
C3—O1	1.3606 (15)	O1—H1	0.844 (14)
C3—C4	1.3949 (17)	O2—H2	0.821 (14)
C4—O2	1.3551 (15)	O3—H3	0.824 (14)
C4—C5	1.3874 (18)	O4—H4	0.850 (15)
C6—C1—C2	120.64 (11)	O3—C5—C4	121.15 (11)
C6—C1—C7	119.36 (11)	C6—C5—C4	120.10 (11)
C2—C1—C7	120.00 (11)	C5—C6—C1	119.77 (12)
C3—C2—C1	119.02 (11)	C5—C6—H6A	120.1
C3—C2—H2A	120.5	C1—C6—H6A	120.1
C1—C2—H2A	120.5	O5—C7—O4	121.64 (11)
O1—C3—C2	125.17 (11)	O5—C7—C1	123.91 (11)
O1—C3—C4	114.22 (11)	O4—C7—C1	114.45 (11)
C2—C3—C4	120.60 (11)	C3—O1—H1	110.2 (12)
O2—C4—C5	118.66 (11)	C4—O2—H2	107.7 (12)
O2—C4—C3	121.50 (11)	C5—O3—H3	109.9 (12)
C5—C4—C3	119.85 (11)	C7—O4—H4	110.8 (12)
O3—C5—C6	118.73 (11)
C6—C1—C2—C3	0.27 (19)	O2—C4—C5—C6	−178.95 (11)
C7—C1—C2—C3	−179.80 (11)	C3—C4—C5—C6	1.06 (19)
C1—C2—C3—O1	−179.47 (12)	O3—C5—C6—C1	−178.09 (11)
C1—C2—C3—C4	1.08 (19)	C4—C5—C6—C1	0.28 (19)
O1—C3—C4—O2	−1.25 (18)	C2—C1—C6—C5	−0.96 (19)
C2—C3—C4—O2	178.26 (11)	C7—C1—C6—C5	179.12 (11)
O1—C3—C4—C5	178.74 (11)	C6—C1—C7—O5	0.77 (19)
C2—C3—C4—C5	−1.75 (19)	C2—C1—C7—O5	−179.16 (12)
O2—C4—C5—O3	−0.62 (18)	C6—C1—C7—O4	−179.37 (11)
C3—C4—C5—O3	179.39 (11)	C2—C1—C7—O4	0.70 (17)

D—H···A	D—H	H···A	D···A	D—H···A
O2—H2···O1	0.82 (1)	2.19 (2)	2.6625 (14)	117 (1)
O3—H3···O2	0.82 (1)	2.35 (2)	2.7464 (14)	110 (1)
O1—H1···O5i	0.84 (1)	1.89 (2)	2.7324 (13)	176 (2)
O3—H3···O3ii	0.82 (1)	2.04 (2)	2.8167 (9)	157 (2)
O4—H4···O5iii	0.85 (2)	1.81 (2)	2.6570 (13)	175 (2)

Table 1

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O2—H2⋯O1	0.82 (1)	2.19 (2)	2.6625 (14)	117 (1)
O3—H3⋯O2	0.82 (1)	2.35 (2)	2.7464 (14)	110 (1)
O1—H1⋯O5i	0.84 (1)	1.89 (2)	2.7324 (13)	176 (2)
O3—H3⋯O3ii	0.82 (1)	2.04 (2)	2.8167 (9)	157 (2)
O4—H4⋯O5iii	0.85 (2)	1.81 (2)	2.6570 (13)	175 (2)

Symmetry codes: (i) ; (ii) ; (iii) .