Triethyl-ammonium 3,4-dihy-droxy-benzoate.

In the title compound, C(6)H(16)N(+)·C(7)H(5)O(4) (-), the hy-droxy groups of the 3,4-dihy-droxy-benzoate anion form O-H⋯O hydrogen bonds to the carboxyl-ate groups of two adjacent anions, generating layers propagating in the ac plane. The triethyl-ammonium cations lie between these layers, forming N-H⋯O hydrogen bonds to the carboxyl-ate groups of the anions. The structure is consolidated by weak inter-molecular C-H⋯O inter-actions.

Related literature

For the pharmacological activity of protocatechuic acid, see: Guan et al. (2006 ▶); Lin et al. (2009 ▶); Yip et al. (2006 ▶). For related structures, see: Li et al. (2007 ▶); Mazurek et al. (2007 ▶).

Experimental

Crystal data

C6H16N+·C7H5O4 −

M = 255.31

Orthorhombic,

a = 12.4341 (16) Å

b = 13.7227 (18) Å

c = 16.150 (2) Å

V = 2755.7 (6) Å3

Z = 8

Mo Kα radiation

μ = 0.09 mm−1

T = 296 K

0.32 × 0.28 × 0.28 mm

Data collection

Bruker APEXII area-detector diffractometer

13215 measured reflections

2483 independent reflections

1981 reflections with I > 2σ(I)

R int = 0.028

Refinement

R[F 2 > 2σ(F 2)] = 0.037

wR(F 2) = 0.107

S = 1.03

2483 reflections

172 parameters

1 restraint

H atoms treated by a mixture of independent and constrained refinement

Δρmax = 0.18 e Å−3

Δρmin = −0.13 e Å−3

Data collection: APEX2 (Bruker, 2004 ▶); cell refinement: SAINT (Bruker, 2004 ▶); 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 ▶); software used to prepare material for publication: SHELXL97.

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536810044764/pv2348sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536810044764/pv2348Isup2.hkl

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

C6H16N+·C7H5O4−	F(000) = 1104
Mr = 255.31	Dx = 1.231 Mg m−3
Orthorhombic, Pbca	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ac 2ab	Cell parameters from 4281 reflections
a = 12.4341 (16) Å	θ = 2.5–27.2°
b = 13.7227 (18) Å	µ = 0.09 mm−1
c = 16.150 (2) Å	T = 296 K
V = 2755.7 (6) Å3	Block, colourless
Z = 8	0.32 × 0.28 × 0.28 mm

Bruker APEXII area-detector diffractometer	1981 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.028
graphite	θmax = 25.2°, θmin = 2.5°
φ and ω scans	h = −14→14
13215 measured reflections	k = −14→16
2483 independent reflections	l = −16→19

Refinement on F2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.037	H atoms treated by a mixture of independent and constrained refinement
wR(F2) = 0.107	w = 1/[σ2(Fo2) + (0.0515P)2 + 0.7195P] where P = (Fo2 + 2Fc2)/3
S = 1.03	(Δ/σ)max = 0.001
2483 reflections	Δρmax = 0.18 e Å−3
172 parameters	Δρmin = −0.13 e Å−3
1 restraint	Extinction correction: SHELXL97 (Sheldrick, 2008), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.0034 (5)

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.

	x	y	z	Uiso*/Ueq
C6	0.3472 (2)	0.97892 (16)	0.41436 (15)	0.0812 (7)
H6A	0.3882	1.0381	0.4166	0.122*
H6B	0.3285	0.9650	0.3579	0.122*
H6C	0.3893	0.9263	0.4364	0.122*
C1	0.32649 (16)	0.94605 (13)	0.60034 (13)	0.0677 (6)
H1A	0.3919	0.9299	0.5706	0.081*
H1B	0.2828	0.8876	0.6034	0.081*
C2	0.3554 (2)	0.97807 (17)	0.68702 (15)	0.0893 (7)
H2A	0.3989	1.0358	0.6844	0.134*
H2B	0.3948	0.9271	0.7142	0.134*
H2C	0.2908	0.9917	0.7175	0.134*
C3	0.16443 (13)	1.05597 (13)	0.59298 (13)	0.0589 (5)
H3A	0.1310	1.1040	0.5572	0.071*
H3B	0.1820	1.0881	0.6448	0.071*
C5	0.24679 (17)	0.99035 (14)	0.46451 (14)	0.0679 (6)
H5A	0.2086	0.9287	0.4650	0.081*
H5B	0.2008	1.0381	0.4378	0.081*
C4	0.08368 (18)	0.97565 (17)	0.61030 (18)	0.0940 (8)
H4A	0.0698	0.9401	0.5602	0.141*
H4B	0.0179	1.0038	0.6302	0.141*
H4C	0.1123	0.9322	0.6514	0.141*
C7	0.79526 (10)	0.26562 (9)	0.58103 (8)	0.0290 (3)
H7	0.7503	0.2736	0.5355	0.035*
C12	0.90639 (10)	0.26034 (9)	0.56871 (8)	0.0279 (3)
C13	0.95215 (10)	0.27035 (9)	0.48341 (8)	0.0305 (3)
C10	0.92903 (11)	0.24288 (10)	0.71567 (9)	0.0365 (3)
H10	0.9743	0.2354	0.7611	0.044*
C9	0.81903 (11)	0.24855 (10)	0.72768 (8)	0.0323 (3)
C8	0.75071 (10)	0.25922 (10)	0.65907 (8)	0.0303 (3)
C11	0.97267 (11)	0.24818 (10)	0.63692 (9)	0.0342 (3)
H11	1.0467	0.2436	0.6298	0.041*
O1	1.04380 (8)	0.23683 (9)	0.47008 (7)	0.0485 (3)
O2	0.89549 (8)	0.31388 (7)	0.42940 (6)	0.0395 (3)
O3	0.77263 (8)	0.24370 (8)	0.80386 (6)	0.0445 (3)
H3	0.8186	0.2309	0.8386	0.067*
O4	0.64348 (8)	0.26312 (9)	0.67366 (6)	0.0479 (3)
H4	0.6110	0.2621	0.6295	0.072*
N1	0.26672 (11)	1.02205 (10)	0.55323 (10)	0.0520 (4)
H12	0.3117 (15)	1.0749 (13)	0.5523 (12)	0.078*

	U11	U22	U33	U12	U13	U23
C6	0.0982 (17)	0.0615 (13)	0.0840 (15)	0.0088 (12)	0.0014 (13)	−0.0160 (11)
C1	0.0641 (12)	0.0484 (10)	0.0906 (15)	0.0088 (9)	−0.0025 (11)	0.0114 (10)
C2	0.113 (2)	0.0760 (15)	0.0786 (15)	0.0189 (14)	−0.0120 (14)	0.0185 (12)
C3	0.0446 (9)	0.0473 (10)	0.0848 (14)	0.0007 (8)	0.0011 (9)	0.0004 (9)
C5	0.0733 (13)	0.0496 (10)	0.0807 (14)	−0.0091 (9)	−0.0151 (11)	−0.0100 (9)
C4	0.0598 (13)	0.0760 (15)	0.146 (2)	−0.0169 (11)	0.0156 (15)	0.0058 (15)
C7	0.0235 (7)	0.0362 (7)	0.0274 (7)	−0.0005 (5)	−0.0044 (5)	−0.0015 (5)
C12	0.0244 (7)	0.0295 (6)	0.0296 (7)	−0.0005 (5)	0.0010 (5)	−0.0004 (5)
C13	0.0259 (7)	0.0350 (7)	0.0307 (7)	−0.0020 (5)	0.0008 (6)	−0.0019 (6)
C10	0.0293 (7)	0.0508 (9)	0.0295 (7)	0.0009 (6)	−0.0083 (6)	0.0011 (6)
C9	0.0326 (7)	0.0384 (7)	0.0261 (7)	−0.0026 (6)	0.0008 (6)	0.0001 (5)
C8	0.0222 (6)	0.0381 (7)	0.0307 (7)	−0.0027 (5)	0.0005 (6)	−0.0015 (6)
C11	0.0207 (6)	0.0447 (8)	0.0372 (8)	0.0010 (6)	−0.0014 (6)	0.0007 (6)
O1	0.0295 (6)	0.0745 (8)	0.0414 (6)	0.0125 (5)	0.0099 (5)	0.0059 (5)
O2	0.0382 (6)	0.0515 (6)	0.0290 (5)	0.0071 (5)	0.0002 (4)	0.0011 (4)
O3	0.0392 (6)	0.0692 (7)	0.0251 (5)	0.0010 (5)	0.0019 (4)	0.0036 (5)
O4	0.0215 (5)	0.0881 (9)	0.0340 (6)	−0.0020 (5)	0.0028 (4)	−0.0031 (6)
N1	0.0448 (8)	0.0357 (7)	0.0756 (10)	−0.0022 (6)	−0.0041 (7)	0.0009 (7)

C6—C5	1.496 (3)	C4—H4B	0.9600
C6—H6A	0.9600	C4—H4C	0.9600
C6—H6B	0.9600	C7—C8	1.3795 (18)
C6—H6C	0.9600	C7—C12	1.3979 (18)
C1—N1	1.490 (2)	C7—H7	0.9300
C1—C2	1.511 (3)	C12—C11	1.386 (2)
C1—H1A	0.9700	C12—C13	1.4968 (19)
C1—H1B	0.9700	C13—O1	1.2476 (17)
C2—H2A	0.9600	C13—O2	1.2705 (16)
C2—H2B	0.9600	C10—C9	1.384 (2)
C2—H2C	0.9600	C10—C11	1.385 (2)
C3—N1	1.499 (2)	C10—H10	0.9300
C3—C4	1.517 (3)	C9—O3	1.3606 (17)
C3—H3A	0.9700	C9—C8	1.4039 (19)
C3—H3B	0.9700	C8—O4	1.3551 (16)
C5—N1	1.518 (3)	C11—H11	0.9300
C5—H5A	0.9700	O3—H3	0.8200
C5—H5B	0.9700	O4—H4	0.8200
C4—H4A	0.9600	N1—H12	0.916 (15)
C5—C6—H6A	109.5	C3—C4—H4C	109.5
C5—C6—H6B	109.5	H4A—C4—H4C	109.5
H6A—C6—H6B	109.5	H4B—C4—H4C	109.5
C5—C6—H6C	109.5	C8—C7—C12	121.57 (12)
H6A—C6—H6C	109.5	C8—C7—H7	119.2
H6B—C6—H6C	109.5	C12—C7—H7	119.2
N1—C1—C2	112.85 (16)	C11—C12—C7	118.75 (12)
N1—C1—H1A	109.0	C11—C12—C13	121.11 (12)
C2—C1—H1A	109.0	C7—C12—C13	120.12 (12)
N1—C1—H1B	109.0	O1—C13—O2	124.15 (13)
C2—C1—H1B	109.0	O1—C13—C12	118.18 (12)
H1A—C1—H1B	107.8	O2—C13—C12	117.67 (11)
C1—C2—H2A	109.5	C9—C10—C11	120.88 (13)
C1—C2—H2B	109.5	C9—C10—H10	119.6
H2A—C2—H2B	109.5	C11—C10—H10	119.6
C1—C2—H2C	109.5	O3—C9—C10	122.90 (12)
H2A—C2—H2C	109.5	O3—C9—C8	117.53 (12)
H2B—C2—H2C	109.5	C10—C9—C8	119.56 (13)
N1—C3—C4	114.51 (16)	O4—C8—C7	123.47 (12)
N1—C3—H3A	108.6	O4—C8—C9	117.53 (12)
C4—C3—H3A	108.6	C7—C8—C9	119.00 (12)
N1—C3—H3B	108.6	C10—C11—C12	120.22 (12)
C4—C3—H3B	108.6	C10—C11—H11	119.9
H3A—C3—H3B	107.6	C12—C11—H11	119.9
C6—C5—N1	113.88 (16)	C9—O3—H3	109.5
C6—C5—H5A	108.8	C8—O4—H4	109.5
N1—C5—H5A	108.8	C1—N1—C3	114.97 (15)
C6—C5—H5B	108.8	C1—N1—C5	111.29 (14)
N1—C5—H5B	108.8	C3—N1—C5	110.78 (14)
H5A—C5—H5B	107.7	C1—N1—H12	105.0 (13)
C3—C4—H4A	109.5	C3—N1—H12	106.2 (13)
C3—C4—H4B	109.5	C5—N1—H12	108.1 (12)
H4A—C4—H4B	109.5

D—H···A	D—H	H···A	D···A	D—H···A
O3—H3···O2i	0.82	1.85	2.6574 (14)	166
O4—H4···O1ii	0.82	1.81	2.6321 (15)	178
C7—H7···O1ii	0.93	2.57	3.235 (2)	128
N1—H12···O2iii	0.92	1.87	2.776 (2)	170
C1—H1B···O3iv	0.97	2.57	3.409 (2)	145
C3—H3A···O1v	0.97	2.55	3.516 (2)	177
C3—H3B···O3vi	0.97	2.56	3.351 (2)	139
C10—H10···O4vii	0.93	2.38	3.222 (2)	150

Table 1

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O3—H3⋯O2i	0.82	1.85	2.6574 (14)	166
O4—H4⋯O1ii	0.82	1.81	2.6321 (15)	178
C7—H7⋯O1ii	0.93	2.57	3.235 (2)	128
N1—H12⋯O2iii	0.92	1.87	2.776 (2)	170
C1—H1B⋯O3iv	0.97	2.57	3.409 (2)	145
C3—H3A⋯O1v	0.97	2.55	3.516 (2)	177
C3—H3B⋯O3vi	0.97	2.56	3.351 (2)	139
C10—H10⋯O4vii	0.93	2.38	3.222 (2)	150

Symmetry codes: (i) ; (ii) ; (iii) ; (iv) ; (v) ; (vi) ; (vii) .