Tetra­methyl­ammonium hydrogen terephthalate

Abstract

The asymmetric unit of the title salt, C₄H₁₂N⁺·C₈H₅O₄ ⁻, contains one half of a tetra­methyl­ammonium cation and one half of a hydrogen terephthalate monoanion. The N atom of the ammonium cation lies on a twofold rotation axis and the centre of mass of the terephthalate anion is on a centre of inversion. In the crystal, the centrosymmetric terephthalate ions are linked by a very short symmetric O—H⋯O hydrogen bond [O⋯O = 2.4610 (19) Å] into a one-dimensional polymeric chain along [1-12]. The tetra­methyl­ammonium cations and terephthalate anions are then connected through a pair of bifurcated acceptor C—H⋯O hydrogen bonds, generating a three-dimensional supra­molecular network. The carboxyl­ate groups at both ends of the terephthalate anion are charge-shared with an equal probability of 0.5.

Related literature  

For a review of very short O—H⋯O hydrogen bonds, see: Speakman (1972 ▶). For recent reports of acidic salts of dicarb­oxy­lic acids with short intra- and inter­molecular O—H⋯O hydrogen bonds, see: Starosta & Leciejewicz (2010 ▶); Hemamalini & Fun (2010 ▶); Sun et al. (2002 ▶); Sharma et al. (2006 ▶); Wang et al. (2004 ▶); Taka et al. (1998 ▶). For examples of diphospho­nates with strong O—H⋯O hydrogen bonds, see: Tsaryk et al. (2011 ▶); Courtney et al. (2006 ▶); Cheng & Lin (2006 ▶). For background to symmetric and asymmetric O—H⋯O hydrogen bonds, see: Misaki et al. (1986 ▶); Catti & Ferraris (1976 ▶). For graph-set analysis of hydrogen bonds, see: Etter et al. (1990 ▶); Bernstein et al. (1995 ▶). For the synthesis of the 5,5′-(o-phenyl­ene)di-1H-tetra­zole ligand, see: Demko & Sharpless (2001 ▶).

Experimental  

Crystal data  

• C₄H₁₂N⁺·C₈H₅O₄ ⁻

• M _r = 239.27

• Monoclinic,

• a = 16.0585 (4) Å

• b = 9.1527 (2) Å

• c = 11.5866 (3) Å

• β = 132.915 (2)°

• V = 1247.21 (7) ų

• Z = 4

• Mo Kα radiation

• μ = 0.10 mm⁻¹

• T = 298 K

• 0.42 × 0.37 × 0.32 mm

Data collection  

• Bruker APEXII CCD diffractometer

• Absorption correction: multi-scan (SADABS; Bruker, 2008 ▶) T _min = 0.708, T _max = 0.746

• 20680 measured reflections

• 1360 independent reflections

• 1269 reflections with I > 2σ(I)

• R _int = 0.022

Refinement  

• R[F ² > 2σ(F ²)] = 0.054

• wR(F ²) = 0.147

• S = 1.07

• 1360 reflections

• 80 parameters

• H-atom parameters constrained

• Δρ_max = 0.57 e Å⁻³

• Δρ_min = −0.43 e Å⁻³

Data collection: APEX2 (Bruker, 2007 ▶); cell refinement: SAINT (Bruker, 2007 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: XPW (Siemens, 1996 ▶) and ORTEP-3 for Windows (Farrugia, 1997 ▶); software used to prepare material for publication: SHELXTL (Sheldrick, 2008 ▶) and enCIFer (Allen et al., 2004 ▶).

Supplementary Material

Supplementary material file. DOI: 10.1107/S1600536812039487/bg2478Isup3.cml

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

Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O2—H2⋯O2i	1.23	1.23	2.4610 (19)	180 (1)
C8—H8A⋯O1ii	0.96	2.39	3.267 (3)	152
C9—H9A⋯O1ii	0.96	2.47	3.321 (3)	148

Symmetry codes: (i) ; (ii) .

supplementary crystallographic information

Comment

Acid salts of dicarboxylic acids usually form very short O—H···O hydrogen bonds (with O···O distances between 2.4 and 2.5 Å) in their crystal structures (Speakman, 1972). This type of hydrogen bond is formed between the carboxyl and carboxylate groups by intramolecular (Starosta & Leciejewicz, 2010; Hemamalini & Fun, 2010; Sun et al., 2002) or intermolecular (Sharma et al., 2006; Wang et al., 2004; Taka et al., 1998) interactions. However, diphosphonates can also display such short and strong hydrogen bonds between neighbouring phosphonate groups (Tsaryk et al., 2011; Courtney et al., 2006; Cheng & Lin, 2006). There are two types of short O—H···O hydrogen bonds: symmetric, in which two O atoms are related by crystallographic symmetry and asymmetric, in which crystal symmetry does not impose the O—H···O hydrogen bond to be symmetric. Furthermore, symmetric hydrogen bonds typically display a shorter (2.43–2.51 Å) O···O distance than asymmetric ones (2.44–2.57 Å) (Misaki et al., 1986). In this work, we report the crystal structure of the title compound, whose structure contains a strong symmetric O—H···O hydrogen bond (Catti & Ferraris, 1976): atom H2 lies on a center of symmetry, located between two crystallographic equivalent carboxyl O2 atoms. The H atom, clearly visible on the Fourier map, is involved in a symmetric O2—H2···O2ⁱ [symmetry code: (i) -x + 1/2, -y + 3/2, -z] hydrogen bond with an O—H bond distance of 1.23 Å (Table 1).

The title compound (Fig. 1), [N(CH₃)₄]⁺[4-COOH-C₆H₄COO]^-, consists of one half tetramethylammonium cation and one half terephthalate anion in the asymmetric unit. The cation lies on a twofold rotation axis and the anion on an inversion center. In the terephthalate anions, the two carboxyl groups are twisted from the mean plane of the benzene ring by a dihedral angle of 6.57 (2)°. Carboxyl atom O2 lies slightly farther [0.083 Å] from this plane than atom O1 [0.065 Å], owing to the strong O—H···O hydrogen bond between the terephthalate anions.

In the crystal, the terephthalate anions are linked end-to-end to form a one-dimensional polymeric chain in which adjacent ions are interconnected by a strong symmetric O—H···O (O···O distance of 2.4610 (19) Å) hydrogen bond (Table 1). Then the weak C—H···O hydrogen bonds link the ammonium cations and terephthalate anions together in a three-dimensional crystal structure. The C8—H8A···O1 and C9—H9A···O1 interactions form a pair of bifurcated acceptor bonds (Fig. 2), involving two C—H donor from an ammonium ion and an acceptor O atom from the terephthalate ion, generating an R₂¹(6) ring motif (Etter et al., 1990; Bernstein et al., 1995).

Experimental

In an attempt to synthesize metal–organic framework materials, we obtained the title compound as a side-product.

The ligand H₂L [5,5'-(o-Phenylene)di-1H-tetrazole] used in this work was synthesized according to literature procedures (Demko & Sharpless, 2001).

A mixture of Zn(NO₃)₂.6H₂O (0.357 g, 1.2 mmol), H₂L (0.086 g, 0.4 mmol), terephthalic acid (0.066 g, 0.4 mmol), 1,4-diazabicyclo[2.2.2]octane (0.045 g, 0.4 mmol) and CH₃OH/DMF (1/2, 15 ml) were sealed in a 25 ml Teflon-lined stainless steel autoclave, heated at 433 K for 40 h, and then cooled to room temperature over a period of 90 h. The resulting solution was filtered and the filtrate was allowed to stand in air at room temperature. After several days, colorless single crystals of the title compound were isolated.

Refinement

C-H atoms were located on a ΔF map, further idealized and finally refined in the riding model aproximation d(C—H) = 0.93Å; U(H) = 1.2U(C)_eq; d(C—H₃) = 0.96Å; U(H) = 1.5U(C)_eq. Atom H2 is fixed by symmetry, and its isotropic displacement factor was freely refined.

Figures

Fig. 1.

ORTEP drawing of the asymmetric unit of title compound with the atom numbering. Displacement ellipsoids are drawn at the 50% probability level. The occupancy factor for atom H2 is 0.5. Symmetry codes: (i) -x + 1, -y + 2, -z + 1; (ii) -x + 1, y, -z + 1/2.

Fig. 2.

A view of crystal packing of the title compound, showing symmetric O—H···H hydrogen bonds (formed between terephthalate anions, dotted lines) and weak C—H···O hydrogen bonds (formed between cations and anions, dashed lines). The latter contains a pair of bifurcated acceptor hydrogen bonds, leading to an R21(6) ring motif.

Crystal data

C4H12N+·C8H5O4−	F(000) = 512
Mr = 239.27	Dx = 1.274 Mg m−3
Monoclinic, C2/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -C 2yc	Cell parameters from 9931 reflections
a = 16.0585 (4) Å	θ = 2.8–30.3°
b = 9.1527 (2) Å	µ = 0.10 mm−1
c = 11.5866 (3) Å	T = 298 K
β = 132.915 (2)°	Irregular, colourless
V = 1247.21 (7) Å3	0.42 × 0.37 × 0.32 mm
Z = 4

Data collection

Bruker APEXII CCD diffractometer	1360 independent reflections
Radiation source: fine-focus sealed tube	1269 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.022
φ and ω scans	θmax = 27.0°, θmin = 2.8°
Absorption correction: multi-scan (SADABS; Bruker, 2008)	h = −20→20
Tmin = 0.708, Tmax = 0.746	k = −11→11
20680 measured reflections	l = −14→14

Refinement

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)] = 0.054	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.147	H-atom parameters constrained
S = 1.07	w = 1/[σ2(Fo2) + (0.0714P)2 + 1.1167P] where P = (Fo2 + 2Fc2)/3
1360 reflections	(Δ/σ)max < 0.001
80 parameters	Δρmax = 0.57 e Å−3
0 restraints	Δρmin = −0.43 e Å−3

Special details

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 > 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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
O2	0.32784 (9)	0.78319 (13)	0.13940 (12)	0.0451 (4)
C5	0.51647 (12)	0.89007 (16)	0.43479 (16)	0.0341 (4)
H5	0.5278	0.8165	0.3914	0.041*
C4	0.40806 (11)	0.94633 (15)	0.34990 (15)	0.0312 (3)
C6	0.30731 (12)	0.89045 (17)	0.18691 (16)	0.0363 (4)
O1	0.21412 (12)	0.94615 (19)	0.11216 (16)	0.0789 (6)
N	0.5000	0.3608 (2)	0.2500	0.0416 (5)
C9	0.4511 (2)	0.4550 (3)	0.2947 (3)	0.0794 (8)
H9A	0.5097	0.5155	0.3823	0.119*
H9B	0.4188	0.3951	0.3239	0.119*
H9C	0.3928	0.5157	0.2070	0.119*
C3	0.39205 (12)	1.05665 (16)	0.41571 (16)	0.0353 (4)
H3	0.3198	1.0950	0.3594	0.042*
C8	0.58943 (19)	0.2666 (3)	0.3849 (3)	0.0695 (6)
H8A	0.6473	0.3266	0.4737	0.104*
H8B	0.6224	0.2071	0.3565	0.104*
H8C	0.5565	0.2049	0.4120	0.104*
H2	0.2500	0.7500	0.0000	0.098 (13)*

Atomic displacement parameters (Ų)

	U11	U22	U33	U12	U13	U23
O2	0.0364 (6)	0.0526 (7)	0.0300 (6)	−0.0050 (5)	0.0162 (5)	−0.0175 (5)
C5	0.0348 (7)	0.0345 (7)	0.0276 (7)	−0.0003 (5)	0.0191 (6)	−0.0076 (5)
C4	0.0315 (7)	0.0324 (7)	0.0218 (6)	−0.0030 (5)	0.0150 (6)	−0.0043 (5)
C6	0.0319 (7)	0.0405 (8)	0.0235 (6)	−0.0026 (6)	0.0138 (6)	−0.0054 (5)
O1	0.0420 (7)	0.0938 (12)	0.0411 (7)	0.0188 (7)	0.0048 (6)	−0.0263 (7)
N	0.0410 (10)	0.0367 (9)	0.0405 (10)	0.000	0.0252 (9)	0.000
C9	0.0718 (15)	0.0875 (17)	0.0706 (14)	0.0197 (12)	0.0452 (13)	−0.0130 (12)
C3	0.0292 (7)	0.0373 (8)	0.0278 (7)	0.0024 (5)	0.0149 (6)	−0.0043 (5)
C8	0.0627 (13)	0.0587 (12)	0.0605 (13)	0.0133 (10)	0.0315 (11)	0.0174 (10)

Geometric parameters (Å, º)

O2—C6	1.2739 (19)	N—C8	1.481 (2)
C5—C4	1.390 (2)	C9—H9A	0.9600
C5—C3i	1.3896 (19)	C9—H9B	0.9600
C5—H5	0.9300	C9—H9C	0.9600
C4—C3	1.391 (2)	C3—C5i	1.3896 (19)
C4—C6	1.5115 (18)	C3—H3	0.9300
C6—O1	1.218 (2)	C8—H8A	0.9600
N—C9ii	1.478 (2)	C8—H8B	0.9600
N—C9	1.478 (2)	C8—H8C	0.9600
N—C8ii	1.481 (2)
C4—C5—C3i	120.25 (13)	N—C9—H9A	109.5
C4—C5—H5	119.9	N—C9—H9B	109.5
C3i—C5—H5	119.9	H9A—C9—H9B	109.5
C5—C4—C3	119.41 (12)	N—C9—H9C	109.5
C5—C4—C6	121.22 (12)	H9A—C9—H9C	109.5
C3—C4—C6	119.37 (13)	H9B—C9—H9C	109.5
O1—C6—O2	124.70 (13)	C5i—C3—C4	120.33 (13)
O1—C6—C4	119.89 (14)	C5i—C3—H3	119.8
O2—C6—C4	115.39 (13)	C4—C3—H3	119.8
C9ii—N—C9	108.6 (3)	N—C8—H8A	109.5
C9ii—N—C8ii	109.57 (15)	N—C8—H8B	109.5
C9—N—C8ii	110.17 (15)	H8A—C8—H8B	109.5
C9ii—N—C8	110.17 (15)	N—C8—H8C	109.5
C9—N—C8	109.57 (15)	H8A—C8—H8C	109.5
C8ii—N—C8	108.7 (2)	H8B—C8—H8C	109.5
C3i—C5—C4—C3	0.2 (3)	C5—C4—C6—O2	4.7 (2)
C3i—C5—C4—C6	179.82 (13)	C3—C4—C6—O2	−175.69 (14)
C5—C4—C6—O1	−176.70 (17)	C5—C4—C3—C5i	−0.2 (3)
C3—C4—C6—O1	2.9 (2)	C6—C4—C3—C5i	−179.83 (13)

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

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O2—H2···O2iii	1.23	1.23	2.4610 (19)	180 (1)
C8—H8A···O1iv	0.96	2.39	3.267 (3)	152
C9—H9A···O1iv	0.96	2.47	3.321 (3)	148

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