Benzene-1,4-dicarboxylic acid-N,N-dimethyl-acetamide (1/2).

The asymmetric unit of title compound, C(8)H(6)O(4)·2C(4)H(9)NO, contains one half-mol-ecule (an inversion centre in P21/n generates the other half of the molecule) of terephthalic acid (TA) and one mol-ecule of N,N-dimethyl-acetamide (DMAC). The DMAC mol-ecules are linked to TA by strong O-H⋯O hydrogen bonds.

Related literature

For the crystal structure of terephthalic acid-bis­(N,N-dimethyl­formamide), see: Dale & Elsegood (2004 ▶). For the polymorphism of terephthalic acid, see: Bailey & Brown (1967 ▶); Sledz et al. (2001 ▶).

Experimental

Crystal data

C8H6O4·2C4H9NO

M = 340.37

Monoclinic,

a = 10.191 (2) Å

b = 8.5228 (17) Å

c = 10.719 (2) Å

β = 110.67 (3)°

V = 871.0 (3) Å3

Z = 2

Mo Kα radiation

μ = 0.10 mm−1

T = 113 K

0.60 × 0.51 × 0.38 mm

Data collection

Rigaku R-AXIS RAPID diffractometer

Absorption correction: multi-scan (ABSCOR; Higashi, 1995 ▶) T min = 0.940, T max = 0.961

6605 measured reflections

1522 independent reflections

1395 reflections with I > 2σ(I)

R int = 0.014

Refinement

R[F 2 > 2σ(F 2)] = 0.043

wR(F 2) = 0.118

S = 1.08

1522 reflections

116 parameters

H atoms treated by a mixture of independent and constrained refinement

Δρmax = 0.58 e Å−3

Δρmin = −0.26 e Å−3

Data collection: RAPID-AUTO (Rigaku, 1998 ▶); cell refinement: RAPID-AUTO; data reduction: RAPID-AUTO; 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/S1600536809025793/gk2216sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809025793/gk2216Isup2.hkl

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

C8H6O4·2C4H9NO	F(000) = 364
Mr = 340.37	Dx = 1.298 Mg m−3
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2yn	Cell parameters from 6873 reflections
a = 10.191 (2) Å	θ = 3.1–27.5°
b = 8.5228 (17) Å	µ = 0.10 mm−1
c = 10.719 (2) Å	T = 113 K
β = 110.67 (3)°	Block, colorless
V = 871.0 (3) Å3	0.60 × 0.51 × 0.38 mm
Z = 2

Rigaku R-AXIS RAPID diffractometer	1522 independent reflections
Radiation source: fine-focus sealed tube	1395 reflections with I > 2σ(I)
graphite	Rint = 0.014
Detector resolution: 0 pixels mm-1	θmax = 25.0°, θmin = 3.1°
ω scans	h = −11→11
Absorption correction: multi-scan (ABSCOR; Higashi, 1995)	k = −9→10
Tmin = 0.940, Tmax = 0.961	l = −12→12
6605 measured reflections

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)] = 0.043	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.118	H atoms treated by a mixture of independent and constrained refinement
S = 1.08	w = 1/[σ2(Fo2) + (0.0571P)2 + 0.6867P] where P = (Fo2 + 2Fc2)/3
1522 reflections	(Δ/σ)max < 0.001
116 parameters	Δρmax = 0.58 e Å−3
0 restraints	Δρmin = −0.26 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 > 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
N1	0.74204 (15)	0.07465 (18)	0.88639 (15)	0.0233 (4)
O1	0.95506 (11)	0.13078 (14)	0.88125 (11)	0.0207 (3)
O2	0.30574 (13)	−0.23616 (15)	0.52621 (12)	0.0248 (3)
O3	0.35578 (12)	−0.10972 (15)	0.72025 (11)	0.0237 (3)
C1	0.89721 (19)	0.2372 (2)	1.06449 (18)	0.0266 (4)
H1A	0.9097	0.1670	1.1378	0.040*
H1B	0.8203	0.3067	1.0557	0.040*
H1C	0.9813	0.2973	1.0806	0.040*
C2	0.86637 (18)	0.1442 (2)	0.93832 (17)	0.0224 (4)
C3	0.71443 (18)	−0.0191 (2)	0.76458 (17)	0.0241 (4)
H3A	0.7248	0.0458	0.6954	0.036*
H3B	0.6206	−0.0598	0.7363	0.036*
H3C	0.7799	−0.1046	0.7824	0.036*
C4	0.63337 (19)	0.0830 (3)	0.9455 (2)	0.0304 (5)
H4A	0.6764	0.0888	1.0408	0.046*
H4B	0.5755	−0.0090	0.9216	0.046*
H4C	0.5768	0.1746	0.9131	0.046*
C5	−0.08828 (17)	−0.03522 (19)	0.37140 (16)	0.0171 (4)
H5	−0.1477	−0.0586	0.2852	0.020*
C6	0.04270 (17)	−0.10394 (19)	0.42154 (16)	0.0175 (4)
H6A	0.0712	−0.1734	0.3692	0.021*
C7	0.13228 (16)	−0.06918 (18)	0.55081 (15)	0.0152 (4)
C8	0.27579 (16)	−0.13973 (18)	0.60876 (15)	0.0163 (4)
H2	0.394 (3)	−0.276 (3)	0.563 (2)	0.052 (7)*

	U11	U22	U33	U12	U13	U23
N1	0.0191 (8)	0.0254 (8)	0.0268 (8)	−0.0007 (6)	0.0097 (6)	0.0006 (6)
O1	0.0166 (6)	0.0255 (7)	0.0209 (6)	−0.0043 (5)	0.0080 (5)	0.0014 (5)
O2	0.0174 (7)	0.0324 (7)	0.0224 (7)	0.0083 (5)	0.0044 (5)	−0.0055 (5)
O3	0.0182 (6)	0.0282 (7)	0.0200 (6)	0.0047 (5)	0.0012 (5)	−0.0035 (5)
C1	0.0258 (9)	0.0256 (10)	0.0299 (10)	−0.0037 (7)	0.0117 (8)	−0.0079 (7)
C2	0.0227 (9)	0.0179 (9)	0.0248 (9)	0.0013 (7)	0.0060 (7)	0.0051 (7)
C3	0.0227 (9)	0.0265 (10)	0.0205 (9)	−0.0061 (7)	0.0047 (7)	−0.0023 (7)
C4	0.0192 (9)	0.0407 (11)	0.0344 (11)	−0.0024 (8)	0.0133 (8)	−0.0086 (8)
C5	0.0168 (8)	0.0189 (8)	0.0145 (8)	−0.0012 (6)	0.0043 (6)	−0.0011 (6)
C6	0.0187 (8)	0.0176 (8)	0.0171 (8)	0.0005 (6)	0.0076 (6)	−0.0018 (6)
C7	0.0140 (8)	0.0156 (8)	0.0170 (8)	−0.0014 (6)	0.0066 (6)	0.0022 (6)
C8	0.0164 (8)	0.0159 (8)	0.0175 (8)	−0.0009 (6)	0.0072 (6)	0.0017 (6)

N1—C2	1.330 (2)	C3—H3B	0.9600
N1—C4	1.459 (2)	C3—H3C	0.9600
N1—C3	1.471 (2)	C4—H4A	0.9600
O1—C2	1.263 (2)	C4—H4B	0.9600
O2—C8	1.320 (2)	C4—H4C	0.9600
O2—H2	0.91 (3)	C5—C6	1.381 (2)
O3—C8	1.213 (2)	C5—C7i	1.397 (2)
C1—C2	1.502 (2)	C5—H5	0.9300
C1—H1A	0.9600	C6—C7	1.396 (2)
C1—H1B	0.9600	C6—H6A	0.9300
C1—H1C	0.9600	C7—C5i	1.397 (2)
C3—H3A	0.9600	C7—C8	1.498 (2)
C2—N1—C4	123.61 (16)	N1—C4—H4A	109.5
C2—N1—C3	117.98 (15)	N1—C4—H4B	109.5
C4—N1—C3	118.39 (14)	H4A—C4—H4B	109.5
C8—O2—H2	111.4 (16)	N1—C4—H4C	109.5
C2—C1—H1A	109.5	H4A—C4—H4C	109.5
C2—C1—H1B	109.5	H4B—C4—H4C	109.5
H1A—C1—H1B	109.5	C6—C5—C7i	120.51 (15)
C2—C1—H1C	109.5	C6—C5—H5	119.7
H1A—C1—H1C	109.5	C7i—C5—H5	119.7
H1B—C1—H1C	109.5	C5—C6—C7	119.99 (15)
O1—C2—N1	119.73 (16)	C5—C6—H6A	120.0
O1—C2—C1	121.74 (15)	C7—C6—H6A	120.0
N1—C2—C1	118.53 (16)	C6—C7—C5i	119.50 (15)
N1—C3—H3A	109.5	C6—C7—C8	121.80 (15)
N1—C3—H3B	109.5	C5i—C7—C8	118.70 (14)
H3A—C3—H3B	109.5	O3—C8—O2	123.91 (15)
N1—C3—H3C	109.5	O3—C8—C7	122.83 (15)
H3A—C3—H3C	109.5	O2—C8—C7	113.26 (14)
H3B—C3—H3C	109.5

D—H···A	D—H	H···A	D···A	D—H···A
O2—H2···O1ii	0.91 (3)	1.65 (3)	2.551 (2)	173 (2)

Table 1

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O2—H2⋯O1i	0.91 (3)	1.65 (3)	2.551 (2)	173 (2)

Symmetry code: (i) .