3,3′-(p-Phenyl­enedimethyl­ene)di-1H-imidazol-1-ium bis­(4-nitro­benzoate)–4-nitro­benzoic acid (1/2)

The asymmetric unit of the title compound, C₁₄H₁₆N₄²⁺·2C₇H₄NO₄⁻·2C₇H₅NO₄, comprises one-half of the 3,3′-(p-phenyl­enedimethyl­ene)di-1H-imidazol-1-ium dication, which lies on an inversion centre, one 4-nitro­benzoate anion and one 4-nitro­benzoic acid mol­ecule. In the crystal, the components are linked into a two-dimensional network parallel to (110) by O—H...O, N—H...O and C—H...O hydrogen bonds.

Key indicators

• Single-crystal X-ray study
• T = 295 K
• Mean [sigma](C-C) = 0.007 Å
• R factor = 0.081
• wR factor = 0.191
• Data-to-parameter ratio = 12.0

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT242_ALERT_2_C Check Low       Ueq as Compared to Neighbors for         N2
PLAT242_ALERT_2_C Check Low       Ueq as Compared to Neighbors for         N1
PLAT250_ALERT_2_C Large U3/U1 Ratio for Average U(i,j) Tensor ....       2.02
PLAT340_ALERT_3_C Low Bond Precision on  C-C Bonds (x 1000) Ang ..          7
PLAT910_ALERT_3_C Missing # of FCF Reflections Below Th(Min) .....          4
PLAT911_ALERT_3_C Missing # FCF Refl Between THmin & STh/L=  0.594          2
PLAT042_ALERT_1_C Calc. and Reported MoietyFormula Strings  Differ          ?

Alert level G
PLAT154_ALERT_1_G The su's on the Cell Angles are Equal  (x 10000)       3000 Deg.

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

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

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S1. Comment

Over the past few years, efforts have been focused on the investigation of coordination polymers with flexible ligands. Di-imidazole flexbile ligands such as 1,4-bis(1H-imidazol-1-yl)methylbenzene (bix) find numerous applications in constructing metal-organic coordination polymers as they can rotate freely about methylene carbon atoms to adjust to the coordination environment. We report here the crystal structure of the title compound.

The asymmetric unit comprises one-half of a bix²⁺ dication lying on an inversion centre, one 4-nitrobenzoate anion and one neutral 4-nitrobenzoic acid molecule (Fig. 1). Bond distances and angles are normal (Chen et al., 2010).

In the crystal structure, the dications, anions and neutral 4-nitrobenzoic acid molecule are interlinked by O—H···O, N—H···O and C—H···O hydrogen bonds (Table 1), forming a two-dimensional hydrogen-bonded network parallel to the (110).

Related literature

For the synthesis of 1,4-bis(imidazol-1-ylmethyl)benzene, see: Hoskins et al. (1997). For a related structure, see: Chen et al. (2010).

S2. Experimental

1,4-Bis(imidazol-1-ylmethyl)benzene (bix) was prepared according to a literature method (Hoskins et al., 1997). 1:4 molar amounts of bix (23.8 mg, 0.1 mmol) and 4-nitrobenzoic acid (66.9 mg , 0.4 mmol) were dissolved in 95% ethanol (30 ml). The mixture was stirred and refluxed for 1 h and then filtered. The resulting colourless solution was allowed to stand in air for two weeks. Colourless crystals of the title compound suitable for X-ray diffraction analysis were obtained by slow evaporation of the solution.

S3. Refinement

H atoms were positioned geometrically [O–H = 0.85 Å, N–H = 0.86 Å and C–H = 0.93 or 0.97 Å] and refined using a riding model, with U_iso(H) = 1.5U_eq(O) and 1.2U_eq(C,N).

Computing details

Data collection: SMART (Bruker, 1998); cell refinement: SAINT (Bruker, 1999); data reduction: SAINT (Bruker, 1999); 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: SHELXTL (Sheldrick, 2008).

Figures

Fig. 1. The asymmetric unit of the title compound, showing the atomic numbering and 30% probability displacement ellipsoids. Atoms labelled with the suffix A are generated by the symmetry operation (-x, 1-y, -z).

3,3'-(p-Phenylenedimethylene)di-1H-imidazol-1-ium bis(4-nitrobenzoate)–4-nitrobenzoic acid (1/2)

Crystal data

C14H16N4^2+·2C7H4NO^4^−·2C7H5NO4	Z = 1
Mr = 906.77	F(000) = 470
Triclinic, P1	Dx = 1.474 Mg m^−3
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 7.2659 (15) Å	Cell parameters from 3889 reflections
b = 12.689 (3) Å	θ = 4.6–22.7°
c = 13.028 (3) Å	µ = 0.12 mm^−1
α = 112.94 (3)°	T = 295 K
β = 102.49 (3)°	Prism, colourless
γ = 101.94 (3)°	0.20 × 0.20 × 0.20 mm
V = 1021.8 (6) Å^3

Data collection

Bruker SMART CCD area-detector diffractometer	3590 independent reflections
Radiation source: fine–focus sealed tube	2019 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.066
φ and ω scans	θmax = 25.0°, θmin = 3.0°
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	h = −8→8
Tmin = 0.968, Tmax = 0.971	k = −15→15
8835 measured reflections	l = −15→15

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)] = 0.081	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.191	H-atom parameters constrained
S = 1.19	w = 1/[σ^2(Fo^2) + (0.0648P)^2 + 0.2399P] where P = (Fo^2 + 2Fc^2)/3
3590 reflections	(Δ/σ)max = 0.001
298 parameters	Δρmax = 0.42 e Å^−3
0 restraints	Δρmin = −0.24 e Å^−3

Special details

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds 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 > 2sigma(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
O7	0.1748 (5)	0.3773 (3)	0.6201 (3)	0.0628 (9)
O8	0.2413 (5)	0.4626 (3)	0.5069 (3)	0.0636 (9)
N4	0.2722 (5)	0.3310 (3)	0.2960 (3)	0.0468 (9)
H4A	0.2596	0.3328	0.3607	0.056*
N3	0.3203 (4)	0.3884 (3)	0.1672 (3)	0.0341 (8)
C11	0.2099 (5)	0.5846 (3)	0.6892 (3)	0.0346 (10)
C12	0.1960 (6)	0.5971 (4)	0.7973 (3)	0.0378 (10)
H12	0.1787	0.5305	0.8124	0.045*
C20	0.0546 (6)	0.4031 (4)	−0.0614 (3)	0.0417 (11)
H20	0.0910	0.3371	−0.1031	0.050*
C10	0.2349 (6)	0.6835 (4)	0.6673 (4)	0.0454 (11)
H10	0.2447	0.6753	0.5947	0.054*
C21	−0.1173 (6)	0.4176 (4)	−0.1146 (4)	0.0417 (11)
H21	−0.1952	0.3621	−0.1918	0.050*
C13	0.2074 (6)	0.7074 (4)	0.8830 (4)	0.0426 (11)
H13	0.1981	0.7160	0.9558	0.051*
C17	0.2842 (6)	0.2657 (4)	0.1182 (4)	0.0397 (10)
H17	0.2808	0.2161	0.0427	0.048*
C8	0.2328 (6)	0.8040 (4)	0.8581 (4)	0.0423 (11)
C14	0.2070 (6)	0.4663 (4)	0.5962 (4)	0.0417 (11)
C19	0.1743 (6)	0.4850 (4)	0.0531 (3)	0.0359 (10)
C9	0.2457 (6)	0.7939 (4)	0.7505 (4)	0.0510 (12)
H9	0.2612	0.8603	0.7351	0.061*
N2	0.2409 (6)	0.9230 (4)	0.9474 (4)	0.0642 (12)
C15	0.3111 (6)	0.4252 (4)	0.2754 (4)	0.0405 (10)
H15	0.3291	0.5044	0.3279	0.049*
O6	0.2194 (6)	0.9302 (3)	1.0400 (3)	0.0946 (14)
C16	0.2548 (6)	0.2308 (4)	0.1995 (4)	0.0445 (11)
H16	0.2277	0.1525	0.1913	0.053*
O5	0.2639 (7)	1.0065 (3)	0.9231 (4)	0.1088 (16)
C18	0.3622 (6)	0.4672 (4)	0.1113 (4)	0.0472 (11)
H18A	0.4226	0.4318	0.0525	0.057*
H18B	0.4567	0.5452	0.1706	0.057*
C4	0.4933 (6)	0.8837 (3)	0.5529 (3)	0.0360 (10)
O3	0.4409 (5)	0.7026 (3)	0.3853 (3)	0.0731 (11)
O2	0.4178 (6)	1.2399 (3)	0.8522 (3)	0.0791 (11)
O4	0.7429 (5)	0.7925 (3)	0.5183 (3)	0.0700 (10)
C1	0.3648 (7)	1.0618 (4)	0.6869 (4)	0.0423 (11)
N1	0.2961 (7)	1.1562 (4)	0.7606 (4)	0.0616 (11)
C5	0.6275 (6)	0.9830 (3)	0.6549 (3)	0.0417 (11)
H5	0.7610	0.9887	0.6779	0.050*
C3	0.2940 (6)	0.8758 (4)	0.5190 (3)	0.0432 (11)
H3	0.2041	0.8099	0.4503	0.052*
C2	0.2281 (7)	0.9650 (4)	0.5863 (4)	0.0473 (11)
H2	0.0947	0.9596	0.5642	0.057*
C6	0.5638 (7)	1.0733 (4)	0.7224 (4)	0.0451 (11)
H6	0.6533	1.1403	0.7903	0.054*
C7	0.5608 (8)	0.7845 (4)	0.4785 (4)	0.0470 (11)
O1	0.1202 (7)	1.1467 (4)	0.7276 (4)	0.1083 (15)
H2A	0.2107	0.3206	0.5773	0.162*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O7	0.086 (3)	0.0432 (19)	0.072 (2)	0.0297 (18)	0.0469 (19)	0.0238 (18)
O8	0.086 (3)	0.065 (2)	0.0381 (19)	0.0274 (19)	0.0290 (18)	0.0162 (17)
N4	0.048 (2)	0.062 (3)	0.035 (2)	0.0202 (19)	0.0143 (17)	0.025 (2)
N3	0.035 (2)	0.038 (2)	0.032 (2)	0.0177 (16)	0.0105 (15)	0.0157 (17)
C11	0.028 (2)	0.039 (2)	0.032 (2)	0.0081 (18)	0.0080 (18)	0.013 (2)
C12	0.039 (3)	0.042 (3)	0.041 (3)	0.016 (2)	0.019 (2)	0.023 (2)
C20	0.049 (3)	0.041 (3)	0.043 (3)	0.023 (2)	0.018 (2)	0.021 (2)
C10	0.058 (3)	0.047 (3)	0.034 (3)	0.017 (2)	0.017 (2)	0.019 (2)
C21	0.049 (3)	0.038 (3)	0.032 (2)	0.013 (2)	0.008 (2)	0.013 (2)
C13	0.041 (3)	0.053 (3)	0.034 (2)	0.017 (2)	0.016 (2)	0.016 (2)
C17	0.045 (3)	0.034 (2)	0.037 (3)	0.020 (2)	0.012 (2)	0.011 (2)
C8	0.038 (3)	0.036 (2)	0.041 (3)	0.013 (2)	0.009 (2)	0.007 (2)
C14	0.029 (2)	0.045 (3)	0.042 (3)	0.009 (2)	0.008 (2)	0.013 (2)
C19	0.036 (3)	0.040 (2)	0.037 (3)	0.008 (2)	0.011 (2)	0.025 (2)
C9	0.064 (3)	0.043 (3)	0.053 (3)	0.019 (2)	0.020 (2)	0.026 (3)
N2	0.065 (3)	0.050 (3)	0.059 (3)	0.022 (2)	0.013 (2)	0.008 (3)
C15	0.033 (3)	0.040 (3)	0.035 (3)	0.015 (2)	0.0044 (19)	0.006 (2)
O6	0.138 (4)	0.083 (3)	0.046 (2)	0.055 (3)	0.026 (2)	0.006 (2)
C16	0.046 (3)	0.034 (3)	0.050 (3)	0.014 (2)	0.010 (2)	0.018 (2)
O5	0.177 (5)	0.046 (2)	0.115 (4)	0.046 (3)	0.072 (3)	0.029 (2)
C18	0.041 (3)	0.054 (3)	0.053 (3)	0.015 (2)	0.014 (2)	0.032 (2)
C4	0.053 (3)	0.025 (2)	0.032 (2)	0.012 (2)	0.015 (2)	0.0134 (19)
O3	0.082 (3)	0.047 (2)	0.051 (2)	0.0251 (18)	−0.0019 (19)	−0.0063 (17)
O2	0.091 (3)	0.054 (2)	0.066 (2)	0.023 (2)	0.032 (2)	−0.001 (2)
O4	0.057 (2)	0.047 (2)	0.076 (2)	0.0193 (17)	0.0156 (19)	0.0005 (18)
C1	0.056 (3)	0.036 (2)	0.046 (3)	0.021 (2)	0.025 (2)	0.021 (2)
N1	0.067 (3)	0.049 (3)	0.065 (3)	0.023 (2)	0.035 (3)	0.015 (2)
C5	0.044 (3)	0.033 (2)	0.042 (3)	0.010 (2)	0.010 (2)	0.014 (2)
C3	0.050 (3)	0.036 (3)	0.033 (2)	0.009 (2)	0.004 (2)	0.013 (2)
C2	0.047 (3)	0.044 (3)	0.043 (3)	0.013 (2)	0.011 (2)	0.016 (2)
C6	0.059 (3)	0.033 (2)	0.034 (2)	0.012 (2)	0.014 (2)	0.009 (2)
C7	0.066 (4)	0.028 (2)	0.042 (3)	0.012 (2)	0.015 (3)	0.014 (2)
O1	0.072 (3)	0.086 (3)	0.129 (4)	0.040 (2)	0.037 (3)	0.003 (3)

Geometric parameters (Å, º)

O7—C14	1.274 (5)	C8—N2	1.484 (5)
O7—H2A	0.85	C19—C21^i	1.387 (5)
O8—C14	1.227 (5)	C19—C18	1.519 (5)
N4—C15	1.313 (5)	C9—H9	0.93
N4—C16	1.354 (5)	N2—O5	1.210 (5)
N4—H4A	0.86	N2—O6	1.220 (5)
N3—C15	1.324 (5)	C15—H15	0.93
N3—C17	1.373 (5)	C16—H16	0.93
N3—C18	1.469 (5)	C18—H18A	0.97
C11—C10	1.378 (5)	C18—H18B	0.97
C11—C12	1.383 (5)	C4—C5	1.389 (5)
C11—C14	1.510 (5)	C4—C3	1.389 (5)
C12—C13	1.380 (5)	C4—C7	1.509 (6)
C12—H12	0.93	O3—C7	1.224 (5)
C20—C21	1.376 (5)	O2—N1	1.225 (5)
C20—C19	1.385 (5)	O4—C7	1.279 (5)
C20—H20	0.93	C1—C2	1.374 (6)
C10—C9	1.370 (6)	C1—C6	1.377 (6)
C10—H10	0.93	C1—N1	1.472 (5)
C21—C19^i	1.387 (5)	N1—O1	1.221 (5)
C21—H21	0.93	C5—C6	1.382 (5)
C13—C8	1.373 (5)	C5—H5	0.93
C13—H13	0.93	C3—C2	1.382 (5)
C17—C16	1.336 (5)	C3—H3	0.93
C17—H17	0.93	C2—H2	0.93
C8—C9	1.382 (6)	C6—H6	0.93
C14—O7—H2A	111.6	O5—N2—O6	123.9 (4)
C15—N4—C16	109.4 (3)	O5—N2—C8	118.0 (5)
C15—N4—H4A	125.3	O6—N2—C8	118.1 (5)
C16—N4—H4A	125.3	N4—C15—N3	108.4 (4)
C15—N3—C17	108.0 (3)	N4—C15—H15	125.8
C15—N3—C18	125.0 (3)	N3—C15—H15	125.8
C17—N3—C18	127.0 (3)	C17—C16—N4	107.0 (4)
C10—C11—C12	119.4 (4)	C17—C16—H16	126.5
C10—C11—C14	119.0 (4)	N4—C16—H16	126.5
C12—C11—C14	121.6 (4)	N3—C18—C19	111.7 (3)
C13—C12—C11	120.7 (4)	N3—C18—H18A	109.3
C13—C12—H12	119.7	C19—C18—H18A	109.3
C11—C12—H12	119.7	N3—C18—H18B	109.3
C21—C20—C19	121.1 (4)	C19—C18—H18B	109.3
C21—C20—H20	119.4	H18A—C18—H18B	107.9
C19—C20—H20	119.4	C5—C4—C3	119.5 (4)
C9—C10—C11	121.2 (4)	C5—C4—C7	121.0 (4)
C9—C10—H10	119.4	C3—C4—C7	119.6 (4)
C11—C10—H10	119.4	C2—C1—C6	122.6 (4)
C20—C21—C19^i	120.0 (4)	C2—C1—N1	118.9 (4)
C20—C21—H21	120.0	C6—C1—N1	118.5 (4)
C19^i—C21—H21	120.0	O1—N1—O2	123.3 (4)
C8—C13—C12	118.3 (4)	O1—N1—C1	118.3 (4)
C8—C13—H13	120.8	O2—N1—C1	118.4 (5)
C12—C13—H13	120.8	C6—C5—C4	120.4 (4)
C16—C17—N3	107.1 (4)	C6—C5—H5	119.8
C16—C17—H17	126.4	C4—C5—H5	119.8
N3—C17—H17	126.4	C2—C3—C4	120.7 (4)
C13—C8—C9	122.2 (4)	C2—C3—H3	119.7
C13—C8—N2	119.5 (4)	C4—C3—H3	119.7
C9—C8—N2	118.2 (4)	C1—C2—C3	118.4 (4)
O8—C14—O7	124.9 (4)	C1—C2—H2	120.8
O8—C14—C11	119.4 (4)	C3—C2—H2	120.8
O7—C14—C11	115.7 (4)	C1—C6—C5	118.5 (4)
C20—C19—C21^i	118.8 (4)	C1—C6—H6	120.7
C20—C19—C18	120.6 (4)	C5—C6—H6	120.7
C21^i—C19—C18	120.5 (4)	O3—C7—O4	124.3 (4)
C10—C9—C8	118.2 (4)	O3—C7—C4	119.0 (5)
C10—C9—H9	120.9	O4—C7—C4	116.7 (4)
C8—C9—H9	120.9

Symmetry code: (i) −x, −y+1, −z.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O7—H2A···O3^ii	0.85	2.57	3.167 (5)	128
O7—H2A···O4^ii	0.85	1.65	2.494 (5)	173
N4—H4A···O8	0.86	2.03	2.690 (5)	133
C15—H15···O3	0.93	2.23	3.073 (7)	150
C17—H17···O5^iii	0.93	2.46	3.228 (7)	140
C21—H21···O3^i	0.93	2.46	3.321 (6)	154

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