Hydrogen-bonded 1,2-bis(4-pyridyl)ethylene and maleic acid

The title compound (systematic name: 4,4′-ethyl­ene­dipyridinium dimaleate), C₁₂H₁₂N₂²⁺·2C₄H₃O₄⁻, is a 1:2 adduct of 1,2-bis(4-pyridyl)­ethyl­ene (BPE) and maleic acid (MA). The interaction between the two components in the molecular complex is due to intermolecular hydrogen bonding via an N⁺—H...O⁻ hydrogen bond.

S1. Comment

There is growing interest in the construction of supramolecular assemblies with hydrogen bonds as building blocks (Aakeroy & Seddon, 1993; Fredericks & Hamilton, 1996). An example is the co-crystal of 4,4'-bipyridine with maleic acid (MA), which forms a hydrogen-bonded adduct in a 1:2 molar ratio from acetone, adopting a herringbone pattern (Chatterjee et al., 1998). In this paper, we report the structural variation in such a complex caused by the replacement of 4,4'-bipyridine with 1,2-bis(4-pyridyl)ethylene (BPE), to give the title salt, (I). \sch

Compound (I) forms a planar two-dimensional hydrogen-bonded network structure, but the 1:2 molar ratio between the constituents is still maintained (Fig. 1). An important feature of this complex structure is that H-atom transfer from MA to BPE results in the formation of an ionic hydrogen bond, N⁺—H···O^-. Both BPE and MA are planar individually, but with a dihedral angle of 12.07(0.54)° between them.

A typical molecular arrangement in each sheet of (I) is shown in Fig. 2 and the hydrogen bonds are listed in Table 1. In each sheet, there are hydrogen bonds between BPE and MA, as well as between adjacent MA molecules, forming linear chains. While BPE and MA interact with each other forming N⁺—H···O^- hydrogen bonds [H···O 1.70 (5) Å], adjacent MA molecules interact through C—H···O hydrogen bonds [H···O 2.55 (4) Å]. In addition, adjacent chains are held together by C—H···O [H···O 2.50 (3) and 2.60 (4) Å] hydrogen bonds.

Examination of the structure of (I) with PLATON (Spek, 1990) showed that there were no solvent accessible voids in the crystal lattice.

S2. Experimental

BPE was prepared following the procedure described by Yam et al. (1998). MA and other reagents were received from commercial suppliers and used as such without any further purification. BPE and MA (in a 1:2 molar ratio) were mixed in a solution of 8:3 (v/v) acetone and ethanol, and heated until they dissolved completely. The resulting solution was slowly evaporated at room temperature for 3 d. After most of the solvent had evaporated, red crystals of (I) were obtained.

S3. Refinement

With one exception, all H-atom positions were found from the difference Fourier map and all their parameters were refined freely. The exception was the single H atom bonded to C10, which was treated using a riding model, with C—H = 0.93 Å and an isotropic displacement parameter of 0.080 Ų. The highest peak was located 0.64 Å from atom C10 and the deepest hole 0.27 Å from atom H10.

Computing details

Data collection: P4 Diffractometer Control Program (Siemens, 1994); cell refinement: P4 Diffractometer Control Program and XSCANS (Siemens, 1994); data reduction: SHELXTL (Bruker, 1997); program(s) used to solve structure: SHELXTL; program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL.

Figures

	Fig. 1. A view of the structure of (I), showing the atom-numbering scheme and with ??% probability displacement ellipsoids. H atoms are shown as small spheres of arbitrary radii. Please provide missing probability level.
	Fig. 2. A packing diagram for (I).

4,4'-ethylenedipyridinium dimaleate

Crystal data

C12H12N2^2+·2C4H3O4^−	Z = 1
Mr = 414.36	F(000) = 216
Triclinic, P1	Dx = 1.485 Mg m^−3
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 5.7148 (9) Å	Cell parameters from 25 reflections
b = 8.6568 (8) Å	θ = 2.1–25.0°
c = 10.6906 (11) Å	µ = 0.12 mm^−1
α = 108.623 (9)°	T = 293 K
β = 99.878 (15)°	Block, red
γ = 105.561 (13)°	0.60 × 0.32 × 0.22 mm
V = 463.26 (10) Å^3

Data collection

Bruker P4 diffractometer	1104 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.023
Graphite monochromator	θmax = 25.0°, θmin = 2.1°
ω scans	h = −1→6
Absorption correction: empirical (using intensity measurements) (SHELXTL; Bruker, 1997)	k = −9→9
Tmin = 0.931, Tmax = 0.975	l = −12→12
2127 measured reflections	3 standard reflections every 97 reflections
1600 independent reflections	intensity decay: none

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)] = 0.066	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.188	H atoms treated by a mixture of independent and constrained refinement
S = 1.05	w = 1/[σ^2(Fo^2) + (0.0975P)^2 + 0.2216P] where P = (Fo^2 + 2Fc^2)/3
1600 reflections	(Δ/σ)max < 0.001
168 parameters	Δρmax = 0.72 e Å^−3
1 restraint	Δρmin = −0.42 e Å^−3

Special details

Geometry. 2.9670 (0.0080) x + 3.3384 (0.0116) y + 3.2390 (0.0161) z = 4.7527 (0.0110)

* 0.0034 (0.0025) N1 * -0.0039 (0.0027) C7 * 0.0002 (0.0029) C8 * 0.0041 (0.0027) C9 * -0.0047 (0.0026) C5 * 0.0010 (0.0027) C6 0.0239 (0.0054) C10

Rms deviation of fitted atoms = 0.0033

1.8828 (0.0343) x + 4.3502 (0.0290) y + 3.8859 (0.0200) z = 5.7471 (0.0311)

Angle to previous plane (with approximate e.s.d.) = 12.07 (0.54)

* -0.0296 (0.0110) O4 * -0.0004 (0.0294) H * 0.0227 (0.0140) O1 * -0.0102 (0.0065) C1 * -0.0086 (0.0034) C2 * 0.0015 (0.0040) C3 * 0.0247 (0.0037) C4 - 0.0500 (0.0072) O2 0.0962 (0.0047) O3

Rms deviation of fitted atoms = 0.0176

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.

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

	x	y	z	Uiso*/Ueq
O4	0.2305 (5)	0.5842 (4)	0.7057 (3)	0.0552 (8)
O1	0.3250 (5)	0.7088 (4)	0.5338 (3)	0.0594 (8)
O3	−0.0131 (6)	0.5944 (4)	0.8446 (3)	0.0649 (9)
O2	0.1612 (6)	0.8548 (4)	0.4311 (3)	0.0657 (9)
C3	−0.0657 (8)	0.7317 (5)	0.6920 (4)	0.0493 (10)
C4	0.0564 (7)	0.6303 (5)	0.7524 (4)	0.0456 (9)
C1	0.1619 (7)	0.7882 (5)	0.5156 (4)	0.0448 (9)
C2	−0.0217 (8)	0.7959 (5)	0.5962 (4)	0.0494 (10)
N1	0.3348 (6)	0.3515 (4)	0.7994 (3)	0.0446 (8)
C9	0.4656 (7)	0.1323 (4)	0.9058 (3)	0.0411 (9)
C10	0.5499 (6)	0.0160 (4)	0.9545 (3)	0.0345 (8)
H10	0.6664	−0.0319	0.9231	0.080*
C5	0.5515 (7)	0.1574 (5)	0.7985 (4)	0.0454 (9)
C7	0.2463 (7)	0.3276 (5)	0.9029 (4)	0.0481 (10)
C8	0.3100 (8)	0.2179 (5)	0.9588 (4)	0.0496 (10)
C6	0.4830 (7)	0.2704 (5)	0.7466 (4)	0.0470 (9)
H5A	0.670 (6)	0.091 (4)	0.757 (3)	0.038 (9)*
H2A	−0.116 (7)	0.861 (5)	0.570 (4)	0.052 (11)*
H3A	−0.212 (7)	0.748 (5)	0.726 (3)	0.045 (10)*
H6A	0.539 (8)	0.297 (5)	0.670 (4)	0.066 (12)*
H1A	0.298 (9)	0.437 (6)	0.766 (5)	0.085 (15)*
H7A	0.141 (7)	0.395 (5)	0.937 (4)	0.048 (10)*
H	0.288 (9)	0.661 (6)	0.599 (5)	0.075 (14)*
H8A	0.240 (9)	0.202 (6)	1.039 (5)	0.083 (15)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O4	0.0625 (17)	0.0686 (18)	0.0703 (18)	0.0429 (15)	0.0331 (15)	0.0478 (15)
O1	0.0629 (18)	0.078 (2)	0.078 (2)	0.0434 (16)	0.0408 (16)	0.0548 (17)
O3	0.091 (2)	0.078 (2)	0.0638 (18)	0.0474 (18)	0.0428 (17)	0.0484 (16)
O2	0.089 (2)	0.076 (2)	0.0716 (18)	0.0478 (17)	0.0403 (16)	0.0526 (17)
C3	0.052 (2)	0.058 (2)	0.060 (2)	0.034 (2)	0.029 (2)	0.032 (2)
C4	0.052 (2)	0.044 (2)	0.048 (2)	0.0204 (18)	0.0178 (18)	0.0236 (17)
C1	0.053 (2)	0.045 (2)	0.048 (2)	0.0223 (18)	0.0204 (17)	0.0246 (18)
C2	0.059 (2)	0.054 (2)	0.057 (2)	0.035 (2)	0.0233 (19)	0.033 (2)
N1	0.0533 (19)	0.0460 (17)	0.0475 (17)	0.0245 (15)	0.0150 (15)	0.0278 (15)
C9	0.046 (2)	0.0388 (19)	0.0452 (19)	0.0169 (16)	0.0146 (16)	0.0221 (16)
C10	0.0445 (19)	0.0352 (17)	0.0413 (17)	0.0263 (15)	0.0186 (15)	0.0234 (15)
C5	0.051 (2)	0.048 (2)	0.053 (2)	0.0258 (19)	0.0219 (18)	0.0275 (18)
C7	0.056 (2)	0.053 (2)	0.053 (2)	0.031 (2)	0.0231 (19)	0.0312 (19)
C8	0.065 (3)	0.052 (2)	0.052 (2)	0.032 (2)	0.028 (2)	0.0313 (19)
C6	0.055 (2)	0.052 (2)	0.049 (2)	0.0239 (19)	0.0207 (18)	0.0303 (18)

Geometric parameters (Å, º)

O4—C4	1.286 (4)	N1—H1A	0.97 (5)
O1—C1	1.321 (5)	C9—C5	1.377 (5)
O1—H	0.94 (5)	C9—C8	1.386 (5)
O3—C4	1.220 (4)	C9—C10	1.424 (5)
O2—C1	1.217 (4)	C10—C10^i	1.274 (4)
C3—C2	1.340 (5)	C10—H10	0.9300
C3—C4	1.487 (5)	C5—C6	1.377 (5)
C3—H3A	0.99 (4)	C5—H5A	1.06 (4)
C1—C2	1.470 (5)	C7—C8	1.366 (5)
C2—H2A	0.95 (4)	C7—H7A	0.98 (4)
N1—C6	1.327 (5)	C8—H8A	1.04 (5)
N1—C7	1.343 (5)	C6—H6A	1.00 (4)
C1—O1—H	107 (3)	C5—C9—C10	115.0 (3)
C2—C3—C4	131.7 (4)	C8—C9—C10	124.7 (3)
C2—C3—H3A	116 (2)	C10^i—C10—C9	113.5 (4)
C4—C3—H3A	112 (2)	C10^i—C10—H10	123.3
O3—C4—O4	122.8 (3)	C9—C10—H10	123.3
O3—C4—C3	118.4 (3)	C9—C5—C6	118.9 (3)
O4—C4—C3	118.8 (3)	C9—C5—H5A	120.5 (18)
O2—C1—O1	120.3 (3)	C6—C5—H5A	120.6 (18)
O2—C1—C2	119.3 (3)	N1—C7—C8	120.2 (4)
O1—C1—C2	120.4 (3)	N1—C7—H7A	117 (2)
C3—C2—C1	131.7 (4)	C8—C7—H7A	123 (2)
C3—C2—H2A	121 (2)	C7—C8—C9	118.4 (3)
C1—C2—H2A	107 (2)	C7—C8—H8A	119 (3)
C6—N1—C7	122.4 (3)	C9—C8—H8A	123 (3)
C6—N1—H1A	118 (3)	N1—C6—C5	119.7 (3)
C7—N1—H1A	119 (3)	N1—C6—H6A	116 (3)
C5—C9—C8	120.3 (3)	C5—C6—H6A	124 (3)
C2—C3—C4—O3	176.4 (4)	C10—C9—C5—C6	−178.8 (3)
C2—C3—C4—O4	−3.5 (7)	C6—N1—C7—C8	0.7 (6)
C4—C3—C2—C1	0.5 (8)	N1—C7—C8—C9	−0.4 (6)
O2—C1—C2—C3	178.4 (4)	C5—C9—C8—C7	−0.4 (6)
O1—C1—C2—C3	−1.2 (7)	C10—C9—C8—C7	179.2 (4)
C5—C9—C10—C10^i	−174.3 (4)	C7—N1—C6—C5	−0.2 (6)
C8—C9—C10—C10^i	6.0 (6)	C9—C5—C6—N1	−0.6 (6)
C8—C9—C5—C6	0.9 (6)

Symmetry code: (i) −x+1, −y, −z+2.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C7—H7A···O3^ii	0.98 (4)	2.55 (4)	3.174 (5)	122 (3)
C8—H8A···O3^ii	1.04 (5)	2.59 (5)	3.234 (5)	120 (3)
C2—H2A···O2^iii	0.95 (4)	2.55 (4)	3.412 (5)	152 (3)
C6—H6A···O1^iv	1.00 (4)	2.43 (4)	3.404 (5)	166 (3)
C6—H6A···O2^iv	1.00 (4)	2.60 (4)	3.179 (5)	117 (3)
C5—H5A···O2^iv	1.06 (4)	2.50 (3)	3.169 (5)	120 (2)
N1—H1A···O4	0.97 (5)	1.70 (5)	2.673 (4)	179 (4)
N1—H1A···O3	0.97 (5)	2.61 (5)	3.245 (4)	123 (4)
O1—H···O4	0.94 (5)	1.53 (5)	2.475 (4)	180 (5)
C7—H7A···O3	0.98 (4)	2.52 (4)	3.218 (5)	128 (3)

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