Redetermined structure of 4,4′-bi­pyridine–1,4-phenyl­enedi­acetic acid (1/1) co-crystal

The asymmetric unit of the title 1:1 co-crystal, C₁₀H₈N₂·C₁₀H₁₀O₄, consists of one half-mol­ecule each of 4,4′-bi­pyridine and 1,4-phenyl­enedi­acetic acid: the complete mol­ecules are generated by crystallographic inversion centres. The dihedral angle between the –CO₂H group and the benzene ring in the diacid is 73.02 (7)°. In the crystal, the components are linked by O—H⋯N hydrogen bonds, generating [1-2-1] chains of alternating amine and carb­oxy­lic acid mol­ecules. The chains are cross-linked by C—H⋯O inter­actions. This structure was previously incorrectly described as a (C₁₀H₁₀N₂)²⁺·(C₁₀H₈O₄)²⁻ mol­ecular salt [Jia et al. (2009). Acta Cryst. E65, o2490–o2490].

1. Related literature

For the previous erroneous report of this structure as a mol­ecular salt, see: Jia et al. (2009). For hydrogen-bonded co-crystals, see: Stahly (2009); Kavuru et al. (2010). For pharmaceutical co-crystals, see: Childs et al. (2009); Walsh et al. (2003). For a similar structure, see: Chinnakali et al. (1999).

2. Experimental

2.1. Crystal data

• C₁₀H₈N₂·C₁₀H₁₀O₄

• M_r = 350.36

• Triclinic,

• a = 4.5577 (5) Å

• b = 6.9806 (8) Å

• c = 13.7995 (15) Å

• α = 99.508 (6)°

• β = 94.297 (6)°

• γ = 97.643 (7)°

• V = 427.05 (8) ų

• Z = 1

• Mo Kα radiation

• μ = 0.10 mm⁻¹

• T = 296 K

• 0.20 × 0.17 × 0.13 mm

2.2. Data collection

• Bruker SMART CCD diffractometer

• 8581 measured reflections

• 2405 independent reflections

• 1876 reflections with I > 2σ(I)

• R_int = 0.028

2.3. Refinement

• R[F² > 2σ(F²)] = 0.041

• wR(F²) = 0.123

• S = 1.05

• 2405 reflections

• 155 parameters

• All H-atom parameters refined

• Δρ_max = 0.19 e Å⁻³

• Δρ_min = −0.16 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O1—H9⋯N1^i	1.02 (2)	1.62 (2)	2.6373 (13)	176 (2)
C7—H6⋯O2^ii	0.954 (16)	2.504 (16)	3.4196 (16)	160.8 (11)
C9—H7⋯O2^iii	1.00 (2)	2.45 (2)	3.4205 (18)	162.2 (16)
Symmetry codes: (i) -x+2, -y+1, -z; (ii) x, y, z+1; (iii) -x+1, -y+2, -z.

Data collection: SMART (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: ORTEP-3 for Windows (Farrugia, 2012); software used to prepare material for publication: SHELXL97.

Supporting information

S1. Comment

Co-crystals represent a class of materials which contain two or more discrete molecular entities held together via non-covalent or supra­molecular inter­actions in the crystal lattice (Stahly, 2009). Due to their robust and directional nature, hydrogen bonds are extensively used as a tool to shape the structure of co-crystals (Kavuru et al., 2010). In this context, hydrogen bonds of varying strengths may be employed, ranging from strong O—H···O/N to weak C—H···π inter­actions. The resulting crystal structures can generate diverse physical and chemical properties such as solubility and stability that differ from the properties of the individual components. Crystal engineering plays an important role in the formation of co-crystals of desired properties so that they can find their applications in pharmaceutical industries (Childs et al., 2009 and Walsh et al., 2003). Herein, we report the supra­molecular architecture of 1,4-phenyl­enedi­acetic acid and 4,4'-bi­pyridine co-crystal formed via O—H···N hydrogen bridges and C—H···π inter­actions.

The title compound can be prepared under hydro­thermal condition using a mixture of 1,4-phenyl­enedi­acetic acid and 4,4'-bi­pyridine (1:1) in water. The acetic acid moiety involving C1, C2, O1 and O2 in 1,4-phenyl­enedi­acetic acid molecule makes dihedral angles of 73.04 (4)° and 2.06 (1)° with the phenyl and pyridyl ring planes respectively. These values are very close to those reported by Chinnakali et al. (1999). The dihedral angle between phenyl and planar pyridyl rings of 4,4'-bi­pyridine is found to be 73.21 (4)°. In the crystal lattice, the molecules are linked with one another through O1—H9···N1 hydrogen bonds with O···N distance of 2.637 (1) Å that extends in one direction leading to a supra­molecular chain like structure. These zig-zag 1D chains are further connected via C—H···O bridges (C7—H6···O2 and C9—H7···O2 with C···O distances of 2.50 (1) Å and 2.45 (2) Å respectively) giving rise to a 2D layered structure in the solid state. In graph set notations (Bernstain et al., 1995), such 1D chains can be described as C₂²(20) where the subscripts and superscripts are the number of hydrogen bond donors and acceptors respectively. There are certain hydrogen bonded rings of descriptors R₁²(7), R₄⁴(16) and R₄⁴(30) which have periodic repetitions throughout the crystal lattice. The adjacent layers are stacked in nearly parallel fashion by means of weak C—H···π inter­actions (C···π distance = 3.838 Å) between the methyl­ene C—H and phenyl ring–π systems. These weak inter­molecular forces together with the strong hydrogen bonds form the overall 3D supra­molecular architecture.

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S2. Synthesis and crystallization

A mixture of 1,4-phenyl­enedi­acetic acid (1 mmol, 0.194 g) and 4,4?-bi­pyridine (1 mmol, 0.156 g) in water (10 ml) were placed in a 23 ml Teflon lined stainless steel reaction vessel. It was then heated to 393K for 24 hours at a heating rate of 5K min^-1. On overnight standing, re­cta­ngular block shaped colourless crystals were obtained. The crystals were then filtered off, washed with water and dried in a vacuum desiccator over fused CaCl₂. Yield: 71%.

S3. Refinement

Structure determination work was done using the WinGX platform (Farrugia, 2012). All the hydrogen atoms were located in difference Fourier maps and refined with isotropic atomic displacement parameters. No restraints were applied for any other parameter during structure refinement.

Related literature

For the previous erroneous report of this structure as a molecular salt, see: Jia et al. (2009). For hydrogen-bonded co-crystals, see: Stahly (2009); Kavuru et al. (2010). For pharmaceutical co-crystals, see: Childs et al. (2009); Walsh et al. (2003). For a similar structure, see: Chinnakali et al. (1999).

Computing details

Data collection: SMART (Bruker, 2004); cell refinement: SAINT (Bruker, 2004); data reduction: SAINT (Bruker, 2004); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).

Figures

	Fig. 1. The molecular structure of (I) showing 50% probability displacement ellipsoids.
	Fig. 2. A view of the O—H···N, C—H···O and C—H···π interactions observed in the crystal structure of the title compound.

4,4'-Bipyridine–1,4-phenylenediacetic acid (1/1)

Crystal data

C10H8N2·C10H10O4	V = 427.05 (8) Å^3
Mr = 350.36	Z = 1
Triclinic, P1	F(000) = 184
a = 4.5577 (5) Å	Dx = 1.362 Mg m^−3
b = 6.9806 (8) Å	Mo Kα radiation, λ = 0.71073 Å
c = 13.7995 (15) Å	µ = 0.10 mm^−1
α = 99.508 (6)°	T = 296 K
β = 94.297 (6)°	Rectangular block, colourless
γ = 97.643 (7)°	0.20 × 0.17 × 0.13 mm

Data collection

Bruker SMART CCD diffractometer	1876 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.028
Graphite monochromator	θmax = 29.8°, θmin = 3.0°
phi and ω scans	h = −6→6
8581 measured reflections	k = −9→9
2405 independent reflections	l = −19→19

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.041	All H-atom parameters refined
wR(F^2) = 0.123	w = 1/[σ^2(Fo^2) + (0.0605P)^2 + 0.0515P] where P = (Fo^2 + 2Fc^2)/3
S = 1.05	(Δ/σ)max = 0.001
2405 reflections	Δρmax = 0.19 e Å^−3
155 parameters	Δρmin = −0.16 e Å^−3
0 restraints	Extinction correction: SHELXL, Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.061 (11)

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
O1	0.8197 (2)	0.45294 (13)	−0.18830 (6)	0.0541 (3)
C1	0.7209 (2)	0.60720 (15)	−0.21279 (8)	0.0408 (3)
C2	0.5619 (3)	0.71533 (19)	−0.13310 (10)	0.0490 (3)
C3	0.7850 (2)	0.86342 (15)	−0.06291 (8)	0.0400 (3)
C4	0.9459 (3)	0.80852 (16)	0.01476 (9)	0.0454 (3)
C5	0.8422 (3)	1.05717 (17)	−0.07687 (8)	0.0446 (3)
O2	0.7616 (3)	0.66207 (15)	−0.28973 (7)	0.0675 (3)
N1	0.8832 (2)	0.73182 (15)	0.32203 (7)	0.0476 (3)
C6	0.8316 (3)	0.67172 (18)	0.40629 (9)	0.0517 (3)
C7	0.6844 (3)	0.77149 (18)	0.47798 (9)	0.0487 (3)
C8	0.5796 (2)	0.94340 (15)	0.46266 (7)	0.0376 (2)
C10	0.7840 (3)	0.8964 (2)	0.30711 (10)	0.0566 (3)
C9	0.6326 (3)	1.00451 (19)	0.37423 (9)	0.0532 (3)
H9	0.927 (5)	0.382 (3)	−0.2421 (15)	0.104 (7)*
H3	0.908 (3)	0.676 (2)	0.0263 (11)	0.061 (4)*
H4	0.731 (3)	1.100 (2)	−0.1302 (11)	0.055 (4)*
H6	0.660 (3)	0.722 (2)	0.5378 (12)	0.067 (4)*
H1	0.462 (4)	0.621 (2)	−0.0977 (12)	0.065 (4)*
H8	0.822 (4)	0.935 (2)	0.2459 (13)	0.073 (5)*
H7	0.560 (4)	1.122 (3)	0.3533 (13)	0.081 (5)*
H2	0.412 (4)	0.787 (3)	−0.1669 (12)	0.071 (5)*
H5	0.902 (4)	0.551 (3)	0.4159 (12)	0.071 (4)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.0764 (6)	0.0483 (5)	0.0463 (5)	0.0272 (4)	0.0173 (4)	0.0141 (4)
C1	0.0449 (6)	0.0370 (5)	0.0403 (5)	0.0071 (4)	0.0035 (4)	0.0055 (4)
C2	0.0434 (6)	0.0489 (6)	0.0549 (7)	0.0115 (5)	0.0119 (5)	0.0025 (5)
C3	0.0431 (5)	0.0405 (5)	0.0396 (5)	0.0148 (4)	0.0163 (4)	0.0046 (4)
C4	0.0580 (7)	0.0363 (5)	0.0467 (6)	0.0141 (5)	0.0146 (5)	0.0116 (4)
C5	0.0545 (7)	0.0452 (6)	0.0394 (5)	0.0184 (5)	0.0097 (5)	0.0116 (4)
O2	0.1023 (8)	0.0630 (6)	0.0502 (5)	0.0351 (6)	0.0215 (5)	0.0232 (4)
N1	0.0507 (6)	0.0478 (5)	0.0450 (5)	0.0158 (4)	0.0075 (4)	0.0023 (4)
C6	0.0643 (8)	0.0439 (6)	0.0511 (7)	0.0221 (6)	0.0096 (6)	0.0075 (5)
C7	0.0631 (7)	0.0441 (6)	0.0443 (6)	0.0189 (5)	0.0116 (5)	0.0117 (5)
C8	0.0370 (5)	0.0374 (5)	0.0379 (5)	0.0073 (4)	0.0026 (4)	0.0045 (4)
C10	0.0714 (9)	0.0614 (8)	0.0466 (7)	0.0285 (6)	0.0200 (6)	0.0159 (6)
C9	0.0691 (8)	0.0515 (7)	0.0490 (6)	0.0284 (6)	0.0181 (6)	0.0166 (5)

Geometric parameters (Å, º)

O1—C1	1.3051 (13)	C5—H4	0.972 (14)
O1—H9	1.02 (2)	N1—C6	1.3264 (16)
C1—O2	1.2056 (14)	N1—C10	1.3301 (16)
C1—C2	1.5147 (16)	C6—C7	1.3820 (17)
C2—C3	1.5108 (17)	C6—H5	0.964 (17)
C2—H1	0.970 (16)	C7—C8	1.3906 (15)
C2—H2	1.027 (17)	C7—H6	0.955 (16)
C3—C4	1.3877 (16)	C8—C9	1.3850 (16)
C3—C5	1.3908 (15)	C8—C8^ii	1.486 (2)
C4—C5^i	1.3844 (18)	C10—C9	1.3810 (17)
C4—H3	0.961 (15)	C10—H8	0.950 (18)
C5—C4^i	1.3844 (18)	C9—H7	0.998 (19)
C1—O1—H9	112.6 (12)	C3—C5—H4	120.1 (8)
O2—C1—O1	123.26 (10)	C6—N1—C10	117.10 (10)
O2—C1—C2	123.39 (11)	N1—C6—C7	123.47 (11)
O1—C1—C2	113.30 (10)	N1—C6—H5	116.3 (10)
C3—C2—C1	109.58 (9)	C7—C6—H5	120.2 (10)
C3—C2—H1	110.0 (9)	C6—C7—C8	119.66 (11)
C1—C2—H1	108.9 (10)	C6—C7—H6	119.0 (10)
C3—C2—H2	109.4 (9)	C8—C7—H6	121.4 (10)
C1—C2—H2	107.7 (9)	C9—C8—C7	116.53 (10)
H1—C2—H2	111.2 (13)	C9—C8—C8^ii	121.59 (12)
C4—C3—C5	118.28 (11)	C7—C8—C8^ii	121.88 (12)
C4—C3—C2	121.06 (10)	N1—C10—C9	123.35 (12)
C5—C3—C2	120.61 (10)	N1—C10—H8	115.3 (10)
C5^i—C4—C3	120.99 (10)	C9—C10—H8	121.3 (10)
C5^i—C4—H3	119.3 (9)	C10—C9—C8	119.89 (11)
C3—C4—H3	119.7 (9)	C10—C9—H7	116.0 (11)
C4^i—C5—C3	120.73 (11)	C8—C9—H7	124.1 (11)
C4^i—C5—H4	119.2 (8)

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

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O1—H9···N1^iii	1.02 (2)	1.62 (2)	2.6373 (13)	176 (2)
C7—H6···O2^iv	0.954 (16)	2.504 (16)	3.4196 (16)	160.8 (11)
C9—H7···O2^v	1.00 (2)	2.45 (2)	3.4205 (18)	162.2 (16)

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