4,4′-Bipyridine–5-fluoro­isophthalic acid (1/1)

Co-crystallization of 5-fluoro­isophthalic acid (H₂fip) with 4,4′-bipyridine (bipy) leads to the formation of the title compound [(H₂fip)(bipy)], C₈H₅FO₄·C₁₀H₈N₂, with an acid–base molar ratio of 1:1. The acid and base subunits are arrange alternately in the crystal structure, displaying a wave-like tape motif via inter­molecular O—H...N and C—H...O hydrogen bonds [carbox­yl–pyridine synthon of R₂²(7) hydrogen-bond notation], which are further combined into a two-dimensional architecture through C—H...F inter­actions involving the bipy and H₂fip mol­ecules.

Key indicators

• Single-crystal X-ray study
• T = 296 K
• Mean [sigma](C-C) = 0.004 Å
• R factor = 0.059
• wR factor = 0.166
• Data-to-parameter ratio = 12.0

checkCIF/PLATON results

No syntax errors found



Alert level C
DIFMX01_ALERT_2_C  The maximum difference density is > 0.1*ZMAX*0.75
            _refine_diff_density_max given =      0.718
            Test value =      0.675
DIFMX02_ALERT_1_C  The maximum difference density is > 0.1*ZMAX*0.75
            The relevant atom site should be identified.
PLAT094_ALERT_2_C Ratio of Maximum / Minimum Residual Density ....       2.20
PLAT097_ALERT_2_C Large Reported Max.  (Positive) Residual Density       0.72 eA-3
PLAT230_ALERT_2_C Hirshfeld Test Diff for    C4     --  C5      ..       6.63 su
PLAT230_ALERT_2_C Hirshfeld Test Diff for    O4     --  C18     ..       5.06 su
PLAT911_ALERT_3_C Missing # FCF Refl Between THmin & STh/L=  0.595          9
PLAT042_ALERT_1_C Calc. and Reported MoietyFormula Strings  Differ          ?

Alert level G
PLAT860_ALERT_3_G Note: Number of Least-Squares Restraints .......          1
PLAT128_ALERT_4_G Alternate Setting of Space-group P21/c   .......      P21/n

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

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

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S1. Comment

In light of the importance of hydrogen bonds in crystal engineering, the supramolecular synthon approach has been widely applied to adapt desired supramolecules by using identified robust intermolecular interactions (Desiraju, 1995; Nangia & Desiraju, 1998). Co-crystallization is a current theme in several research groups to study hydrogen bonding through X-ray diffraction technique (Aakeröy & Salmon, 2005), for the synthesis of interpenetrated networks (Sharma & Zaworotko, 1996), and especially in pharmaceutical developments (Schultheiss & Newman, 2009). At this stage, strong hydrogen bonds, such as O—H···N or charge-assisted N—H···O, are always essential in the co-crystallization of carboxylic acids with pyridyl bases, usually combining the auxiliary weak C—H···O interactions, lead to the familiar carboxyl/pyridyl heterosynthon [R₂²(7)] (Shan et al., 2002). Although aromatic dicarboxylic acids have been verified to be excellent building blocks in binary co-crystal assemblies with bipyridine-type components (Du et al., 2005), halogen substituented dicarboxylic acids have been seldom studied in this aspect (He, et al., 2009). Doubtless, substituents will profoundly influence the structural assemblies by demonstrating distinct hydrogen-bonding capability and potential steric/electronic effect. To further investigate the hydrogen-bonding networks involving halogen substituents, 5-fluoroisophthalic acid (H₂fip) was chosen to construct binary cocrystal with familiar 4,4'-bipyridine (bipy) component as a hydrogen-bonding participant for the first time.

In this work, the reaction of 5-fluoroisophthalic acid (H₂fip) with 4,4'-bipyridine (bipy) under ambient conditions and evaporation from the mixed CH₃OH/H₂O (2:1) solution of the reactants yields the crystalline binary adduct [(H₂fip)(bipy)] (I). Single crystal X-ray diffraction reveals that compound (I) contains one-dimensional supramolecular tape via the connection of predictable carboxylate-bipyridine O—H···N/C—H···O interactions of R₂²(7) heterosynthon. Then, further C—H···F interactions extend the adjacent tape moieties into a two-dimensional (2-D) corrugated layer. The molecular structure contains one H₂fip and one bipy molecule (Fig. 1). The two pyridyl rings within the basic unit form a dihedral angle of 30.9 (2) °. The heterosynthon R₂²(7) ring pattern of O—H···N/C—H···O bonds (synthon I in Fig. 2, Table 1), connecting the base and acid moieties, is responsible for the formation of a 1-D wavelike tape structure. Analysis of the crystal packing of (I) suggests that a further C—H···F interaction (Table 1) expands the 1-D motif into a 2-D hydrogen-bonding network (Figu. 2). Within the 2-D layer, a new hydrogen-bonding pattern denoted as R₂⁴(14) (synthon II in Fig. 2, Etter, 1990) is found to link two pairs of centrosymmetry related carboxyl-bipyridine motifs from adjacent tape structures. By comparison, a closely related 1:1 binary cocrystal of isophthalic acid and bipy exhibits similar tapes of acid:base components formed via R₂²(7) synthons. But these tapes extend to form supramolecular sheets via additional C—H···O interactions (Shan et al., 2002).

In conclusion, this work demonstrates the first example for H₂fip as a good participant in co-crystallization with basic modules. When co-crystallizing with rod-like 4,4'-bipyridine building block, the H₂fip subunits fulfill the reliable carboxylic-pyridine synthon R₂²(7). Although the associated C—H···O bonds are not present between adjoining tape motifs, the introduction of fluorine substituents leads to a new hydrogen-bonding synthon R₂⁴(14). This result presents a new challenge in the exploration of crystalline products based on such halogen substituted benzene dicarboxylic acids.

Related literature

For the supramolecular synthon approach in crystal engineering, see: Desiraju (1995); Nangia & Desiraju (1998). For background to co-crystallization, see: Aakeröy & Salmon (2005); Sharma & Zaworotko (1996); Schultheiss & Newman (2009). For co-crystals with a carboxyl–pyridyl heterosynthon, see: Etter (1990); Shan et al. (2002); Du et al. (2005). For co-crystals of halogen-substituted dicarboxylic acids, see: He et al. (2009).

S2. Experimental

All the reagents and solvents for synthesis were commercially available and used as received. For the preparation of compound (I), to a CH₃OH/H₂O (2:1) solution (6 ml) of H₂fip (18.4 mg, 0.1 mmol) was added a solution of bipy (15.8 mg, 0.1 mmol) in CH₃OH (5 ml). After stirring for ca. 30 minutes, the reaction mixture was filtered and left to stand at ambient temperature. Colorless block crystals of (I) suitable for X-ray diffraction were gained through one week evaporation of the filtrate with a yield of 75 % (25.5 mg, based on bipy). Anal. Calcd for C₁₈H₁₃FN₂O₄: C, 63.53; H, 3.85; N, 8.23 %. Found: C, 63.50; H, 3.85; N, 8.29 %.

S3. Refinement

One restraint was applied to bonded N1 and C5 atoms to equalize each anisotropic vector component parallel to the bond (DELU command). H atoms bonded to C atoms were positioned geometrically (C—H = 0.93 Å for pyridyl and phenyl H atoms) and included in the refinement in the riding-model approximation, with U_iso(H) = 1.2 U_eq(C). O-bound H atoms were refined as rigid groups, allowed to rotate but not tip. Isotropic displacement parameters were derived from the parent atoms with U_iso(H) = 1.5 U_eq(O) and O—H distance of 0.82 Å.

Computing details

Data collection: APEX2 (Bruker, 2007); cell refinement: APEX2 and SAINT (Bruker, 2007); data reduction: SAINT (Bruker, 2007); program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008) and DIAMOND (Brandenburg, 2005); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

Figures

	Fig. 1. The molecular structure of compound (I) drawn with 30% probability ellipsoids.
	Fig. 2. Two-dimensional hydrogen-bonded layer of (I). Hydrogen bonds are indicated as dashed lines. I and II indicate the synthons R2^2(7) and R2^4(14), respectively.

4,4'-Bipyridine–5-fluorobenzene-1,3-dicarboxylic acid (1/1)

Crystal data

C8H5FO4·C10H8N2	F(000) = 704
Mr = 340.30	Dx = 1.453 Mg m^−3
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2yn	Cell parameters from 2260 reflections
a = 7.1711 (13) Å	θ = 2.1–21.8°
b = 20.106 (4) Å	µ = 0.11 mm^−1
c = 11.272 (2) Å	T = 296 K
β = 106.781 (2)°	Block, colorless
V = 1556.0 (5) Å^3	0.34 × 0.32 × 0.32 mm
Z = 4

Data collection

Bruker APEXII CCD area-detector diffractometer	2742 independent reflections
Radiation source: fine-focus sealed tube	1956 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.042
ϕ and ω scans	θmax = 25.0°, θmin = 2.0°
Absorption correction: multi-scan (SADABS; Sheldrick, 2003)	h = −8→8
Tmin = 0.963, Tmax = 0.967	k = −23→22
11109 measured reflections	l = −13→13

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)] = 0.059	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.166	H-atom parameters constrained
S = 1.09	w = 1/[σ^2(Fo^2) + (0.067P)^2 + 1.097P] where P = (Fo^2 + 2Fc^2)/3
2742 reflections	(Δ/σ)max < 0.001
228 parameters	Δρmax = 0.72 e Å^−3
1 restraint	Δρmin = −0.33 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
C1	0.2245 (5)	0.3051 (2)	−0.1085 (3)	0.0680 (10)
H1	0.2529	0.2771	−0.1667	0.082*
C2	0.2595 (5)	0.28299 (18)	0.0108 (3)	0.0578 (9)
H2	0.3103	0.2406	0.0319	0.069*
C3	0.2198 (4)	0.32356 (15)	0.1013 (3)	0.0463 (7)
C4	0.1530 (5)	0.38653 (18)	0.0671 (3)	0.0618 (9)
H4	0.1293	0.4163	0.1242	0.074*
C5	0.1208 (5)	0.40493 (18)	−0.0617 (4)	0.0681 (9)
H5	0.0760	0.4475	−0.0870	0.082*
C6	0.2374 (4)	0.29661 (14)	0.2275 (2)	0.0390 (6)
C7	0.2065 (4)	0.22960 (14)	0.2432 (3)	0.0472 (7)
H7	0.1809	0.2009	0.1758	0.057*
C8	0.2138 (5)	0.20553 (15)	0.3592 (3)	0.0484 (7)
H8	0.1927	0.1603	0.3672	0.058*
C9	0.2766 (5)	0.33605 (15)	0.3328 (3)	0.0512 (8)
H9	0.2999	0.3813	0.3279	0.061*
C10	0.2807 (5)	0.30759 (15)	0.4452 (3)	0.0522 (8)
H10	0.3070	0.3350	0.5146	0.063*
C11	0.1900 (4)	0.11407 (14)	0.6366 (3)	0.0420 (7)
C12	0.1879 (4)	0.07233 (13)	0.7462 (2)	0.0374 (6)
C13	0.2825 (4)	0.09158 (14)	0.8674 (2)	0.0401 (7)
H13	0.3453	0.1325	0.8829	0.048*
C14	0.2827 (4)	0.04932 (14)	0.9653 (2)	0.0431 (7)
C15	0.1878 (5)	−0.01089 (15)	0.9423 (3)	0.0498 (8)
H15	0.1868	−0.0393	1.0072	0.060*
C16	0.0951 (5)	−0.02820 (14)	0.8225 (3)	0.0482 (7)
C17	0.0933 (4)	0.01109 (14)	0.7225 (3)	0.0424 (7)
H17	0.0313	−0.0027	0.6420	0.051*
C18	0.3876 (5)	0.06363 (18)	1.0980 (3)	0.0558 (9)
F1	0.0045 (3)	−0.08851 (9)	0.80111 (18)	0.0751 (7)
N1	0.1528 (4)	0.36369 (18)	−0.1434 (3)	0.0707 (8)
N2	0.2493 (4)	0.24332 (12)	0.4599 (2)	0.0453 (6)
O1	0.2483 (3)	0.17584 (10)	0.66511 (18)	0.0521 (6)
H1A	0.2473	0.1961	0.6018	0.078*
O2	0.1424 (4)	0.09213 (11)	0.53240 (18)	0.0615 (7)
O3	0.4816 (4)	0.12082 (13)	1.11386 (19)	0.0662 (7)
H3	0.5535	0.1231	1.1850	0.099*
O4	0.3880 (4)	0.02582 (13)	1.1812 (2)	0.0745 (8)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.065 (2)	0.091 (3)	0.046 (2)	−0.003 (2)	0.0142 (17)	0.0128 (19)
C2	0.061 (2)	0.075 (2)	0.0364 (17)	−0.0063 (17)	0.0124 (15)	0.0050 (16)
C3	0.0388 (15)	0.0540 (18)	0.0413 (17)	−0.0042 (13)	0.0037 (13)	0.0110 (14)
C4	0.062 (2)	0.060 (2)	0.061 (2)	0.0019 (16)	0.0123 (17)	0.0205 (17)
C5	0.068 (2)	0.052 (2)	0.078 (2)	0.0076 (17)	0.0099 (19)	0.0185 (15)
C6	0.0388 (15)	0.0420 (16)	0.0348 (15)	−0.0001 (12)	0.0081 (12)	0.0051 (12)
C7	0.0608 (19)	0.0430 (17)	0.0358 (16)	−0.0047 (14)	0.0110 (14)	−0.0032 (13)
C8	0.0643 (19)	0.0401 (17)	0.0395 (17)	−0.0050 (14)	0.0130 (14)	0.0029 (13)
C9	0.072 (2)	0.0363 (16)	0.0461 (18)	−0.0036 (15)	0.0182 (16)	0.0005 (13)
C10	0.074 (2)	0.0449 (18)	0.0371 (17)	−0.0070 (15)	0.0158 (15)	−0.0064 (13)
C11	0.0455 (16)	0.0424 (17)	0.0364 (16)	−0.0014 (13)	0.0090 (13)	−0.0012 (13)
C12	0.0407 (15)	0.0392 (15)	0.0317 (14)	0.0026 (12)	0.0095 (12)	0.0003 (11)
C13	0.0442 (16)	0.0368 (15)	0.0377 (15)	0.0009 (12)	0.0092 (12)	−0.0053 (12)
C14	0.0488 (16)	0.0508 (18)	0.0285 (14)	0.0109 (13)	0.0091 (12)	0.0004 (12)
C15	0.067 (2)	0.0463 (18)	0.0365 (16)	0.0066 (15)	0.0154 (15)	0.0074 (13)
C16	0.0629 (19)	0.0372 (16)	0.0444 (17)	−0.0057 (14)	0.0156 (15)	0.0032 (13)
C17	0.0491 (17)	0.0424 (16)	0.0325 (15)	−0.0023 (13)	0.0066 (13)	−0.0017 (12)
C18	0.059 (2)	0.067 (2)	0.0395 (18)	0.0141 (17)	0.0113 (15)	−0.0101 (17)
F1	0.1104 (17)	0.0482 (11)	0.0623 (12)	−0.0268 (11)	0.0179 (11)	0.0032 (9)
N1	0.0663 (19)	0.091 (2)	0.0517 (18)	−0.0038 (17)	0.0114 (14)	0.0132 (14)
N2	0.0574 (15)	0.0436 (14)	0.0347 (13)	−0.0042 (11)	0.0131 (11)	0.0021 (11)
O1	0.0731 (14)	0.0454 (12)	0.0361 (11)	−0.0108 (10)	0.0129 (10)	0.0004 (9)
O2	0.0936 (18)	0.0562 (14)	0.0324 (12)	−0.0184 (12)	0.0147 (11)	−0.0025 (10)
O3	0.0738 (16)	0.0816 (18)	0.0352 (12)	0.0014 (13)	0.0030 (11)	−0.0124 (11)
O4	0.101 (2)	0.0853 (18)	0.0302 (12)	0.0180 (15)	0.0084 (12)	0.0083 (12)

Geometric parameters (Å, º)

C1—N1	1.301 (5)	C10—H10	0.9300
C1—C2	1.368 (4)	C11—O2	1.208 (3)
C1—H1	0.9300	C11—O1	1.320 (3)
C2—C3	1.398 (4)	C11—C12	1.497 (4)
C2—H2	0.9300	C12—C13	1.393 (4)
C3—C4	1.369 (4)	C12—C17	1.394 (4)
C3—C6	1.493 (4)	C13—C14	1.392 (4)
C4—C5	1.451 (5)	C13—H13	0.9300
C4—H4	0.9300	C14—C15	1.376 (4)
C5—N1	1.308 (5)	C14—C18	1.496 (4)
C5—H5	0.9300	C15—C16	1.367 (4)
C6—C7	1.385 (4)	C15—H15	0.9300
C6—C9	1.387 (4)	C16—F1	1.364 (3)
C7—C8	1.381 (4)	C16—C17	1.373 (4)
C7—H7	0.9300	C17—H17	0.9300
C8—N2	1.328 (4)	C18—O4	1.207 (4)
C8—H8	0.9300	C18—O3	1.319 (4)
C9—C10	1.382 (4)	O1—H1A	0.8200
C9—H9	0.9300	O3—H3	0.8200
C10—N2	1.330 (4)
N1—C1—C2	122.4 (4)	C9—C10—H10	118.1
N1—C1—H1	118.8	O2—C11—O1	124.1 (3)
C2—C1—H1	118.8	O2—C11—C12	122.0 (3)
C1—C2—C3	120.6 (4)	O1—C11—C12	113.9 (2)
C1—C2—H2	119.7	C13—C12—C17	120.4 (2)
C3—C2—H2	119.7	C13—C12—C11	122.4 (2)
C4—C3—C2	117.6 (3)	C17—C12—C11	117.2 (2)
C4—C3—C6	122.0 (3)	C14—C13—C12	119.7 (3)
C2—C3—C6	120.3 (3)	C14—C13—H13	120.1
C3—C4—C5	117.3 (3)	C12—C13—H13	120.1
C3—C4—H4	121.3	C15—C14—C13	120.0 (3)
C5—C4—H4	121.3	C15—C14—C18	115.9 (3)
N1—C5—C4	122.3 (3)	C13—C14—C18	124.1 (3)
N1—C5—H5	118.9	C16—C15—C14	118.9 (3)
C4—C5—H5	118.9	C16—C15—H15	120.6
C7—C6—C9	116.6 (2)	C14—C15—H15	120.6
C7—C6—C3	120.1 (3)	F1—C16—C15	118.2 (3)
C9—C6—C3	123.3 (3)	F1—C16—C17	118.4 (3)
C8—C7—C6	119.9 (3)	C15—C16—C17	123.4 (3)
C8—C7—H7	120.1	C16—C17—C12	117.5 (3)
C6—C7—H7	120.1	C16—C17—H17	121.2
N2—C8—C7	123.7 (3)	C12—C17—H17	121.2
N2—C8—H8	118.2	O4—C18—O3	123.9 (3)
C7—C8—H8	118.2	O4—C18—C14	122.9 (3)
C10—C9—C6	119.5 (3)	O3—C18—C14	113.2 (3)
C10—C9—H9	120.2	C1—N1—C5	119.7 (3)
C6—C9—H9	120.2	C8—N2—C10	116.5 (2)
N2—C10—C9	123.8 (3)	C11—O1—H1A	109.5
N2—C10—H10	118.1	C18—O3—H3	109.5
N1—C1—C2—C3	−0.3 (5)	C17—C12—C13—C14	0.1 (4)
C1—C2—C3—C4	−2.7 (5)	C11—C12—C13—C14	−177.2 (2)
C1—C2—C3—C6	173.2 (3)	C12—C13—C14—C15	−0.7 (4)
C2—C3—C4—C5	2.7 (5)	C12—C13—C14—C18	176.9 (3)
C6—C3—C4—C5	−173.2 (3)	C13—C14—C15—C16	0.3 (4)
C3—C4—C5—N1	0.2 (5)	C18—C14—C15—C16	−177.6 (3)
C4—C3—C6—C7	146.8 (3)	C14—C15—C16—F1	178.9 (3)
C2—C3—C6—C7	−29.0 (4)	C14—C15—C16—C17	0.9 (5)
C4—C3—C6—C9	−30.5 (4)	F1—C16—C17—C12	−179.6 (3)
C2—C3—C6—C9	153.8 (3)	C15—C16—C17—C12	−1.5 (5)
C9—C6—C7—C8	0.6 (4)	C13—C12—C17—C16	1.0 (4)
C3—C6—C7—C8	−176.9 (3)	C11—C12—C17—C16	178.4 (3)
C6—C7—C8—N2	0.1 (5)	C15—C14—C18—O4	−1.2 (4)
C7—C6—C9—C10	−0.7 (4)	C13—C14—C18—O4	−179.0 (3)
C3—C6—C9—C10	176.7 (3)	C15—C14—C18—O3	177.7 (3)
C6—C9—C10—N2	0.1 (5)	C13—C14—C18—O3	−0.1 (4)
O2—C11—C12—C13	165.0 (3)	C2—C1—N1—C5	3.4 (5)
O1—C11—C12—C13	−14.8 (4)	C4—C5—N1—C1	−3.3 (5)
O2—C11—C12—C17	−12.3 (4)	C7—C8—N2—C10	−0.7 (5)
O1—C11—C12—C17	167.9 (2)	C9—C10—N2—C8	0.6 (5)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1A···N2	0.82	1.86	2.684 (3)	179
O3—H3···N1^i	0.82	1.88	2.674 (4)	164
C8—H8···O2	0.93	2.42	3.138 (4)	134
C8—H8···F1^ii	0.93	2.48	3.101 (4)	125

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