organic compounds
4,4′-Bipyridine–pyroglutamic acid (1/2)
aDepartment of Chemistry, The University of Texas at San Antonio, One UTSA Circle, San Antonio, Texas 78249-0698, USA, and bDepartment of Chemistry, University of Malaya, 50603 Kuala Lumpur, Malaysia
*Correspondence e-mail: edward.tiekink@gmail.com
In the title 10H8N2·2C5H7NO3, the 4,4′-bipyridine molecule [dihedral angle between the pyridine rings = 36.33 (11)°] accepts O—H⋯N hydrogen bonds from the two pyroglutamic (pga) acid molecules. The pga molecules at each end of the trimeric aggregate self-associate via centrosymmetric eight-membered amide {⋯HNCO}2 synthons, so that the comprises one-dimensional supramolecular chains propagating in [13]. C—H⋯O and π–π stacking interactions [centroid–centroid separation = 3.590 (2) Å] consolidate the structure.
CRelated literature
For background to the co-crystallization of active pharmaceutical agents and discussion on the definition of a ); Zukerman-Schpector & Tiekink (2008). For related studies on formation, see: Broker & Tiekink (2007); Broker et al. (2008); Ellis et al. (2009). For structure analysis, see: Spek (2009). For hydrogen-bonding considerations, see: Etter (1990).
see: Shan & Zaworotko (2008Experimental
Crystal data
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Refinement
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Data collection: CrystalClear (Rigaku/MSC, 2005); cell CrystalClear; data reduction: CrystalClear; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: DIAMOND (Brandenburg, 2006); software used to prepare material for publication: SHELXL97.
Supporting information
https://doi.org/10.1107/S1600536809045000/hb5194sup1.cif
contains datablocks global, I. DOI:Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S1600536809045000/hb5194Isup2.hkl
Colourless crystals of (I) were isolated from the co-crystallization of 1 molar equivalent of DL-pyroglutamic acid (Fluka, 20 mg) and 4,4'-bipyridine (Aldrich, 12 mg) in methanol/ethanol (1/1, 8 ml); m. pt. 425–427 K.
The H-atoms were placed in calculated positions (O–H = 0.84 Å, N–H = 0.88 Å and C–H 0.95–1.00 Å) and were included in the
in the riding model approximation with Uiso(H) set to 1.2–1.5Ueq(carrier atom).The co-crystallization of active pharmaceutical ingredients is an active area of contemporary crystal engineering (Shan & Zaworotko, 2008); see Zukerman-Schpector & Tiekink (2008) for a discussion of terminology. As a continuation of studies into the phenomenon of co-crystallization (Broker & Tiekink, 2007; Broker et al., 2008; Ellis et al., 2009), the co-crystallization of DL-pyroglutamic acid with 4,4'-bipyridine was investigated.
The title
(I), comprises two molecules of pyroglutamic acid and one of 4,4'-bipyridine, Fig. 1. The independent molecules of pyroglutamic acid are virtually identical with RMS values for bond distances and angles of 0.006 Å and 0.552 °, respectively (Spek, 2009). The connections between molecules are hydrogen bonds of the type O–H···N, Table 1, in accord with the strongest donor associating with the strongest acceptor (Etter, 1990).The trimeric aggregates associate into a supramolecular chain via eight-membered amide {···HNCO}2 synthons. The most convenient description of the chain is given in the following terms. Centrosymmetrically related pyroglutamic acid molecules are connected by the {···HNCO}2 synthons and these are bridged by the 4,4'-bipyridine molecules, Table 1 and Fig. 2. The supramolecular chains have a base vector [1 3 - 2] in which alternate 4,4'-bipyridine molecules are connected to pyroglutamic acid molecules of the same chirality.
The chains are consolidated into the 3-D π···π interactions involving both pyridyl rings [the closest Cg···Cgi = 3.590 (2) Å where Cg is the ring centroid of N2, C16—C20 for i: 2 - x, -y, 1 - z].
by a large number of C–H···O contacts, the shortest two are listed in Table 1, as well asFor background to the co-crystallization of active pharmaceutical agents and discussion on the definition of a
see: Shan & Zaworotko (2008); Zukerman-Schpector & Tiekink (2008). For related studies on formation, see: Broker & Tiekink (2007); Broker et al. (2008); Ellis et al. (2009). For structure analysis, see: Spek (2009). For hydrogen-bonding considerations, see: Etter (1990).Data collection: CrystalClear (Rigaku/MSC, 2005); cell
CrystalClear (Rigaku/MSC, 2005); data reduction: CrystalClear (Rigaku/MSC, 2005); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: DIAMOND (Brandenburg, 2006); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).Fig. 1. Molecular structure of the asymmetric unit of (I) showing atom-labelling scheme and displacement ellipsoids at the 70% probability level. The O–H···N hydrogen bonds are shown as orange dashed lines. | |
Fig. 2. Supramolecular chain formation in (I) mediated by O—H···N (orange dashed lines) and N—H···N (blue dashed lines) hydrogen bonding. |
C10H8N2·2C5H7NO3 | Z = 2 |
Mr = 414.42 | F(000) = 436 |
Triclinic, P1 | Dx = 1.422 Mg m−3 |
Hall symbol: -P 1 | Mo Kα radiation, λ = 0.71073 Å |
a = 7.444 (3) Å | Cell parameters from 3819 reflections |
b = 11.511 (4) Å | θ = 1.8–40.3° |
c = 12.845 (4) Å | µ = 0.11 mm−1 |
α = 66.274 (17)° | T = 98 K |
β = 74.203 (17)° | Block, colourless |
γ = 86.91 (2)° | 0.22 × 0.15 × 0.12 mm |
V = 967.6 (6) Å3 |
Rigaku Saturn724 diffractometer | 3375 independent reflections |
Radiation source: sealed tube | 2851 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.041 |
Detector resolution: 28.5714 pixels mm-1 | θmax = 25.0°, θmin = 1.8° |
ω scans | h = −8→8 |
Absorption correction: multi-scan (ABSCOR; Higashi, 1995) | k = −13→13 |
Tmin = 0.706, Tmax = 1.000 | l = −11→15 |
5618 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)] = 0.056 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.128 | H-atom parameters constrained |
S = 1.16 | w = 1/[σ2(Fo2) + (0.0416P)2 + 0.3826P] where P = (Fo2 + 2Fc2)/3 |
3375 reflections | (Δ/σ)max < 0.001 |
281 parameters | Δρmax = 0.29 e Å−3 |
2 restraints | Δρmin = −0.26 e Å−3 |
C10H8N2·2C5H7NO3 | γ = 86.91 (2)° |
Mr = 414.42 | V = 967.6 (6) Å3 |
Triclinic, P1 | Z = 2 |
a = 7.444 (3) Å | Mo Kα radiation |
b = 11.511 (4) Å | µ = 0.11 mm−1 |
c = 12.845 (4) Å | T = 98 K |
α = 66.274 (17)° | 0.22 × 0.15 × 0.12 mm |
β = 74.203 (17)° |
Rigaku Saturn724 diffractometer | 3375 independent reflections |
Absorption correction: multi-scan (ABSCOR; Higashi, 1995) | 2851 reflections with I > 2σ(I) |
Tmin = 0.706, Tmax = 1.000 | Rint = 0.041 |
5618 measured reflections |
R[F2 > 2σ(F2)] = 0.056 | 2 restraints |
wR(F2) = 0.128 | H-atom parameters constrained |
S = 1.16 | Δρmax = 0.29 e Å−3 |
3375 reflections | Δρmin = −0.26 e Å−3 |
281 parameters |
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. |
x | y | z | Uiso*/Ueq | ||
O1 | 0.7958 (3) | 0.80500 (15) | 0.34215 (15) | 0.0306 (4) | |
H1o | 0.8071 | 0.7262 | 0.3706 | 0.046* | |
O2 | 0.7021 (3) | 0.76264 (15) | 0.20917 (14) | 0.0300 (4) | |
O3 | 0.6914 (2) | 1.13445 (15) | −0.10317 (14) | 0.0250 (4) | |
O4 | 0.6382 (2) | −0.34079 (15) | 0.69099 (15) | 0.0295 (4) | |
H4o | 0.6741 | −0.2635 | 0.6605 | 0.044* | |
O5 | 0.3864 (2) | −0.27410 (15) | 0.78866 (14) | 0.0278 (4) | |
O6 | 0.0822 (2) | −0.65238 (15) | 1.10646 (14) | 0.0263 (4) | |
N1 | 0.6307 (3) | 1.00631 (18) | 0.09308 (17) | 0.0239 (5) | |
H1N | 0.5362 | 0.9583 | 0.1002 | 0.027 (7)* | |
N2 | 0.2248 (3) | −0.51418 (18) | 0.91661 (17) | 0.0233 (5) | |
H2N | 0.1380 | −0.4596 | 0.9022 | 0.028 (7)* | |
N3 | 0.8270 (3) | 0.56170 (18) | 0.42251 (18) | 0.0266 (5) | |
N4 | 0.7503 (3) | −0.10455 (18) | 0.60996 (17) | 0.0247 (5) | |
C1 | 0.7328 (3) | 0.8368 (2) | 0.24872 (19) | 0.0217 (5) | |
C2 | 0.7041 (3) | 0.9777 (2) | 0.19365 (19) | 0.0215 (5) | |
H2 | 0.6154 | 1.0033 | 0.2536 | 0.026* | |
C3 | 0.7237 (3) | 1.1014 (2) | −0.0062 (2) | 0.0218 (5) | |
C4 | 0.8716 (3) | 1.1608 (2) | 0.02102 (19) | 0.0228 (5) | |
H4A | 0.8325 | 1.2423 | 0.0263 | 0.027* | |
H4B | 0.9921 | 1.1764 | −0.0406 | 0.027* | |
C5 | 0.8887 (3) | 1.0625 (2) | 0.1407 (2) | 0.0225 (5) | |
H5A | 0.9011 | 1.1045 | 0.1924 | 0.027* | |
H5B | 0.9984 | 1.0116 | 0.1302 | 0.027* | |
C6 | 0.4717 (3) | −0.3581 (2) | 0.76693 (19) | 0.0219 (5) | |
C7 | 0.3977 (3) | −0.4950 (2) | 0.82374 (19) | 0.0213 (5) | |
H7 | 0.3747 | −0.5203 | 0.7624 | 0.026* | |
C8 | 0.2141 (3) | −0.6187 (2) | 1.0153 (2) | 0.0214 (5) | |
C9 | 0.3900 (3) | −0.6883 (2) | 0.9955 (2) | 0.0236 (5) | |
H9A | 0.3657 | −0.7619 | 0.9788 | 0.028* | |
H9B | 0.4397 | −0.7187 | 1.0655 | 0.028* | |
C10 | 0.5264 (3) | −0.5884 (2) | 0.8884 (2) | 0.0248 (5) | |
H10A | 0.6061 | −0.6274 | 0.8373 | 0.030* | |
H10B | 0.6074 | −0.5452 | 0.9133 | 0.030* | |
C11 | 0.9039 (3) | 0.5073 (2) | 0.3470 (2) | 0.0268 (6) | |
H11 | 0.9653 | 0.5605 | 0.2674 | 0.032* | |
C12 | 0.8973 (3) | 0.3770 (2) | 0.3805 (2) | 0.0243 (5) | |
H12 | 0.9549 | 0.3417 | 0.3251 | 0.029* | |
C13 | 0.8049 (3) | 0.2985 (2) | 0.4965 (2) | 0.0223 (5) | |
C14 | 0.7272 (3) | 0.3554 (2) | 0.5749 (2) | 0.0253 (5) | |
H14 | 0.6659 | 0.3047 | 0.6552 | 0.030* | |
C15 | 0.7406 (3) | 0.4857 (2) | 0.5344 (2) | 0.0273 (6) | |
H15 | 0.6860 | 0.5234 | 0.5883 | 0.033* | |
C16 | 0.7879 (3) | 0.1585 (2) | 0.5364 (2) | 0.0208 (5) | |
C17 | 0.7629 (3) | 0.1045 (2) | 0.4611 (2) | 0.0254 (5) | |
H17 | 0.7590 | 0.1570 | 0.3829 | 0.030* | |
C18 | 0.7440 (3) | −0.0258 (2) | 0.5017 (2) | 0.0259 (6) | |
H18 | 0.7256 | −0.0613 | 0.4500 | 0.031* | |
C19 | 0.7758 (3) | −0.0528 (2) | 0.6826 (2) | 0.0258 (5) | |
H19 | 0.7810 | −0.1079 | 0.7600 | 0.031* | |
C20 | 0.7947 (3) | 0.0765 (2) | 0.6494 (2) | 0.0242 (5) | |
H20 | 0.8121 | 0.1093 | 0.7032 | 0.029* |
U11 | U22 | U33 | U12 | U13 | U23 | |
O1 | 0.0477 (12) | 0.0234 (9) | 0.0292 (9) | 0.0069 (8) | −0.0215 (9) | −0.0126 (8) |
O2 | 0.0405 (11) | 0.0279 (9) | 0.0303 (9) | 0.0029 (8) | −0.0146 (9) | −0.0173 (8) |
O3 | 0.0261 (9) | 0.0300 (9) | 0.0229 (9) | 0.0051 (7) | −0.0089 (8) | −0.0135 (7) |
O4 | 0.0262 (10) | 0.0242 (8) | 0.0340 (10) | −0.0013 (7) | 0.0038 (8) | −0.0151 (8) |
O5 | 0.0265 (9) | 0.0257 (9) | 0.0310 (10) | 0.0063 (7) | −0.0029 (8) | −0.0150 (8) |
O6 | 0.0241 (9) | 0.0280 (9) | 0.0226 (9) | 0.0027 (7) | −0.0015 (8) | −0.0093 (7) |
N1 | 0.0239 (11) | 0.0249 (11) | 0.0243 (11) | 0.0001 (9) | −0.0090 (9) | −0.0097 (9) |
N2 | 0.0205 (11) | 0.0244 (10) | 0.0229 (10) | 0.0061 (9) | −0.0055 (9) | −0.0085 (9) |
N3 | 0.0288 (12) | 0.0268 (11) | 0.0284 (11) | 0.0040 (9) | −0.0116 (10) | −0.0133 (9) |
N4 | 0.0194 (11) | 0.0269 (10) | 0.0277 (11) | 0.0034 (9) | −0.0023 (9) | −0.0140 (9) |
C1 | 0.0185 (12) | 0.0278 (12) | 0.0203 (12) | 0.0007 (10) | −0.0030 (10) | −0.0126 (10) |
C2 | 0.0211 (12) | 0.0266 (12) | 0.0209 (12) | 0.0036 (10) | −0.0052 (10) | −0.0144 (10) |
C3 | 0.0222 (13) | 0.0230 (12) | 0.0252 (13) | 0.0081 (10) | −0.0071 (11) | −0.0151 (10) |
C4 | 0.0209 (12) | 0.0264 (12) | 0.0218 (12) | 0.0016 (10) | −0.0013 (10) | −0.0134 (10) |
C5 | 0.0219 (13) | 0.0240 (12) | 0.0260 (12) | 0.0047 (10) | −0.0090 (11) | −0.0132 (10) |
C6 | 0.0229 (13) | 0.0264 (12) | 0.0183 (12) | 0.0031 (10) | −0.0053 (10) | −0.0113 (10) |
C7 | 0.0229 (12) | 0.0238 (12) | 0.0188 (11) | 0.0026 (10) | −0.0045 (10) | −0.0110 (10) |
C8 | 0.0246 (13) | 0.0197 (11) | 0.0231 (12) | −0.0007 (10) | −0.0072 (11) | −0.0111 (10) |
C9 | 0.0258 (13) | 0.0245 (12) | 0.0230 (12) | 0.0025 (10) | −0.0072 (11) | −0.0120 (10) |
C10 | 0.0252 (13) | 0.0263 (12) | 0.0255 (12) | 0.0031 (10) | −0.0064 (11) | −0.0134 (11) |
C11 | 0.0287 (14) | 0.0302 (13) | 0.0220 (12) | 0.0026 (11) | −0.0090 (11) | −0.0097 (11) |
C12 | 0.0231 (13) | 0.0297 (12) | 0.0235 (12) | 0.0064 (10) | −0.0076 (11) | −0.0140 (11) |
C13 | 0.0198 (12) | 0.0268 (12) | 0.0250 (12) | 0.0032 (10) | −0.0085 (10) | −0.0139 (10) |
C14 | 0.0240 (13) | 0.0301 (13) | 0.0231 (12) | 0.0006 (10) | −0.0040 (11) | −0.0136 (11) |
C15 | 0.0270 (14) | 0.0303 (13) | 0.0308 (14) | 0.0025 (11) | −0.0077 (12) | −0.0189 (12) |
C16 | 0.0164 (12) | 0.0250 (12) | 0.0219 (12) | 0.0019 (9) | −0.0041 (10) | −0.0113 (10) |
C17 | 0.0289 (13) | 0.0267 (12) | 0.0213 (12) | 0.0035 (11) | −0.0056 (11) | −0.0115 (10) |
C18 | 0.0268 (14) | 0.0297 (13) | 0.0272 (13) | 0.0036 (11) | −0.0063 (11) | −0.0183 (11) |
C19 | 0.0246 (13) | 0.0293 (13) | 0.0220 (12) | 0.0001 (11) | −0.0037 (11) | −0.0103 (11) |
C20 | 0.0204 (12) | 0.0307 (13) | 0.0239 (12) | 0.0002 (10) | −0.0038 (11) | −0.0148 (11) |
O1—C1 | 1.314 (3) | C6—C7 | 1.506 (3) |
O1—H1o | 0.8400 | C7—C10 | 1.538 (3) |
O2—C1 | 1.213 (3) | C7—H7 | 1.0000 |
O3—C3 | 1.235 (3) | C8—C9 | 1.514 (3) |
O4—C6 | 1.319 (3) | C9—C10 | 1.529 (3) |
O4—H4o | 0.8400 | C9—H9A | 0.9900 |
O5—C6 | 1.213 (3) | C9—H9B | 0.9900 |
O6—C8 | 1.239 (3) | C10—H10A | 0.9900 |
N1—C3 | 1.335 (3) | C10—H10B | 0.9900 |
N1—C2 | 1.449 (3) | C11—C12 | 1.383 (3) |
N1—H1N | 0.8800 | C11—H11 | 0.9500 |
N2—C8 | 1.338 (3) | C12—C13 | 1.391 (3) |
N2—C7 | 1.453 (3) | C12—H12 | 0.9500 |
N2—H2N | 0.8800 | C13—C14 | 1.397 (3) |
N3—C15 | 1.338 (3) | C13—C16 | 1.482 (3) |
N3—C11 | 1.345 (3) | C14—C15 | 1.374 (3) |
N4—C18 | 1.332 (3) | C14—H14 | 0.9500 |
N4—C19 | 1.349 (3) | C15—H15 | 0.9500 |
C1—C2 | 1.517 (3) | C16—C20 | 1.390 (3) |
C2—C5 | 1.550 (3) | C16—C17 | 1.396 (3) |
C2—H2 | 1.0000 | C17—C18 | 1.377 (3) |
C3—C4 | 1.511 (3) | C17—H17 | 0.9500 |
C4—C5 | 1.533 (3) | C18—H18 | 0.9500 |
C4—H4A | 0.9900 | C19—C20 | 1.376 (3) |
C4—H4B | 0.9900 | C19—H19 | 0.9500 |
C5—H5A | 0.9900 | C20—H20 | 0.9500 |
C5—H5B | 0.9900 | ||
C1—O1—H1o | 109.5 | O6—C8—C9 | 126.3 (2) |
C6—O4—H4o | 109.5 | N2—C8—C9 | 108.0 (2) |
C3—N1—C2 | 115.02 (18) | C8—C9—C10 | 104.03 (18) |
C3—N1—H1N | 125.7 | C8—C9—H9A | 111.0 |
C2—N1—H1N | 119.2 | C10—C9—H9A | 111.0 |
C8—N2—C7 | 114.5 (2) | C8—C9—H9B | 111.0 |
C8—N2—H2N | 127.0 | C10—C9—H9B | 111.0 |
C7—N2—H2N | 118.5 | H9A—C9—H9B | 109.0 |
C15—N3—C11 | 118.1 (2) | C9—C10—C7 | 103.70 (19) |
C18—N4—C19 | 117.74 (19) | C9—C10—H10A | 111.0 |
O2—C1—O1 | 124.3 (2) | C7—C10—H10A | 111.0 |
O2—C1—C2 | 123.0 (2) | C9—C10—H10B | 111.0 |
O1—C1—C2 | 112.71 (18) | C7—C10—H10B | 111.0 |
N1—C2—C1 | 110.12 (18) | H10A—C10—H10B | 109.0 |
N1—C2—C5 | 103.77 (17) | N3—C11—C12 | 122.7 (2) |
C1—C2—C5 | 113.37 (19) | N3—C11—H11 | 118.6 |
N1—C2—H2 | 109.8 | C12—C11—H11 | 118.6 |
C1—C2—H2 | 109.8 | C11—C12—C13 | 119.0 (2) |
C5—C2—H2 | 109.8 | C11—C12—H12 | 120.5 |
O3—C3—N1 | 124.9 (2) | C13—C12—H12 | 120.5 |
O3—C3—C4 | 126.5 (2) | C12—C13—C14 | 118.0 (2) |
N1—C3—C4 | 108.55 (19) | C12—C13—C16 | 121.4 (2) |
C3—C4—C5 | 104.45 (18) | C14—C13—C16 | 120.6 (2) |
C3—C4—H4A | 110.9 | C15—C14—C13 | 119.3 (2) |
C5—C4—H4A | 110.9 | C15—C14—H14 | 120.4 |
C3—C4—H4B | 110.9 | C13—C14—H14 | 120.4 |
C5—C4—H4B | 110.9 | N3—C15—C14 | 122.9 (2) |
H4A—C4—H4B | 108.9 | N3—C15—H15 | 118.5 |
C4—C5—C2 | 104.29 (17) | C14—C15—H15 | 118.5 |
C4—C5—H5A | 110.9 | C20—C16—C17 | 117.6 (2) |
C2—C5—H5A | 110.9 | C20—C16—C13 | 121.71 (19) |
C4—C5—H5B | 110.9 | C17—C16—C13 | 120.7 (2) |
C2—C5—H5B | 110.9 | C18—C17—C16 | 119.2 (2) |
H5A—C5—H5B | 108.9 | C18—C17—H17 | 120.4 |
O5—C6—O4 | 124.4 (2) | C16—C17—H17 | 120.4 |
O5—C6—C7 | 123.4 (2) | N4—C18—C17 | 123.2 (2) |
O4—C6—C7 | 112.18 (19) | N4—C18—H18 | 118.4 |
N2—C7—C6 | 111.09 (19) | C17—C18—H18 | 118.4 |
N2—C7—C10 | 103.22 (18) | N4—C19—C20 | 122.7 (2) |
C6—C7—C10 | 114.16 (19) | N4—C19—H19 | 118.6 |
N2—C7—H7 | 109.4 | C20—C19—H19 | 118.6 |
C6—C7—H7 | 109.4 | C19—C20—C16 | 119.5 (2) |
C10—C7—H7 | 109.4 | C19—C20—H20 | 120.3 |
O6—C8—N2 | 125.7 (2) | C16—C20—H20 | 120.3 |
C3—N1—C2—C1 | −128.8 (2) | C8—C9—C10—C7 | −24.8 (2) |
C3—N1—C2—C5 | −7.2 (3) | N2—C7—C10—C9 | 23.4 (2) |
O2—C1—C2—N1 | 2.0 (3) | C6—C7—C10—C9 | 144.11 (19) |
O1—C1—C2—N1 | −178.66 (19) | C15—N3—C11—C12 | −0.1 (3) |
O2—C1—C2—C5 | −113.8 (2) | N3—C11—C12—C13 | 1.1 (3) |
O1—C1—C2—C5 | 65.6 (3) | C11—C12—C13—C14 | −1.8 (3) |
C2—N1—C3—O3 | 174.8 (2) | C11—C12—C13—C16 | 178.0 (2) |
C2—N1—C3—C4 | −5.7 (3) | C12—C13—C14—C15 | 1.6 (3) |
O3—C3—C4—C5 | −164.3 (2) | C16—C13—C14—C15 | −178.1 (2) |
N1—C3—C4—C5 | 16.1 (2) | C11—N3—C15—C14 | 0.0 (3) |
C3—C4—C5—C2 | −19.6 (2) | C13—C14—C15—N3 | −0.7 (4) |
N1—C2—C5—C4 | 16.5 (2) | C12—C13—C16—C20 | 144.2 (2) |
C1—C2—C5—C4 | 135.96 (19) | C14—C13—C16—C20 | −36.0 (3) |
C8—N2—C7—C6 | −136.67 (19) | C12—C13—C16—C17 | −36.3 (3) |
C8—N2—C7—C10 | −13.9 (2) | C14—C13—C16—C17 | 143.4 (2) |
O5—C6—C7—N2 | −7.0 (3) | C20—C16—C17—C18 | 0.8 (3) |
O4—C6—C7—N2 | 173.39 (18) | C13—C16—C17—C18 | −178.7 (2) |
O5—C6—C7—C10 | −123.2 (2) | C19—N4—C18—C17 | 0.2 (4) |
O4—C6—C7—C10 | 57.2 (3) | C16—C17—C18—N4 | −0.7 (4) |
C7—N2—C8—O6 | 178.2 (2) | C18—N4—C19—C20 | 0.2 (4) |
C7—N2—C8—C9 | −2.1 (2) | N4—C19—C20—C16 | −0.2 (4) |
O6—C8—C9—C10 | −163.0 (2) | C17—C16—C20—C19 | −0.3 (3) |
N2—C8—C9—C10 | 17.4 (2) | C13—C16—C20—C19 | 179.2 (2) |
D—H···A | D—H | H···A | D···A | D—H···A |
O1—H1o···N3 | 0.84 | 1.75 | 2.588 (3) | 177 |
O4—H4o···N4 | 0.84 | 1.75 | 2.582 (3) | 175 |
N1—H1n···O3i | 0.88 | 2.03 | 2.911 (3) | 174 |
N2—H2n···O6ii | 0.88 | 2.03 | 2.903 (3) | 172 |
C15—H15···O4iii | 0.95 | 2.38 | 3.294 (3) | 162 |
C18—H18···O1iv | 0.95 | 2.41 | 3.293 (3) | 155 |
Symmetry codes: (i) −x+1, −y+2, −z; (ii) −x, −y−1, −z+2; (iii) x, y+1, z; (iv) x, y−1, z. |
Experimental details
Crystal data | |
Chemical formula | C10H8N2·2C5H7NO3 |
Mr | 414.42 |
Crystal system, space group | Triclinic, P1 |
Temperature (K) | 98 |
a, b, c (Å) | 7.444 (3), 11.511 (4), 12.845 (4) |
α, β, γ (°) | 66.274 (17), 74.203 (17), 86.91 (2) |
V (Å3) | 967.6 (6) |
Z | 2 |
Radiation type | Mo Kα |
µ (mm−1) | 0.11 |
Crystal size (mm) | 0.22 × 0.15 × 0.12 |
Data collection | |
Diffractometer | Rigaku Saturn724 |
Absorption correction | Multi-scan (ABSCOR; Higashi, 1995) |
Tmin, Tmax | 0.706, 1.000 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 5618, 3375, 2851 |
Rint | 0.041 |
(sin θ/λ)max (Å−1) | 0.595 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.056, 0.128, 1.16 |
No. of reflections | 3375 |
No. of parameters | 281 |
No. of restraints | 2 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.29, −0.26 |
Computer programs: CrystalClear (Rigaku/MSC, 2005), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), DIAMOND (Brandenburg, 2006).
D—H···A | D—H | H···A | D···A | D—H···A |
O1—H1o···N3 | 0.84 | 1.75 | 2.588 (3) | 177 |
O4—H4o···N4 | 0.84 | 1.75 | 2.582 (3) | 175 |
N1—H1n···O3i | 0.88 | 2.03 | 2.911 (3) | 174 |
N2—H2n···O6ii | 0.88 | 2.03 | 2.903 (3) | 172 |
C15—H15···O4iii | 0.95 | 2.38 | 3.294 (3) | 162 |
C18—H18···O1iv | 0.95 | 2.41 | 3.293 (3) | 155 |
Symmetry codes: (i) −x+1, −y+2, −z; (ii) −x, −y−1, −z+2; (iii) x, y+1, z; (iv) x, y−1, z. |
References
Brandenburg, K. (2006). DIAMOND. Crystal Impact GbR, Bonn, Germany. Google Scholar
Broker, G. A., Bettens, R. P. A. & Tiekink, E. R. T. (2008). CrystEngComm, 10, 879–887. Web of Science CSD CrossRef CAS Google Scholar
Broker, G. A. & Tiekink, E. R. T. (2007). CrystEngComm, 9, 1096–1109. Web of Science CSD CrossRef CAS Google Scholar
Ellis, C. A., Miller, M. A., Spencer, J., Zukerman-Schpector, J. & Tiekink, E. R. T. (2009). CrystEngComm, 11, 1352–1361. Web of Science CSD CrossRef CAS Google Scholar
Etter, M. C. (1990). Acc. Chem. Res. 23, 120–126. CrossRef CAS Web of Science Google Scholar
Higashi, T. (1995). ABSCOR. Rigaku Corporation, Tokyo, Japan. Google Scholar
Rigaku/MSC (2005). CrystalClear. Rigaku/MSC Inc., The Woodlands, Texas, USA. Google Scholar
Shan, N. & Zaworotko, M. J. (2008). Drug Discovery Today, 13, 440–446. Web of Science CrossRef PubMed CAS Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Spek, A. L. (2009). Acta Cryst. D65, 148–155. Web of Science CrossRef CAS IUCr Journals Google Scholar
Zukerman-Schpector, J. & Tiekink, E. R. T. (2008). Z. Kristallogr. 223, 233–234. Web of Science CrossRef CAS Google Scholar
This is an open-access article distributed under the terms of the Creative Commons Attribution (CC-BY) Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are cited.
The co-crystallization of active pharmaceutical ingredients is an active area of contemporary crystal engineering (Shan & Zaworotko, 2008); see Zukerman-Schpector & Tiekink (2008) for a discussion of terminology. As a continuation of studies into the phenomenon of co-crystallization (Broker & Tiekink, 2007; Broker et al., 2008; Ellis et al., 2009), the co-crystallization of DL-pyroglutamic acid with 4,4'-bipyridine was investigated.
The title co-crystal, (I), comprises two molecules of pyroglutamic acid and one of 4,4'-bipyridine, Fig. 1. The independent molecules of pyroglutamic acid are virtually identical with RMS values for bond distances and angles of 0.006 Å and 0.552 °, respectively (Spek, 2009). The connections between molecules are hydrogen bonds of the type O–H···N, Table 1, in accord with the strongest donor associating with the strongest acceptor (Etter, 1990).
The trimeric aggregates associate into a supramolecular chain via eight-membered amide {···HNCO}2 synthons. The most convenient description of the chain is given in the following terms. Centrosymmetrically related pyroglutamic acid molecules are connected by the {···HNCO}2 synthons and these are bridged by the 4,4'-bipyridine molecules, Table 1 and Fig. 2. The supramolecular chains have a base vector [1 3 - 2] in which alternate 4,4'-bipyridine molecules are connected to pyroglutamic acid molecules of the same chirality.
The chains are consolidated into the 3-D crystal structure by a large number of C–H···O contacts, the shortest two are listed in Table 1, as well as π···π interactions involving both pyridyl rings [the closest Cg···Cgi = 3.590 (2) Å where Cg is the ring centroid of N2, C16—C20 for i: 2 - x, -y, 1 - z].