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organic compounds\(\def\hfill{\hskip 5em}\def\hfil{\hskip 3em}\def\eqno#1{\hfil {#1}}\)

Journal logoCRYSTALLOGRAPHIC
COMMUNICATIONS
ISSN: 2056-9890
Volume 63| Part 3| March 2007| Pages o1240-o1242
https://doi.org/10.1107/S1600536807005156

Short N⋯O hydrogen bonds in the 1:1 adduct of 4,4′-bi­pyridyl and oxalic acid

CROSSMARK_Color_square_no_text.svg
John A. Cowan,a* Judith A. K. Howard,a Horst Puschmanna and Ian D. Williamsb

aDepartment of Chemistry, University of Durham, Durham DH1 3LE, England, and bDepartment of Chemistry, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, People's Republic of China
*Correspondence e-mail: j.a.cowan@dl.ac.uk

(Received 16 January 2007; accepted 31 January 2007; online 9 February 2007)

Oxalic acid, C2O4H2, and 4,4′-bipyridyl, C10H8N2, crystallize in a 1:1 ratio. The asymmetric unit consists of one oxalic acid (OXA) molecule and one 4,4'bipyridyl (BPY) molecule in general positions, together with one half-OXA molecule and one half-BPY molecule; the latter two molecules are centrosymmetric. The mol­ecules are linked in two parallel independent chains by strong O—H⋯N hydrogen bonds. In one chain there is one independent O—H⋯N hydrogen bond [N⋯O = 2.557 (3) Å] and the mol­ecules lie on centres of symmetry and are therefore constrained to have planar central portions. The second chain contains two independent O—H⋯N hydrogen bonds [O⋯N = 2.549 (3) and 2.581 (3) Å] and both mol­ecules are twisted about their central bonds.

Comment

Temperature-dependent proton migration has recently been observed in short N⋯O hydrogen bonds between carboxylic acid and pyridyl groups (Cowan et al., 2003[Cowan, J. A., Howard, J. A. K., McIntyre, G. J., Lo, S. M.-F. & Williams, I. D. (2003). Acta Cryst. B59, 794-801.], 2005[Cowan, J. A., Howard, J. A. K., McIntyre, G. J., Lo, S. M.-F. & Williams, I. D. (2005). Acta Cryst. B61, 724-730.]). It occurred to us that 4,4′-bipyridyl (BPY) and oxalic acid (OXA) would be likely to co-crystallize in the same inter­molecular configuration, but hopefully with only one independent N—H⋯O hydrogen bond in the asymmetric unit. We present here the crystal structure of the title 1:1 adduct of BPY and OXA, (I)[link].

[Scheme 1]

The asymmetric unit of (I) consists of one oxalic acid (OXA) molecule and one 4,4′-bipyridyl (BPY) molecule in general positions, together with one half-OXA molecule and one half-BPY molecule; the latter two molecules are centrosymmetric. BPY and OXA crystallize to form two similar independent one-dimensional chains. In both chains the OXA and BPY mol­ecules are linked together by strong O—H⋯N hydrogen bonds in concert with C—H⋯O hydrogen bonds (Table 1[link]). A similar configuration is often observed in co-crystals of BPY and carboxylic acids, for example in the co-crystals of BPY with fumaric acid (Chatterjee et al., 1998[Chatterjee, S., Pedireddi, V. R. & Rao, C. N. R. (1998). Tetrahedron Lett. 39, 2843-2846.]), phosphono­acetic acid (Bowes et al., 2003[Bowes, K. F., Ferguson, G., Lough, A. J., Zakaria, C. M. & Glidewell, C. (2003). Acta Cryst. B59, 87-99.]) and malonic acid (Pedireddi et al., 1998[Pedireddi, V. R., Chatterjee, S., Ranganathan, A. & Rao, C. N. R. (1998). Tetrahedron, 54, 9457-9474.]). That one-dimensional tapes are formed is unsurprising considering the co-crystals of BPY with 2,5-dihydroxy­benzoquinone (Cowan et al., 2001[Cowan, J. A., Howard, J. A. K. & Leech, M. A. (2001). Acta Cryst. C57, 302-303.]), squaric acid (Reetz et al., 1994[Reetz, M. T., Höger, S. & Harms, K. (1994). Angew. Chem. Int. Ed. Engl. 33, 181-183.]) and 2,5-dichloro-3,6-dihydroxy­benzo­quinone (Zaman et al., 1999[Zaman, M. B., Tomura, M. & Yamashita, Y. (1999). Chem. Commun. pp. 999-1000.]), which all have a similar arrangement of O atoms to OXA and which all form one-dimensional tapes.

The two types of chains are distinguished by the twists within the mol­ecules. In one chain, the planes of the pyridyl rings of the BPY mol­ecule are twisted by 23.75 (6)° with respect to each other and there is a twist of 5.35 (11)° between the carboxylic acid groups of the OXA mol­ecule, while in the other chain, the OXA and BPY mol­ecules lie on centres of symmetry and are consequently both have planar central portions. Both chains lie in the ab plane and propagate in the [1[\overline{1}]0] direction (Fig. 2[link]). The chains are linked by C—H⋯O hydrogen bonds into parallel planes. One set of planes consists of only flat mol­ecules and the other consists of only twisted mol­ecules. The only significant inter­action linking the planes is a C—H⋯O hydrogen bond (C11⋯O3) between adjacent planes of twisted mol­ecules.

There are three similar O—H⋯N hydrogen bonds in the structure of (I)[link]. Although the H-atom positions were constrained in the final refinement, O—H distances between 1.15 and 1.25 Å in earlier free refinements hint that the true H-atom positions may be close to the centres of the hydrogen bonds. The graph produced by Steiner (2002[Steiner, T. (2002). Angew. Chem. Int. Ed. 41, 48-76.]) from neutron diffraction data of N⋯O hydrogen bonds suggests that the O—H distance becomes significantly elongated when the N—O distance is below ∼2.6 Å. Although not as short as the hydrogen bonds in which temperature-dependent proton migration has been observed, the N⋯O distances in the three hydrogen bonds in (I)[link] are all below ∼2.6 Å. Therefore, a large elongation of the O—H bond is expected and the H-atom position may be temperature-dependent. Neutron diffraction is required for accurate H-atom positions.

[Figure 1]
Figure 1
The structures of segments of both independent chain, with the atom-numbering scheme. Displacement ellipsoids are drawn at the 50% probability level. Dashed lines indicate hydrogen bonds and H atoms are shown as small spheres of arbitrary radii. [Symmetry codes: (I)[link] 2 − x, 2 − y, 1 − z; (II) 3 − x, 1 − y, 1 − z.]
[Figure 2]
Figure 2
A packing diagram for (I)[link], illustrating the mol­ecular chains. All H atoms, except those involved in strong hydrogen bonds, have been omitted for clarity.

Experimental

Equimolar quanti­ties of BPY and OXA were dissolved in methanol. Crystals of (I)[link] suitable for X-ray structure determination were prepared by slow evaporation of the solvent at room temperature.

Crystal data

  • C10H8N2·C2H2O4

  • Mr = 246.22

  • Triclinic, [P \overline 1]

  • a = 8.7365 (18) Å

  • b = 9.9154 (19) Å

  • c = 10.380 (2) Å

  • α = 100.253 (10)°

  • β = 105.349 (11)°

  • γ = 107.569 (10)°

  • V = 793.5 (3) Å3

  • Z = 3

  • Dx = 1.546 Mg m−3

  • Mo Kα radiation

  • μ = 0.12 mm−1

  • T = 100 (2) K

  • Block, brown

  • 0.3 × 0.2 × 0.15 mm
Data collection

  • Bruker SMART CCD area-detector diffractometer

  • ω scans

  • Absorption correction: none

  • 8434 measured reflections

  • 3601 independent reflections

  • 2523 reflections with I > 2σ(I)

  • Rint = 0.058

  • θmax = 27.5°
Refinement

  • Refinement on F2

  • R[F2 > 2σ(F2)] = 0.070

  • wR(F2) = 0.193

  • S = 1.09

  • 3601 reflections

  • 259 parameters

  • Only H-atom displacement parameters refined

  • w = 1/[σ2(Fo2) + (0.0821P)2 + 0.9233P] where P = (Fo2 + 2Fc2)/3

  • (Δ/σ)max < 0.001

  • Δρmax = 0.53 e Å−3

  • Δρmin = −0.34 e Å−3

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A D⋯A D—H⋯A
O2—H1⋯N2i 0.82 1.77 2.586 (3) 174
O4—H2⋯N1 0.82 1.74 2.553 (3) 174
O6—H3⋯N3 0.82 1.74 2.560 (3) 174
C11—H11⋯O3ii 0.93 2.59 3.270 (4) 130
C22—H22⋯O3iii 0.93 2.45 3.375 (3) 172
C24—H24⋯O1iv 0.93 2.40 3.326 (4) 171
C25—H25⋯O4iv 0.93 2.48 3.216 (3) 136
C32—H32⋯O5v 0.93 2.56 3.418 (3) 153
C34—H34⋯O5iii 0.93 2.52 3.373 (3) 153
C35—H35⋯O6vi 0.93 2.57 3.207 (3) 126
Symmetry codes: (i) x-1, y+1, z; (ii) -x, -y+1, -z; (iii) x+1, y, z; (iv) x, y-1, z; (v) -x+2, -y+1, -z+1; (vi) -x+3, -y+2, -z+1.

All H atoms were located in a difference Fourier map and then repositioned in idealized locations, with O—H = 0.82 Å and C—H = 0.93 Å. They were refined with their coordinates, but not their isotropic displacement parameters, riding on their parent atoms.

Data collection: SMART (Bruker, 1998[Bruker (1998). SMART and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.]); cell refinement: SMART; data reduction: SAINT (Bruker, 1998[Bruker (1998). SMART and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.]); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997[Sheldrick, G. M. (1997). SHELXS97 and SHELXL97. University of Göttingen, Germany.]); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997[Sheldrick, G. M. (1997). SHELXS97 and SHELXL97. University of Göttingen, Germany.]); molecular graphics: SHELXTL/PC (Sheldrick, 1999[Sheldrick, G. M. (1999). SHELXTL/PC. Version 5.10 for Windows NT. Bruker AXS Inc., Madison, Wisconsin, USA.]); software used to prepare material for publication: SHELXL97.

Supporting information

Crystal structure: contains datablocks I, global. DOI: https://doi.org/10.1107/S1600536807005156/sg2117sup1.cif

Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S1600536807005156/sg2117Isup2.hkl


Computing details top

Data collection: SMART (Bruker, 1998); cell refinement: SMART; data reduction: SAINT (Bruker, 1998); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL/PC (Sheldrick, 1999); software used to prepare material for publication: SHELXL97.

4,4'-bipyridyl–oxalic acid (1/1) top
Crystal data top
C10H8N2·C2H2O4Z = 3
Mr = 246.22F(000) = 384
Triclinic, P1Dx = 1.546 Mg m−3
Hall symbol: -P 1Mo Kα radiation, λ = 0.71073 Å
a = 8.7365 (18) ÅCell parameters from 874 reflections
b = 9.9154 (19) Åθ = 10.1–19.0°
c = 10.380 (2) ŵ = 0.12 mm−1
α = 100.253 (10)°T = 100 K
β = 105.349 (11)°Block, brown
γ = 107.569 (10)°0.3 × 0.2 × 0.15 mm
V = 793.5 (3) Å3
Data collection top
Bruker SMART CCD area-detector
diffractometer		2523 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tubeRint = 0.058
Graphite monochromatorθmax = 27.5°, θmin = 2.1°
ω scansh = −11→9
8434 measured reflectionsk = −12→12
3601 independent reflectionsl = −13→13
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.070Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.193Only H-atom displacement parameters refined
S = 1.09 w = 1/[σ2(Fo2) + (0.0821P)2 + 0.9233P]
where P = (Fo2 + 2Fc2)/3
3601 reflections(Δ/σ)max < 0.001
259 parametersΔρmax = 0.53 e Å−3
0 restraintsΔρmin = −0.34 e Å−3
Special details top

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'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 > 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 (Å2) top
xyzUiso*/Ueq
C10.0631 (4)0.9499 (3)0.1702 (3)0.0157 (6)
O10.1464 (3)1.0696 (2)0.1636 (2)0.0204 (5)
O2−0.0932 (3)0.9108 (2)0.1751 (2)0.0195 (5)
H1−0.12520.98050.17450.080 (18)*
C20.1318 (4)0.8219 (3)0.1705 (3)0.0150 (5)
O30.0336 (3)0.6941 (2)0.1412 (2)0.0247 (5)
O40.2955 (2)0.8668 (2)0.2015 (2)0.0192 (5)
H20.32480.79540.19330.10 (2)*
N10.4089 (3)0.6576 (2)0.1828 (2)0.0128 (5)
C110.3087 (4)0.5142 (3)0.1246 (3)0.0148 (6)
H110.19090.48810.09090.021 (8)*
C120.3763 (3)0.4040 (3)0.1134 (3)0.0136 (5)
H120.30460.30570.07310.020 (8)*
C130.5547 (3)0.4431 (3)0.1638 (3)0.0112 (5)
C140.6565 (3)0.5934 (3)0.2216 (3)0.0144 (5)
H140.77480.62350.25360.022 (8)*
C150.5800 (3)0.6968 (3)0.2308 (3)0.0145 (5)
H150.64850.79590.27120.014 (7)*
N20.7855 (3)0.1180 (2)0.1646 (2)0.0156 (5)
C210.8754 (4)0.2565 (3)0.1681 (3)0.0178 (6)
H210.98840.28050.17210.024 (9)*
C220.8046 (4)0.3642 (3)0.1659 (3)0.0163 (6)
H220.86940.45870.16800.034 (10)*
C230.6351 (3)0.3295 (3)0.1604 (3)0.0130 (5)
C240.5416 (4)0.1853 (3)0.1546 (3)0.0144 (5)
H240.42770.15740.14850.023 (9)*
C250.6229 (4)0.0842 (3)0.1581 (3)0.0155 (6)
H250.5613−0.01130.15590.012 (7)*
C31.0356 (3)0.9366 (3)0.5023 (3)0.0142 (5)
O50.9471 (2)0.8154 (2)0.5031 (2)0.0185 (4)
O61.1925 (2)0.9765 (2)0.5046 (2)0.0192 (5)
H31.22320.90600.50330.10 (2)*
N31.3099 (3)0.7691 (2)0.5027 (2)0.0155 (5)
C311.2128 (4)0.6253 (3)0.4680 (3)0.0160 (6)
H311.09510.59790.44460.013 (7)*
C321.2821 (3)0.5163 (3)0.4658 (3)0.0154 (6)
H321.21160.41780.44150.030 (9)*
C331.4596 (3)0.5564 (3)0.5007 (3)0.0132 (5)
C341.5585 (3)0.7073 (3)0.5373 (3)0.0143 (5)
H341.67650.73870.56070.020 (8)*
C351.4788 (4)0.8091 (3)0.5382 (3)0.0161 (6)
H351.54570.90890.56450.024 (9)*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
C10.0173 (14)0.0156 (13)0.0141 (12)0.0053 (11)0.0061 (11)0.0040 (9)
O10.0169 (11)0.0149 (9)0.0321 (11)0.0053 (8)0.0114 (9)0.0095 (8)
O20.0149 (10)0.0191 (10)0.0285 (11)0.0085 (8)0.0098 (9)0.0088 (8)
C20.0159 (14)0.0146 (13)0.0163 (12)0.0063 (11)0.0069 (11)0.0051 (10)
O30.0185 (11)0.0137 (10)0.0411 (13)0.0053 (8)0.0090 (9)0.0081 (8)
O40.0143 (10)0.0122 (9)0.0330 (11)0.0064 (8)0.0096 (8)0.0056 (8)
N10.0131 (12)0.0116 (10)0.0169 (11)0.0049 (9)0.0083 (9)0.0064 (8)
C110.0129 (14)0.0167 (13)0.0164 (12)0.0061 (10)0.0048 (11)0.0075 (10)
C120.0135 (13)0.0116 (12)0.0163 (12)0.0041 (10)0.0060 (10)0.0047 (9)
C130.0141 (13)0.0111 (12)0.0131 (11)0.0069 (10)0.0081 (10)0.0054 (9)
C140.0117 (13)0.0150 (12)0.0167 (13)0.0056 (10)0.0043 (10)0.0049 (10)
C150.0150 (14)0.0102 (12)0.0180 (13)0.0043 (10)0.0064 (11)0.0027 (9)
N20.0175 (12)0.0154 (11)0.0170 (11)0.0081 (9)0.0074 (9)0.0063 (8)
C210.0161 (14)0.0178 (13)0.0191 (13)0.0046 (11)0.0062 (11)0.0066 (10)
C220.0158 (14)0.0137 (12)0.0199 (13)0.0046 (11)0.0068 (11)0.0065 (10)
C230.0156 (13)0.0140 (12)0.0099 (11)0.0071 (10)0.0033 (10)0.0035 (9)
C240.0153 (14)0.0143 (12)0.0171 (12)0.0070 (10)0.0076 (10)0.0068 (10)
C250.0157 (14)0.0131 (12)0.0174 (13)0.0038 (10)0.0065 (11)0.0045 (10)
C30.0132 (13)0.0140 (13)0.0146 (12)0.0041 (10)0.0046 (10)0.0035 (9)
O50.0151 (10)0.0131 (9)0.0279 (11)0.0043 (8)0.0079 (8)0.0076 (8)
O60.0143 (10)0.0138 (9)0.0319 (11)0.0053 (8)0.0113 (9)0.0065 (8)
N30.0156 (12)0.0176 (11)0.0150 (11)0.0073 (9)0.0063 (9)0.0047 (8)
C310.0109 (13)0.0164 (13)0.0197 (13)0.0045 (11)0.0033 (11)0.0067 (10)
C320.0121 (13)0.0127 (12)0.0220 (13)0.0045 (10)0.0043 (11)0.0089 (10)
C330.0137 (13)0.0148 (12)0.0108 (11)0.0033 (10)0.0038 (10)0.0064 (9)
C340.0111 (13)0.0135 (12)0.0159 (12)0.0021 (10)0.0058 (10)0.0009 (9)
C350.0165 (14)0.0117 (12)0.0201 (13)0.0038 (10)0.0079 (11)0.0047 (10)
Geometric parameters (Å, º) top
C1—O11.215 (3)C22—C231.399 (4)
C1—O21.320 (3)C22—H220.9300
C1—C21.559 (4)C23—C241.398 (4)
O2—H10.8200C24—C251.393 (4)
C2—O31.226 (3)C24—H240.9300
C2—O41.292 (3)C25—H250.9300
O4—H20.8200C3—O51.220 (3)
N1—C111.348 (3)C3—O61.299 (3)
N1—C151.349 (3)C3—C3i1.563 (5)
C11—C121.392 (4)O6—H30.8200
C11—H110.9300N3—C351.334 (4)
C12—C131.408 (4)N3—C311.344 (3)
C12—H120.9300C31—C321.388 (4)
C13—C141.404 (3)C31—H310.9300
C13—C231.497 (4)C32—C331.406 (4)
C14—C151.385 (4)C32—H320.9300
C14—H140.9300C33—C341.404 (4)
C15—H150.9300C33—C33ii1.492 (5)
N2—C251.337 (4)C34—C351.389 (4)
N2—C211.350 (3)C34—H340.9300
C21—C221.386 (4)C35—H350.9300
C21—H210.9300
O1—C1—O2125.6 (3)C23—C22—H22120.3
O1—C1—C2122.3 (3)C24—C23—C22118.3 (2)
O2—C1—C2112.1 (2)C24—C23—C13120.1 (2)
C1—O2—H1109.5C22—C23—C13121.7 (2)
O3—C2—O4126.4 (3)C25—C24—C23118.5 (3)
O3—C2—C1120.7 (3)C25—C24—H24120.8
O4—C2—C1112.9 (2)C23—C24—H24120.8
C2—O4—H2109.5N2—C25—C24123.1 (2)
C11—N1—C15119.5 (2)N2—C25—H25118.4
N1—C11—C12121.9 (3)C24—C25—H25118.4
N1—C11—H11119.0O5—C3—O6126.3 (2)
C12—C11—H11119.0O5—C3—C3i121.0 (3)
C11—C12—C13119.2 (2)O6—C3—C3i112.7 (3)
C11—C12—H12120.4C3—O6—H3109.5
C13—C12—H12120.4C35—N3—C31119.1 (2)
C14—C13—C12117.8 (2)N3—C31—C32122.3 (3)
C14—C13—C23120.4 (2)N3—C31—H31118.9
C12—C13—C23121.8 (2)C32—C31—H31118.9
C15—C14—C13119.7 (3)C31—C32—C33119.4 (2)
C15—C14—H14120.1C31—C32—H32120.3
C13—C14—H14120.1C33—C32—H32120.3
N1—C15—C14121.8 (2)C34—C33—C32117.3 (2)
N1—C15—H15119.1C34—C33—C33ii121.2 (3)
C14—C15—H15119.1C32—C33—C33ii121.5 (3)
C25—N2—C21118.6 (2)C35—C34—C33119.5 (3)
N2—C21—C22122.1 (3)C35—C34—H34120.2
N2—C21—H21119.0C33—C34—H34120.2
C22—C21—H21119.0N3—C35—C34122.4 (2)
C21—C22—C23119.5 (2)N3—C35—H35118.8
C21—C22—H22120.3C34—C35—H35118.8
Symmetry codes: (i) −x+2, −y+2, −z+1; (ii) −x+3, −y+1, −z+1.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O2—H1···N2iii0.821.772.586 (3)174
O4—H2···N10.821.742.553 (3)174
O6—H3···N30.821.742.560 (3)174
C11—H11···O3iv0.932.593.270 (4)130
C22—H22···O3v0.932.453.375 (3)172
C24—H24···O1vi0.932.403.326 (4)171
C25—H25···O4vi0.932.483.216 (3)136
C32—H32···O5vii0.932.563.418 (3)153
C34—H34···O5v0.932.523.373 (3)153
C35—H35···O6viii0.932.573.207 (3)126
Symmetry codes: (iii) x−1, y+1, z; (iv) −x, −y+1, −z; (v) x+1, y, z; (vi) x, y−1, z; (vii) −x+2, −y+1, −z+1; (viii) −x+3, −y+2, −z+1.
 

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ISSN: 2056-9890
Volume 63| Part 3| March 2007| Pages o1240-o1242
https://doi.org/10.1107/S1600536807005156
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