4,4′-Bipyridine-1,1′-diium acetylenedicarboxylate: a new member of the (H₂bipy)[Cu(ox)₂] (bipy is 4,4′-bipyridine and ox is oxalate) family

4,4′-Bipyridine-1,1′-diium (H₂bipy) acetylenedicarboxylate, C₁₀H₁₂N₂²⁺·C₄O₄²⁻, (1), is a new member of a family of related structures with similar unit-cell parameters. The structures in this family reported previously [Chen et al. (2012). CrystEngComm, 14, 6400–6403] are (H₂bipy)[Cu(ox)₂] (ox is oxalate), (2), (H₂bipy)[NaH(ox)₂], (3), and (H₂bipy)[H₂(ox)₂], (4). Compound (1) has a one-dimensional structure, in which H₂bipy²⁺ cations and acetylenedicarboxylate (ADC²⁻) anions are linked through a typical supramolecular synthon, i.e. R₂²(7), and form linear `–cation–anion–' ribbons. Through an array of nonclassical C—H...O hydrogen bonds, adjacent ribbons interact to give two-dimensional sheets. These sheets stack to form a layered structure via π–π interactions between the H₂bipy²⁺ cations of neighbouring layers. The supramolecular isostructurality of compounds (1)–(4) is ascribed to the synergistic effect of multiple interactions in these structures. The balanced strong and weak intermolecular interactions stabilizing this structure type include strong charge-assisted N—H...O hydrogen bonds, C—H...O contacts and π–π interactions.

S1. Experimental

S1.1. Refinement

Crystal data, data collection and structure refinement details are summarized in Table 1.

S2. Results and discussion

Computing details

Data collection: APEX2 (Bruker, 2013); cell refinement: APEX2 (Bruker, 2013); data reduction: APEX2 (Bruker, 2013); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008) DIAMOND (Brandenburg, 1999) and Mercury (Macrae et al., 2006); software used to prepare material for publication: SHELXTL (Sheldrick, 2008) and PLATON (Spek, 2009).

Figures

4,4'-Bipyridine-1,1'-diium ethynedicarboxylate

Crystal data

C10H12N2^2+·C4O4^2^−	Z = 1
Mr = 270.24	F(000) = 140
Triclinic, P1	Dx = 1.552 Mg m^−3
a = 3.8050 (3) Å	Mo Kα radiation, λ = 0.71073 Å
b = 8.6739 (7) Å	Cell parameters from 3272 reflections
c = 9.9138 (8) Å	θ = 4.2–27.4°
α = 114.334 (3)°	µ = 0.12 mm^−1
β = 96.159 (3)°	T = 180 K
γ = 98.995 (3)°	Plate, colourless
V = 289.05 (4) Å^3	0.30 × 0.25 × 0.06 mm

Data collection

Bruker D8 Venture diffractometer with a PHOTON 100 CMOS detector	1291 independent reflections
Radiation source: fine-focus sealed tube	1147 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.018
ϕ and ω scans	θmax = 27.4°, θmin = 4.2°
Absorption correction: multi-scan (SADABS; Sheldrick, 2003)	h = −4→4
Tmin = 0.966, Tmax = 0.993	k = −11→11
5593 measured reflections	l = −12→12

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)] = 0.038	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.110	H atoms treated by a mixture of independent and constrained refinement
S = 1.07	w = 1/[σ^2(Fo^2) + (0.0632P)^2 + 0.0825P] where P = (Fo^2 + 2Fc^2)/3
1291 reflections	(Δ/σ)max < 0.001
94 parameters	Δρmax = 0.32 e Å^−3
1 restraint	Δρmin = −0.27 e Å^−3

Special details

Experimental. The H atom of the N—H was first located from the difference Fourier map with its distance to N1 around 0.87 Å, but was found not stable during the refinement process. The N1—H distance was thus restrained to 0.87 Å, with U_iso(H) = 1.2Ueq(N).

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.

H atoms bonded to C atoms were treated as riding atoms, with C—H = 0.95 Å (aromatic and heterocyclic) and U_iso(H) = 1.2Ueq(C). The N—H was first located in the difference Fourier map with its distance to N1 around 0.87 Å, but was found not stable during the refinement process. The N1—H distance was thus restrained to 0.87 Å, with U_iso(H) = 1.2Ueq(N).

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

	x	y	z	Uiso*/Ueq
N1	0.2778 (3)	0.38063 (13)	0.24637 (11)	0.0213 (3)
H1N	0.210 (4)	0.4767 (14)	0.3075 (15)	0.026*
C1	0.3057 (3)	0.25583 (15)	0.28971 (13)	0.0238 (3)
H1A	0.2642	0.2713	0.3868	0.029*
C2	0.3942 (3)	0.10455 (15)	0.19538 (13)	0.0227 (3)
H2A	0.4137	0.0166	0.2276	0.027*
C3	0.4546 (3)	0.08125 (13)	0.05294 (12)	0.0173 (3)
C4	0.4219 (3)	0.21391 (16)	0.01106 (14)	0.0242 (3)
H4A	0.4609	0.2026	−0.0853	0.029*
C5	0.3326 (4)	0.36181 (16)	0.11060 (15)	0.0262 (3)
H5A	0.3098	0.4521	0.0817	0.031*
C6	0.0882 (3)	0.76011 (15)	0.36049 (13)	0.0215 (3)
C7	0.0243 (3)	0.93075 (16)	0.45982 (14)	0.0231 (3)
O1	0.1344 (3)	0.73297 (12)	0.23308 (11)	0.0369 (3)
O2	0.0909 (3)	0.65538 (11)	0.41973 (10)	0.0303 (3)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
N1	0.0273 (5)	0.0159 (5)	0.0203 (5)	0.0087 (4)	0.0095 (4)	0.0049 (4)
C1	0.0333 (6)	0.0219 (6)	0.0177 (6)	0.0111 (5)	0.0098 (5)	0.0072 (5)
C2	0.0339 (6)	0.0190 (6)	0.0201 (6)	0.0120 (5)	0.0099 (5)	0.0099 (5)
C3	0.0187 (5)	0.0146 (5)	0.0178 (6)	0.0055 (4)	0.0057 (4)	0.0053 (4)
C4	0.0378 (7)	0.0211 (6)	0.0203 (6)	0.0134 (5)	0.0149 (5)	0.0106 (5)
C5	0.0393 (7)	0.0194 (6)	0.0276 (7)	0.0139 (5)	0.0153 (5)	0.0130 (5)
C6	0.0282 (6)	0.0167 (5)	0.0219 (6)	0.0094 (4)	0.0101 (4)	0.0078 (5)
C7	0.0304 (6)	0.0188 (5)	0.0238 (6)	0.0098 (4)	0.0102 (5)	0.0102 (5)
O1	0.0684 (7)	0.0263 (5)	0.0264 (5)	0.0225 (5)	0.0244 (5)	0.0137 (4)
O2	0.0551 (6)	0.0200 (5)	0.0245 (5)	0.0201 (4)	0.0202 (4)	0.0111 (4)

Geometric parameters (Å, º)

N1—C5	1.3311 (16)	C3—C3^i	1.489 (2)
N1—C1	1.3331 (16)	C4—C5	1.3784 (16)
N1—H1N	0.902 (9)	C4—H4A	0.9500
C1—C2	1.3799 (16)	C5—H5A	0.9500
C1—H1A	0.9500	C6—O1	1.2237 (15)
C2—C3	1.3918 (16)	C6—O2	1.2695 (15)
C2—H2A	0.9500	C6—C7	1.4773 (16)
C3—C4	1.3926 (16)	C7—C7^ii	1.193 (2)
C5—N1—C1	120.75 (10)	C4—C3—C3^i	120.76 (12)
C5—N1—H1N	119.3 (10)	C5—C4—C3	119.48 (11)
C1—N1—H1N	119.9 (10)	C5—C4—H4A	120.3
N1—C1—C2	120.86 (11)	C3—C4—H4A	120.3
N1—C1—H1A	119.6	N1—C5—C4	121.27 (11)
C2—C1—H1A	119.6	N1—C5—H5A	119.4
C1—C2—C3	119.77 (11)	C4—C5—H5A	119.4
C1—C2—H2A	120.1	O1—C6—O2	126.61 (11)
C3—C2—H2A	120.1	O1—C6—C7	118.78 (11)
C2—C3—C4	117.87 (10)	O2—C6—C7	114.61 (10)
C2—C3—C3^i	121.36 (13)	C7^ii—C7—C6	179.44 (17)
C5—N1—C1—C2	0.38 (18)	C3^i—C3—C4—C5	179.08 (13)
N1—C1—C2—C3	−0.11 (19)	C1—N1—C5—C4	−0.41 (19)
C1—C2—C3—C4	−0.12 (18)	C3—C4—C5—N1	0.2 (2)
C1—C2—C3—C3^i	−179.10 (12)	O1—C6—C7—C7^ii	−71 (18)
C2—C3—C4—C5	0.09 (18)	O2—C6—C7—C7^ii	109 (18)

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

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C1—H1A···O2^iii	0.95	2.39	3.2612 (15)	152
C2—H2A···O1^iv	0.95	2.55	3.4030 (16)	150
C4—H4A···O1^v	0.95	2.39	3.2363 (16)	148
C5—H5A···O1	0.95	2.52	3.1847 (15)	127
N1—H1N···O2	0.90 (1)	1.66 (1)	2.5605 (13)	179 (1)

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