Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536801009011/cf6075sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S1600536801009011/cf6075Isup2.hkl |
CCDC reference: 170752
Approximately 0.5 mlof a 0.2 M solution of 4-aminopyridine in methanol was poured slowly into a narrow test tube containing approximately 0.5 ml of 0.2 M aqueous solution of 2,5-dihydroxybenzonquinone to produce a water/methanol interface. Thin red plate-like crystals suitable for X-ray analysis were produced by slow diffusion at the interface of the solutions.
All H atoms were found in the difference Fourier maps and were refined with isotropic displacement parameters; the C—H, N—H and O—H distances all refined to within standard ranges and there are no anomolous values of Uiso. As we are interested in the behaviour of the H atoms with respect to any hydrogen-bonded networks, it would be artificial to add any constraints to this stable and converged refinement.
Data collection: SMART (Bruker, 1998); cell refinement: SMART; data reduction: SAINT (Bruker, 1998); program(s) used to solve structure: SHELXS97 (Sheldrick, 1990); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); software used to prepare material for publication: SHELXL97.
2C5H7N2+·C6H2O42−·2H2O | F(000) = 384 |
Mr = 364.36 | Dx = 1.426 Mg m−3 |
Monoclinic, P21/c | Mo Kα radiation, λ = 0.71073 Å |
a = 6.345 (4) Å | Cell parameters from 980 reflections |
b = 11.353 (8) Å | θ = 5.0–23.9° |
c = 11.838 (8) Å | µ = 0.11 mm−1 |
β = 95.684 (16)° | T = 100 K |
V = 848.5 (10) Å3 | Plate, red |
Z = 2 | 0.65 × 0.35 × 0.05 mm |
Bruker SMART-CCD diffractometer | 1861 independent reflections |
Radiation source: fine-focus sealed tube | 1475 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.055 |
ω scans | θmax = 27.1°, θmin = 2.5° |
Absorption correction: multi-scan (SADABS; Sheldrick, 1996) | h = −8→8 |
Tmin = 0.804, Tmax = 1.000 | k = −14→14 |
7323 measured reflections | l = −14→15 |
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)] = 0.068 | Hydrogen site location: difference Fourier map |
wR(F2) = 0.148 | All H-atom parameters refined |
S = 1.66 | w = 1/[σ2(Fo2) + (0.05P)2] where P = (Fo2 + 2Fc2)/3 |
1861 reflections | (Δ/σ)max < 0.001 |
158 parameters | Δρmax = 0.29 e Å−3 |
0 restraints | Δρmin = −0.38 e Å−3 |
2C5H7N2+·C6H2O42−·2H2O | V = 848.5 (10) Å3 |
Mr = 364.36 | Z = 2 |
Monoclinic, P21/c | Mo Kα radiation |
a = 6.345 (4) Å | µ = 0.11 mm−1 |
b = 11.353 (8) Å | T = 100 K |
c = 11.838 (8) Å | 0.65 × 0.35 × 0.05 mm |
β = 95.684 (16)° |
Bruker SMART-CCD diffractometer | 1861 independent reflections |
Absorption correction: multi-scan (SADABS; Sheldrick, 1996) | 1475 reflections with I > 2σ(I) |
Tmin = 0.804, Tmax = 1.000 | Rint = 0.055 |
7323 measured reflections |
R[F2 > 2σ(F2)] = 0.068 | 0 restraints |
wR(F2) = 0.148 | All H-atom parameters refined |
S = 1.66 | Δρmax = 0.29 e Å−3 |
1861 reflections | Δρmin = −0.38 e Å−3 |
158 parameters |
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. |
x | y | z | Uiso*/Ueq | ||
C1 | 1.8229 (3) | −0.06776 (18) | 0.94682 (19) | 0.0160 (5) | |
O1 | 1.6626 (3) | −0.11905 (13) | 0.89569 (14) | 0.0200 (4) | |
C2 | 1.8462 (4) | 0.06544 (19) | 0.92583 (18) | 0.0153 (5) | |
O2 | 1.6999 (2) | 0.11425 (13) | 0.86112 (14) | 0.0186 (4) | |
C3 | 2.0225 (4) | 0.12489 (19) | 0.9788 (2) | 0.0181 (5) | |
H3 | 2.039 (4) | 0.210 (2) | 0.969 (2) | 0.017 (6)* | |
N1 | 1.3352 (3) | 0.00917 (17) | 0.76266 (18) | 0.0191 (5) | |
H1 | 1.475 (5) | 0.009 (2) | 0.800 (3) | 0.039 (9)* | |
C11 | 1.2239 (4) | −0.0928 (2) | 0.7516 (2) | 0.0207 (5) | |
H11 | 1.296 (4) | −0.161 (2) | 0.784 (2) | 0.019 (6)* | |
C12 | 1.0248 (4) | −0.09632 (18) | 0.69516 (19) | 0.0175 (5) | |
H12 | 0.950 (4) | −0.168 (2) | 0.689 (2) | 0.027 (7)* | |
C13 | 0.9301 (4) | 0.00777 (18) | 0.64651 (19) | 0.0152 (5) | |
N2 | 0.7376 (3) | 0.00589 (18) | 0.58957 (17) | 0.0197 (5) | |
H2A | 0.679 (4) | 0.074 (2) | 0.554 (2) | 0.022 (7)* | |
H2B | 0.659 (4) | −0.064 (2) | 0.574 (2) | 0.021 (7)* | |
C14 | 1.0523 (4) | 0.11252 (19) | 0.6605 (2) | 0.0172 (5) | |
H14 | 0.993 (4) | 0.178 (2) | 0.630 (2) | 0.019 (6)* | |
C15 | 1.2494 (4) | 0.1106 (2) | 0.7176 (2) | 0.0194 (5) | |
H15 | 1.336 (4) | 0.179 (3) | 0.733 (2) | 0.031 (7)* | |
O10 | 0.5121 (3) | 0.20783 (14) | 0.47749 (16) | 0.0212 (4) | |
H10A | 0.435 (5) | 0.261 (3) | 0.520 (3) | 0.048 (10)* | |
H10B | 0.570 (6) | 0.254 (3) | 0.426 (3) | 0.051 (10)* |
U11 | U22 | U33 | U12 | U13 | U23 | |
C1 | 0.0134 (12) | 0.0178 (11) | 0.0172 (12) | 0.0000 (9) | 0.0042 (10) | −0.0038 (9) |
O1 | 0.0178 (9) | 0.0188 (8) | 0.0227 (9) | −0.0013 (6) | −0.0020 (7) | −0.0004 (7) |
C2 | 0.0167 (12) | 0.0186 (11) | 0.0113 (11) | 0.0028 (9) | 0.0043 (9) | 0.0000 (8) |
O2 | 0.0156 (9) | 0.0187 (8) | 0.0209 (9) | 0.0024 (6) | −0.0013 (7) | 0.0013 (6) |
C3 | 0.0216 (13) | 0.0132 (10) | 0.0193 (12) | −0.0010 (9) | 0.0012 (10) | 0.0002 (9) |
N1 | 0.0121 (10) | 0.0259 (10) | 0.0188 (10) | 0.0004 (8) | −0.0008 (8) | −0.0028 (8) |
C11 | 0.0222 (13) | 0.0217 (11) | 0.0189 (12) | 0.0049 (10) | 0.0046 (10) | 0.0002 (10) |
C12 | 0.0197 (12) | 0.0133 (10) | 0.0195 (13) | −0.0007 (9) | 0.0027 (10) | −0.0012 (9) |
C13 | 0.0153 (11) | 0.0203 (11) | 0.0112 (11) | 0.0007 (9) | 0.0068 (9) | −0.0014 (9) |
N2 | 0.0185 (10) | 0.0200 (10) | 0.0196 (11) | 0.0005 (8) | −0.0035 (8) | −0.0009 (8) |
C14 | 0.0204 (13) | 0.0152 (11) | 0.0163 (12) | 0.0008 (9) | 0.0039 (10) | 0.0029 (9) |
C15 | 0.0203 (13) | 0.0200 (11) | 0.0183 (12) | −0.0048 (9) | 0.0039 (10) | −0.0014 (9) |
O10 | 0.0200 (9) | 0.0161 (8) | 0.0275 (10) | 0.0000 (7) | 0.0021 (8) | 0.0017 (7) |
C1—O1 | 1.272 (3) | C12—C13 | 1.420 (3) |
C1—C3i | 1.409 (4) | C12—H12 | 0.96 (3) |
C1—C2 | 1.542 (3) | C13—N2 | 1.337 (3) |
C2—O2 | 1.271 (3) | C13—C14 | 1.421 (3) |
C2—C3 | 1.403 (4) | N2—H2A | 0.94 (3) |
C3—C1i | 1.409 (4) | N2—H2B | 0.93 (3) |
C3—H3 | 0.96 (3) | C14—C15 | 1.361 (4) |
N1—C11 | 1.354 (3) | C14—H14 | 0.91 (3) |
N1—C15 | 1.357 (3) | C15—H15 | 0.94 (3) |
N1—H1 | 0.93 (3) | O10—H10A | 0.91 (4) |
C11—C12 | 1.371 (4) | O10—H10B | 0.91 (4) |
C11—H11 | 0.97 (3) | ||
O1—C1—C3i | 124.1 (2) | C11—C12—H12 | 118.7 (18) |
O1—C1—C2 | 117.1 (2) | C13—C12—H12 | 121.0 (18) |
C3i—C1—C2 | 118.8 (2) | N2—C13—C12 | 121.3 (2) |
O2—C2—C3 | 124.2 (2) | N2—C13—C14 | 122.3 (2) |
O2—C2—C1 | 116.7 (2) | C12—C13—C14 | 116.5 (2) |
C3—C2—C1 | 119.1 (2) | C13—N2—H2A | 120.6 (17) |
C2—C3—C1i | 122.1 (2) | C13—N2—H2B | 123.4 (18) |
C2—C3—H3 | 121.4 (16) | H2A—N2—H2B | 116 (2) |
C1i—C3—H3 | 116.5 (17) | C15—C14—C13 | 120.6 (2) |
C11—N1—C15 | 120.3 (2) | C15—C14—H14 | 121.2 (18) |
C11—N1—H1 | 119 (2) | C13—C14—H14 | 118.3 (18) |
C15—N1—H1 | 120 (2) | N1—C15—C14 | 121.2 (2) |
N1—C11—C12 | 121.1 (2) | N1—C15—H15 | 115.4 (18) |
N1—C11—H11 | 115.6 (18) | C14—C15—H15 | 123.4 (18) |
C12—C11—H11 | 123.2 (18) | H10A—O10—H10B | 106 (3) |
C11—C12—C13 | 120.3 (2) |
Symmetry code: (i) −x+4, −y, −z+2. |
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1···O1 | 0.95 (3) | 2.14 (3) | 2.875 (3) | 133 (2) |
N1—H1···O2 | 0.95 (3) | 1.94 (3) | 2.757 (3) | 142 (2) |
C11—H11···O1 | 0.96 (3) | 2.60 (3) | 3.132 (4) | 115 (2) |
C15—H15···O2 | 0.96 (3) | 2.74 (3) | 3.177 (3) | 109 (2) |
N2—H2A···O10 | 0.94 (3) | 2.02 (3) | 2.948 (3) | 172 (2) |
N2—H2B···O10ii | 0.94 (3) | 2.02 (3) | 2.963 (3) | 174 (2) |
O10—H10A···O1iii | 0.95 (4) | 1.83 (4) | 2.770 (3) | 168 (3) |
O10—H10B···O2iv | 0.91 (4) | 1.90 (4) | 2.779 (3) | 161 (3) |
Symmetry codes: (ii) −x+1, −y, −z+1; (iii) −x+2, y+1/2, −z+3/2; (iv) x−1, −y+1/2, z−1/2. |
Experimental details
Crystal data | |
Chemical formula | 2C5H7N2+·C6H2O42−·2H2O |
Mr | 364.36 |
Crystal system, space group | Monoclinic, P21/c |
Temperature (K) | 100 |
a, b, c (Å) | 6.345 (4), 11.353 (8), 11.838 (8) |
β (°) | 95.684 (16) |
V (Å3) | 848.5 (10) |
Z | 2 |
Radiation type | Mo Kα |
µ (mm−1) | 0.11 |
Crystal size (mm) | 0.65 × 0.35 × 0.05 |
Data collection | |
Diffractometer | Bruker SMART-CCD diffractometer |
Absorption correction | Multi-scan (SADABS; Sheldrick, 1996) |
Tmin, Tmax | 0.804, 1.000 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 7323, 1861, 1475 |
Rint | 0.055 |
(sin θ/λ)max (Å−1) | 0.641 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.068, 0.148, 1.66 |
No. of reflections | 1861 |
No. of parameters | 158 |
H-atom treatment | All H-atom parameters refined |
Δρmax, Δρmin (e Å−3) | 0.29, −0.38 |
Computer programs: SMART (Bruker, 1998), SMART, SAINT (Bruker, 1998), SHELXS97 (Sheldrick, 1990), SHELXL97 (Sheldrick, 1997), SHELXL97.
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1···O1 | 0.95 (3) | 2.14 (3) | 2.875 (3) | 133 (2) |
N1—H1···O2 | 0.95 (3) | 1.94 (3) | 2.757 (3) | 142 (2) |
C11—H11···O1 | 0.96 (3) | 2.60 (3) | 3.132 (4) | 115 (2) |
C15—H15···O2 | 0.96 (3) | 2.74 (3) | 3.177 (3) | 109 (2) |
N2—H2A···O10 | 0.94 (3) | 2.02 (3) | 2.948 (3) | 172 (2) |
N2—H2B···O10i | 0.94 (3) | 2.02 (3) | 2.963 (3) | 174 (2) |
O10—H10A···O1ii | 0.95 (4) | 1.83 (4) | 2.770 (3) | 168 (3) |
O10—H10B···O2iii | 0.91 (4) | 1.90 (4) | 2.779 (3) | 161 (3) |
Symmetry codes: (i) −x+1, −y, −z+1; (ii) −x+2, y+1/2, −z+3/2; (iii) x−1, −y+1/2, z−1/2. |
To investigate a variety of molecular interactions in the solid state, in particular N—H···O and O—H···N hydrogen bonds, we have produced cocrystals of 2,5-dihydoxybenzoquinone (DHBQ) and 4-aminopyridine (4AP).
DHBQ is a weak organic acid structurally and chemically very similar to squaric acid. This is reflected in the crystal structures it forms; the recently reported structure of DHBQ with 4,4'-bipyridine (Cowan et al., 2001) is closely related to the squarate analogue reported by Reetz et al. (1994) and the present structure is very similar to that observed in 4AP and squarate (Karle et al., 1996).
The DHBQ molecule has become deprotonated and consequently shows partial delocalization in the present structure. The conformation is similar to that reported by Kulpe (1974) for the potassium salt and discussed by Kulpe & Dähne (1978). They describe DHBQ as two coupled trimethineoxonol (TMO, see below) connected by two long Csp2—Csp2 bonds. The long Csp2—Csp2 bond is between C1 and C2 [C1—C2 1.542 (3) Å] and is even longer than the typical Csp3—Csp3 bond length (C—C = 1.53 Å; Allen et al., 1992).
The pyridine group of the 4AP has become protonated and forms N—H···O hydrogen bonds to the DHBQ. In contrast to the squarate and 4AP system in which one strong N—H···O hydrogen bond is formed (Karle et al., 1996), a bifurcated N—H···O hydrogen bond is formed with similar N···O distances [N1···O1 2.875 (3) Å and N1···O2 2.757 (3) Å] (Fig. 1). The bifurcated N—H···O hydrogen bond is assisted by two almost equal-length weak C—H···O bonds [C11···O1 3.132 (4) Å and C11–H11–O1 115 (2)°, and C15···O2 3.177 (3) Å and C15–H15–O2 109 (2)°]. The aromatic rings of the DHBQ and the 4AP are inclined at an angle of 8.2° with respect to each other, but an imaginary torsion angle, O1···O2···C15···C11 of 0.4°, shows that most of this is a fold along an axis through O1 and O2. These C—H···O bonds are short and have large C—H···O angles compared with similar C—H···O bonds (Steiner, 1997), but they prevent rotation of the 4AP about an axis through N1 and N2 that would be allowed by the other hydrogen bonds in the chain.
The 4AP molecules pack with each other amino group to amino group. The unlikely close proximity of these two basic groups [N2···N2ii 3.511 (5) Å and H2A···H2Bii 2.52 (4) Å; symmetry code: (ii) 1 - x, -y, 1 - z] is caused by hydrogen-bond formation to the lone pairs of the water molecule oxygen (Fig. 1) (N2—H2A···O10 and N2—H2B···O10ii).
The molecules pack to form infinite hydrogen-bonded chains that propagate along the [301] direction. The chains form columns along the [103] direction. The water is an essential part of the supramolecular structure, it links the one-dimensional chains together by accepting hydrogen bonds from the amino groups of the 4AP molecules and also forms hydrogen bonds to the DHBQ molecules, which join adjacent chains together into a three-dimensional network (Fig. 2).