Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270199014821/ta1270sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S0108270199014821/ta1270Isup2.hkl |
CCDC reference: 143244
Crystals of (I) were grown by dissolving 2-amino-5-cyanopyridine in water (37 ml) and concentrated HCl (3 ml). Colourless rod-shaped crystals were collected after slow evaporation of the solvent. Infrared spectra showed, and X-ray data confirmed, that the cyano group had been hydrolyzed, resulting in the title compound. We were very surprised that under these mild conditions the cyano group hydrolyzed to the carboxylic acid. It is known that 6-aminonicotinic acid can be prepared by hydrolysis of 2-amino-5-cyanopyridine, but at elevated temperature and significantly higher HCl concentrations (Binz & Rath, 1928).
Data collection: SMART (Siemens, 1996); cell refinement: SAINT (Siemens, 1996); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997a); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997b); software used to prepare material for publication: SHELXL97.
C6H7N2O2+·Cl− | Z = 2 |
Mr = 174.59 | F(000) = 180 |
Triclinic, P1 | Dx = 1.502 Mg m−3 |
a = 6.844 (2) Å | Mo Kα radiation, λ = 0.71073 Å |
b = 6.908 (2) Å | Cell parameters from 4366 reflections |
c = 9.061 (3) Å | θ = 2.3–26.4° |
α = 101.398 (4)° | µ = 0.44 mm−1 |
β = 90.799 (4)° | T = 170 K |
γ = 112.515 (3)° | Prism, colourless |
V = 386.01 (19) Å3 | 0.80 × 0.54 × 0.37 mm |
Siemens CCD area detector diffractometer | 1566 independent reflections |
Radiation source: fine-focus sealed tube | 1459 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.025 |
ϕ and ω scans | θmax = 26.4°, θmin = 2.3° |
Absorption correction: empirical (using intensity measurements) (SADABS; Sheldrick, 1996) | h = −8→7 |
Tmin = 0.532, Tmax = 0.849 | k = −8→8 |
4979 measured reflections | l = −11→11 |
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)] = 0.034 | Hydrogen site location: difference Fourier map |
wR(F2) = 0.091 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.14 | Calculated w = 1/[σ2(Fo2) + (0.0467P)2 + 0.1511P] where P = (Fo2 + 2Fc2)/3 |
1566 reflections | (Δ/σ)max < 0.001 |
112 parameters | Δρmax = 0.27 e Å−3 |
0 restraints | Δρmin = −0.27 e Å−3 |
C6H7N2O2+·Cl− | γ = 112.515 (3)° |
Mr = 174.59 | V = 386.01 (19) Å3 |
Triclinic, P1 | Z = 2 |
a = 6.844 (2) Å | Mo Kα radiation |
b = 6.908 (2) Å | µ = 0.44 mm−1 |
c = 9.061 (3) Å | T = 170 K |
α = 101.398 (4)° | 0.80 × 0.54 × 0.37 mm |
β = 90.799 (4)° |
Siemens CCD area detector diffractometer | 1566 independent reflections |
Absorption correction: empirical (using intensity measurements) (SADABS; Sheldrick, 1996) | 1459 reflections with I > 2σ(I) |
Tmin = 0.532, Tmax = 0.849 | Rint = 0.025 |
4979 measured reflections |
R[F2 > 2σ(F2)] = 0.034 | 0 restraints |
wR(F2) = 0.091 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.14 | Δρmax = 0.27 e Å−3 |
1566 reflections | Δρmin = −0.27 e Å−3 |
112 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 | ||
Cl | 0.06059 (6) | 0.71023 (7) | 0.34461 (4) | 0.02601 (16) | |
N1 | −0.2274 (2) | 0.7457 (2) | −0.40259 (16) | 0.0221 (3) | |
H1 | −0.138 (4) | 0.738 (3) | −0.475 (3) | 0.027* | |
C2 | −0.4106 (3) | 0.7616 (2) | −0.44241 (18) | 0.0213 (3) | |
N2 | −0.4539 (3) | 0.7663 (2) | −0.58491 (17) | 0.0264 (3) | |
H2A | −0.578 (4) | 0.762 (3) | −0.612 (3) | 0.032* | |
H2B | −0.374 (4) | 0.750 (3) | −0.652 (3) | 0.032* | |
C3 | −0.5497 (3) | 0.7698 (3) | −0.32878 (19) | 0.0262 (4) | |
H3 | −0.6815 | 0.7777 | −0.3532 | 0.031* | |
C4 | −0.4937 (3) | 0.7667 (3) | −0.1843 (2) | 0.0273 (4) | |
H4 | −0.5867 | 0.7730 | −0.1084 | 0.033* | |
C5 | −0.2992 (3) | 0.7534 (3) | −0.14738 (19) | 0.0240 (4) | |
C6 | −0.1700 (3) | 0.7422 (3) | −0.25972 (19) | 0.0234 (4) | |
H6 | −0.0388 | 0.7317 | −0.2373 | 0.028* | |
C7 | −0.2376 (3) | 0.7500 (3) | 0.0101 (2) | 0.0287 (4) | |
O1 | −0.0572 (2) | 0.7249 (3) | 0.02368 (15) | 0.0397 (4) | |
H1O | −0.030 (4) | 0.717 (4) | 0.111 (3) | 0.048* | |
O2 | −0.3430 (3) | 0.7716 (3) | 0.11382 (15) | 0.0474 (4) |
U11 | U22 | U33 | U12 | U13 | U23 | |
Cl | 0.0249 (2) | 0.0351 (3) | 0.0205 (2) | 0.01343 (18) | 0.00302 (16) | 0.00815 (16) |
N1 | 0.0227 (7) | 0.0266 (7) | 0.0178 (7) | 0.0101 (6) | 0.0042 (6) | 0.0055 (5) |
C2 | 0.0234 (8) | 0.0202 (8) | 0.0191 (8) | 0.0067 (6) | 0.0009 (6) | 0.0054 (6) |
N2 | 0.0268 (8) | 0.0355 (8) | 0.0182 (7) | 0.0126 (7) | 0.0022 (6) | 0.0081 (6) |
C3 | 0.0233 (9) | 0.0342 (9) | 0.0245 (9) | 0.0136 (7) | 0.0045 (7) | 0.0091 (7) |
C4 | 0.0276 (9) | 0.0355 (9) | 0.0218 (8) | 0.0144 (8) | 0.0075 (7) | 0.0085 (7) |
C5 | 0.0274 (9) | 0.0263 (8) | 0.0184 (8) | 0.0105 (7) | 0.0021 (7) | 0.0055 (6) |
C6 | 0.0236 (8) | 0.0253 (8) | 0.0211 (8) | 0.0096 (7) | −0.0001 (6) | 0.0050 (6) |
C7 | 0.0315 (10) | 0.0347 (9) | 0.0210 (9) | 0.0136 (8) | 0.0011 (7) | 0.0075 (7) |
O1 | 0.0425 (9) | 0.0658 (10) | 0.0206 (7) | 0.0306 (8) | 0.0005 (6) | 0.0123 (7) |
O2 | 0.0501 (9) | 0.0869 (12) | 0.0207 (7) | 0.0401 (9) | 0.0106 (6) | 0.0189 (7) |
N1—C2 | 1.350 (2) | C4—C5 | 1.409 (3) |
N1—C6 | 1.355 (2) | C4—H4 | 0.9500 |
N1—H1 | 0.91 (2) | C5—C6 | 1.367 (2) |
C2—N2 | 1.330 (2) | C5—C7 | 1.489 (2) |
C2—C3 | 1.420 (2) | C6—H6 | 0.9500 |
N2—H2A | 0.87 (3) | C7—O2 | 1.213 (2) |
N2—H2B | 0.84 (2) | C7—O1 | 1.318 (2) |
C3—C4 | 1.365 (2) | O1—H1O | 0.83 (3) |
C3—H3 | 0.9500 | ||
C2—N1—C6 | 122.97 (15) | C3—C4—H4 | 119.7 |
C2—N1—H1 | 118.4 (13) | C5—C4—H4 | 119.8 |
C6—N1—H1 | 118.6 (13) | C6—C5—C4 | 118.34 (16) |
N2—C2—N1 | 119.18 (16) | C6—C5—C7 | 121.11 (16) |
N2—C2—C3 | 123.12 (17) | C4—C5—C7 | 120.55 (16) |
N1—C2—C3 | 117.70 (15) | N1—C6—C5 | 120.65 (16) |
C2—N2—H2A | 118.3 (15) | N1—C6—H6 | 119.7 |
C2—N2—H2B | 121.1 (15) | C5—C6—H6 | 119.6 |
H2A—N2—H2B | 120 (2) | O2—C7—O1 | 124.46 (17) |
C4—C3—C2 | 119.91 (16) | O2—C7—C5 | 122.64 (17) |
C4—C3—H3 | 120.0 | O1—C7—C5 | 112.90 (15) |
C2—C3—H3 | 120.0 | C7—O1—H1O | 110.9 (19) |
C3—C4—C5 | 120.43 (16) |
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1···Cli | 0.91 (2) | 2.17 (2) | 3.0766 (16) | 177.1 (19) |
N2—H2A···Clii | 0.87 (3) | 2.37 (3) | 3.234 (2) | 170 (2) |
O1—H1O···Cl | 0.83 (3) | 2.21 (3) | 3.0381 (16) | 177 (2) |
N2—H2B···O2i | 0.84 (2) | 2.17 (2) | 2.847 (2) | 138 (2) |
Symmetry codes: (i) x, y, z−1; (ii) x−1, y, z−1. |
Experimental details
Crystal data | |
Chemical formula | C6H7N2O2+·Cl− |
Mr | 174.59 |
Crystal system, space group | Triclinic, P1 |
Temperature (K) | 170 |
a, b, c (Å) | 6.844 (2), 6.908 (2), 9.061 (3) |
α, β, γ (°) | 101.398 (4), 90.799 (4), 112.515 (3) |
V (Å3) | 386.01 (19) |
Z | 2 |
Radiation type | Mo Kα |
µ (mm−1) | 0.44 |
Crystal size (mm) | 0.80 × 0.54 × 0.37 |
Data collection | |
Diffractometer | Siemens CCD area detector diffractometer |
Absorption correction | Empirical (using intensity measurements) (SADABS; Sheldrick, 1996) |
Tmin, Tmax | 0.532, 0.849 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 4979, 1566, 1459 |
Rint | 0.025 |
(sin θ/λ)max (Å−1) | 0.626 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.034, 0.091, 1.14 |
No. of reflections | 1566 |
No. of parameters | 112 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 0.27, −0.27 |
Computer programs: SMART (Siemens, 1996), SAINT (Siemens, 1996), SAINT, SHELXS97 (Sheldrick, 1997a), SHELXL97 (Sheldrick, 1997b), SHELXL97.
N1—C2 | 1.350 (2) | C4—C5 | 1.409 (3) |
N1—C6 | 1.355 (2) | C5—C6 | 1.367 (2) |
C2—N2 | 1.330 (2) | C5—C7 | 1.489 (2) |
C2—C3 | 1.420 (2) | C7—O2 | 1.213 (2) |
C3—C4 | 1.365 (2) | C7—O1 | 1.318 (2) |
C2—N1—C6 | 122.97 (15) | C6—C5—C4 | 118.34 (16) |
C2—N1—H1 | 118.4 (13) | C6—C5—C7 | 121.11 (16) |
C6—N1—H1 | 118.6 (13) | C4—C5—C7 | 120.55 (16) |
N2—C2—N1 | 119.18 (16) | N1—C6—C5 | 120.65 (16) |
N2—C2—C3 | 123.12 (17) | O2—C7—O1 | 124.46 (17) |
N1—C2—C3 | 117.70 (15) | O2—C7—C5 | 122.64 (17) |
C4—C3—C2 | 119.91 (16) | O1—C7—C5 | 112.90 (15) |
C3—C4—C5 | 120.43 (16) |
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1···Cli | 0.91 (2) | 2.17 (2) | 3.0766 (16) | 177.1 (19) |
N2—H2A···Clii | 0.87 (3) | 2.37 (3) | 3.234 (2) | 170 (2) |
O1—H1O···Cl | 0.83 (3) | 2.21 (3) | 3.0381 (16) | 177 (2) |
N2—H2B···O2i | 0.84 (2) | 2.17 (2) | 2.847 (2) | 138 (2) |
Symmetry codes: (i) x, y, z−1; (ii) x−1, y, z−1. |
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In our laboratories we are interested in the preparation and study of low-dimensional magnetic lattices which have the general formula A2MX4, where M is a 2+ transition metal ion, X = Cl or Br and A is a protonated organic base. Usually, these compounds pack in crystal lattices that create interesting low-dimensional magnetic lattices. The magnetic lattice arises from interactions between the MX4- ions. The nature of these interactions is controlled by the crystal lattice, which changes as the organic base is changed. Aromatic compounds containing substituents in the 5-position, such 2-amino-5-methylpyridine (Place & Willet, 1987) and 2-amino-5-chloropyridine (Albrecht et al., 1997, 1999; Hammar et al., 1997) have been shown to have very interesting magnetic properties. 2-Amino-5-cyanopyridine was synthesized according to the procedure of Gregory et al. (1947) in order to compare its suitability as a base with that of the previously mentioned derivatives. We have prepared metal complexes of 2-amino-5-cyanopyridine (J. Giantsidis & M. M. Turnbull, unpublished results) and were interested in what kind of interactions we might expect between the organic groups themselves. Therefore, 6-aminonicotinic acid hydrochloride, (I), was crystallized from a solution of 2-amino-5-cyanopyridine in aqueous HCl and its structure is presented here.
The aromatic ring of (I) is planar, with a mean plane deviation of 0.0047 Å. The carboxyl and the amino groups are canted from that plane, likely as a result of hydrogen bonding in the lattice.
The crystal lattice exists as nearly planar sheets of protonated 6-aminonicotinic acid molecules and chloride ions that run roughly parallel to the B-face. The plane of the ring is canted 3.8 (2)° relative the B-face. The ring axis, defined as the C2—C5 vector, is inclined at an angle of 16.4 (2)° relative to the c axis. The layers are close together [3.21 (3) Å], but are not linked by hydrogen bonding. However, within the sheets, hydrogen bonds form from the pyridinium proton to the chloride ion, and from one of the amino protons to the choride ion (Table 2). Also, there is a weak hydrogen bond from the other amino proton to the carbonyl oxygen. Even though the distance between N2 and O2 is the shortest, the angle is far from linear, resulting in a weaker interaction. An additional hydrogen bond forms from the carboxylic proton to the chloride ion.
Crystals of the 5-cyano compound are being prepared under anhydrous conditions and the use of 6-aminonicotinic acid for the preparation of low-dimensional magnetic lattices is underway.