Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536807044030/fl2162sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S1600536807044030/fl2162Isup2.hkl |
CCDC reference: 663756
Key indicators
- Single-crystal X-ray study
- T = 150 K
- Mean (C-C) = 0.002 Å
- R factor = 0.029
- wR factor = 0.082
- Data-to-parameter ratio = 16.1
checkCIF/PLATON results
No syntax errors found
Alert level C PLAT094_ALERT_2_C Ratio of Maximum / Minimum Residual Density .... 2.25 PLAT213_ALERT_2_C Atom O2 has ADP max/min Ratio ............. 3.60 prola PLAT250_ALERT_2_C Large U3/U1 Ratio for Average U(i,j) Tensor .... 3.97
0 ALERT level A = In general: serious problem 0 ALERT level B = Potentially serious problem 3 ALERT level C = Check and explain 0 ALERT level G = General alerts; check 0 ALERT type 1 CIF construction/syntax error, inconsistent or missing data 3 ALERT type 2 Indicator that the structure model may be wrong or deficient 0 ALERT type 3 Indicator that the structure quality may be low 0 ALERT type 4 Improvement, methodology, query or suggestion 0 ALERT type 5 Informative message, check
Picolinic acid (0.115 g; 0.934 mmol) in methanol/ethanol (10 ml, 1:1) was added dropwise to a solution of Cu(PPh3)2(BH4) (0.450 g; 0.746 mmol) in CH2Cl2 (10 ml). The solution was stirred for 15 min, then reduced in volume to give a yellow precipitate (0.468 g). Crystals were obtained by vapour diffusion from methanol/ethanol (1:1) with diethylether as precipitant. The source of the HCl is thought to have been the dichloromethane solvent in the initial reaction.
Aromatic H atoms were placed in geometric positions (C—H distance = 0.95 Å) using a riding model. NH and OH hydrogen coordinates were freely refined.Uiso values were set to 1.2Ueq of the carrier atom for CH and NH, 1.5Ueq for OH.
As part of our studies into complexes, co-crystals and solvates of pyridine and pyrazine (poly)carboxylates we inadvertently produced crystals of pyridine-2-carboxylic acid hydrochloride (I). Fig. 1. shows the asymmetric unit. The structure had been determined previously at ambient temperature with an R factor of 0.147 (Laurent, 1965). Comparison of the unit-cell parameters reveals that on cooling to 150 K, taking into account the different unit cell and space group settings, a contracts by 0.45%, b by 1.85% and c by 0.13% (see Figs. 2 & 3). We note that b/2 is the interlayer spacing with soft π-π stacking interactions only, while a and c incorporate the strong, less compressable, hydrogen bonds. The basic structure was discussed in datail in Laurent's paper. See tables for hydrogen bond geomery which has been determined here more precisely. Laurent notes an apparently very short C═O bond length of 1.17 Å, but the current study suggests a more normal value of 1.200 (2) Å.
Laurent (1965) previously determined the stucture of the title compound at ambient temperature with R1 = 0.147.
Data collection: APEX2 (Bruker, 2006); cell refinement: SAINT (Bruker, 2006); data reduction: SAINT (Bruker, 2006); program(s) used to solve structure: SHELXTL (Bruker, 2000); program(s) used to refine structure: SHELXTL (Bruker, 2000); molecular graphics: SHELXTL (Bruker, 2000); software used to prepare material for publication: SHELXTL (Bruker, 2000) and local programs.
C6H6NO2+·Cl− | F(000) = 328 |
Mr = 159.57 | Dx = 1.519 Mg m−3 |
Orthorhombic, Pnma | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -P 2ac 2n | Cell parameters from 3266 reflections |
a = 13.7876 (15) Å | θ = 3.0–30.4° |
b = 6.5268 (7) Å | µ = 0.48 mm−1 |
c = 7.7517 (9) Å | T = 150 K |
V = 697.57 (13) Å3 | Plate, colourless |
Z = 4 | 0.54 × 0.33 × 0.10 mm |
Bruker APEXII CCD diffractometer | 1045 independent reflections |
Radiation source: fine-focus sealed tube | 939 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.024 |
ω rotation with narrow frames scans | θmax = 29.5°, θmin = 3.0° |
Absorption correction: multi-scan (SADABS; Sheldrick, 2007) | h = −19→18 |
Tmin = 0.782, Tmax = 0.954 | k = −9→9 |
7281 measured reflections | l = −10→10 |
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)] = 0.029 | Hydrogen site location: geom except NH & OH coords freely refined |
wR(F2) = 0.082 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.13 | w = 1/[σ2(Fo2) + (0.0415P)2 + 0.234P] where P = (Fo2 + 2Fc2)/3 |
1045 reflections | (Δ/σ)max < 0.001 |
65 parameters | Δρmax = 0.42 e Å−3 |
0 restraints | Δρmin = −0.19 e Å−3 |
C6H6NO2+·Cl− | V = 697.57 (13) Å3 |
Mr = 159.57 | Z = 4 |
Orthorhombic, Pnma | Mo Kα radiation |
a = 13.7876 (15) Å | µ = 0.48 mm−1 |
b = 6.5268 (7) Å | T = 150 K |
c = 7.7517 (9) Å | 0.54 × 0.33 × 0.10 mm |
Bruker APEXII CCD diffractometer | 1045 independent reflections |
Absorption correction: multi-scan (SADABS; Sheldrick, 2007) | 939 reflections with I > 2σ(I) |
Tmin = 0.782, Tmax = 0.954 | Rint = 0.024 |
7281 measured reflections |
R[F2 > 2σ(F2)] = 0.029 | 0 restraints |
wR(F2) = 0.082 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.13 | Δρmax = 0.42 e Å−3 |
1045 reflections | Δρmin = −0.19 e Å−3 |
65 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 | ||
Cl1 | 0.12483 (3) | 0.2500 | 0.87284 (5) | 0.02637 (14) | |
C1 | 0.36168 (11) | 0.2500 | 0.35614 (19) | 0.0214 (3) | |
C2 | 0.31249 (12) | 0.2500 | 0.20260 (19) | 0.0245 (3) | |
H2 | 0.2436 | 0.2500 | 0.2010 | 0.029* | |
C3 | 0.36462 (12) | 0.2500 | 0.0493 (2) | 0.0270 (4) | |
H3 | 0.3315 | 0.2500 | −0.0582 | 0.032* | |
C4 | 0.46489 (13) | 0.2500 | 0.0538 (2) | 0.0294 (4) | |
H4 | 0.5014 | 0.2500 | −0.0502 | 0.035* | |
C5 | 0.51094 (12) | 0.2500 | 0.2117 (2) | 0.0292 (4) | |
H5 | 0.5798 | 0.2500 | 0.2173 | 0.035* | |
N1 | 0.45886 (11) | 0.2500 | 0.35628 (17) | 0.0233 (3) | |
H1 | 0.4884 (16) | 0.2500 | 0.448 (3) | 0.028* | |
C6 | 0.31613 (13) | 0.2500 | 0.5312 (2) | 0.0302 (4) | |
O1 | 0.22104 (9) | 0.2500 | 0.52598 (16) | 0.0299 (3) | |
H1A | 0.204 (2) | 0.2500 | 0.628 (3) | 0.045* | |
O2 | 0.36553 (11) | 0.2500 | 0.65865 (18) | 0.0631 (7) |
U11 | U22 | U33 | U12 | U13 | U23 | |
Cl1 | 0.0215 (2) | 0.0388 (2) | 0.0188 (2) | 0.000 | 0.00604 (13) | 0.000 |
C1 | 0.0184 (7) | 0.0329 (8) | 0.0129 (6) | 0.000 | 0.0009 (5) | 0.000 |
C2 | 0.0178 (7) | 0.0410 (9) | 0.0147 (7) | 0.000 | −0.0002 (5) | 0.000 |
C3 | 0.0252 (8) | 0.0440 (10) | 0.0118 (6) | 0.000 | −0.0018 (6) | 0.000 |
C4 | 0.0254 (8) | 0.0478 (11) | 0.0150 (7) | 0.000 | 0.0046 (6) | 0.000 |
C5 | 0.0186 (7) | 0.0475 (11) | 0.0216 (8) | 0.000 | 0.0023 (6) | 0.000 |
N1 | 0.0186 (6) | 0.0378 (8) | 0.0135 (6) | 0.000 | −0.0029 (5) | 0.000 |
C6 | 0.0229 (8) | 0.0544 (11) | 0.0134 (7) | 0.000 | 0.0019 (6) | 0.000 |
O1 | 0.0211 (6) | 0.0534 (8) | 0.0150 (5) | 0.000 | 0.0035 (4) | 0.000 |
O2 | 0.0252 (7) | 0.152 (2) | 0.0117 (6) | 0.000 | −0.0012 (5) | 0.000 |
C1—N1 | 1.340 (2) | C4—H4 | 0.9500 |
C1—C2 | 1.370 (2) | C5—N1 | 1.331 (2) |
C1—C6 | 1.495 (2) | C5—H5 | 0.9500 |
C2—C3 | 1.389 (2) | N1—H1 | 0.82 (2) |
C2—H2 | 0.9500 | C6—O2 | 1.200 (2) |
C3—C4 | 1.383 (2) | C6—O1 | 1.312 (2) |
C3—H3 | 0.9500 | O1—H1A | 0.82 (3) |
C4—C5 | 1.379 (2) | ||
N1—C1—C2 | 119.72 (14) | C3—C4—H4 | 120.6 |
N1—C1—C6 | 114.79 (14) | N1—C5—C4 | 119.94 (16) |
C2—C1—C6 | 125.48 (15) | N1—C5—H5 | 120.0 |
C1—C2—C3 | 119.16 (15) | C4—C5—H5 | 120.0 |
C1—C2—H2 | 120.4 | C5—N1—C1 | 122.61 (14) |
C3—C2—H2 | 120.4 | C5—N1—H1 | 117.5 (16) |
C4—C3—C2 | 119.72 (15) | C1—N1—H1 | 119.9 (16) |
C4—C3—H3 | 120.1 | O2—C6—O1 | 126.34 (16) |
C2—C3—H3 | 120.1 | O2—C6—C1 | 120.58 (16) |
C5—C4—C3 | 118.85 (16) | O1—C6—C1 | 113.08 (14) |
C5—C4—H4 | 120.6 | C6—O1—H1A | 105 (2) |
N1—C1—C2—C3 | 0.0 | C2—C1—N1—C5 | 0.0 |
C6—C1—C2—C3 | 180.0 | C6—C1—N1—C5 | 180.0 |
C1—C2—C3—C4 | 0.0 | N1—C1—C6—O2 | 0.0 |
C2—C3—C4—C5 | 0.0 | C2—C1—C6—O2 | 180.0 |
C3—C4—C5—N1 | 0.0 | N1—C1—C6—O1 | 180.0 |
C4—C5—N1—C1 | 0.0 | C2—C1—C6—O1 | 0.0 |
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1···Cl1i | 0.82 (2) | 2.34 (2) | 3.1058 (14) | 156 (2) |
O1—H1A···Cl1 | 0.82 (3) | 2.19 (3) | 2.9982 (13) | 167 (3) |
Symmetry code: (i) x+1/2, y, −z+3/2. |
Experimental details
Crystal data | |
Chemical formula | C6H6NO2+·Cl− |
Mr | 159.57 |
Crystal system, space group | Orthorhombic, Pnma |
Temperature (K) | 150 |
a, b, c (Å) | 13.7876 (15), 6.5268 (7), 7.7517 (9) |
V (Å3) | 697.57 (13) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 0.48 |
Crystal size (mm) | 0.54 × 0.33 × 0.10 |
Data collection | |
Diffractometer | Bruker APEXII CCD diffractometer |
Absorption correction | Multi-scan (SADABS; Sheldrick, 2007) |
Tmin, Tmax | 0.782, 0.954 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 7281, 1045, 939 |
Rint | 0.024 |
(sin θ/λ)max (Å−1) | 0.692 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.029, 0.082, 1.13 |
No. of reflections | 1045 |
No. of parameters | 65 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 0.42, −0.19 |
Computer programs: APEX2 (Bruker, 2006), SAINT (Bruker, 2006), SHELXTL (Bruker, 2000) and local programs.
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1···Cl1i | 0.82 (2) | 2.34 (2) | 3.1058 (14) | 156 (2) |
O1—H1A···Cl1 | 0.82 (3) | 2.19 (3) | 2.9982 (13) | 167 (3) |
Symmetry code: (i) x+1/2, y, −z+3/2. |
As part of our studies into complexes, co-crystals and solvates of pyridine and pyrazine (poly)carboxylates we inadvertently produced crystals of pyridine-2-carboxylic acid hydrochloride (I). Fig. 1. shows the asymmetric unit. The structure had been determined previously at ambient temperature with an R factor of 0.147 (Laurent, 1965). Comparison of the unit-cell parameters reveals that on cooling to 150 K, taking into account the different unit cell and space group settings, a contracts by 0.45%, b by 1.85% and c by 0.13% (see Figs. 2 & 3). We note that b/2 is the interlayer spacing with soft π-π stacking interactions only, while a and c incorporate the strong, less compressable, hydrogen bonds. The basic structure was discussed in datail in Laurent's paper. See tables for hydrogen bond geomery which has been determined here more precisely. Laurent notes an apparently very short C═O bond length of 1.17 Å, but the current study suggests a more normal value of 1.200 (2) Å.