Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270106018373/dn3016sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S0108270106018373/dn3016Isup2.hkl |
CCDC reference: 616146
The title compound, (I), was crystallized from liquid mixtures [Solutions? In what solvents?] of pyridoxinium chloride with picric acid in the stoichiometric ratio 1:1 at room temperature by the technique of slow evaporation.
All H atoms were placed in geometrically calculated positions and included in the refinement in the riding–model approximation, with O—H = 0.82 Å, C—H = 0.93–0.96 Å and N—H = 0.86 Å, and with Uiso(H) = 1.2–1.5Ueq of the carrier atom.
Data collection: CAD-4 EXPRESS (Enraf–Nonius, 1994); cell refinement: CAD-4 EXPRESS; data reduction: XCAD4 (Harms & Wocadlo, 1995); program(s) used to solve structure: SHELXTL/PC (Bruker, 2000); program(s) used to refine structure: SHELXTL/PC; molecular graphics: ORTEPIII (Burnett & Johnson, 1996), ORTEP-3 for Windows (Farrugia, 1997), PLATON (Spek, 2003) and Mercury (Version 1.4.1; Macrae et al., 2006); software used to prepare material for publication: SHELXTL/PC.
C8H12NO3+·C6H2N3O7− | Z = 2 |
Mr = 398.29 | F(000) = 412 |
Triclinic, P1 | Dx = 1.640 Mg m−3 Dm = 1.64 Mg m−3 Dm measured by flotation using a mixture of CCl4 and bromoform |
Hall symbol: -P 1 | Mo Kα radiation, λ = 0.71073 Å |
a = 8.094 (2) Å | Cell parameters from 25 reflections |
b = 8.522 (3) Å | θ = 9.8–13.6° |
c = 12.847 (5) Å | µ = 0.14 mm−1 |
α = 87.20 (2)° | T = 293 K |
β = 85.70 (1)° | Nearly cubic block, yellow |
γ = 65.92 (2)° | 0.3 × 0.25 × 0.2 mm |
V = 806.6 (5) Å3 |
Nonius MACH3 diffractometer | 2191 reflections with I > 2σ(I) |
Radiation source: fine-focus sealed tube | Rint = 0.009 |
Graphite monochromator | θmax = 25.0°, θmin = 2.6° |
ω/2θ scans | h = −1→9 |
Absorption correction: ψ scan (North et al., 1968) | k = −9→10 |
Tmin = 0.912, Tmax = 0.999 | l = −15→15 |
3502 measured reflections | 3 standard reflections every 60 min |
2844 independent reflections | intensity decay: none |
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)] = 0.043 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.130 | H-atom parameters constrained |
S = 1.05 | w = 1/[σ2(Fo2) + (0.0655P)2 + 0.4805P] where P = (Fo2 + 2Fc2)/3 |
2844 reflections | (Δ/σ)max < 0.001 |
256 parameters | Δρmax = 0.66 e Å−3 |
0 restraints | Δρmin = −0.32 e Å−3 |
C8H12NO3+·C6H2N3O7− | γ = 65.92 (2)° |
Mr = 398.29 | V = 806.6 (5) Å3 |
Triclinic, P1 | Z = 2 |
a = 8.094 (2) Å | Mo Kα radiation |
b = 8.522 (3) Å | µ = 0.14 mm−1 |
c = 12.847 (5) Å | T = 293 K |
α = 87.20 (2)° | 0.3 × 0.25 × 0.2 mm |
β = 85.70 (1)° |
Nonius MACH3 diffractometer | 2191 reflections with I > 2σ(I) |
Absorption correction: ψ scan (North et al., 1968) | Rint = 0.009 |
Tmin = 0.912, Tmax = 0.999 | 3 standard reflections every 60 min |
3502 measured reflections | intensity decay: none |
2844 independent reflections |
R[F2 > 2σ(F2)] = 0.043 | 0 restraints |
wR(F2) = 0.130 | H-atom parameters constrained |
S = 1.05 | Δρmax = 0.66 e Å−3 |
2844 reflections | Δρmin = −0.32 e Å−3 |
256 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 | Occ. (<1) | |
N1 | 0.6717 (3) | 0.3997 (2) | 0.79623 (15) | 0.0379 (5) | |
H1 | 0.7458 | 0.4187 | 0.7512 | 0.045* | |
C2 | 0.7410 (3) | 0.2717 (3) | 0.86655 (17) | 0.0332 (5) | |
C21 | 0.9399 (3) | 0.1699 (3) | 0.8642 (2) | 0.0443 (6) | |
H21A | 0.9976 | 0.2126 | 0.8087 | 0.066* | 0.50 |
H21B | 0.9662 | 0.0514 | 0.8526 | 0.066* | 0.50 |
H21C | 0.9845 | 0.1798 | 0.9296 | 0.066* | 0.50 |
H21D | 0.9679 | 0.0833 | 0.9186 | 0.066* | 0.50 |
H21E | 0.9994 | 0.2444 | 0.8747 | 0.066* | 0.50 |
H21F | 0.9810 | 0.1160 | 0.7977 | 0.066* | 0.50 |
C3 | 0.6181 (3) | 0.2422 (3) | 0.93803 (16) | 0.0325 (5) | |
O3 | 0.6923 (2) | 0.1113 (2) | 1.00772 (14) | 0.0495 (5) | |
H3 | 0.6160 | 0.1157 | 1.0546 | 0.074* | |
C4 | 0.4322 (3) | 0.3418 (3) | 0.93571 (16) | 0.0306 (5) | |
C5 | 0.3703 (3) | 0.4754 (3) | 0.86080 (17) | 0.0331 (5) | |
C6 | 0.4956 (3) | 0.4993 (3) | 0.79160 (18) | 0.0386 (5) | |
H6 | 0.4573 | 0.5861 | 0.7408 | 0.046* | |
C41 | 0.2996 (3) | 0.3057 (3) | 1.01079 (18) | 0.0407 (6) | |
H41A | 0.1892 | 0.4090 | 1.0204 | 0.049* | |
H41B | 0.2691 | 0.2174 | 0.9836 | 0.049* | |
O4 | 0.3809 (3) | 0.2499 (3) | 1.10729 (14) | 0.0618 (6) | |
H4 | 0.3133 | 0.2228 | 1.1477 | 0.093* | |
C51 | 0.1735 (3) | 0.5936 (3) | 0.8535 (2) | 0.0411 (6) | |
H51A | 0.1266 | 0.6516 | 0.9192 | 0.049* | |
H51B | 0.1618 | 0.6803 | 0.7994 | 0.049* | |
O5 | 0.0709 (2) | 0.5007 (2) | 0.83026 (14) | 0.0485 (5) | |
H5 | 0.0119 | 0.5452 | 0.7794 | 0.073* | |
C11 | 0.7920 (3) | 0.6687 (3) | 0.58805 (17) | 0.0321 (5) | |
O11 | 0.8381 (2) | 0.5760 (2) | 0.66901 (12) | 0.0417 (4) | |
C12 | 0.7925 (3) | 0.8386 (3) | 0.57296 (17) | 0.0335 (5) | |
N11 | 0.8429 (3) | 0.9155 (3) | 0.65702 (15) | 0.0410 (5) | |
O12 | 0.8313 (3) | 0.8681 (3) | 0.74744 (13) | 0.0564 (5) | |
O13 | 0.9049 (4) | 1.0227 (3) | 0.63355 (16) | 0.0762 (7) | |
C13 | 0.7509 (3) | 0.9349 (3) | 0.48230 (17) | 0.0354 (5) | |
H13 | 0.7544 | 1.0427 | 0.4774 | 0.042* | |
C14 | 0.7039 (3) | 0.8697 (3) | 0.39857 (17) | 0.0344 (5) | |
N12 | 0.6560 (3) | 0.9713 (3) | 0.30265 (16) | 0.0443 (5) | |
O14 | 0.6626 (4) | 1.1115 (3) | 0.29815 (16) | 0.0737 (7) | |
O15 | 0.6133 (3) | 0.9123 (3) | 0.22987 (15) | 0.0674 (6) | |
C15 | 0.7008 (3) | 0.7087 (3) | 0.40373 (17) | 0.0355 (5) | |
H15 | 0.6717 | 0.6649 | 0.3462 | 0.043* | |
C16 | 0.7414 (3) | 0.6143 (3) | 0.49516 (17) | 0.0323 (5) | |
N13 | 0.7326 (3) | 0.4471 (2) | 0.49512 (16) | 0.0398 (5) | |
O16 | 0.7795 (3) | 0.3653 (2) | 0.41452 (15) | 0.0582 (5) | |
O17 | 0.6714 (3) | 0.3983 (3) | 0.57398 (15) | 0.0658 (6) |
U11 | U22 | U33 | U12 | U13 | U23 | |
N1 | 0.0395 (11) | 0.0431 (11) | 0.0357 (10) | −0.0226 (9) | −0.0020 (8) | 0.0082 (8) |
C2 | 0.0362 (12) | 0.0337 (11) | 0.0331 (11) | −0.0167 (10) | −0.0069 (9) | −0.0005 (9) |
C21 | 0.0377 (13) | 0.0462 (14) | 0.0488 (14) | −0.0163 (11) | −0.0042 (11) | −0.0017 (11) |
C3 | 0.0392 (13) | 0.0307 (11) | 0.0305 (11) | −0.0166 (10) | −0.0097 (9) | 0.0053 (9) |
O3 | 0.0457 (10) | 0.0462 (10) | 0.0497 (10) | −0.0133 (8) | −0.0092 (8) | 0.0240 (8) |
C4 | 0.0364 (12) | 0.0335 (11) | 0.0280 (10) | −0.0201 (10) | −0.0056 (9) | 0.0009 (8) |
C5 | 0.0387 (12) | 0.0311 (11) | 0.0328 (11) | −0.0167 (10) | −0.0097 (9) | 0.0032 (9) |
C6 | 0.0453 (14) | 0.0370 (12) | 0.0359 (12) | −0.0194 (11) | −0.0103 (10) | 0.0135 (10) |
C41 | 0.0417 (13) | 0.0497 (14) | 0.0349 (12) | −0.0234 (11) | −0.0054 (10) | 0.0081 (10) |
O4 | 0.0558 (12) | 0.0954 (16) | 0.0388 (10) | −0.0379 (11) | −0.0074 (8) | 0.0277 (10) |
C51 | 0.0396 (13) | 0.0382 (13) | 0.0441 (13) | −0.0135 (11) | −0.0109 (10) | 0.0043 (10) |
O5 | 0.0469 (10) | 0.0559 (11) | 0.0511 (11) | −0.0284 (9) | −0.0217 (8) | 0.0180 (8) |
C11 | 0.0286 (11) | 0.0351 (11) | 0.0331 (11) | −0.0142 (9) | −0.0036 (9) | 0.0076 (9) |
O11 | 0.0509 (10) | 0.0474 (9) | 0.0363 (9) | −0.0292 (8) | −0.0163 (7) | 0.0174 (7) |
C12 | 0.0370 (12) | 0.0358 (12) | 0.0302 (11) | −0.0172 (10) | −0.0050 (9) | 0.0028 (9) |
N11 | 0.0521 (12) | 0.0387 (11) | 0.0365 (11) | −0.0224 (10) | −0.0085 (9) | 0.0050 (8) |
O12 | 0.0837 (14) | 0.0683 (12) | 0.0325 (9) | −0.0466 (11) | −0.0059 (9) | 0.0036 (8) |
O13 | 0.131 (2) | 0.0796 (15) | 0.0555 (12) | −0.0798 (16) | −0.0200 (12) | 0.0097 (11) |
C13 | 0.0372 (12) | 0.0312 (11) | 0.0375 (12) | −0.0140 (10) | −0.0039 (10) | 0.0052 (9) |
C14 | 0.0360 (12) | 0.0337 (12) | 0.0305 (11) | −0.0116 (10) | −0.0050 (9) | 0.0090 (9) |
N12 | 0.0501 (12) | 0.0383 (11) | 0.0391 (11) | −0.0124 (9) | −0.0110 (9) | 0.0112 (9) |
O14 | 0.119 (2) | 0.0486 (12) | 0.0639 (13) | −0.0424 (13) | −0.0376 (13) | 0.0291 (10) |
O15 | 0.1050 (17) | 0.0571 (12) | 0.0413 (10) | −0.0308 (12) | −0.0331 (11) | 0.0130 (9) |
C15 | 0.0370 (12) | 0.0378 (12) | 0.0313 (11) | −0.0146 (10) | −0.0051 (9) | 0.0007 (9) |
C16 | 0.0337 (11) | 0.0296 (11) | 0.0349 (11) | −0.0143 (9) | −0.0035 (9) | 0.0037 (9) |
N13 | 0.0458 (12) | 0.0353 (10) | 0.0414 (11) | −0.0193 (9) | −0.0094 (9) | 0.0054 (9) |
O16 | 0.0796 (14) | 0.0472 (11) | 0.0541 (11) | −0.0311 (10) | −0.0041 (10) | −0.0101 (9) |
O17 | 0.1070 (18) | 0.0627 (13) | 0.0502 (11) | −0.0583 (13) | −0.0075 (11) | 0.0123 (9) |
N1—C6 | 1.333 (3) | C51—O5 | 1.415 (3) |
N1—C2 | 1.342 (3) | C51—H51A | 0.9700 |
N1—H1 | 0.8600 | C51—H51B | 0.9700 |
C2—C3 | 1.394 (3) | O5—H5 | 0.8200 |
C2—C21 | 1.483 (3) | C11—O11 | 1.258 (3) |
C21—H21A | 0.9600 | C11—C16 | 1.445 (3) |
C21—H21B | 0.9600 | C11—C12 | 1.453 (3) |
C21—H21C | 0.9600 | C12—C13 | 1.372 (3) |
C21—H21D | 0.9600 | C12—N11 | 1.455 (3) |
C21—H21E | 0.9600 | N11—O12 | 1.221 (3) |
C21—H21F | 0.9600 | N11—O13 | 1.226 (3) |
C3—O3 | 1.357 (3) | C13—C14 | 1.379 (3) |
C3—C4 | 1.396 (3) | C13—H13 | 0.9300 |
O3—H3 | 0.8200 | C14—C15 | 1.381 (3) |
C4—C5 | 1.405 (3) | C14—N12 | 1.453 (3) |
C4—C41 | 1.503 (3) | N12—O14 | 1.216 (3) |
C5—C6 | 1.370 (3) | N12—O15 | 1.218 (3) |
C5—C51 | 1.505 (3) | C15—C16 | 1.373 (3) |
C6—H6 | 0.9300 | C15—H15 | 0.9300 |
C41—O4 | 1.416 (3) | C16—N13 | 1.455 (3) |
C41—H41A | 0.9700 | N13—O17 | 1.223 (3) |
C41—H41B | 0.9700 | N13—O16 | 1.224 (3) |
O4—H4 | 0.8200 | ||
C6—N1—C2 | 124.4 (2) | O4—C41—H41A | 110.0 |
C6—N1—H1 | 117.8 | C4—C41—H41A | 110.0 |
C2—N1—H1 | 117.8 | O4—C41—H41B | 110.0 |
N1—C2—C3 | 116.7 (2) | C4—C41—H41B | 110.0 |
N1—C2—C21 | 119.5 (2) | H41A—C41—H41B | 108.4 |
C3—C2—C21 | 123.8 (2) | C41—O4—H4 | 109.5 |
C2—C21—H21A | 109.5 | O5—C51—C5 | 110.83 (19) |
C2—C21—H21B | 109.5 | O5—C51—H51A | 109.5 |
H21A—C21—H21B | 109.5 | C5—C51—H51A | 109.5 |
C2—C21—H21C | 109.5 | O5—C51—H51B | 109.5 |
H21A—C21—H21C | 109.5 | C5—C51—H51B | 109.5 |
H21B—C21—H21C | 109.5 | H51A—C51—H51B | 108.1 |
C2—C21—H21D | 109.5 | C51—O5—H5 | 109.5 |
H21A—C21—H21D | 141.1 | O11—C11—C16 | 123.7 (2) |
H21B—C21—H21D | 56.3 | O11—C11—C12 | 125.0 (2) |
H21C—C21—H21D | 56.3 | C16—C11—C12 | 111.2 (2) |
C2—C21—H21E | 109.5 | C13—C12—C11 | 124.5 (2) |
H21A—C21—H21E | 56.3 | C13—C12—N11 | 115.7 (2) |
H21B—C21—H21E | 141.1 | C11—C12—N11 | 119.73 (19) |
H21C—C21—H21E | 56.3 | O12—N11—O13 | 121.4 (2) |
H21D—C21—H21E | 109.5 | O12—N11—C12 | 120.55 (19) |
C2—C21—H21F | 109.5 | O13—N11—C12 | 117.9 (2) |
H21A—C21—H21F | 56.3 | C12—C13—C14 | 119.2 (2) |
H21B—C21—H21F | 56.3 | C12—C13—H13 | 120.4 |
H21C—C21—H21F | 141.1 | C14—C13—H13 | 120.4 |
H21D—C21—H21F | 109.5 | C13—C14—C15 | 121.3 (2) |
H21E—C21—H21F | 109.5 | C13—C14—N12 | 119.9 (2) |
O3—C3—C2 | 115.3 (2) | C15—C14—N12 | 118.8 (2) |
O3—C3—C4 | 123.6 (2) | O14—N12—O15 | 122.7 (2) |
C2—C3—C4 | 121.07 (19) | O14—N12—C14 | 118.3 (2) |
C3—O3—H3 | 109.5 | O15—N12—C14 | 119.0 (2) |
C3—C4—C5 | 118.8 (2) | C16—C15—C14 | 118.9 (2) |
C3—C4—C41 | 120.85 (19) | C16—C15—H15 | 120.6 |
C5—C4—C41 | 120.3 (2) | C14—C15—H15 | 120.6 |
C6—C5—C4 | 118.2 (2) | C15—C16—C11 | 125.0 (2) |
C6—C5—C51 | 118.6 (2) | C15—C16—N13 | 115.7 (2) |
C4—C5—C51 | 123.1 (2) | C11—C16—N13 | 119.34 (19) |
N1—C6—C5 | 120.8 (2) | O17—N13—O16 | 123.0 (2) |
N1—C6—H6 | 119.6 | O17—N13—C16 | 118.6 (2) |
C5—C6—H6 | 119.6 | O16—N13—C16 | 118.3 (2) |
O4—C41—C4 | 108.31 (19) | ||
C6—N1—C2—C3 | 0.8 (3) | C13—C12—N11—O12 | −158.8 (2) |
C6—N1—C2—C21 | −179.6 (2) | C11—C12—N11—O12 | 22.2 (4) |
N1—C2—C3—O3 | 179.7 (2) | C13—C12—N11—O13 | 24.7 (3) |
C21—C2—C3—O3 | 0.2 (3) | C11—C12—N11—O13 | −154.3 (2) |
N1—C2—C3—C4 | −0.1 (3) | C11—C12—C13—C14 | −0.4 (4) |
C21—C2—C3—C4 | −179.6 (2) | N11—C12—C13—C14 | −179.4 (2) |
O3—C3—C4—C5 | 179.3 (2) | C12—C13—C14—C15 | 1.1 (4) |
C2—C3—C4—C5 | −1.0 (3) | C12—C13—C14—N12 | −178.8 (2) |
O3—C3—C4—C41 | −1.7 (3) | C15—C14—N12—O14 | 178.4 (3) |
C2—C3—C4—C41 | 178.0 (2) | C13—C14—N12—O14 | −1.7 (4) |
C3—C4—C5—C6 | 1.3 (3) | C15—C14—N12—O15 | −0.5 (4) |
C41—C4—C5—C6 | −177.7 (2) | C13—C14—N12—O15 | 179.4 (2) |
C3—C4—C5—C51 | −178.1 (2) | C13—C14—C15—C16 | −1.6 (4) |
C41—C4—C5—C51 | 2.8 (3) | N12—C14—C15—C16 | 178.3 (2) |
C2—N1—C6—C5 | −0.5 (4) | C14—C15—C16—C11 | 1.4 (4) |
C4—C5—C6—N1 | −0.6 (3) | C14—C15—C16—N13 | −179.0 (2) |
C51—C5—C6—N1 | 178.9 (2) | O11—C11—C16—C15 | 176.0 (2) |
C3—C4—C41—O4 | 35.1 (3) | C12—C11—C16—C15 | −0.7 (3) |
C5—C4—C41—O4 | −145.9 (2) | O11—C11—C16—N13 | −3.5 (4) |
C6—C5—C51—O5 | 117.9 (2) | C12—C11—C16—N13 | 179.8 (2) |
C4—C5—C51—O5 | −62.6 (3) | C15—C16—N13—O17 | 141.4 (2) |
O11—C11—C12—C13 | −176.5 (2) | C11—C16—N13—O17 | −39.1 (3) |
C16—C11—C12—C13 | 0.2 (3) | C15—C16—N13—O16 | −35.4 (3) |
O11—C11—C12—N11 | 2.4 (4) | C11—C16—N13—O16 | 144.1 (2) |
C16—C11—C12—N11 | 179.1 (2) |
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1···O11 | 0.86 | 2.01 | 2.797 (2) | 152 |
O3—H3···O4 | 0.82 | 1.87 | 2.572 (3) | 143 |
O4—H4···O12i | 0.82 | 2.05 | 2.862 (3) | 174 |
O5—H5···O11ii | 0.82 | 2.01 | 2.779 (2) | 157 |
C21—H21B···O12iii | 0.96 | 2.70 | 3.472 (3) | 138 |
C21—H21F···O13iii | 0.96 | 2.49 | 3.348 (3) | 148 |
C6—H6···O14iv | 0.93 | 2.40 | 3.217 (3) | 147 |
Symmetry codes: (i) −x+1, −y+1, −z+2; (ii) x−1, y, z; (iii) x, y−1, z; (iv) −x+1, −y+2, −z+1. |
Experimental details
Crystal data | |
Chemical formula | C8H12NO3+·C6H2N3O7− |
Mr | 398.29 |
Crystal system, space group | Triclinic, P1 |
Temperature (K) | 293 |
a, b, c (Å) | 8.094 (2), 8.522 (3), 12.847 (5) |
α, β, γ (°) | 87.20 (2), 85.70 (1), 65.92 (2) |
V (Å3) | 806.6 (5) |
Z | 2 |
Radiation type | Mo Kα |
µ (mm−1) | 0.14 |
Crystal size (mm) | 0.3 × 0.25 × 0.2 |
Data collection | |
Diffractometer | Nonius MACH3 diffractometer |
Absorption correction | ψ scan (North et al., 1968) |
Tmin, Tmax | 0.912, 0.999 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 3502, 2844, 2191 |
Rint | 0.009 |
(sin θ/λ)max (Å−1) | 0.595 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.043, 0.130, 1.05 |
No. of reflections | 2844 |
No. of parameters | 256 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.66, −0.32 |
Computer programs: CAD-4 EXPRESS (Enraf–Nonius, 1994), CAD-4 EXPRESS, XCAD4 (Harms & Wocadlo, 1995), SHELXTL/PC (Bruker, 2000), SHELXTL/PC, ORTEPIII (Burnett & Johnson, 1996), ORTEP-3 for Windows (Farrugia, 1997), PLATON (Spek, 2003) and Mercury (Version 1.4.1; Macrae et al., 2006).
N1—C6 | 1.333 (3) | C11—O11 | 1.258 (3) |
N1—C2 | 1.342 (3) | ||
C6—N1—C2 | 124.4 (2) | O11—C11—C12 | 125.0 (2) |
O11—C11—C16 | 123.7 (2) | C16—C11—C12 | 111.2 (2) |
N1—C2—C3—O3 | 179.7 (2) | C4—C5—C51—O5 | −62.6 (3) |
C21—C2—C3—O3 | 0.2 (3) | C11—C12—N11—O12 | 22.2 (4) |
O3—C3—C4—C5 | 179.3 (2) | C13—C12—N11—O13 | 24.7 (3) |
O3—C3—C4—C41 | −1.7 (3) | C13—C14—N12—O14 | −1.7 (4) |
C3—C4—C41—O4 | 35.1 (3) | C15—C14—N12—O15 | −0.5 (4) |
C5—C4—C41—O4 | −145.9 (2) | C11—C16—N13—O17 | −39.1 (3) |
C6—C5—C51—O5 | 117.9 (2) | C15—C16—N13—O16 | −35.4 (3) |
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1···O11 | 0.86 | 2.01 | 2.797 (2) | 152.2 |
O3—H3···O4 | 0.82 | 1.87 | 2.572 (3) | 143.1 |
O4—H4···O12i | 0.82 | 2.05 | 2.862 (3) | 173.8 |
O5—H5···O11ii | 0.82 | 2.01 | 2.779 (2) | 156.9 |
C21—H21B···O12iii | 0.96 | 2.70 | 3.472 (3) | 138.1 |
C21—H21F···O13iii | 0.96 | 2.49 | 3.348 (3) | 148.2 |
C6—H6···O14iv | 0.93 | 2.40 | 3.217 (3) | 147.2 |
Symmetry codes: (i) −x+1, −y+1, −z+2; (ii) x−1, y, z; (iii) x, y−1, z; (iv) −x+1, −y+2, −z+1. |
Vitamin B6, also known as pyridoxine, is one of the B group vitamins and is water-soluble. It is required for both mental and physical health. Pyridoxine is one of the most versatile enzyme cofactors that support amino acid metabolism. It controls the absorption, metabolism and conversion of amino acids into neurotransmitters, antibodies, digestive enzymes, muscles and tissues in the body. Pyridoxal phosphate is a cofactor in the metabolism of amino acids and neurotransmitters and in the breakdown of glycogen. Pyridoxal phosphate can bind to steroid hormone receptors and may have a role in regulating steroid hormone action. Pyridoxal phosphate can be converted to pyridoxamine phosphate, which can also serve as an enzyme cofactor (Leklem, 1990). Pyridoxine has been found to play an essential role in the nervous system and aids in the metabolism of fats, carbohydrates and proteins. Other forms of vitamin B6 include pyridoxal and pyridoxamine.
The crystal structures of pyridoxine (Longo et al., 1982), pyridoxinium chloride (Bacon & Plant, 1980), pyridoxamine monohydrochloride (Longo & Richardson, 1980), copper complexes of neutral pyridoxamine (Franklin & Richardson, 1980), cis-(oxalato-O,O')bis(pyridoxine-N)palladium(II) (Dey et al., 2003), 6-dimethylaminopyridoxine-α4-(tert-butyldimethylsilyl ether) (Culbertson et al., 2003) and aquabis(2-methyl-4,5-bis(hydroxymethyl)pyridinium-3-oxalato-O,O')dioxouranium dichloride (Bonfada et al., 2005) are already known. In the present work, the crystal structure of pyridoxinium picrate, (I), is reported.
The asymmetric part of the unit cell contains one pyridoxinium cation and one picrate anion (Fig. 1). The bond distances and angles are similar to those observed in other vitamin B6 compounds (Bacon & Plant, 1980). The protonation of pyridine N is confirmed by the bond distances and angles, as in other pyridoxine complexes. Generally, in all the structures so far determined, the vitamin B6 exists as a zwitterion in which the phenolic group is deprotonated and the pyridine N is protonated (Longo & Richardson, 1980). In the present structure, both the phenolic group and the pyridine N are protonated, as in pyridoxinium chloride (Bacon & Plant, 1980). In both CH2OH groups, the OH group is symmetric with CH2, as evident from the dihedral angles. Both CH2OH groups are twisted from the plane of the pyridine ring, but the phenolic group is coplanar. The angle between the picrate and pyridoxine rings is 83.19?(7)°. The cations are linked to the picrate anions by an extensive hydrogen-bonding network.
The loss of a proton in the picrate anion is confirmed by the C—C distances near to the phenolic group (C11—C12 and C11—C16). The picrate anion plays a vital role in forming hydrogen bonds with the pyridoxinium residue. The anion forms a strong asymmetric O—H···O hydrogen bond and an N—H···O hydrogen bond with the pyridoxinium residue. Of the three nitro groups, two (N1–O2/O3 and N3–O6/O7) are twisted from the plane of the ring. This twisting property does not depend upon the C—N bond distances (Soriano-Garcia et al., 1978). The torsion angles are shown in Table 1. The picrate anions are stacked nearly parallel to the bc plane, making an angle of 15.86° with the bc plane. N1—H1···O11 and O5—H5···O11/O12 are the intermolecular hydrogen bonds which link pairs of picric acid molecules through O and NO2 groups. In addition to the hydrogen bonds, intramolecular contacts between phenolic O and nitro groups are observed. These are the important features observed in all aromatic picrate complexes.
The pyridine N and atom O5 form bifurcated hydrogen bonds with picrate anions, thus forming an infinite chain running along the a axis (Fig. 2). An intramolecular hydrogen bond between OH and a nearby CH2OH group is observed, with graph-set motif R11(6) (Etter et al., 1990). The pyridoxinium cation forms a closed dimer with an inversely related cation via C—H···O and O—H···O hydrogen bonds. The cation also forms a head-to-tail sequence with inversely related cations through picrate anions via N—H···O and O—H···O hydrogen bonds. The hydrophobic layers at y = 1/2 are packed between the hydrophilic layers at y = 0 (Fig. 3).