Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S160053680704038X/im2026sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S160053680704038X/im2026Isup2.hkl |
CCDC reference: 660330
The title compound was synthesized from a mixture of 2-amino-6-methylpyridine (1 mmol, 0.11 g) and ferulic acid (1 mmol, 0.19 g). The mixture was dissolved in 10 ml water, then heated to 373 K and stirred for half an hour. After the reaction system was cooled to room temperature after five days the colorless crystals were collected.
H atoms attaching to N and O atoms were deduced from difference Fourier maps and incorporated in the refinement freely. Others were placed in calculated positions and allowed to ride on their parent atoms at distances of 0.93 Å for alkene and aromatic group and 0.96 Å for methyl, with isotropic displacement parameters 1.2 times Ueq of the parent atoms.
As reported, the synthesis and characterization of noncentrosymmetric supramolecular systems have attracted a great of interest in th past few years (Sarma et al., 1997; Thalladi et al., 1999; Kaminskii et al., 2006; Kiebacha et al., 2006; Kaminskii et al., 2007). Herein, we report a novel noncentrosymmetric crystal of the title complex (Fig. 3), (I), and discuss the structure (Table 1).
In the structure, 2-amino-6-methylpyridinium (AMP) and 3-(4-hydroxy-3-methoxyphenyl)-2-propenoate (ferulate) are linked through hydrogen bonding of N1—H1N···O4 and N2—H2B···O3 to produce an eight-membered hydrogen bonded ring system of R22(8) arrangement (Etter, 1990). This component shows an interaction with the water molecule by a N2—H2A···O5 hydrogen bond (Fig. 1 & Table 2). This is different from the componentially similar complex 2-amino-5-methylpyridinium ferulate monohydrate (Xuan et al., 2003), where the water molecule is incorporated with AMP by an O—H···O hydrogen bond.
Protonation of 2-aminopyridine always induces aminium-iminium tautomerism (Scheme 2) (Inuzuka & Fujimoto, 1986 and 1990). Obvious features of the iminium tautomer in (I) are revealed by the following bond length comparison. First, the N2—C1 [1.330 (3) Å] bond is slightly but significantly shorter than the N1—C1 [1.349 (3) Å] and N1—C5 [1.361 (3) Å] bonds (Table 1). Second, the C2—C3 [1.352 (4) Å] and C4—C5 [1.353 (4) Å] bonds are shorter than the C1—C2 [1.410 (3) Å] and C3—C4 [1.386 (4) Å] bonds. That means the imimium tautomer makes a great contribution to the structure. This situation is similiar to those observed in 2-amino-5-methylpyridinium ferulate (Xuan et al., 2003), 2-aminopyridinium acetate (Ishikawa et al., 2002), 2-amino-3-methylpyridinium maleate (Jin et al., 2002) and AMP neoabietate (Jin et al., 2000).
As shown in Fig. 2, one-dimensional C2 chains along the (101) direction are formed by O1—H1O···O3i hydrogen bonds. The presence of water molecules in the structure causes the following hydrogen bonds: N2—H2A···O5, O5—H5A···O1ii, O5—H5B···O4iii and C6—H6A···O5iv (Table 2). These chains link into chiral layers parallel to the (101) plane via the O5—H5B···O4iii hydrogen bonds. Neighbouring enantiomeric layers, which are mutual images on the plane of (101) are associated via the O5—H5A···O1ii hydrogen bonds. The whole noncentrosymmetric structure is stablized by π–π interactions between neighboring layers, with the relevant centroid···centroid separations between the pyridine and the benzene rings at (x, 1 - y, z + 1/2), 3.813 (4) Å and (x - 1/2, -y + 1/2, z - 1/2), 3.658 (3) Å.
For related literature, see: Etter (1990); Inuzuka & Fujimoto (1986, 1990); Ishikawa et al. (2002); Jin et al. (2000, 2002); Kaminskii et al. (2006, 2007); Kiebacha et al. (2006); Sarma et al. (1997); Thalladi et al. (1999); Xuan et al. (2003).
Data collection: XSCANS (Siemens, 1994); cell refinement: XSCANS; data reduction: SHELXTL (Bruker, 1998); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL.
C6H9N2+·C10H9O4−·H2O | F(000) = 680 |
Mr = 320.34 | Dx = 1.337 Mg m−3 |
Monoclinic, Cc | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: C -2yc | Cell parameters from 30 reflections |
a = 11.266 (2) Å | θ = 3.7–12.0° |
b = 9.711 (1) Å | µ = 0.10 mm−1 |
c = 15.024 (2) Å | T = 296 K |
β = 104.547 (8)° | Block, colourless |
V = 1591.0 (4) Å3 | 0.40 × 0.40 × 0.36 mm |
Z = 4 |
Siemens P4 diffractometer | 1571 reflections with I > 2σ(I) |
Radiation source: fine-focus sealed tube | Rint = 0.012 |
Graphite monochromator | θmax = 28.0°, θmin = 2.8° |
ω scans | h = 0→14 |
Absorption correction: empirical (using intensity measurements) (SHELXTL; Bruker, 1998) | k = 0→12 |
Tmin = 0.955, Tmax = 0.960 | l = −19→19 |
2235 measured reflections | 3 standard reflections every 97 reflections |
1920 independent reflections | intensity decay: 1.4% |
Refinement on F2 | Secondary atom site location: difference Fourier map |
Least-squares matrix: full | Hydrogen site location: inferred from neighbouring sites |
R[F2 > 2σ(F2)] = 0.033 | H atoms treated by a mixture of independent and constrained refinement |
wR(F2) = 0.075 | w = 1/[σ2(Fo2) + (0.04P)2] where P = (Fo2 + 2Fc2)/3 |
S = 0.98 | (Δ/σ)max < 0.001 |
1920 reflections | Δρmax = 0.16 e Å−3 |
234 parameters | Δρmin = −0.13 e Å−3 |
4 restraints | Extinction correction: SHELXL97 (Sheldrick, 1997), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
Primary atom site location: structure-invariant direct methods | Extinction coefficient: 0.0225 (15) |
C6H9N2+·C10H9O4−·H2O | V = 1591.0 (4) Å3 |
Mr = 320.34 | Z = 4 |
Monoclinic, Cc | Mo Kα radiation |
a = 11.266 (2) Å | µ = 0.10 mm−1 |
b = 9.711 (1) Å | T = 296 K |
c = 15.024 (2) Å | 0.40 × 0.40 × 0.36 mm |
β = 104.547 (8)° |
Siemens P4 diffractometer | 1571 reflections with I > 2σ(I) |
Absorption correction: empirical (using intensity measurements) (SHELXTL; Bruker, 1998) | Rint = 0.012 |
Tmin = 0.955, Tmax = 0.960 | 3 standard reflections every 97 reflections |
2235 measured reflections | intensity decay: 1.4% |
1920 independent reflections |
R[F2 > 2σ(F2)] = 0.033 | 4 restraints |
wR(F2) = 0.075 | H atoms treated by a mixture of independent and constrained refinement |
S = 0.98 | Δρmax = 0.16 e Å−3 |
1920 reflections | Δρmin = −0.13 e Å−3 |
234 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) | |
O1 | 0.63139 (17) | 0.81309 (17) | 0.79651 (11) | 0.0505 (5) | |
O2 | 0.55462 (15) | 0.56111 (16) | 0.80161 (10) | 0.0480 (5) | |
O3 | 0.21872 (16) | 0.43919 (16) | 0.29836 (10) | 0.0488 (4) | |
O4 | 0.29544 (17) | 0.24240 (15) | 0.36111 (11) | 0.0446 (4) | |
O5 | 0.0234 (2) | 0.3630 (3) | −0.04758 (14) | 0.0691 (6) | |
N1 | 0.26566 (16) | 0.09244 (19) | 0.20202 (13) | 0.0365 (4) | |
N2 | 0.1546 (2) | 0.2764 (2) | 0.12847 (16) | 0.0472 (5) | |
C1 | 0.2028 (2) | 0.1526 (2) | 0.12329 (15) | 0.0377 (5) | |
C2 | 0.1912 (2) | 0.0791 (3) | 0.04057 (16) | 0.0472 (6) | |
H2 | 0.1486 | 0.1168 | −0.0152 | 0.057* | |
C3 | 0.2429 (3) | −0.0470 (3) | 0.04365 (19) | 0.0556 (7) | |
H3 | 0.2364 | −0.0955 | −0.0107 | 0.067* | |
C4 | 0.3054 (3) | −0.1052 (3) | 0.1264 (2) | 0.0579 (7) | |
H4 | 0.3401 | −0.1922 | 0.1272 | 0.069* | |
C5 | 0.3159 (2) | −0.0355 (2) | 0.20598 (17) | 0.0450 (6) | |
C6 | 0.3764 (3) | −0.0885 (3) | 0.2995 (2) | 0.0630 (8) | |
H6A | 0.3721 | −0.0198 | 0.3446 | 0.076* | 0.50 |
H6B | 0.4607 | −0.1093 | 0.3029 | 0.076* | 0.50 |
H6C | 0.3352 | −0.1704 | 0.3114 | 0.076* | 0.50 |
H6D | 0.4065 | −0.1799 | 0.2947 | 0.076* | 0.50 |
H6E | 0.3180 | −0.0904 | 0.3364 | 0.076* | 0.50 |
H6F | 0.4434 | −0.0292 | 0.3279 | 0.076* | 0.50 |
C7 | 0.4530 (2) | 0.5648 (2) | 0.63826 (15) | 0.0355 (5) | |
H7 | 0.4247 | 0.4752 | 0.6404 | 0.043* | |
C8 | 0.5218 (2) | 0.6252 (2) | 0.71738 (14) | 0.0356 (5) | |
C9 | 0.56482 (19) | 0.7597 (2) | 0.71563 (14) | 0.0366 (5) | |
C10 | 0.5380 (2) | 0.8308 (2) | 0.63346 (15) | 0.0409 (5) | |
H10 | 0.5667 | 0.9202 | 0.6313 | 0.049* | |
C11 | 0.4682 (2) | 0.7693 (2) | 0.55374 (15) | 0.0386 (5) | |
H11 | 0.4502 | 0.8186 | 0.4989 | 0.046* | |
C12 | 0.42502 (19) | 0.6361 (2) | 0.55453 (14) | 0.0334 (5) | |
C13 | 0.3556 (2) | 0.5708 (2) | 0.46945 (13) | 0.0348 (5) | |
H13 | 0.3198 | 0.6293 | 0.4211 | 0.042* | |
C14 | 0.3384 (2) | 0.4371 (2) | 0.45420 (14) | 0.0416 (5) | |
H14 | 0.3665 | 0.3790 | 0.5043 | 0.050* | |
C15 | 0.2784 (2) | 0.3701 (2) | 0.36480 (14) | 0.0357 (5) | |
C16 | 0.5134 (2) | 0.4233 (2) | 0.80484 (16) | 0.0434 (5) | |
H16A | 0.4254 | 0.4214 | 0.7876 | 0.052* | |
H16B | 0.5427 | 0.3880 | 0.8661 | 0.052* | |
H16C | 0.5444 | 0.3676 | 0.7629 | 0.052* | |
H2A | 0.121 (2) | 0.316 (2) | 0.0782 (17) | 0.038 (7)* | |
H1N | 0.274 (2) | 0.135 (2) | 0.2531 (17) | 0.036 (6)* | |
H2B | 0.173 (2) | 0.318 (3) | 0.181 (2) | 0.055 (8)* | |
H1O | 0.659 (3) | 0.896 (3) | 0.7919 (19) | 0.058 (8)* | |
H5A | 0.061 (4) | 0.348 (5) | −0.087 (2) | 0.13 (2)* | |
H5B | −0.0448 (18) | 0.329 (4) | −0.069 (2) | 0.091 (13)* |
U11 | U22 | U33 | U12 | U13 | U23 | |
O1 | 0.0690 (12) | 0.0358 (9) | 0.0363 (8) | −0.0158 (9) | −0.0058 (8) | −0.0049 (7) |
O2 | 0.0680 (12) | 0.0397 (9) | 0.0286 (7) | −0.0130 (8) | −0.0022 (7) | 0.0024 (7) |
O3 | 0.0656 (11) | 0.0393 (9) | 0.0310 (8) | 0.0093 (9) | −0.0077 (7) | −0.0041 (7) |
O4 | 0.0623 (10) | 0.0338 (8) | 0.0308 (8) | 0.0009 (8) | −0.0011 (7) | −0.0031 (7) |
O5 | 0.0660 (14) | 0.0864 (16) | 0.0450 (11) | −0.0116 (13) | −0.0045 (11) | 0.0133 (10) |
N1 | 0.0411 (10) | 0.0338 (10) | 0.0331 (10) | −0.0021 (8) | 0.0064 (8) | −0.0079 (8) |
N2 | 0.0603 (14) | 0.0447 (11) | 0.0302 (10) | 0.0074 (10) | −0.0007 (10) | −0.0028 (10) |
C1 | 0.0381 (12) | 0.0400 (12) | 0.0331 (11) | −0.0055 (10) | 0.0054 (9) | −0.0052 (10) |
C2 | 0.0497 (14) | 0.0563 (15) | 0.0344 (12) | −0.0096 (13) | 0.0082 (10) | −0.0123 (11) |
C3 | 0.0592 (16) | 0.0570 (17) | 0.0514 (15) | −0.0077 (13) | 0.0152 (13) | −0.0268 (13) |
C4 | 0.0633 (18) | 0.0416 (13) | 0.0672 (18) | 0.0029 (12) | 0.0137 (14) | −0.0182 (13) |
C5 | 0.0450 (15) | 0.0340 (11) | 0.0523 (14) | −0.0024 (10) | 0.0054 (12) | −0.0078 (10) |
C6 | 0.0729 (19) | 0.0411 (14) | 0.0640 (17) | 0.0115 (14) | −0.0035 (14) | 0.0022 (13) |
C7 | 0.0441 (12) | 0.0287 (10) | 0.0307 (9) | −0.0034 (9) | 0.0038 (9) | −0.0033 (9) |
C8 | 0.0432 (12) | 0.0327 (11) | 0.0283 (10) | 0.0004 (9) | 0.0041 (9) | 0.0005 (8) |
C9 | 0.0411 (13) | 0.0308 (11) | 0.0338 (10) | −0.0014 (10) | 0.0016 (9) | −0.0053 (9) |
C10 | 0.0530 (14) | 0.0256 (11) | 0.0394 (12) | −0.0011 (10) | 0.0031 (10) | −0.0001 (9) |
C11 | 0.0505 (13) | 0.0321 (11) | 0.0291 (10) | 0.0057 (10) | 0.0025 (9) | 0.0035 (8) |
C12 | 0.0379 (12) | 0.0305 (10) | 0.0297 (10) | 0.0046 (9) | 0.0047 (9) | −0.0031 (8) |
C13 | 0.0419 (12) | 0.0344 (11) | 0.0238 (9) | 0.0045 (9) | 0.0004 (8) | 0.0012 (8) |
C14 | 0.0559 (14) | 0.0391 (13) | 0.0248 (10) | −0.0011 (11) | 0.0008 (10) | −0.0005 (9) |
C15 | 0.0441 (12) | 0.0346 (11) | 0.0253 (10) | −0.0012 (10) | 0.0028 (9) | −0.0020 (9) |
C16 | 0.0550 (14) | 0.0403 (12) | 0.0338 (11) | −0.0027 (11) | 0.0091 (10) | 0.0045 (10) |
O1—C9 | 1.360 (2) | C6—H6B | 0.9600 |
O1—H1O | 0.87 (3) | C6—H6C | 0.9600 |
O2—C8 | 1.375 (3) | C6—H6D | 0.9600 |
O2—C16 | 1.421 (2) | C6—H6E | 0.9600 |
O3—C15 | 1.250 (3) | C6—H6F | 0.9600 |
O4—C15 | 1.258 (3) | C7—C8 | 1.376 (3) |
O5—H5A | 0.819 (10) | C7—C12 | 1.401 (3) |
O5—H5B | 0.824 (10) | C7—H7 | 0.9300 |
N1—C1 | 1.349 (3) | C8—C9 | 1.396 (3) |
N1—C5 | 1.361 (3) | C9—C10 | 1.380 (3) |
N1—H1N | 0.86 (2) | C10—C11 | 1.392 (3) |
N2—C1 | 1.330 (3) | C10—H10 | 0.9300 |
N2—H2A | 0.85 (2) | C11—C12 | 1.383 (3) |
N2—H2B | 0.86 (3) | C11—H11 | 0.9300 |
C1—C2 | 1.410 (3) | C12—C13 | 1.465 (3) |
C2—C3 | 1.352 (4) | C13—C14 | 1.324 (3) |
C2—H2 | 0.9300 | C13—H13 | 0.9300 |
C3—C4 | 1.386 (4) | C14—C15 | 1.493 (3) |
C3—H3 | 0.9300 | C14—H14 | 0.9300 |
C4—C5 | 1.353 (4) | C16—H16A | 0.9600 |
C4—H4 | 0.9300 | C16—H16B | 0.9600 |
C5—C6 | 1.491 (4) | C16—H16C | 0.9600 |
C6—H6A | 0.9600 | ||
C9—O1—H1O | 114.1 (19) | C5—C6—H6F | 109.5 |
C8—O2—C16 | 116.29 (16) | H6A—C6—H6F | 56.3 |
H5A—O5—H5B | 105 (4) | H6B—C6—H6F | 56.3 |
C1—N1—C5 | 123.7 (2) | H6C—C6—H6F | 141.1 |
C1—N1—H1N | 119.1 (16) | H6D—C6—H6F | 109.5 |
C5—N1—H1N | 117.2 (16) | H6E—C6—H6F | 109.5 |
C1—N2—H2A | 117.2 (16) | C8—C7—C12 | 121.08 (19) |
C1—N2—H2B | 118.0 (18) | C8—C7—H7 | 119.5 |
H2A—N2—H2B | 123 (2) | C12—C7—H7 | 119.5 |
N2—C1—N1 | 118.2 (2) | O2—C8—C7 | 124.40 (19) |
N2—C1—C2 | 124.1 (2) | O2—C8—C9 | 115.24 (18) |
N1—C1—C2 | 117.8 (2) | C7—C8—C9 | 120.35 (19) |
C3—C2—C1 | 119.0 (2) | O1—C9—C10 | 123.83 (19) |
C3—C2—H2 | 120.5 | O1—C9—C8 | 117.13 (19) |
C1—C2—H2 | 120.5 | C10—C9—C8 | 119.04 (19) |
C2—C3—C4 | 121.2 (2) | C9—C10—C11 | 120.3 (2) |
C2—C3—H3 | 119.4 | C9—C10—H10 | 119.8 |
C4—C3—H3 | 119.4 | C11—C10—H10 | 119.8 |
C5—C4—C3 | 120.1 (2) | C12—C11—C10 | 121.2 (2) |
C5—C4—H4 | 120.0 | C12—C11—H11 | 119.4 |
C3—C4—H4 | 120.0 | C10—C11—H11 | 119.4 |
C4—C5—N1 | 118.3 (2) | C11—C12—C7 | 118.00 (19) |
C4—C5—C6 | 125.4 (2) | C11—C12—C13 | 120.61 (19) |
N1—C5—C6 | 116.3 (2) | C7—C12—C13 | 121.36 (18) |
C5—C6—H6A | 109.5 | C14—C13—C12 | 126.75 (18) |
C5—C6—H6B | 109.5 | C14—C13—H13 | 116.6 |
H6A—C6—H6B | 109.5 | C12—C13—H13 | 116.6 |
C5—C6—H6C | 109.5 | C13—C14—C15 | 126.62 (19) |
H6A—C6—H6C | 109.5 | C13—C14—H14 | 116.7 |
H6B—C6—H6C | 109.5 | C15—C14—H14 | 116.7 |
C5—C6—H6D | 109.5 | O3—C15—O4 | 123.49 (19) |
H6A—C6—H6D | 141.1 | O3—C15—C14 | 121.05 (19) |
H6B—C6—H6D | 56.3 | O4—C15—C14 | 115.43 (19) |
H6C—C6—H6D | 56.3 | O2—C16—H16A | 109.5 |
C5—C6—H6E | 109.5 | O2—C16—H16B | 109.5 |
H6A—C6—H6E | 56.3 | H16A—C16—H16B | 109.5 |
H6B—C6—H6E | 141.1 | O2—C16—H16C | 109.5 |
H6C—C6—H6E | 56.3 | H16A—C16—H16C | 109.5 |
H6D—C6—H6E | 109.5 | H16B—C16—H16C | 109.5 |
C5—N1—C1—N2 | 177.9 (2) | C7—C8—C9—O1 | 179.5 (2) |
C5—N1—C1—C2 | −1.3 (3) | O2—C8—C9—C10 | 178.8 (2) |
N2—C1—C2—C3 | −179.2 (2) | C7—C8—C9—C10 | −0.3 (3) |
N1—C1—C2—C3 | 0.0 (3) | O1—C9—C10—C11 | −179.4 (2) |
C1—C2—C3—C4 | 0.8 (4) | C8—C9—C10—C11 | 0.5 (3) |
C2—C3—C4—C5 | −0.3 (4) | C9—C10—C11—C12 | −0.5 (3) |
C3—C4—C5—N1 | −1.0 (4) | C10—C11—C12—C7 | 0.4 (3) |
C3—C4—C5—C6 | 177.5 (3) | C10—C11—C12—C13 | −177.7 (2) |
C1—N1—C5—C4 | 1.8 (4) | C8—C7—C12—C11 | −0.2 (3) |
C1—N1—C5—C6 | −176.8 (2) | C8—C7—C12—C13 | 177.8 (2) |
C16—O2—C8—C7 | 0.1 (3) | C11—C12—C13—C14 | 159.9 (2) |
C16—O2—C8—C9 | −179.1 (2) | C7—C12—C13—C14 | −18.2 (3) |
C12—C7—C8—O2 | −178.9 (2) | C12—C13—C14—C15 | −173.4 (2) |
C12—C7—C8—C9 | 0.2 (3) | C13—C14—C15—O3 | −12.9 (4) |
O2—C8—C9—O1 | −1.3 (3) | C13—C14—C15—O4 | 165.1 (2) |
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1N···O4 | 0.86 (2) | 1.89 (3) | 2.746 (2) | 175 |
N2—H2A···O5 | 0.85 (2) | 1.99 (2) | 2.815 (3) | 166 |
N2—H2B···O3 | 0.86 (2) | 2.08 (3) | 2.934 (4) | 173 |
O1—H1O···O3i | 0.87 (3) | 1.73 (3) | 2.596 (3) | 172 |
O5—H5A···O1ii | 0.82 (1) | 2.13 (1) | 2.938 (5) | 171 |
O5—H5B···O4iii | 0.82 (1) | 1.97 (1) | 2.785 (2) | 171 |
C6—H6A···O5iv | 0.96 | 2.54 | 3.302 (3) | 136 |
C13—H13···O1v | 0.93 | 2.52 | 3.332 (2) | 147 |
Symmetry codes: (i) x+1/2, −y+3/2, z+1/2; (ii) x−1/2, y−1/2, z−1; (iii) x−1/2, −y+1/2, z−1/2; (iv) x+1/2, −y+1/2, z+1/2; (v) x−1/2, −y+3/2, z−1/2. |
Experimental details
Crystal data | |
Chemical formula | C6H9N2+·C10H9O4−·H2O |
Mr | 320.34 |
Crystal system, space group | Monoclinic, Cc |
Temperature (K) | 296 |
a, b, c (Å) | 11.266 (2), 9.711 (1), 15.024 (2) |
β (°) | 104.547 (8) |
V (Å3) | 1591.0 (4) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 0.10 |
Crystal size (mm) | 0.40 × 0.40 × 0.36 |
Data collection | |
Diffractometer | Siemens P4 |
Absorption correction | Empirical (using intensity measurements) (SHELXTL; Bruker, 1998) |
Tmin, Tmax | 0.955, 0.960 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 2235, 1920, 1571 |
Rint | 0.012 |
(sin θ/λ)max (Å−1) | 0.661 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.033, 0.075, 0.98 |
No. of reflections | 1920 |
No. of parameters | 234 |
No. of restraints | 4 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 0.16, −0.13 |
Computer programs: XSCANS (Siemens, 1994), XSCANS, SHELXTL (Bruker, 1998), SHELXS97 (Sheldrick, 1997), SHELXL97 (Sheldrick, 1997), SHELXTL.
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1N···O4 | 0.86 (2) | 1.89 (3) | 2.746 (2) | 175 |
N2—H2A···O5 | 0.85 (2) | 1.99 (2) | 2.815 (3) | 166 |
N2—H2B···O3 | 0.86 (2) | 2.08 (3) | 2.934 (4) | 173 |
O1—H1O···O3i | 0.87 (3) | 1.73 (3) | 2.596 (3) | 172 |
O5—H5A···O1ii | 0.82 (1) | 2.13 (1) | 2.938 (5) | 171 |
O5—H5B···O4iii | 0.82 (1) | 1.97 (1) | 2.785 (2) | 171 |
C6—H6A···O5iv | 0.96 | 2.54 | 3.302 (3) | 136 |
C13—H13···O1v | 0.93 | 2.52 | 3.332 (2) | 147 |
Symmetry codes: (i) x+1/2, −y+3/2, z+1/2; (ii) x−1/2, y−1/2, z−1; (iii) x−1/2, −y+1/2, z−1/2; (iv) x+1/2, −y+1/2, z+1/2; (v) x−1/2, −y+3/2, z−1/2. |
As reported, the synthesis and characterization of noncentrosymmetric supramolecular systems have attracted a great of interest in th past few years (Sarma et al., 1997; Thalladi et al., 1999; Kaminskii et al., 2006; Kiebacha et al., 2006; Kaminskii et al., 2007). Herein, we report a novel noncentrosymmetric crystal of the title complex (Fig. 3), (I), and discuss the structure (Table 1).
In the structure, 2-amino-6-methylpyridinium (AMP) and 3-(4-hydroxy-3-methoxyphenyl)-2-propenoate (ferulate) are linked through hydrogen bonding of N1—H1N···O4 and N2—H2B···O3 to produce an eight-membered hydrogen bonded ring system of R22(8) arrangement (Etter, 1990). This component shows an interaction with the water molecule by a N2—H2A···O5 hydrogen bond (Fig. 1 & Table 2). This is different from the componentially similar complex 2-amino-5-methylpyridinium ferulate monohydrate (Xuan et al., 2003), where the water molecule is incorporated with AMP by an O—H···O hydrogen bond.
Protonation of 2-aminopyridine always induces aminium-iminium tautomerism (Scheme 2) (Inuzuka & Fujimoto, 1986 and 1990). Obvious features of the iminium tautomer in (I) are revealed by the following bond length comparison. First, the N2—C1 [1.330 (3) Å] bond is slightly but significantly shorter than the N1—C1 [1.349 (3) Å] and N1—C5 [1.361 (3) Å] bonds (Table 1). Second, the C2—C3 [1.352 (4) Å] and C4—C5 [1.353 (4) Å] bonds are shorter than the C1—C2 [1.410 (3) Å] and C3—C4 [1.386 (4) Å] bonds. That means the imimium tautomer makes a great contribution to the structure. This situation is similiar to those observed in 2-amino-5-methylpyridinium ferulate (Xuan et al., 2003), 2-aminopyridinium acetate (Ishikawa et al., 2002), 2-amino-3-methylpyridinium maleate (Jin et al., 2002) and AMP neoabietate (Jin et al., 2000).
As shown in Fig. 2, one-dimensional C2 chains along the (101) direction are formed by O1—H1O···O3i hydrogen bonds. The presence of water molecules in the structure causes the following hydrogen bonds: N2—H2A···O5, O5—H5A···O1ii, O5—H5B···O4iii and C6—H6A···O5iv (Table 2). These chains link into chiral layers parallel to the (101) plane via the O5—H5B···O4iii hydrogen bonds. Neighbouring enantiomeric layers, which are mutual images on the plane of (101) are associated via the O5—H5A···O1ii hydrogen bonds. The whole noncentrosymmetric structure is stablized by π–π interactions between neighboring layers, with the relevant centroid···centroid separations between the pyridine and the benzene rings at (x, 1 - y, z + 1/2), 3.813 (4) Å and (x - 1/2, -y + 1/2, z - 1/2), 3.658 (3) Å.