All three title compounds, C
4H
7N
2+·C
4H
5O
4-, (I), C
4H
7N
2+·C
5H
7O
4-, (II), and C
4H
7N
2+·C
6H
9O
4-·H
2O, (III), can be regarded as 1:1 organic salts. The dicarboxylic acids join through short acid bridges into infinite chains. Compound (I) crystallizes in the noncentrosymmetric
Cmc2
1 space group and the asymmetric unit consists of a hydrogen succinate anion located on a mirror plane and a 2-methylimidazolium cation disordered across the same mirror. The other two compounds crystallize in the triclinic
P space group. The carboxylic acid H atom in (II) is disordered over both ends of the anion and sits on inversion centres between adjacent anions, forming symmetric short O
H
O bridges. Two independent anions in (III) sit across inversion centres, again with the carboxylic acid H atom disordered in short O
H
O bridges. The molecules in all three compounds are linked into two-dimensional networks by combinations of imidazolium-carboxylate N
+-H
O and carboxylate-carboxylate O-H
O hydrogen bonds. The two-dimensional networks are further linked into three-dimensional networks by C-H
O hydrogen bonds in (I) and by O
water-H
O hydrogen bonds in (III). According to the
p
Ka rule, such 1:1 types of organic salts can be expected unambiguously. However, a 2:1 type of organic salt may be more easily obtained in (II) and (III) than in (I).
Supporting information
CCDC references: 735125; 735126; 735127
1:2 Molar quantities of succinic acid (0.2 mmol, 23.6 mg) and 2-methylimidazole
(0.4 mmol, 32.8 mg) for (I), glutaric acid (0.2 mmol, 26.4 mg) and
2-methylimidazole (0.4 mmol, 32.8 mg) for (II), and adipic acid (0.2 mmol,
29.2 mg) and 2-methylimidazole (0.4 mmol, 32.8 mg) for (III) were dissolved in
water (15 ml). The mixtures were stirred for 10 min at ambient temperature and
then filtered. The resulting colourless solutions were kept in air for several
days. Crystals of (I), (II) and (III) were grown by slow evaporation.
For all three compounds, H atoms bonded to C atoms were positioned
geometrically, with C—H = 0.93 (aromatic), 0.96 (methyl) or 0.97 Å
(methylene), and refined in riding mode, with Uiso(H) =
1.2Ueq(aromatic and methylene C) or 1.5Ueq(methyl C). In
(I), H atoms bonded to N and O atoms were found in a difference map and the
N—H and O—H distances were refined with constraints [Restraints?]
of N—H = 0.86 (2) Å and O—H = 0.82 (2) Å, and with Uiso(H) =
1.2Ueq(N) and 1.5Ueq(O). The cation is disordered over a
mirror plane. Friedel pairs were averaged. H atoms bonded to N atoms in (II)
were also found in a difference map and refined with the restraint N—H =
0.86 (2) Å and with Uiso(H) = 1.2Ueq(N). The acid H atom is
statistically disordered over two locations, both of which lie on inversion
centres, and was refined with Uiso(H1B) = 1.5Ueq(O1)
and Uiso(H1C) = 1.5Ueq(O3). In (III), H atoms bonded
to N atoms were similarly found in a difference map and refined with the
restraint N—H = 0.86 (2) Å and with Uiso(H) = 1.2Ueq(N).
Atom H2B was found 1.22 Å away from atom O2 and placed on a general
position. The O2—H2B distance was refined freely and the final
outcome gave an indication of hydrogen-bridging in the adipate monoanion. Two
water H atoms were also found in a difference map, one of which was disordered
over two sites with occupancies of 0.5; these H atoms were refined with
restraints of O—H = 0.82 (2) Å and H···H = 1.35 (2) Å, and with
Uiso(H) = 1.5Ueq(O).
For all compounds, data collection: SMART (Bruker, 2001); cell refinement: SMART (Bruker, 2001); data reduction: SAINT-Plus (Bruker, 2001); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: PLATON (Spek, 2009); software used to prepare material for publication: PLATON (Spek, 2009).
(I) 2-Methylimidazolium hydrogen succinate
top
Crystal data top
C4H7N2+·C4H5O4− | F(000) = 424 |
Mr = 200.20 | Dx = 1.374 Mg m−3 |
Orthorhombic, Cmc21 | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: C 2c -2 | Cell parameters from 2108 reflections |
a = 6.8017 (10) Å | θ = 2.3–26.6° |
b = 8.1580 (11) Å | µ = 0.11 mm−1 |
c = 17.438 (2) Å | T = 296 K |
V = 967.6 (2) Å3 | Block, colourless |
Z = 4 | 0.25 × 0.12 × 0.08 mm |
Data collection top
Bruker SMART APEX CCD area-detector diffractometer | 654 independent reflections |
Radiation source: fine focus sealed Siemens Mo tube | 573 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.024 |
0.3° wide ω exposures scans | θmax = 28.2°, θmin = 2.3° |
Absorption correction: multi-scan (SADABS; Sheldrick, 1997) | h = −9→8 |
Tmin = 0.963, Tmax = 0.991 | k = −10→10 |
5389 measured reflections | l = −22→20 |
Refinement top
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: inferred from neighbouring sites |
wR(F2) = 0.092 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.10 | w = 1/[σ2(Fo2) + (0.0665P)2 + 0.0213P] where P = (Fo2 + 2Fc2)/3 |
654 reflections | (Δ/σ)max < 0.001 |
112 parameters | Δρmax = 0.21 e Å−3 |
4 restraints | Δρmin = −0.14 e Å−3 |
Crystal data top
C4H7N2+·C4H5O4− | V = 967.6 (2) Å3 |
Mr = 200.20 | Z = 4 |
Orthorhombic, Cmc21 | Mo Kα radiation |
a = 6.8017 (10) Å | µ = 0.11 mm−1 |
b = 8.1580 (11) Å | T = 296 K |
c = 17.438 (2) Å | 0.25 × 0.12 × 0.08 mm |
Data collection top
Bruker SMART APEX CCD area-detector diffractometer | 654 independent reflections |
Absorption correction: multi-scan (SADABS; Sheldrick, 1997) | 573 reflections with I > 2σ(I) |
Tmin = 0.963, Tmax = 0.991 | Rint = 0.024 |
5389 measured reflections | |
Refinement top
R[F2 > 2σ(F2)] = 0.034 | 4 restraints |
wR(F2) = 0.092 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.10 | Δρmax = 0.21 e Å−3 |
654 reflections | Δρmin = −0.14 e Å−3 |
112 parameters | |
Special details top
Geometry. All esds (except the esd in the dihedral angle between two l.s. planes)
are estimated using the full covariance matrix. The cell esds are taken
into account individually in the estimation of esds in distances, angles
and torsion angles; correlations between esds in cell parameters are only
used when they are defined by crystal symmetry. An approximate (isotropic)
treatment of cell esds is used for estimating esds 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 > 2sigma(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. |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top | x | y | z | Uiso*/Ueq | Occ. (<1) |
C1 | 0.5457 (4) | 0.0023 (4) | 0.7332 (2) | 0.0344 (11) | 0.50 |
C2 | 0.2982 (7) | 0.1668 (6) | 0.7569 (3) | 0.0504 (11) | 0.50 |
H6 | 0.2088 | 0.2323 | 0.7832 | 0.061* | 0.50 |
C3 | 0.3004 (7) | 0.1383 (5) | 0.6818 (3) | 0.0497 (10) | 0.50 |
H7 | 0.2133 | 0.1799 | 0.6455 | 0.060* | 0.50 |
C4 | 0.7232 (7) | −0.1032 (4) | 0.74288 (13) | 0.0603 (12) | 0.50 |
H4A | 0.8296 | −0.0385 | 0.7627 | 0.090* | 0.50 |
H4B | 0.7601 | −0.1484 | 0.6941 | 0.090* | 0.50 |
H4C | 0.6942 | −0.1905 | 0.7780 | 0.090* | 0.50 |
C5 | 0.5000 (8) | 0.67258 (16) | 0.96057 (13) | 0.0312 (6) | |
C6 | 0.5000 (8) | 0.51001 (15) | 1.00107 (11) | 0.0329 (6) | |
H6A | 0.3848 | 0.5034 | 1.0337 | 0.040* | 0.50 |
H6B | 0.6152 | 0.5034 | 1.0337 | 0.040* | 0.50 |
C7 | 0.5000 (8) | 0.36551 (16) | 0.94673 (10) | 0.0319 (6) | |
H7A | 0.6151 | 0.3729 | 0.9141 | 0.038* | 0.50 |
H7B | 0.3849 | 0.3729 | 0.9141 | 0.038* | 0.50 |
C8 | 0.5000 (8) | 0.19911 (18) | 0.98588 (10) | 0.0269 (5) | |
N1 | 0.4561 (6) | 0.0359 (4) | 0.66822 (18) | 0.0413 (15) | 0.50 |
H1 | 0.470 (8) | −0.013 (5) | 0.6247 (16) | 0.050* | 0.50 |
N2 | 0.4518 (5) | 0.0818 (4) | 0.78840 (19) | 0.0409 (12) | 0.50 |
H2 | 0.475 (9) | 0.079 (4) | 0.8376 (13) | 0.049* | 0.50 |
O1 | 0.5000 | 0.7967 (2) | 1.00811 (13) | 0.0503 (6) | |
H1A | 0.5000 | 0.878 (4) | 0.982 (2) | 0.075* | |
O2 | 0.5000 | 0.6891 (3) | 0.89195 (12) | 0.0536 (6) | |
O3 | 0.5000 | 0.1882 (2) | 1.05627 (11) | 0.0442 (5) | |
O4 | 0.5000 | 0.0755 (2) | 0.94090 (11) | 0.0418 (5) | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
C1 | 0.040 (3) | 0.0301 (13) | 0.0331 (18) | −0.0017 (11) | −0.0004 (12) | −0.0013 (14) |
C2 | 0.057 (3) | 0.053 (2) | 0.041 (2) | 0.0156 (19) | −0.0008 (17) | −0.0063 (18) |
C3 | 0.064 (3) | 0.051 (2) | 0.034 (2) | 0.0155 (19) | −0.0054 (17) | −0.0010 (18) |
C4 | 0.072 (3) | 0.059 (3) | 0.050 (3) | 0.022 (2) | −0.007 (2) | 0.003 (2) |
C5 | 0.0402 (14) | 0.0210 (11) | 0.0325 (14) | 0.000 | 0.000 | 0.0019 (9) |
C6 | 0.0494 (13) | 0.0201 (10) | 0.0294 (13) | 0.000 | 0.000 | 0.0024 (9) |
C7 | 0.0510 (14) | 0.0192 (10) | 0.0255 (13) | 0.000 | 0.000 | 0.0052 (9) |
C8 | 0.0375 (13) | 0.0190 (10) | 0.0244 (12) | 0.000 | 0.000 | 0.0019 (8) |
N1 | 0.062 (4) | 0.0367 (15) | 0.0255 (15) | 0.0043 (14) | 0.0004 (13) | −0.0054 (12) |
N2 | 0.062 (4) | 0.0386 (15) | 0.0220 (14) | −0.0007 (13) | −0.0013 (12) | −0.0026 (12) |
O1 | 0.0936 (16) | 0.0201 (8) | 0.0371 (13) | 0.000 | 0.000 | 0.0010 (8) |
O2 | 0.1059 (17) | 0.0274 (10) | 0.0276 (12) | 0.000 | 0.000 | 0.0027 (8) |
O3 | 0.0789 (15) | 0.0266 (9) | 0.0273 (11) | 0.000 | 0.000 | 0.0044 (8) |
O4 | 0.0776 (12) | 0.0182 (7) | 0.0296 (10) | 0.000 | 0.000 | −0.0008 (8) |
Geometric parameters (Å, º) top
C1—N2i | 1.160 (5) | C6—C7 | 1.513 (2) |
C1—N1i | 1.166 (5) | C6—H6A | 0.9700 |
C1—N1 | 1.316 (5) | C6—H6B | 0.9700 |
C1—N2 | 1.324 (5) | C7—C8 | 1.520 (2) |
C1—C4 | 1.492 (5) | C7—H7A | 0.9700 |
C2—C3 | 1.331 (6) | C7—H7B | 0.9700 |
C2—N2 | 1.369 (5) | C8—O3 | 1.231 (3) |
C2—N2i | 1.917 (5) | C8—O4 | 1.278 (2) |
C2—H6 | 0.9300 | N1—N1i | 0.598 (8) |
C3—N1 | 1.370 (6) | N1—C1i | 1.166 (5) |
C3—N1i | 1.871 (6) | N1—C3i | 1.871 (6) |
C3—H7 | 0.9300 | N1—H1 | 0.86 (2) |
C4—H4A | 0.9600 | N2—N2i | 0.655 (6) |
C4—H4B | 0.9600 | N2—C1i | 1.160 (5) |
C4—H4C | 0.9600 | N2—C2i | 1.917 (5) |
C5—O2 | 1.204 (3) | N2—H2 | 0.87 (2) |
C5—O1 | 1.309 (3) | O1—H1A | 0.81 (2) |
C5—C6 | 1.503 (2) | | |
| | | |
N2i—C1—N1i | 132.4 (4) | H6A—C6—H6B | 107.8 |
N2i—C1—N1 | 127.2 (4) | C6—C7—C8 | 114.51 (14) |
N1i—C1—N2 | 125.9 (4) | C6—C7—H7A | 108.6 |
N1—C1—N2 | 107.5 (3) | C8—C7—H7A | 108.6 |
N2i—C1—C4 | 102.5 (3) | C6—C7—H7B | 108.6 |
N1i—C1—C4 | 104.7 (3) | C8—C7—H7B | 108.6 |
N1—C1—C4 | 126.3 (3) | H7A—C7—H7B | 107.6 |
N2—C1—C4 | 126.2 (3) | O3—C8—O4 | 123.73 (16) |
C3—C2—N2 | 107.3 (4) | O3—C8—C7 | 120.83 (13) |
C3—C2—N2i | 102.1 (3) | O4—C8—C7 | 115.43 (12) |
C3—C2—H6 | 126.3 | N1i—N1—C3 | 140.6 (3) |
N2—C2—H6 | 126.3 | C1—N1—C3 | 109.7 (3) |
N2i—C2—H6 | 130.3 | C3—N1—C3i | 113.0 (4) |
C2—C3—N1 | 106.6 (4) | C1i—N1—H1 | 138 (3) |
C2—C3—N1i | 102.3 (3) | C1—N1—H1 | 127 (3) |
C2—C3—H7 | 126.7 | C3—N1—H1 | 121 (3) |
N1—C3—H7 | 126.7 | C3i—N1—H1 | 103 (3) |
N1i—C3—H7 | 129.9 | N2i—N2—C2 | 139.8 (3) |
O2—C5—O1 | 122.89 (17) | C1—N2—C2 | 108.9 (3) |
O2—C5—C6 | 124.44 (13) | C2—N2—C2i | 112.3 (4) |
O1—C5—C6 | 112.66 (12) | C1i—N2—H2 | 143 (3) |
C5—C6—C7 | 113.17 (16) | C1—N2—H2 | 128 (3) |
C5—C6—H6A | 108.9 | C2—N2—H2 | 123 (4) |
C7—C6—H6A | 108.9 | C2i—N2—H2 | 97 (4) |
C5—C6—H6B | 108.9 | C5—O1—H1A | 106 (3) |
C7—C6—H6B | 108.9 | | |
| | | |
N2—C2—C3—N1 | 0.0 (5) | C2—C3—N1—C1 | 0.2 (5) |
N2i—C2—C3—N1 | 12.0 (5) | N1i—C3—N1—C1 | 70.1 (4) |
N2—C2—C3—N1i | −11.2 (5) | C2—C3—N1—C3i | −69.9 (5) |
N2i—C2—C3—N1i | 0.8 (4) | N1i—C3—N1—C3i | 0.001 (2) |
O2—C5—C6—C7 | 0.0 (3) | N1i—C1—N2—N2i | −114.4 (4) |
O1—C5—C6—C7 | 180.0 (3) | N1—C1—N2—N2i | −136.7 (3) |
C5—C6—C7—C8 | 180.0 | C4—C1—N2—N2i | 42.1 (3) |
C6—C7—C8—O3 | 0.0 (3) | N2i—C1—N2—C1i | 180.001 (3) |
C6—C7—C8—O4 | 180.0 (3) | N1i—C1—N2—C1i | 65.6 (4) |
N2i—C1—N1—N1i | 112.1 (4) | N1—C1—N2—C1i | 43.3 (3) |
N2—C1—N1—N1i | 137.3 (3) | C4—C1—N2—C1i | −137.9 (3) |
C4—C1—N1—N1i | −41.5 (3) | N2i—C1—N2—C2 | 137.1 (3) |
N2i—C1—N1—C1i | −67.9 (4) | N1i—C1—N2—C2 | 22.7 (6) |
N1i—C1—N1—C1i | 179.999 (4) | N1—C1—N2—C2 | 0.4 (4) |
N2—C1—N1—C1i | −42.7 (3) | C4—C1—N2—C2 | 179.2 (4) |
C4—C1—N1—C1i | 138.5 (3) | N2i—C1—N2—C2i | 31.2 (2) |
N2i—C1—N1—C3 | −25.6 (6) | N1i—C1—N2—C2i | −83.2 (4) |
N1i—C1—N1—C3 | −137.7 (3) | N1—C1—N2—C2i | −105.5 (3) |
N2—C1—N1—C3 | −0.4 (4) | C4—C1—N2—C2i | 73.3 (4) |
C4—C1—N1—C3 | −179.2 (4) | C3—C2—N2—N2i | 67.2 (5) |
N2i—C1—N1—C3i | 81.2 (4) | C3—C2—N2—C1i | −18.9 (5) |
N1i—C1—N1—C3i | −30.9 (2) | N2i—C2—N2—C1i | −86.1 (3) |
N2—C1—N1—C3i | 106.5 (3) | C3—C2—N2—C1 | −0.2 (5) |
C4—C1—N1—C3i | −72.4 (4) | N2i—C2—N2—C1 | −67.5 (3) |
C2—C3—N1—N1i | −69.9 (5) | C3—C2—N2—C2i | 67.2 (5) |
C2—C3—N1—C1i | 18.8 (4) | N2i—C2—N2—C2i | −0.003 (4) |
N1i—C3—N1—C1i | 88.7 (4) | | |
Symmetry code: (i) −x+1, y, z. |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1···O3ii | 0.86 (2) | 1.87 (2) | 2.691 (4) | 158 (4) |
N2—H2···O4 | 0.87 (2) | 1.81 (2) | 2.680 (4) | 175 (6) |
O1—H1A···O4iii | 0.81 (2) | 1.76 (2) | 2.558 (3) | 169 (5) |
C2—H6···O2iv | 0.93 | 2.40 | 3.113 (5) | 134 |
C3—H7···O3v | 0.93 | 2.38 | 3.311 (5) | 175 |
C4—H4C···O2vi | 0.96 | 2.58 | 3.455 (5) | 152 |
Symmetry codes: (ii) −x+1, −y, z−1/2; (iii) x, y+1, z; (iv) x−1/2, y−1/2, z; (v) −x+1/2, −y+1/2, z−1/2; (vi) x, y−1, z. |
(II) 2-methylimidazolium hydrogen glutarate]
top
Crystal data top
C4H7N2+·C5H7O4− | Z = 2 |
Mr = 214.22 | F(000) = 228 |
Triclinic, P1 | Dx = 1.283 Mg m−3 |
Hall symbol: -P 1 | Mo Kα radiation, λ = 0.71073 Å |
a = 5.4433 (10) Å | Cell parameters from 2213 reflections |
b = 8.3842 (16) Å | θ = 2.5–27.2° |
c = 12.598 (2) Å | µ = 0.10 mm−1 |
α = 77.910 (3)° | T = 295 K |
β = 82.342 (3)° | Plate, colourless |
γ = 82.971 (3)° | 0.40 × 0.15 × 0.04 mm |
V = 554.51 (18) Å3 | |
Data collection top
Bruker SMART APEX CCD area-detector diffractometer | 2151 independent reflections |
Radiation source: fine focus sealed Siemens Mo tube | 1720 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.022 |
0.3° wide ω exposures scans | θmax = 26.0°, θmin = 2.5° |
Absorption correction: multi-scan (SADABS; Sheldrick, 1997) | h = −6→6 |
Tmin = 0.951, Tmax = 0.996 | k = −10→10 |
5770 measured reflections | l = −15→15 |
Refinement top
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)] = 0.052 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.158 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.09 | w = 1/[σ2(Fo2) + (0.0847P)2 + 0.1211P] where P = (Fo2 + 2Fc2)/3 |
2151 reflections | (Δ/σ)max < 0.001 |
144 parameters | Δρmax = 0.30 e Å−3 |
2 restraints | Δρmin = −0.20 e Å−3 |
Crystal data top
C4H7N2+·C5H7O4− | γ = 82.971 (3)° |
Mr = 214.22 | V = 554.51 (18) Å3 |
Triclinic, P1 | Z = 2 |
a = 5.4433 (10) Å | Mo Kα radiation |
b = 8.3842 (16) Å | µ = 0.10 mm−1 |
c = 12.598 (2) Å | T = 295 K |
α = 77.910 (3)° | 0.40 × 0.15 × 0.04 mm |
β = 82.342 (3)° | |
Data collection top
Bruker SMART APEX CCD area-detector diffractometer | 2151 independent reflections |
Absorption correction: multi-scan (SADABS; Sheldrick, 1997) | 1720 reflections with I > 2σ(I) |
Tmin = 0.951, Tmax = 0.996 | Rint = 0.022 |
5770 measured reflections | |
Refinement top
R[F2 > 2σ(F2)] = 0.052 | 2 restraints |
wR(F2) = 0.158 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.09 | Δρmax = 0.30 e Å−3 |
2151 reflections | Δρmin = −0.20 e Å−3 |
144 parameters | |
Special details top
Geometry. All esds (except the esd in the dihedral angle between two l.s. planes)
are estimated using the full covariance matrix. The cell esds are taken
into account individually in the estimation of esds in distances, angles
and torsion angles; correlations between esds in cell parameters are only
used when they are defined by crystal symmetry. An approximate (isotropic)
treatment of cell esds is used for estimating esds 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 > 2sigma(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. |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top | x | y | z | Uiso*/Ueq | |
C1 | 1.3853 (4) | 0.3476 (2) | 0.31741 (16) | 0.0485 (5) | |
C2 | 1.5761 (4) | 0.3084 (3) | 0.15818 (17) | 0.0533 (5) | |
H2 | 1.6106 | 0.3135 | 0.0833 | 0.064* | |
C3 | 1.7171 (4) | 0.2286 (3) | 0.23501 (17) | 0.0539 (5) | |
H3 | 1.8694 | 0.1674 | 0.2239 | 0.065* | |
C4 | 1.2019 (4) | 0.4052 (3) | 0.4020 (2) | 0.0693 (7) | |
H4A | 1.1511 | 0.3128 | 0.4560 | 0.104* | |
H4B | 1.0594 | 0.4633 | 0.3689 | 0.104* | |
H4C | 1.2761 | 0.4769 | 0.4360 | 0.104* | |
C5 | 0.8425 (3) | 0.6691 (2) | 0.09582 (15) | 0.0458 (5) | |
C6 | 0.6260 (4) | 0.7925 (3) | 0.12038 (16) | 0.0541 (5) | |
H6A | 0.6654 | 0.9008 | 0.0820 | 0.065* | |
H6B | 0.4805 | 0.7678 | 0.0923 | 0.065* | |
C7 | 0.5627 (3) | 0.7953 (2) | 0.24066 (14) | 0.0453 (5) | |
H7A | 0.6950 | 0.8401 | 0.2661 | 0.054* | |
H7B | 0.5519 | 0.6841 | 0.2813 | 0.054* | |
C8 | 0.3183 (3) | 0.8970 (2) | 0.26297 (14) | 0.0445 (5) | |
H8A | 0.3319 | 1.0086 | 0.2234 | 0.053* | |
H8B | 0.1883 | 0.8540 | 0.2348 | 0.053* | |
C9 | 0.2418 (3) | 0.9001 (2) | 0.38207 (15) | 0.0434 (4) | |
N1 | 1.3706 (3) | 0.3814 (2) | 0.21091 (14) | 0.0520 (5) | |
H1A | 1.254 (4) | 0.450 (2) | 0.1791 (18) | 0.062* | |
N2 | 1.5957 (3) | 0.2536 (2) | 0.33310 (14) | 0.0521 (5) | |
H2A | 1.641 (4) | 0.218 (3) | 0.3976 (14) | 0.062* | |
O1 | 0.8437 (3) | 0.61753 (19) | 0.00735 (11) | 0.0612 (5) | |
H1B | 1.0000 | 0.5000 | 0.0000 | 0.092* | |
O2 | 1.0001 (3) | 0.6231 (2) | 0.15861 (15) | 0.0774 (6) | |
O3 | 0.0638 (3) | 1.0070 (2) | 0.40194 (11) | 0.0676 (5) | |
H1C | 0.0000 | 1.0000 | 0.5000 | 0.101* | |
O4 | 0.3432 (3) | 0.8026 (2) | 0.45303 (12) | 0.0759 (6) | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
C1 | 0.0462 (10) | 0.0512 (11) | 0.0479 (11) | 0.0012 (9) | −0.0067 (8) | −0.0114 (9) |
C2 | 0.0522 (11) | 0.0641 (13) | 0.0431 (11) | 0.0048 (10) | −0.0076 (9) | −0.0142 (9) |
C3 | 0.0460 (11) | 0.0615 (12) | 0.0519 (12) | 0.0092 (9) | −0.0064 (9) | −0.0136 (10) |
C4 | 0.0612 (14) | 0.0805 (16) | 0.0641 (14) | 0.0048 (12) | 0.0043 (11) | −0.0234 (12) |
C5 | 0.0430 (10) | 0.0518 (11) | 0.0413 (10) | 0.0118 (8) | −0.0044 (8) | −0.0155 (8) |
C6 | 0.0547 (11) | 0.0634 (12) | 0.0405 (10) | 0.0250 (10) | −0.0069 (8) | −0.0182 (9) |
C7 | 0.0435 (10) | 0.0524 (11) | 0.0387 (10) | 0.0112 (8) | −0.0060 (8) | −0.0144 (8) |
C8 | 0.0413 (9) | 0.0539 (11) | 0.0374 (10) | 0.0100 (8) | −0.0059 (7) | −0.0145 (8) |
C9 | 0.0418 (9) | 0.0502 (10) | 0.0376 (10) | 0.0067 (8) | −0.0047 (7) | −0.0135 (8) |
N1 | 0.0482 (9) | 0.0571 (10) | 0.0495 (10) | 0.0106 (8) | −0.0154 (7) | −0.0106 (8) |
N2 | 0.0523 (10) | 0.0617 (11) | 0.0398 (9) | 0.0056 (8) | −0.0126 (7) | −0.0063 (8) |
O1 | 0.0630 (9) | 0.0801 (10) | 0.0388 (7) | 0.0296 (8) | −0.0106 (6) | −0.0260 (7) |
O2 | 0.0673 (10) | 0.0933 (12) | 0.0841 (12) | 0.0448 (9) | −0.0411 (9) | −0.0554 (10) |
O3 | 0.0694 (10) | 0.0807 (11) | 0.0419 (8) | 0.0377 (8) | −0.0005 (7) | −0.0172 (7) |
O4 | 0.0836 (11) | 0.0936 (12) | 0.0380 (8) | 0.0439 (10) | −0.0083 (8) | −0.0143 (8) |
Geometric parameters (Å, º) top
C1—N2 | 1.322 (3) | C6—H6A | 0.9700 |
C1—N1 | 1.323 (3) | C6—H6B | 0.9700 |
C1—C4 | 1.476 (3) | C7—C8 | 1.516 (2) |
C2—C3 | 1.332 (3) | C7—H7A | 0.9700 |
C2—N1 | 1.368 (3) | C7—H7B | 0.9700 |
C2—H2 | 0.9300 | C8—C9 | 1.508 (2) |
C3—N2 | 1.366 (3) | C8—H8A | 0.9700 |
C3—H3 | 0.9300 | C8—H8B | 0.9700 |
C4—H4A | 0.9600 | C9—O4 | 1.219 (2) |
C4—H4B | 0.9600 | C9—O3 | 1.273 (2) |
C4—H4C | 0.9600 | N1—H1A | 0.879 (16) |
C5—O2 | 1.218 (2) | N2—H2A | 0.863 (15) |
C5—O1 | 1.276 (2) | O1—H1B | 1.2300 |
C5—C6 | 1.514 (2) | O3—H1C | 1.2300 |
C6—C7 | 1.513 (2) | | |
| | | |
N2—C1—N1 | 106.83 (17) | C6—C7—H7A | 109.2 |
N2—C1—C4 | 126.8 (2) | C8—C7—H7A | 109.2 |
N1—C1—C4 | 126.36 (19) | C6—C7—H7B | 109.2 |
C3—C2—N1 | 106.63 (18) | C8—C7—H7B | 109.2 |
C3—C2—H2 | 126.7 | H7A—C7—H7B | 107.9 |
N1—C2—H2 | 126.7 | C9—C8—C7 | 114.24 (15) |
C2—C3—N2 | 107.02 (18) | C9—C8—H8A | 108.7 |
C2—C3—H3 | 126.5 | C7—C8—H8A | 108.7 |
N2—C3—H3 | 126.5 | C9—C8—H8B | 108.7 |
C1—C4—H4A | 109.5 | C7—C8—H8B | 108.7 |
C1—C4—H4B | 109.5 | H8A—C8—H8B | 107.6 |
H4A—C4—H4B | 109.5 | O4—C9—O3 | 123.56 (17) |
C1—C4—H4C | 109.5 | O4—C9—C8 | 120.82 (16) |
H4A—C4—H4C | 109.5 | O3—C9—C8 | 115.60 (16) |
H4B—C4—H4C | 109.5 | C1—N1—C2 | 109.79 (17) |
O2—C5—O1 | 123.74 (16) | C1—N1—O2 | 110.98 (13) |
O2—C5—C6 | 120.79 (16) | C2—N1—O2 | 137.56 (14) |
O1—C5—C6 | 115.46 (16) | C1—N1—H1A | 124.3 (15) |
C7—C6—C5 | 113.96 (16) | C2—N1—H1A | 125.5 (15) |
C7—C6—H6A | 108.8 | C1—N2—C3 | 109.72 (17) |
C5—C6—H6A | 108.8 | C1—N2—H2A | 121.6 (15) |
C7—C6—H6B | 108.8 | C3—N2—H2A | 128.6 (15) |
C5—C6—H6B | 108.8 | C5—O1—H1B | 112 |
H6A—C6—H6B | 107.7 | C5—O2—N1 | 142.40 (13) |
C6—C7—C8 | 111.89 (15) | C9—O3—H1C | 113 |
| | | |
N1—C2—C3—N2 | 0.2 (2) | C4—C1—N1—O2 | 11.3 (3) |
O2—C5—C6—C7 | −24.7 (3) | C3—C2—N1—C1 | 0.1 (2) |
O1—C5—C6—C7 | 154.35 (19) | C3—C2—N1—O2 | 163.37 (17) |
C5—C6—C7—C8 | −169.60 (17) | N1—C1—N2—C3 | 0.5 (2) |
C6—C7—C8—C9 | 178.28 (17) | C4—C1—N2—C3 | −179.1 (2) |
C7—C8—C9—O4 | −14.0 (3) | C2—C3—N2—C1 | −0.4 (2) |
C7—C8—C9—O3 | 167.67 (18) | O1—C5—O2—N1 | −16.5 (4) |
N2—C1—N1—C2 | −0.4 (2) | C6—C5—O2—N1 | 162.5 (2) |
C4—C1—N1—C2 | 179.2 (2) | C1—N1—O2—C5 | −145.3 (3) |
N2—C1—N1—O2 | −168.37 (13) | C2—N1—O2—C5 | 51.5 (4) |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
N2—H2A···O4i | 0.86 (2) | 1.87 (2) | 2.695 (2) | 161 (2) |
O1—H1B···O1ii | 1.23 | 1.23 | 2.462 (3) | 180 |
O3—H1C···O3iii | 1.23 | 1.23 | 2.458 (3) | 180 |
N1—H1A···O2 | 0.88 (2) | 1.88 (2) | 2.720 (2) | 159 (2) |
Symmetry codes: (i) −x+2, −y+1, −z+1; (ii) −x+2, −y+1, −z; (iii) −x, −y+2, −z+1. |
(III) 2-methylimidazolium hydrogen adipate monohydrate
top
Crystal data top
C4H7N2+·C6H9O4−·H2O | Z = 2 |
Mr = 246.26 | F(000) = 264 |
Triclinic, P1 | Dx = 1.298 Mg m−3 |
Hall symbol: -P 1 | Mo Kα radiation, λ = 0.71073 Å |
a = 4.9383 (4) Å | Cell parameters from 2128 reflections |
b = 8.0682 (6) Å | θ = 2.5–28.3° |
c = 16.6840 (13) Å | µ = 0.10 mm−1 |
α = 96.880 (1)° | T = 297 K |
β = 92.794 (1)° | Block, colourless |
γ = 106.611 (1)° | 0.20 × 0.20 × 0.10 mm |
V = 630.00 (8) Å3 | |
Data collection top
Bruker SMART APEX CCD area-detector diffractometer | 2421 independent reflections |
Radiation source: fine focus sealed Siemens Mo tube | 1905 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.019 |
0.3° wide ω exposures scans | θmax = 26.0°, θmin = 2.5° |
Absorption correction: multi-scan (SADABS; Sheldrick, 1997) | h = −6→6 |
Tmin = 0.970, Tmax = 0.990 | k = −9→9 |
6477 measured reflections | l = −20→20 |
Refinement top
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)] = 0.050 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.159 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.10 | w = 1/[σ2(Fo2) + (0.0972P)2 + 0.0502P] where P = (Fo2 + 2Fc2)/3 |
2421 reflections | (Δ/σ)max < 0.001 |
173 parameters | Δρmax = 0.25 e Å−3 |
7 restraints | Δρmin = −0.21 e Å−3 |
Crystal data top
C4H7N2+·C6H9O4−·H2O | γ = 106.611 (1)° |
Mr = 246.26 | V = 630.00 (8) Å3 |
Triclinic, P1 | Z = 2 |
a = 4.9383 (4) Å | Mo Kα radiation |
b = 8.0682 (6) Å | µ = 0.10 mm−1 |
c = 16.6840 (13) Å | T = 297 K |
α = 96.880 (1)° | 0.20 × 0.20 × 0.10 mm |
β = 92.794 (1)° | |
Data collection top
Bruker SMART APEX CCD area-detector diffractometer | 2421 independent reflections |
Absorption correction: multi-scan (SADABS; Sheldrick, 1997) | 1905 reflections with I > 2σ(I) |
Tmin = 0.970, Tmax = 0.990 | Rint = 0.019 |
6477 measured reflections | |
Refinement top
R[F2 > 2σ(F2)] = 0.050 | 7 restraints |
wR(F2) = 0.159 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.10 | Δρmax = 0.25 e Å−3 |
2421 reflections | Δρmin = −0.21 e Å−3 |
173 parameters | |
Special details top
Geometry. All esds (except the esd in the dihedral angle between two l.s. planes)
are estimated using the full covariance matrix. The cell esds are taken
into account individually in the estimation of esds in distances, angles
and torsion angles; correlations between esds in cell parameters are only
used when they are defined by crystal symmetry. An approximate (isotropic)
treatment of cell esds is used for estimating esds 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 > 2sigma(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. |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top | x | y | z | Uiso*/Ueq | Occ. (<1) |
C1 | 0.2664 (4) | 0.9849 (2) | 0.26207 (12) | 0.0407 (5) | |
C2 | 0.2364 (4) | 0.8946 (2) | 0.38189 (13) | 0.0486 (5) | |
H2 | 0.1930 | 0.8843 | 0.4350 | 0.058* | |
C3 | 0.3761 (5) | 0.8038 (3) | 0.33743 (14) | 0.0530 (5) | |
H3 | 0.4482 | 0.7174 | 0.3537 | 0.064* | |
C4 | 0.2385 (5) | 1.0795 (3) | 0.19338 (13) | 0.0579 (6) | |
H4A | 0.0583 | 1.0243 | 0.1630 | 0.087* | |
H4B | 0.3880 | 1.0775 | 0.1589 | 0.087* | |
H4C | 0.2510 | 1.1983 | 0.2134 | 0.087* | |
C5 | 0.7289 (4) | 0.5974 (2) | 0.16367 (10) | 0.0371 (4) | |
C6 | 0.8623 (5) | 0.4902 (3) | 0.10637 (11) | 0.0445 (5) | |
H6A | 1.0337 | 0.4815 | 0.1342 | 0.053* | |
H6B | 0.7327 | 0.3730 | 0.0939 | 0.053* | |
C7 | 0.9369 (4) | 0.5593 (2) | 0.02766 (11) | 0.0400 (5) | |
H7A | 1.0723 | 0.6748 | 0.0393 | 0.048* | |
H7B | 0.7674 | 0.5703 | −0.0004 | 0.048* | |
C8 | 0.8109 (3) | 0.3255 (2) | 0.36414 (11) | 0.0341 (4) | |
C9 | 0.6488 (4) | 0.4454 (2) | 0.39884 (10) | 0.0333 (4) | |
H9A | 0.4761 | 0.4240 | 0.3639 | 0.040* | |
H9B | 0.7616 | 0.5648 | 0.3970 | 0.040* | |
C10 | 0.5691 (4) | 0.4305 (2) | 0.48431 (10) | 0.0326 (4) | |
H10A | 0.7378 | 0.4424 | 0.5195 | 0.039* | |
H10B | 0.4386 | 0.3156 | 0.4859 | 0.039* | |
N1 | 0.3944 (4) | 0.8610 (2) | 0.26335 (11) | 0.0463 (4) | |
H1 | 0.472 (4) | 0.821 (3) | 0.2210 (11) | 0.056* | |
N2 | 0.1689 (3) | 1.0066 (2) | 0.33376 (10) | 0.0428 (4) | |
H2A | 0.076 (4) | 1.086 (2) | 0.3508 (12) | 0.051* | |
O1 | 0.6446 (3) | 0.71668 (17) | 0.14081 (8) | 0.0495 (4) | |
O2 | 0.7027 (3) | 0.5613 (2) | 0.23510 (8) | 0.0565 (4) | |
H2B | 0.795 (5) | 0.453 (3) | 0.2611 (15) | 0.085* | |
O3 | 0.8821 (3) | 0.33834 (18) | 0.29100 (8) | 0.0516 (4) | |
O4 | 0.8761 (3) | 0.22082 (16) | 0.40353 (8) | 0.0445 (4) | |
O5 | 0.7220 (4) | 0.9398 (4) | 0.01894 (16) | 0.0995 (8) | |
H5D | 0.699 (9) | 0.876 (5) | 0.053 (2) | 0.149* | |
H5E | 0.610 (13) | 0.998 (8) | 0.018 (4) | 0.149* | 0.50 |
H5F | 0.870 (9) | 0.964 (11) | 0.001 (4) | 0.149* | 0.50 |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
C1 | 0.0427 (10) | 0.0395 (9) | 0.0424 (11) | 0.0173 (8) | 0.0078 (8) | 0.0005 (8) |
C2 | 0.0633 (13) | 0.0473 (11) | 0.0439 (12) | 0.0252 (9) | 0.0188 (10) | 0.0125 (9) |
C3 | 0.0687 (13) | 0.0504 (11) | 0.0548 (13) | 0.0349 (10) | 0.0185 (10) | 0.0176 (9) |
C4 | 0.0728 (15) | 0.0595 (13) | 0.0463 (13) | 0.0262 (11) | 0.0057 (11) | 0.0098 (10) |
C5 | 0.0465 (10) | 0.0427 (9) | 0.0289 (10) | 0.0207 (8) | 0.0135 (8) | 0.0088 (7) |
C6 | 0.0622 (12) | 0.0503 (10) | 0.0345 (11) | 0.0328 (9) | 0.0206 (9) | 0.0126 (8) |
C7 | 0.0528 (11) | 0.0465 (10) | 0.0310 (10) | 0.0271 (8) | 0.0170 (8) | 0.0090 (8) |
C8 | 0.0360 (9) | 0.0373 (9) | 0.0331 (10) | 0.0177 (7) | 0.0066 (7) | 0.0024 (7) |
C9 | 0.0412 (9) | 0.0376 (9) | 0.0294 (10) | 0.0229 (7) | 0.0104 (7) | 0.0061 (7) |
C10 | 0.0401 (9) | 0.0373 (9) | 0.0276 (9) | 0.0218 (7) | 0.0082 (7) | 0.0052 (7) |
N1 | 0.0551 (10) | 0.0455 (9) | 0.0475 (11) | 0.0279 (7) | 0.0186 (8) | 0.0046 (7) |
N2 | 0.0485 (9) | 0.0402 (8) | 0.0461 (10) | 0.0239 (7) | 0.0132 (7) | 0.0006 (7) |
O1 | 0.0721 (9) | 0.0555 (8) | 0.0392 (8) | 0.0406 (7) | 0.0257 (7) | 0.0162 (6) |
O2 | 0.0887 (11) | 0.0718 (10) | 0.0346 (8) | 0.0548 (8) | 0.0298 (7) | 0.0207 (7) |
O3 | 0.0747 (10) | 0.0631 (9) | 0.0363 (8) | 0.0454 (7) | 0.0260 (7) | 0.0115 (6) |
O4 | 0.0567 (8) | 0.0489 (7) | 0.0420 (8) | 0.0354 (6) | 0.0121 (6) | 0.0098 (6) |
O5 | 0.0818 (14) | 0.1386 (19) | 0.1154 (19) | 0.0578 (14) | 0.0331 (12) | 0.0908 (15) |
Geometric parameters (Å, º) top
C1—N2 | 1.322 (2) | C7—H7A | 0.9700 |
C1—N1 | 1.329 (2) | C7—H7B | 0.9700 |
C1—C4 | 1.472 (3) | C8—O4 | 1.232 (2) |
C2—C3 | 1.331 (3) | C8—O3 | 1.294 (2) |
C2—N2 | 1.376 (3) | C8—C9 | 1.505 (2) |
C2—H2 | 0.9300 | C9—C10 | 1.507 (2) |
C3—N1 | 1.368 (3) | C9—H9A | 0.9700 |
C3—H3 | 0.9300 | C9—H9B | 0.9700 |
C4—H4A | 0.9600 | C10—C10ii | 1.526 (3) |
C4—H4B | 0.9600 | C10—H10A | 0.9700 |
C4—H4C | 0.9600 | C10—H10B | 0.9700 |
C5—O1 | 1.244 (2) | N1—H1 | 0.890 (15) |
C5—O2 | 1.264 (2) | N2—H2A | 0.915 (15) |
C5—C6 | 1.511 (2) | O2—H2B | 1.21 (3) |
C6—C7 | 1.509 (3) | O3—H2B | 1.26 (3) |
C6—H6A | 0.9700 | O5—H5D | 0.80 (4) |
C6—H6B | 0.9700 | O5—H5E | 0.82 (2) |
C7—C7i | 1.530 (3) | O5—H5F | 0.785 (19) |
| | | |
N2—C1—N1 | 107.10 (18) | C7i—C7—H7B | 109.1 |
N2—C1—C4 | 126.71 (18) | H7A—C7—H7B | 107.9 |
N1—C1—C4 | 126.18 (18) | O4—C8—O3 | 121.13 (15) |
C3—C2—N2 | 106.48 (18) | O4—C8—C9 | 121.84 (16) |
C3—C2—H2 | 126.8 | O3—C8—C9 | 117.03 (14) |
N2—C2—H2 | 126.8 | C8—C9—C10 | 116.58 (14) |
C2—C3—N1 | 107.48 (19) | C8—C9—H9A | 108.1 |
C2—C3—H3 | 126.3 | C10—C9—H9A | 108.1 |
N1—C3—H3 | 126.3 | C8—C9—H9B | 108.1 |
C1—C4—H4A | 109.5 | C10—C9—H9B | 108.2 |
C1—C4—H4B | 109.5 | H9A—C9—H9B | 107.3 |
H4A—C4—H4B | 109.5 | C9—C10—C10ii | 111.84 (17) |
C1—C4—H4C | 109.5 | C9—C10—H10A | 109.2 |
H4A—C4—H4C | 109.5 | C10ii—C10—H10A | 109.2 |
H4B—C4—H4C | 109.5 | C9—C10—H10B | 109.3 |
O1—C5—O2 | 120.97 (16) | C10ii—C10—H10B | 109.2 |
O1—C5—C6 | 120.80 (15) | H10A—C10—H10B | 107.9 |
O2—C5—C6 | 118.23 (16) | C1—N1—C3 | 109.24 (17) |
C7—C6—C5 | 115.71 (15) | C1—N1—H1 | 123.6 (14) |
C7—C6—H6A | 108.4 | C3—N1—H1 | 127.1 (14) |
C5—C6—H6A | 108.4 | C1—N2—C2 | 109.70 (16) |
C7—C6—H6B | 108.4 | C1—N2—H2A | 126.5 (13) |
C5—C6—H6B | 108.4 | C2—N2—H2A | 123.8 (13) |
H6A—C6—H6B | 107.4 | C5—O2—H2B | 123.0 (13) |
C6—C7—C7i | 112.34 (18) | C8—O3—H2B | 111.4 (12) |
C6—C7—H7A | 109.1 | H5D—O5—H5E | 114 (3) |
C7i—C7—H7A | 109.1 | H5D—O5—H5F | 118 (4) |
C6—C7—H7B | 109.1 | H5E—O5—H5F | 125 (6) |
| | | |
N2—C2—C3—N1 | 0.3 (2) | N2—C1—N1—C3 | 0.1 (2) |
O1—C5—C6—C7 | 11.5 (3) | C4—C1—N1—C3 | −179.76 (19) |
O2—C5—C6—C7 | −169.22 (17) | C2—C3—N1—C1 | −0.3 (2) |
C5—C6—C7—C7i | −178.4 (2) | N1—C1—N2—C2 | 0.1 (2) |
O4—C8—C9—C10 | −0.2 (2) | C4—C1—N2—C2 | 179.98 (18) |
O3—C8—C9—C10 | −179.49 (14) | C3—C2—N2—C1 | −0.3 (2) |
C8—C9—C10—C10ii | 174.59 (17) | | |
Symmetry codes: (i) −x+2, −y+1, −z; (ii) −x+1, −y+1, −z+1. |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1···O1 | 0.89 (2) | 1.87 (2) | 2.751 (2) | 172 (2) |
N2—H2A···O4iii | 0.91 (2) | 1.85 (2) | 2.7464 (19) | 168 (2) |
O2—H2B···O3 | 1.22 (2) | 1.25 (2) | 2.4747 (19) | 177 (2) |
O5—H5D···O1 | 0.80 (4) | 2.04 (4) | 2.843 (2) | 178 (4) |
O5—H5F···O5iv | 0.79 (2) | 2.01 (3) | 2.770 (4) | 162 (7) |
O5—H5E···O5v | 0.83 (2) | 1.93 (3) | 2.715 (4) | 157 (7) |
Symmetry codes: (iii) x−1, y+1, z; (iv) −x+2, −y+2, −z; (v) −x+1, −y+2, −z. |
Experimental details
| (I) | (II) | (III) |
Crystal data |
Chemical formula | C4H7N2+·C4H5O4− | C4H7N2+·C5H7O4− | C4H7N2+·C6H9O4−·H2O |
Mr | 200.20 | 214.22 | 246.26 |
Crystal system, space group | Orthorhombic, Cmc21 | Triclinic, P1 | Triclinic, P1 |
Temperature (K) | 296 | 295 | 297 |
a, b, c (Å) | 6.8017 (10), 8.1580 (11), 17.438 (2) | 5.4433 (10), 8.3842 (16), 12.598 (2) | 4.9383 (4), 8.0682 (6), 16.6840 (13) |
α, β, γ (°) | 90, 90, 90 | 77.910 (3), 82.342 (3), 82.971 (3) | 96.880 (1), 92.794 (1), 106.611 (1) |
V (Å3) | 967.6 (2) | 554.51 (18) | 630.00 (8) |
Z | 4 | 2 | 2 |
Radiation type | Mo Kα | Mo Kα | Mo Kα |
µ (mm−1) | 0.11 | 0.10 | 0.10 |
Crystal size (mm) | 0.25 × 0.12 × 0.08 | 0.40 × 0.15 × 0.04 | 0.20 × 0.20 × 0.10 |
|
Data collection |
Diffractometer | Bruker SMART APEX CCD area-detector diffractometer | Bruker SMART APEX CCD area-detector diffractometer | Bruker SMART APEX CCD area-detector diffractometer |
Absorption correction | Multi-scan (SADABS; Sheldrick, 1997) | Multi-scan (SADABS; Sheldrick, 1997) | Multi-scan (SADABS; Sheldrick, 1997) |
Tmin, Tmax | 0.963, 0.991 | 0.951, 0.996 | 0.970, 0.990 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 5389, 654, 573 | 5770, 2151, 1720 | 6477, 2421, 1905 |
Rint | 0.024 | 0.022 | 0.019 |
(sin θ/λ)max (Å−1) | 0.666 | 0.617 | 0.617 |
|
Refinement |
R[F2 > 2σ(F2)], wR(F2), S | 0.034, 0.092, 1.10 | 0.052, 0.158, 1.09 | 0.050, 0.159, 1.10 |
No. of reflections | 654 | 2151 | 2421 |
No. of parameters | 112 | 144 | 173 |
No. of restraints | 4 | 2 | 7 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement | H atoms treated by a mixture of independent and constrained refinement | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 0.21, −0.14 | 0.30, −0.20 | 0.25, −0.21 |
Hydrogen-bond geometry (Å, º) for (I) top
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1···O3i | 0.86 (2) | 1.87 (2) | 2.691 (4) | 158 (4) |
N2—H2···O4 | 0.87 (2) | 1.81 (2) | 2.680 (4) | 175 (6) |
O1—H1A···O4ii | 0.81 (2) | 1.76 (2) | 2.558 (3) | 169 (5) |
C2—H6···O2iii | 0.93 | 2.40 | 3.113 (5) | 133.8 |
C3—H7···O3iv | 0.93 | 2.38 | 3.311 (5) | 174.5 |
C4—H4C···O2v | 0.96 | 2.58 | 3.455 (5) | 151.5 |
Symmetry codes: (i) −x+1, −y, z−1/2; (ii) x, y+1, z; (iii) x−1/2, y−1/2, z; (iv) −x+1/2, −y+1/2, z−1/2; (v) x, y−1, z. |
Hydrogen-bond geometry (Å, º) for (II) top
D—H···A | D—H | H···A | D···A | D—H···A |
N2—H2A···O4i | 0.863 (15) | 1.865 (17) | 2.695 (2) | 161 (2) |
O1—H1B···O1ii | 1.23 | 1.23 | 2.462 (3) | 180 |
O3—H1C···O3iii | 1.23 | 1.23 | 2.458 (3) | 180 |
N1—H1A···O2 | 0.879 (16) | 1.881 (17) | 2.720 (2) | 159 (2) |
Symmetry codes: (i) −x+2, −y+1, −z+1; (ii) −x+2, −y+1, −z; (iii) −x, −y+2, −z+1. |
Hydrogen-bond geometry (Å, º) for (III) top
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1···O1 | 0.889 (15) | 1.867 (16) | 2.751 (2) | 172 (2) |
N2—H2A···O4i | 0.913 (15) | 1.846 (16) | 2.7464 (19) | 168.4 (19) |
O2—H2B···O3 | 1.22 (2) | 1.25 (2) | 2.4747 (19) | 177 (2) |
O5—H5D···O1 | 0.80 (4) | 2.04 (4) | 2.843 (2) | 178 (4) |
O5—H5F···O5ii | 0.785 (19) | 2.01 (3) | 2.770 (4) | 162 (7) |
O5—H5E···O5iii | 0.825 (19) | 1.93 (3) | 2.715 (4) | 157 (7) |
Symmetry codes: (i) x−1, y+1, z; (ii) −x+2, −y+2, −z; (iii) −x+1, −y+2, −z. |
ΔpKa [= pKa (BaseH+ - Acid)] for the three title
compounds in water topCompound | Molecular component | ΔpKa1 | ΔpKa2 |
(I) | 2-MeIm and Succ | 3.91 | 2.63 |
(II) | 2-MeIm and Glut | 3.82 | 2.88 |
(III) | 2-MeIm and Adip | 3.76 | 3.02 |
2-MeIm = 2-methyl-imidazole, pKa = 8.15 for its conjugated cation.
Succ = succinic acid, pKa1 = 4.24, pKa2 = 5.52.
Glut = glutaric acid, pKa1 = 4.33, pKa2 = 5.27.
Adip = adipic acid, pKa1 = 4.39, pKa2 = 5.13.
All the pKa values were calculated using SOLARIS
(Advanced Chemistry Development, 2005). |
In a continuation of our studies of organic salts formed by organic acids and imidazole derivatives (Meng, Xiao et al., 2008; Meng, Lin & Li 2008; Zhou et al., 2009), we now report our findings on the three title compounds, (I)–(III), formed by aliphatic diacids and 2-methylimidazole (2-MeIm).
All three title compounds were obtained as 1:1 organic salts with one H atom transferred from a carboxyl group to an imidazole N atom. This can be corroborated by the distinct variations in the two carboxyl C—O bond lengths [C8—O3 = 1.231 (3) and C8—O4 = 1.278 (2) Å in (I); C5—O1 = 1.276 (2), C5—O2 = 1.218 (2), C9—O3 = 1.273 (2) and C9—O4 = 1.219 (2) Å in (II); C5—O1 = 1.244 (2), C50—O2 = 1.264 (2), C8—O4 = 1.232 (2) and C8—O3 = 1.294 (2) Å in (III)], and by the C—N—C bond angles in the 2-HMeIm cation [108.9 (3) and 109.7 (3)° in (I); 109.79 (17) and 109.72 (17)° in (II); 109.70 (16) and 109.24 (17)° in (III)]. These angles are 108.5 and 109.0° in an analogous compound in the Cambridge Structural Database (Allen, 2002), refcode HILSOL (Qu, 2007). Besides the above-mentioned variations, some differences are also observed in the crystal structures of the three compounds.
Compound (I) crystallizes in the noncentrosymmetric space group Cmc21 and its asymmetric unit consists of a succinate monoanion and a 2-HMeIm cation. During the initial structure determination of (I), two sets of peaks were identified forming intertwined five-membered rings, related by a crystallographic mirror plane (Fig. 1). In the packing of (I), molecules are linked by six intermolecular hydrogen bonds (Table 1) into a three-dimensional network which can be easily analysed in terms of three substructures. Firstly, the succinate anion forms a one-dimensional anionic chain through the O1—H1A···O4(x, 1 + y, z) hydrogen bond running parallel to the [010] direction. Secondly, the 2-HMeIm cation joins these adjacent [010] chains together via an R66(28) hydrogen-bond motif (Bernstein et al., 1995), generating a two-dimensional network parallel to the (100) plane (Fig. 2). Finally, these neighbouring (100) networks are linked by C2—H6···O2(x - 1/2, y - 1/2, z) and C3—H7···O3(-x + 1/2, -y + 1/2, z - 1/2) hydrogen bonds into a three-dimensional network.
The asymmetric unit of (II) contains one 2-HMeIm cation and one hydrogen glutarate anion (Fig. 3). The single carboxylic acid H atom is statistically distributed over the two ends of the carboxylate in short O···H···O bridges over centres of inversion. They link the glutarate anions into a one-dimensional chain parallel to the [211] direction. The 2-HMeIm cations then connect adjacent chains via N1—H1A···O2 and N2—H2A···O4(2 - x, 1 - y, 1 - z) hydrogen bonds, resulting in a two-dimensional network parallel to the (120) plane (Fig. 4). In contrast with (I), all methyl groups on one side of the [211] chain in (II) adopt a head-to-head arrangement, i.e. methyl pointing to methyl (Fig. 4). In the two-dimensional network, R44(24) and R44(32) hydrogen-bonding motifs are shaped by a combination of O1···H1B···O1(2 - x, 1 - y, -z) and O3···H1C···O3(-x, 2 - y, 1 - z) hydrogen bonds. No hydrogen-bond interactions are present between adjacent two-dimensional networks, as reported by PLATON (Spek, 2009).
Similar to (II), compound (III) crystallizes in the P1 space group, but its asymmetric unit is composed of two independent adipate half-molecules and one water molecule (Fig. 5). The two half-molecules are linked into a one-dimensional chain parallel to the [101] direction via the O2—H2B···O3 hydrogen bond. The 2-HMeIm cation links neighbouring chains together, forming a two-dimensional network parallel to the (111) plane. If atom H2B is regarded as a discrete atom, two types of R44(34) hydrogen-bonding motifs are formed (Fig. 6), one narrow and the other wide. It is worth mentioning that the methyl groups on both sides of the [101] chain in (III) adopt an inclined side-by-side arrangement, which is very different from those in (I) and (II). Unlike the anhydrous compounds, (I) and (II), one water solvent molecule is incorporated into the crystal lattice of (III) and plays a pivotal role in forming the three-dimensional network. These water molecules assemble into a one-dimensional water chain via two Owater···Owater hydrogen bonds [2.715 (4) Å, symmetry code (1 - x, 2 - y, -z), and 2.770 (4) Å, symmetry code (2 - x, 2 - y, -z)] parallel to the [100] direction (Fig. 7). The water chain is hydrogen-bonded to the two-dimensional (111) network via O5···O1 [2.843 (2) Å], resulting in a three-dimensional network in (III).
In summary, compounds (I) to (III) are all 1:1 organic salts in which two- or three-dimensional networks are formed. One remaining question is whether a 1:2 salt of an aliphatic diacid with 2-MeIm can be formed. According to the ΔpKa rule [ΔpKa = pKa(base H+) - pKa(acid)], an organic salt is formed when ΔpKa is greater than 3 and a cocrystal is obtained when ΔpKa is less than 0 (Childs & Hardcastle, 2007; Childs et al., 2007). For a system with 0 < ΔpKa < 3, the outcome will be easily affected by the crystallization conditions, such as solvent polarity, temperature, concentration, rate of cooling, etc. In order to identify whether a 1:2 salt of an aliphatic diacid with 2-MeIm exists theoretically, the pKa and ΔpKa values of these diacids and bases in an aqueous medium at 300 K have been calculated using the program SOLARIS (Advanced Chemistry Development, 2005). It can be seen from Table 4 that 1:1 organic salts can be easily formed when they are mixed in aqueous solution. In addition, 2:1 salts may be more likely to be formed in (II) and (III) than in (I). Further work on this is in progress.