Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270103001458/sk1612sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S0108270103001458/sk1612Isup2.hkl |
CCDC reference: 208006
2-Amino-4,6-bis(piperidino)-5-nitrosopyrimidine (Marchal, 2001) was converted into 2-amino-4,6-bis(piperidino)-5-nitropyrimidine by oxidation with 1.1 molar equivalents of 3-chloroperoxybenzoic acid in acetonitrile solution. After work-up, including exposure of a solution of amino-4,6-bis(piperidino)-5-nitropyrimidine to anhydrous sodium sulfate, used as a drying agent, the nitro compound crystallized as the hydrogensulfate salt. Crystals of (I) suitable for single-crystal X-ray diffraction were obtained by slow evaporation of a solution in water-ethanol-acetonitrile (1/1/1 by volume).
Space group P21/c was uniquely assigned from the systematic absences. H atoms bonded to O atoms were located from difference maps and treated as riding atoms, with O—H distances derived from the difference maps, viz. 0.82 (anion) and 0.99 Å (water). Other H atoms were treated as riding, with N—H distances of 0.88 Å and C—H distances of 0.99 Å.
Data collection: KappaCCD Server Software (Nonius, 1997); cell refinement: DENZO–SMN (Otwinowski & Minor, 1997); data reduction: DENZO–SMN; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: PLATON (Spek, 2002); software used to prepare material for publication: SHELXL97 and PRPKAPPA (Ferguson, 1999).
C14H23N6O2+·HO4S−·H2O | F(000) = 896 |
Mr = 422.48 | Dx = 1.518 Mg m−3 |
Monoclinic, P21/c | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -P 2ybc | Cell parameters from 4111 reflections |
a = 14.0307 (3) Å | θ = 3.4–27.5° |
b = 6.1277 (1) Å | µ = 0.23 mm−1 |
c = 21.5135 (5) Å | T = 120 K |
β = 91.485 (1)° | Needle, colourless |
V = 1849.02 (7) Å3 | 0.20 × 0.04 × 0.02 mm |
Z = 4 |
Nonius KappaCCD diffractometer | 4111 independent reflections |
Radiation source: Rotating Anode | 3452 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.057 |
ϕ scans, and ω scans with κ offsets | θmax = 27.5°, θmin = 3.4° |
Absorption correction: multi-scan (DENZO–SMN, Otwinowski & Minor, 1997) | h = −13→18 |
Tmin = 0.946, Tmax = 0.996 | k = −7→7 |
14285 measured reflections | l = −27→27 |
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)] = 0.045 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.123 | H-atom parameters constrained |
S = 1.06 | w = 1/[σ2(Fo2) + (0.0664P)2 + 0.8404P] where P = (Fo2 + 2Fc2)/3 |
4111 reflections | (Δ/σ)max = 0.001 |
253 parameters | Δρmax = 0.58 e Å−3 |
0 restraints | Δρmin = −0.65 e Å−3 |
C14H23N6O2+·HO4S−·H2O | V = 1849.02 (7) Å3 |
Mr = 422.48 | Z = 4 |
Monoclinic, P21/c | Mo Kα radiation |
a = 14.0307 (3) Å | µ = 0.23 mm−1 |
b = 6.1277 (1) Å | T = 120 K |
c = 21.5135 (5) Å | 0.20 × 0.04 × 0.02 mm |
β = 91.485 (1)° |
Nonius KappaCCD diffractometer | 4111 independent reflections |
Absorption correction: multi-scan (DENZO–SMN, Otwinowski & Minor, 1997) | 3452 reflections with I > 2σ(I) |
Tmin = 0.946, Tmax = 0.996 | Rint = 0.057 |
14285 measured reflections |
R[F2 > 2σ(F2)] = 0.045 | 0 restraints |
wR(F2) = 0.123 | H-atom parameters constrained |
S = 1.06 | Δρmax = 0.58 e Å−3 |
4111 reflections | Δρmin = −0.65 e Å−3 |
253 parameters |
x | y | z | Uiso*/Ueq | ||
N1 | 0.35950 (10) | 0.8253 (2) | 0.21146 (7) | 0.0142 (3) | |
C2 | 0.36798 (12) | 0.6762 (3) | 0.25504 (8) | 0.0134 (3) | |
N2 | 0.44503 (11) | 0.5536 (2) | 0.25916 (7) | 0.0180 (3) | |
N3 | 0.30117 (10) | 0.6465 (2) | 0.30023 (6) | 0.0142 (3) | |
C4 | 0.21289 (12) | 0.7390 (3) | 0.29458 (8) | 0.0138 (3) | |
N4 | 0.15067 (10) | 0.7003 (2) | 0.33825 (7) | 0.0147 (3) | |
C41 | 0.15104 (13) | 0.5018 (3) | 0.37739 (8) | 0.0175 (4) | |
C42 | 0.15968 (14) | 0.5596 (3) | 0.44592 (8) | 0.0224 (4) | |
C43 | 0.08198 (14) | 0.7214 (3) | 0.46352 (9) | 0.0240 (4) | |
C44 | 0.08465 (13) | 0.9206 (3) | 0.42086 (8) | 0.0205 (4) | |
C45 | 0.07389 (13) | 0.8545 (3) | 0.35280 (8) | 0.0172 (4) | |
C5 | 0.19551 (12) | 0.8699 (3) | 0.24064 (8) | 0.0134 (3) | |
N5 | 0.10624 (10) | 0.8458 (2) | 0.20829 (7) | 0.0156 (3) | |
O51 | 0.09797 (9) | 0.9227 (2) | 0.15452 (6) | 0.0197 (3) | |
O52 | 0.04111 (9) | 0.7403 (2) | 0.23176 (6) | 0.0214 (3) | |
C6 | 0.27842 (12) | 0.9432 (3) | 0.20722 (7) | 0.0131 (3) | |
N6 | 0.27924 (10) | 1.1197 (2) | 0.17184 (6) | 0.0140 (3) | |
C61 | 0.20926 (12) | 1.2975 (3) | 0.17605 (8) | 0.0154 (4) | |
C62 | 0.17517 (13) | 1.3751 (3) | 0.11210 (8) | 0.0176 (4) | |
C63 | 0.25982 (13) | 1.4374 (3) | 0.07255 (8) | 0.0204 (4) | |
C64 | 0.32920 (13) | 1.2469 (3) | 0.06910 (8) | 0.0184 (4) | |
C65 | 0.36217 (12) | 1.1725 (3) | 0.13367 (8) | 0.0165 (4) | |
S1 | 0.40346 (3) | 0.18484 (7) | 0.38826 (2) | 0.0158 (1) | |
O1 | 0.39781 (10) | 0.1434 (2) | 0.32170 (6) | 0.0213 (3) | |
O2 | 0.38376 (10) | 0.4149 (2) | 0.40125 (6) | 0.0223 (3) | |
O3 | 0.33651 (10) | 0.0435 (2) | 0.42136 (6) | 0.0255 (3) | |
O4 | 0.50332 (10) | 0.1311 (2) | 0.40980 (8) | 0.0325 (4) | |
O8 | 0.58819 (16) | 0.2711 (3) | 0.50806 (8) | 0.0545 (6) | |
H2A | 0.4911 | 0.5715 | 0.2326 | 0.022* | |
H2B | 0.4505 | 0.4538 | 0.2885 | 0.022* | |
H3 | 0.3157 | 0.5668 | 0.3332 | 0.017* | |
H41A | 0.2051 | 0.4073 | 0.3661 | 0.021* | |
H41B | 0.0913 | 0.4191 | 0.3695 | 0.021* | |
H42A | 0.2231 | 0.6245 | 0.4550 | 0.027* | |
H42B | 0.1540 | 0.4254 | 0.4712 | 0.027* | |
H43A | 0.0920 | 0.7677 | 0.5073 | 0.029* | |
H43B | 0.0188 | 0.6502 | 0.4596 | 0.029* | |
H44A | 0.0325 | 1.0218 | 0.4314 | 0.025* | |
H44B | 0.1459 | 0.9985 | 0.4276 | 0.025* | |
H45A | 0.0110 | 0.7849 | 0.3451 | 0.021* | |
H45B | 0.0779 | 0.9851 | 0.3259 | 0.021* | |
H61A | 0.2385 | 1.4214 | 0.1991 | 0.018* | |
H61B | 0.1539 | 1.2461 | 0.1996 | 0.018* | |
H62A | 0.1328 | 1.5031 | 0.1166 | 0.021* | |
H62B | 0.1381 | 1.2577 | 0.0911 | 0.021* | |
H63A | 0.2369 | 1.4772 | 0.0301 | 0.024* | |
H63B | 0.2927 | 1.5658 | 0.0910 | 0.024* | |
H64A | 0.2978 | 1.1237 | 0.0469 | 0.022* | |
H64B | 0.3852 | 1.2915 | 0.0451 | 0.022* | |
H65A | 0.4033 | 1.0420 | 0.1301 | 0.020* | |
H65B | 0.4002 | 1.2895 | 0.1541 | 0.020* | |
H4 | 0.5253 | 0.1994 | 0.4396 | 0.039* | |
H81 | 0.6178 | 0.1786 | 0.5410 | 0.065* | |
H82 | 0.5923 | 0.3968 | 0.5370 | 0.065* |
U11 | U22 | U33 | U12 | U13 | U23 | |
N1 | 0.0106 (7) | 0.0162 (7) | 0.0158 (7) | 0.0003 (5) | 0.0001 (5) | 0.0003 (5) |
C2 | 0.0100 (8) | 0.0154 (8) | 0.0148 (8) | −0.0016 (6) | −0.0009 (6) | −0.0019 (6) |
N2 | 0.0136 (8) | 0.0221 (8) | 0.0185 (7) | 0.0040 (6) | 0.0029 (6) | 0.0049 (6) |
N3 | 0.0103 (7) | 0.0181 (7) | 0.0140 (7) | 0.0015 (5) | −0.0005 (6) | 0.0031 (6) |
C4 | 0.0103 (8) | 0.0135 (8) | 0.0178 (8) | −0.0003 (6) | −0.0004 (6) | −0.0027 (6) |
N4 | 0.0108 (7) | 0.0156 (7) | 0.0178 (7) | 0.0019 (5) | 0.0020 (5) | 0.0029 (5) |
C41 | 0.0127 (9) | 0.0179 (8) | 0.0219 (9) | 0.0006 (7) | 0.0018 (7) | 0.0056 (7) |
C42 | 0.0185 (10) | 0.0278 (10) | 0.0208 (9) | 0.0008 (7) | 0.0005 (7) | 0.0067 (7) |
C43 | 0.0194 (10) | 0.0346 (11) | 0.0183 (9) | 0.0001 (8) | 0.0026 (7) | 0.0022 (8) |
C44 | 0.0146 (9) | 0.0239 (9) | 0.0231 (9) | 0.0015 (7) | 0.0028 (7) | −0.0026 (7) |
C45 | 0.0106 (8) | 0.0201 (8) | 0.0211 (9) | 0.0026 (7) | 0.0022 (7) | 0.0017 (7) |
C5 | 0.0078 (8) | 0.0159 (8) | 0.0164 (8) | −0.0002 (6) | −0.0009 (6) | 0.0000 (6) |
N5 | 0.0114 (7) | 0.0156 (7) | 0.0197 (7) | 0.0006 (5) | −0.0019 (6) | −0.0005 (6) |
O51 | 0.0164 (7) | 0.0231 (6) | 0.0192 (6) | −0.0019 (5) | −0.0058 (5) | 0.0046 (5) |
O52 | 0.0121 (6) | 0.0266 (7) | 0.0254 (7) | −0.0077 (5) | −0.0010 (5) | 0.0022 (5) |
C6 | 0.0126 (8) | 0.0145 (8) | 0.0120 (7) | −0.0014 (6) | −0.0022 (6) | −0.0022 (6) |
N6 | 0.0091 (7) | 0.0166 (7) | 0.0164 (7) | 0.0000 (5) | 0.0001 (5) | 0.0003 (6) |
C61 | 0.0138 (9) | 0.0140 (8) | 0.0183 (8) | 0.0003 (6) | 0.0002 (7) | −0.0003 (6) |
C62 | 0.0134 (9) | 0.0184 (8) | 0.0210 (9) | 0.0020 (7) | −0.0005 (7) | 0.0024 (7) |
C63 | 0.0171 (9) | 0.0230 (9) | 0.0211 (8) | 0.0008 (7) | 0.0011 (7) | 0.0065 (7) |
C64 | 0.0142 (9) | 0.0233 (9) | 0.0177 (8) | −0.0007 (7) | 0.0008 (7) | 0.0024 (7) |
C65 | 0.0102 (8) | 0.0204 (9) | 0.0192 (8) | 0.0004 (6) | 0.0026 (7) | 0.0032 (7) |
S1 | 0.0152 (2) | 0.0167 (2) | 0.0156 (2) | 0.00161 (16) | 0.00183 (16) | 0.00025 (15) |
O1 | 0.0247 (7) | 0.0232 (7) | 0.0163 (6) | −0.0015 (5) | 0.0049 (5) | −0.0032 (5) |
O2 | 0.0271 (8) | 0.0193 (6) | 0.0203 (6) | 0.0072 (6) | −0.0057 (5) | −0.0028 (5) |
O3 | 0.0228 (7) | 0.0295 (7) | 0.0246 (7) | −0.0017 (6) | 0.0063 (6) | 0.0076 (6) |
O4 | 0.0166 (8) | 0.0286 (7) | 0.0516 (9) | 0.0060 (6) | −0.0125 (7) | −0.0075 (7) |
O8 | 0.1103 (18) | 0.0216 (8) | 0.0324 (9) | −0.0127 (9) | 0.0170 (10) | −0.0043 (7) |
N1—C2 | 1.312 (2) | C44—H44A | 0.99 |
C2—N3 | 1.380 (2) | C44—H44B | 0.99 |
N3—C4 | 1.365 (2) | C45—H45A | 0.99 |
C4—C5 | 1.426 (2) | C45—H45B | 0.99 |
C5—C6 | 1.454 (2) | N6—C61 | 1.471 (2) |
C6—N1 | 1.349 (2) | N6—C65 | 1.477 (2) |
C2—N2 | 1.318 (2) | C61—C62 | 1.521 (2) |
C4—N4 | 1.321 (2) | C61—H61A | 0.99 |
C5—N5 | 1.425 (2) | C61—H61B | 0.99 |
N5—O51 | 1.252 (2) | C62—C63 | 1.527 (3) |
N5—O52 | 1.238 (2) | C62—H62A | 0.99 |
C6—N6 | 1.323 (2) | C62—H62B | 0.99 |
N2—H2A | 0.88 | C63—C64 | 1.523 (3) |
N2—H2B | 0.88 | C63—H63A | 0.99 |
N3—H3 | 0.88 | C63—H63B | 0.99 |
N4—C45 | 1.473 (2) | C64—C65 | 1.523 (2) |
N4—C41 | 1.479 (2) | C64—H64A | 0.99 |
C41—C42 | 1.518 (2) | C64—H64B | 0.99 |
C41—H41A | 0.99 | C65—H65A | 0.99 |
C41—H41B | 0.99 | C65—H65B | 0.99 |
C42—C43 | 1.528 (3) | S1—O1 | 1.4545 (13) |
C42—H42A | 0.99 | S1—O2 | 1.4650 (13) |
C42—H42B | 0.99 | S1—O3 | 1.4743 (14) |
C43—C44 | 1.529 (3) | S1—O4 | 1.5008 (14) |
C43—H43A | 0.99 | O4—H4 | 0.82 |
C43—H43B | 0.99 | O8—H81 | 0.99 |
C44—C45 | 1.523 (2) | O8—H82 | 0.99 |
C2—N1—C6 | 118.80 (15) | C4—C5—C6 | 116.97 (14) |
N1—C2—N2 | 120.26 (16) | O52—N5—O51 | 121.47 (14) |
N1—C2—N3 | 123.00 (16) | O52—N5—C5 | 120.25 (14) |
N2—C2—N3 | 116.65 (15) | O51—N5—C5 | 118.15 (14) |
C2—N2—H2A | 120.0 | N6—C6—N1 | 117.19 (16) |
C2—N2—H2B | 120.0 | N6—C6—C5 | 123.76 (15) |
H2A—N2—H2B | 120.0 | N1—C6—C5 | 119.04 (15) |
C4—N3—C2 | 120.93 (14) | C6—N6—C61 | 123.67 (15) |
C4—N3—H3 | 119.5 | C6—N6—C65 | 121.16 (14) |
C2—N3—H3 | 119.5 | C61—N6—C65 | 114.13 (13) |
N4—C4—N3 | 118.49 (15) | N6—C61—C62 | 111.76 (14) |
N4—C4—C5 | 125.29 (15) | N6—C61—H61A | 109.3 |
N3—C4—C5 | 116.21 (15) | C62—C61—H61A | 109.3 |
C4—N4—C41 | 124.08 (15) | N6—C61—H61B | 109.3 |
C4—N4—C45 | 122.44 (14) | C62—C61—H61B | 109.3 |
C41—N4—C45 | 113.48 (14) | H61A—C61—H61B | 107.9 |
N4—C41—C42 | 111.10 (15) | C61—C62—C63 | 110.56 (14) |
N4—C41—H41A | 109.4 | C61—C62—H62A | 109.5 |
C42—C41—H41A | 109.4 | C63—C62—H62A | 109.5 |
N4—C41—H41B | 109.4 | C61—C62—H62B | 109.5 |
C42—C41—H41B | 109.4 | C63—C62—H62B | 109.5 |
H41A—C41—H41B | 108.0 | H62A—C62—H62B | 108.1 |
C41—C42—C43 | 110.63 (15) | C64—C63—C62 | 110.06 (15) |
C41—C42—H42A | 109.5 | C64—C63—H63A | 109.6 |
C43—C42—H42A | 109.5 | C62—C63—H63A | 109.6 |
C41—C42—H42B | 109.5 | C64—C63—H63B | 109.6 |
C43—C42—H42B | 109.5 | C62—C63—H63B | 109.6 |
H42A—C42—H42B | 108.1 | H63A—C63—H63B | 108.2 |
C42—C43—C44 | 109.92 (15) | C65—C64—C63 | 111.39 (15) |
C42—C43—H43A | 109.7 | C65—C64—H64A | 109.4 |
C44—C43—H43A | 109.7 | C63—C64—H64A | 109.4 |
C42—C43—H43B | 109.7 | C65—C64—H64B | 109.4 |
C44—C43—H43B | 109.7 | C63—C64—H64B | 109.4 |
H43A—C43—H43B | 108.2 | H64A—C64—H64B | 108.0 |
C45—C44—C43 | 111.18 (15) | N6—C65—C64 | 110.34 (14) |
C45—C44—H44A | 109.4 | N6—C65—H65A | 109.6 |
C43—C44—H44A | 109.4 | C64—C65—H65A | 109.6 |
C45—C44—H44B | 109.4 | N6—C65—H65B | 109.6 |
C43—C44—H44B | 109.4 | C64—C65—H65B | 109.6 |
H44A—C44—H44B | 108.0 | H65A—C65—H65B | 108.1 |
N4—C45—C44 | 108.67 (14) | O1—S1—O2 | 110.50 (8) |
N4—C45—H45A | 110.0 | O1—S1—O3 | 110.71 (8) |
C44—C45—H45A | 110.0 | O2—S1—O3 | 110.32 (8) |
N4—C45—H45B | 110.0 | O1—S1—O4 | 106.99 (9) |
C44—C45—H45B | 110.0 | O2—S1—O4 | 109.35 (8) |
H45A—C45—H45B | 108.3 | O3—S1—O4 | 108.88 (8) |
N5—C5—C4 | 117.95 (15) | S1—O4—H4 | 117.3 |
N5—C5—C6 | 119.66 (14) | H81—O8—H82 | 88.7 |
C6—N1—C2—N2 | 177.84 (15) | C42—C43—C44—C45 | 56.8 (2) |
N1—C2—N3—C4 | 14.0 (2) | C4—N4—C45—C44 | −121.15 (17) |
C2—N3—C4—C5 | −1.4 (2) | C41—N4—C45—C44 | 58.43 (18) |
N3—C4—C5—C6 | −17.2 (2) | C43—C44—C45—N4 | −57.76 (19) |
C4—C5—C6—N1 | 25.6 (2) | N4—C4—C5—N5 | −42.6 (2) |
C5—C6—N1—C2 | −14.1 (2) | C4—C5—N5—O52 | 10.9 (2) |
C6—N1—C2—N3 | −5.7 (2) | C6—C5—N5—O52 | 164.14 (15) |
C2—N3—C4—N4 | 178.06 (15) | C4—C5—N5—O51 | −164.96 (15) |
C6—C5—C4—N4 | 163.43 (16) | C6—C5—N5—O51 | −11.7 (2) |
N3—C4—C5—N5 | 136.80 (16) | N5—C5—C6—N6 | 51.4 (2) |
N1—C6—C5—N5 | −127.89 (16) | N1—C6—N6—C61 | −161.59 (14) |
C2—N1—C6—N6 | 166.58 (15) | C5—C6—N6—C61 | 19.1 (2) |
C4—C5—C6—N6 | −155.08 (16) | N1—C6—N6—C65 | 6.1 (2) |
N2—C2—N3—C4 | −169.36 (15) | C5—C6—N6—C65 | −173.24 (15) |
N3—C4—N4—C45 | 152.66 (15) | C6—N6—C61—C62 | −136.79 (16) |
C5—C4—N4—C45 | −28.0 (3) | C65—N6—C61—C62 | 54.77 (18) |
N3—C4—N4—C41 | −26.9 (2) | N6—C61—C62—C63 | −54.14 (19) |
C5—C4—N4—C41 | 152.51 (16) | C61—C62—C63—C64 | 55.16 (19) |
C4—N4—C41—C42 | 122.03 (18) | C62—C63—C64—C65 | −56.25 (19) |
C45—N4—C41—C42 | −57.55 (19) | C6—N6—C65—C64 | 136.61 (16) |
N4—C41—C42—C43 | 54.2 (2) | C61—N6—C65—C64 | −54.63 (18) |
C41—C42—C43—C44 | −54.2 (2) | C63—C64—C65—N6 | 55.07 (19) |
D—H···A | D—H | H···A | D···A | D—H···A |
N2—H2A···O1i | 0.88 | 2.02 | 2.896 (2) | 173 |
N2—H2B···O1 | 0.88 | 2.17 | 2.935 (2) | 145 |
N3—H3···O2 | 0.88 | 1.96 | 2.820 (2) | 164 |
O4—H4···O8 | 0.82 | 1.75 | 2.548 (2) | 163 |
O8—H81···O3ii | 0.99 | 1.70 | 2.656 (2) | 161 |
O8—H82···O2iii | 0.99 | 1.78 | 2.761 (2) | 168 |
Symmetry codes: (i) −x+1, y+1/2, −z+1/2; (ii) −x+1, −y, −z+1; (iii) −x+1, −y+1, −z+1. |
Experimental details
Crystal data | |
Chemical formula | C14H23N6O2+·HO4S−·H2O |
Mr | 422.48 |
Crystal system, space group | Monoclinic, P21/c |
Temperature (K) | 120 |
a, b, c (Å) | 14.0307 (3), 6.1277 (1), 21.5135 (5) |
β (°) | 91.485 (1) |
V (Å3) | 1849.02 (7) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 0.23 |
Crystal size (mm) | 0.20 × 0.04 × 0.02 |
Data collection | |
Diffractometer | Nonius KappaCCD diffractometer |
Absorption correction | Multi-scan (DENZO–SMN, Otwinowski & Minor, 1997) |
Tmin, Tmax | 0.946, 0.996 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 14285, 4111, 3452 |
Rint | 0.057 |
(sin θ/λ)max (Å−1) | 0.649 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.045, 0.123, 1.06 |
No. of reflections | 4111 |
No. of parameters | 253 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.58, −0.65 |
Computer programs: KappaCCD Server Software (Nonius, 1997), DENZO–SMN (Otwinowski & Minor, 1997), DENZO–SMN, SHELXS97 (Sheldrick, 1997), SHELXL97 (Sheldrick, 1997), PLATON (Spek, 2002), SHELXL97 and PRPKAPPA (Ferguson, 1999).
N1—C2 | 1.312 (2) | C2—N2 | 1.318 (2) |
C2—N3 | 1.380 (2) | C4—N4 | 1.321 (2) |
N3—C4 | 1.365 (2) | C5—N5 | 1.425 (2) |
C4—C5 | 1.426 (2) | N5—O51 | 1.252 (2) |
C5—C6 | 1.454 (2) | N5—O52 | 1.238 (2) |
C6—N1 | 1.349 (2) | C6—N6 | 1.323 (2) |
C4—N4—C41 | 124.08 (15) | C6—N6—C61 | 123.67 (15) |
C4—N4—C45 | 122.44 (14) | C6—N6—C65 | 121.16 (14) |
C41—N4—C45 | 113.48 (14) | C61—N6—C65 | 114.13 (13) |
N1—C2—N3—C4 | 14.0 (2) | C2—N3—C4—N4 | 178.06 (15) |
C2—N3—C4—C5 | −1.4 (2) | C6—C5—C4—N4 | 163.43 (16) |
N3—C4—C5—C6 | −17.2 (2) | N3—C4—C5—N5 | 136.80 (16) |
C4—C5—C6—N1 | 25.6 (2) | N1—C6—C5—N5 | −127.89 (16) |
C5—C6—N1—C2 | −14.1 (2) | C2—N1—C6—N6 | 166.58 (15) |
C6—N1—C2—N3 | −5.7 (2) | C4—C5—C6—N6 | −155.08 (16) |
D—H···A | D—H | H···A | D···A | D—H···A |
N2—H2A···O1i | 0.88 | 2.02 | 2.896 (2) | 173 |
N2—H2B···O1 | 0.88 | 2.17 | 2.935 (2) | 145 |
N3—H3···O2 | 0.88 | 1.96 | 2.820 (2) | 164 |
O4—H4···O8 | 0.82 | 1.75 | 2.548 (2) | 163 |
O8—H81···O3ii | 0.99 | 1.70 | 2.656 (2) | 161 |
O8—H82···O2iii | 0.99 | 1.78 | 2.761 (2) | 168 |
Symmetry codes: (i) −x+1, y+1/2, −z+1/2; (ii) −x+1, −y, −z+1; (iii) −x+1, −y+1, −z+1. |
We have recently described the structure of 2-amino-4,6-bis(1-pyrrolidyl)-5-nitrosopyrimidine (Quesada et al., 2002). In this compound, the pyrimidine ring is considerably distorted from planarity, and this was interpreted as resulting from the compromise between maximizing the electronic delocalization between the amino substituents and the nitroso group, and the relief of steric hindrance between adjacent substituents, in particular, the nitroso group lying between the two pyrrolidyl substituents. The question then arises concerning the behaviour of an analogous system containing a nitro substituent at the 5-position, which is not only bulkier than a nitroso substituent, but may be expected to be a stronger electron acceptor. Accordingly, we have synthesized several 2-amino-5-nitropyrimidines containing secondary amino substituents (viz. 1-pyrrolidyl, 1-piperidyl and 4-morpholyl) at the 4- and 6-positions. Of these, only the piperidyl derivative has so far been crystallized, as a hydrated hydrogensulfate salt {(C14H22N6O2)H}+·(HSO4)−·H2O, (I), in which a single H atom has been transferred from the acid component to one of the ring N atoms of the pyrimidine.
The pyrimidinium cation in (I) exhibits an unusual pattern of bond lengths (Table 1). Firstly, the exocyclic C—N bonds are all short for their types: the mean values (Allen et al., 1987) for Car—NH2, Car—NR2 and Car—NO2 bond lengths are 1.355, 1.371 and 1.468 Å, respectively. Secondly, the pyrimidine-ring bond lengths N1—C2 and N1—C6 are both much shorter than the C2—N3 bond. Finally, the nitro group N—O distances are both significantly longer than the mean value, 1.217 Å, for bonds of this type. These observations, taken together with the planarity at the piperidino N atoms, N4 and N6, are indicative of significant contributions to the overall electronic structure of polarized forms such as (IIa) and (IIb) (see Scheme).
The participation of the piperidino N atoms in the electronic delocalization is surprising, in view of the likely steric clashing between the piperidine rings at positions 4 and 6 and the nitro group at position 5; avoidance of such clashing via rotation of each of these adjacent substituents about their exocyclic C—N bonds might have been expected, although at the cost of the electron delocalization. Instead, this delocalization is maintained, but at the cost of a significant distortion of the pyrimidinium ring into a twist–boat conformation, with ring-puckering parameters (Cremer & Pople, 1975) θ = 105.9 (5)° and ϕ = 82.9 (5)°, This distortion may perhaps more readily be demonstrated by the torsion angles (Table 1), where for a fully planar system, those torsion angles within the pyrimidine ring would all be effectively 0°, while those involving one exocyclic atom would all be close to 180°. If we define a reference plane containing atoms C2, C4 and C6, the deviations of the N atoms from this plane are as follows: ring atoms N1 and N3, −0.015 (2) and 0.146 (2) Å, respectively; exocyclic N atoms N2, N4, N5 and N6, −0.057 (3), 0.111 (3), −1.273 (3) and 0.257 (3) Å, respectively. Of the exocyclic N atoms, the biggest deviations from the C2/C4/C6 plane are observed for the adjacent atoms N4, N5 and N6, with nitro atom N5 enhibiting the biggest displacement, and on the side of the plane opposite from the displacements of atoms N4 and N6.
This electronic interpretation receives strong support from a comparison of the structures of two related benzene derivatives. In 1-amino-2,4,6-trinitro-3,5-bis(1-piperidino)benzene [Cambridge Structural Database (CSD; Allen, 2002) refcode TEWJAG; Wolff et al., 1996], where both electron-donor amino groups and electron-acceptor nitro groups are present, the benzene ring has a chair conformation. However, in 1,3,5-tri-isopropyl-2-nitrobenzene (CSD refcode HALJUZ; de Ridder et al., 1993; Marsh, 1997), where there are no obvious electron-donor substituents, the benzene ring remains planar, while the nitro group is twisted into an almost orthogonal conformation.
Within the selected asymmetric unit (Fig. 1), atoms N2 and N3 act as hydrogen-bond donors to O1 and O2, respectively, while O4 acts as hydrogen-bond donor to water atom O8. Three further hydrogen bonds, two of the O—H···O type and one of the N—H···O type (Table 2), link the three molecular components into continuous sheets, whose construction is most readily analysed in terms of the two-component one-dimensional substructure formed by the anions and the water molecules.
Water atom O8 at (x, y, z) acts as hydrogen-bond donor, via H81 and H82, respectively, to O3 in the anion at (1 − x, −y, 1 − z) and to O2 in the anion at (1 − x, 1 − y, 1 − z); propagation by inversion of these two hydrogen bonds then generates a chain of edge-fused R44(12) (Bernstein et al., 1995) rings, with rings containing O2 atoms centred at (1/2, n+0.5, 1/2) (n = zero or integer) and rings containing O3 atoms centred at (1/2, n, 1/2) (n = zero or integer) (Fig. 2). This chain of rings runs along the line (1/2, y, 1/2) and a second such chain, related to the first by the action of the 21 screw axes, runs along the line (1/2, y, 0). Adjacent chains are linked by the cations into (100) sheets.
The cation at (x, y, z) acts as donor, via H2B, to atom O1 in the anion at (x, y, z), which forms part of the anion/water chain along (1/2, y, 1/2); the same cation also acts as donor, via H2A, to O1 in the anion at (1 − x, 0.5 + y, 0.5 − z), which lies in the chain along (1/2, y, 0). The amino group in the cation at (1 − x, 1 − y, 1 − z) likewise acts as donor to O1 atoms at (1 − x, 1 − y, 1 − z) and (x, 0.5 − y, 0.5 + z), which lie respectively in the chains along (1/2, y, 1/2) and (1/2, y, 1). These interactions thus link the anion/water chain along (1/2, y, 1/2) to those along (1/2, y, 0) and (1/2, y, 1.0) (Fig. 3), and propagation of these links by inversion thus generates a (100) sheet centred at x = 0.5. There are no direction-specific interactions between adjacent sheets. Despite the polarized nature of the cationic donor and the anionic acceptor, none of the N—H···O hydrogen bonds is particularly short (Table 2). The shortest of the O—H···O hydrogen bonds involves two essentially neutral O atoms.