Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536802016550/ci6154sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S1600536802016550/ci6154Isup2.hkl |
CCDC reference: 198968
Key indicators
- Single-crystal X-ray study
- T = 293 K
- Mean (C-C) = 0.003 Å
- R factor = 0.055
- wR factor = 0.174
- Data-to-parameter ratio = 14.9
checkCIF results
No syntax errors found ADDSYM reports no extra symmetry
The synthesis of the title compound, (I), was carried out by heating 1 mmol quantities of 2,4,6-trinitrobenzoic acid and 1,2,3,4-tetrahydroquinoline in 50 ml of 80% ethanol/water under reflux for ca 10 min. After concentration to ca 30 ml, partial room temperature evaporation of the hot-filtered solution gave black data crystals suitable for X-ray diffraction.
Data collection: SMART (Bruker, 2000); cell refinement: SMART; data reduction: SAINT (Bruker, 1999); program(s) used to solve structure: SHELXTL (Bruker, 1997); program(s) used to refine structure: SHELXTL; molecular graphics: PLATON (Spek, 1999); software used to prepare material for publication: SHELXTL.
C9H11N·C6H3N3O6 | F(000) = 720 |
Mr = 346.30 | Dx = 1.453 Mg m−3 |
Monoclinic, P21/c | Melting point = 378.9–381.2 K |
Hall symbol: -P 2ybc | Mo Kα radiation, λ = 0.71073 Å |
a = 13.8474 (12) Å | Cell parameters from 3297 reflections |
b = 6.8830 (6) Å | θ = 2.5–27.1° |
c = 16.8328 (15) Å | µ = 0.12 mm−1 |
β = 99.273 (3)° | T = 293 K |
V = 1583.4 (2) Å3 | Block, black |
Z = 4 | 0.45 × 0.40 × 0.24 mm |
Bruker SMART CCD area detector diffractometer | 2519 reflections with I > 2σ(I) |
Radiation source: fine-focus sealed tube | Rint = 0.055 |
Graphite monochromator | θmax = 27.5°, θmin = 2.5° |
ϕ and ω scans | h = −17→16 |
9501 measured reflections | k = −8→6 |
3583 independent reflections | l = −21→21 |
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)] = 0.055 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.174 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.07 | w = 1/[σ2(Fo2) + (0.1118P)2 + 0.1838P] where P = (Fo2 + 2Fc2)/3 |
3583 reflections | (Δ/σ)max < 0.001 |
240 parameters | Δρmax = 0.21 e Å−3 |
6 restraints | Δρmin = −0.24 e Å−3 |
C9H11N·C6H3N3O6 | V = 1583.4 (2) Å3 |
Mr = 346.30 | Z = 4 |
Monoclinic, P21/c | Mo Kα radiation |
a = 13.8474 (12) Å | µ = 0.12 mm−1 |
b = 6.8830 (6) Å | T = 293 K |
c = 16.8328 (15) Å | 0.45 × 0.40 × 0.24 mm |
β = 99.273 (3)° |
Bruker SMART CCD area detector diffractometer | 2519 reflections with I > 2σ(I) |
9501 measured reflections | Rint = 0.055 |
3583 independent reflections |
R[F2 > 2σ(F2)] = 0.055 | 6 restraints |
wR(F2) = 0.174 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.07 | Δρmax = 0.21 e Å−3 |
3583 reflections | Δρmin = −0.24 e Å−3 |
240 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 > 2σ(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) | |
O11 | −0.03141 (10) | 0.1035 (3) | 0.19855 (9) | 0.1181 (6) | |
O12 | 0.06653 (10) | 0.0722 (3) | 0.30820 (8) | 0.1104 (6) | |
O31 | 0.39948 (11) | 0.3037 (3) | 0.31929 (9) | 0.1267 (7) | |
O32 | 0.46076 (10) | 0.3156 (3) | 0.21237 (10) | 0.1216 (7) | |
O51 | 0.25608 (12) | 0.2106 (2) | −0.04427 (7) | 0.0915 (5) | |
O52 | 0.10354 (13) | 0.1429 (3) | −0.04884 (8) | 0.1043 (5) | |
N1 | 0.04922 (10) | 0.1072 (2) | 0.23706 (8) | 0.0669 (4) | |
N3 | 0.39302 (11) | 0.2886 (2) | 0.24764 (10) | 0.0781 (4) | |
N5 | 0.18439 (13) | 0.1788 (2) | −0.01271 (8) | 0.0732 (4) | |
C1 | 0.13178 (11) | 0.1542 (2) | 0.19604 (8) | 0.0529 (4) | |
C2 | 0.22066 (11) | 0.2001 (2) | 0.24188 (8) | 0.0539 (4) | |
H2 | 0.2284 | 0.2059 | 0.2978 | 0.065* | |
C3 | 0.29740 (11) | 0.2372 (2) | 0.20113 (9) | 0.0551 (4) | |
C4 | 0.28861 (12) | 0.2294 (2) | 0.11823 (9) | 0.0581 (4) | |
H4 | 0.3417 | 0.2530 | 0.0920 | 0.070* | |
C5 | 0.19757 (12) | 0.1851 (2) | 0.07631 (8) | 0.0561 (4) | |
C6 | 0.11800 (11) | 0.1462 (2) | 0.11318 (9) | 0.0562 (4) | |
H6 | 0.0574 | 0.1157 | 0.0834 | 0.067* | |
N11 | 0.58851 (13) | 0.2611 (3) | 0.45209 (13) | 0.0995 (6) | |
C21 | 0.56587 (18) | 0.2660 (4) | 0.53086 (17) | 0.1111 (8) | |
H21A | 0.5006 | 0.2139 | 0.5300 | 0.133* | 0.733 (7) |
H21B | 0.5656 | 0.4000 | 0.5486 | 0.133* | 0.733 (7) |
H21C | 0.5421 | 0.1401 | 0.5429 | 0.133* | 0.267 (7) |
H21D | 0.5129 | 0.3560 | 0.5307 | 0.133* | 0.267 (7) |
C31 | 0.63550 (18) | 0.1544 (6) | 0.58906 (19) | 0.0942 (13) | 0.733 (7) |
H31A | 0.6263 | 0.0168 | 0.5780 | 0.113* | 0.733 (7) |
H31B | 0.6221 | 0.1786 | 0.6430 | 0.113* | 0.733 (7) |
C31A | 0.6464 (3) | 0.3045 (15) | 0.5974 (4) | 0.111 (4) | 0.267 (7) |
H31C | 0.6280 | 0.2588 | 0.6473 | 0.133* | 0.267 (7) |
H31D | 0.6572 | 0.4435 | 0.6021 | 0.133* | 0.267 (7) |
C41 | 0.73914 (15) | 0.2078 (3) | 0.58515 (11) | 0.0785 (5) | |
H41A | 0.7826 | 0.1181 | 0.6179 | 0.094* | 0.733 (7) |
H41B | 0.7522 | 0.3373 | 0.6070 | 0.094* | 0.733 (7) |
H41C | 0.7378 | 0.0776 | 0.6054 | 0.094* | 0.267 (7) |
H41D | 0.7913 | 0.2761 | 0.6181 | 0.094* | 0.267 (7) |
C51 | 0.85214 (12) | 0.1687 (3) | 0.48272 (13) | 0.0756 (5) | |
H51 | 0.9035 | 0.1498 | 0.5249 | 0.091* | |
C61 | 0.87092 (18) | 0.1624 (3) | 0.40494 (17) | 0.0908 (7) | |
H61 | 0.9340 | 0.1398 | 0.3948 | 0.109* | |
C71 | 0.7948 (2) | 0.1900 (3) | 0.34225 (14) | 0.0891 (7) | |
H71 | 0.8065 | 0.1855 | 0.2894 | 0.107* | |
C81 | 0.70233 (17) | 0.2240 (2) | 0.35760 (11) | 0.0778 (5) | |
H81 | 0.6517 | 0.2438 | 0.3149 | 0.093* | |
C91 | 0.68250 (12) | 0.2294 (2) | 0.43629 (10) | 0.0626 (4) | |
C101 | 0.75947 (11) | 0.2022 (2) | 0.50010 (10) | 0.0593 (4) | |
H11 | 0.548 (2) | 0.280 (3) | 0.4111 (17) | 0.110 (8)* |
U11 | U22 | U33 | U12 | U13 | U23 | |
O11 | 0.0601 (8) | 0.2011 (19) | 0.0937 (10) | −0.0268 (10) | 0.0142 (7) | −0.0080 (11) |
O12 | 0.0874 (9) | 0.1753 (17) | 0.0768 (8) | −0.0026 (10) | 0.0380 (7) | 0.0215 (9) |
O31 | 0.0771 (9) | 0.232 (2) | 0.0677 (9) | −0.0294 (10) | 0.0019 (7) | −0.0207 (10) |
O32 | 0.0581 (8) | 0.205 (2) | 0.1048 (11) | −0.0171 (9) | 0.0228 (8) | −0.0043 (11) |
O51 | 0.1221 (12) | 0.1034 (10) | 0.0566 (7) | 0.0027 (8) | 0.0375 (8) | 0.0010 (6) |
O52 | 0.1131 (11) | 0.1379 (13) | 0.0546 (7) | −0.0006 (9) | −0.0087 (7) | −0.0003 (7) |
N1 | 0.0605 (8) | 0.0758 (9) | 0.0681 (8) | −0.0022 (6) | 0.0212 (7) | −0.0067 (7) |
N3 | 0.0570 (8) | 0.1083 (12) | 0.0690 (9) | −0.0001 (7) | 0.0105 (7) | −0.0027 (8) |
N5 | 0.0992 (12) | 0.0735 (9) | 0.0488 (7) | 0.0089 (8) | 0.0180 (8) | 0.0024 (6) |
C1 | 0.0561 (8) | 0.0507 (8) | 0.0541 (8) | 0.0058 (6) | 0.0161 (6) | 0.0000 (6) |
C2 | 0.0586 (8) | 0.0593 (9) | 0.0449 (7) | 0.0048 (6) | 0.0116 (6) | −0.0008 (6) |
C3 | 0.0513 (8) | 0.0611 (9) | 0.0538 (8) | 0.0037 (6) | 0.0116 (6) | −0.0003 (6) |
C4 | 0.0634 (9) | 0.0581 (9) | 0.0572 (8) | 0.0083 (7) | 0.0229 (7) | 0.0039 (7) |
C5 | 0.0708 (9) | 0.0534 (8) | 0.0452 (7) | 0.0095 (7) | 0.0127 (7) | 0.0004 (6) |
C6 | 0.0589 (8) | 0.0552 (8) | 0.0535 (8) | 0.0051 (6) | 0.0057 (6) | −0.0021 (6) |
N11 | 0.0630 (10) | 0.1443 (18) | 0.0872 (13) | 0.0186 (10) | 0.0003 (9) | −0.0048 (11) |
C21 | 0.0818 (15) | 0.141 (2) | 0.119 (2) | 0.0205 (14) | 0.0421 (14) | −0.0041 (16) |
C31 | 0.088 (2) | 0.122 (3) | 0.0817 (19) | −0.0026 (18) | 0.0416 (16) | 0.0040 (19) |
C31A | 0.123 (8) | 0.123 (9) | 0.102 (6) | −0.044 (6) | 0.067 (6) | −0.031 (6) |
C41 | 0.0839 (12) | 0.0888 (13) | 0.0615 (10) | −0.0026 (10) | 0.0083 (9) | 0.0076 (9) |
C51 | 0.0589 (10) | 0.0671 (10) | 0.1022 (14) | −0.0038 (8) | 0.0171 (9) | 0.0057 (9) |
C61 | 0.0905 (14) | 0.0641 (11) | 0.133 (2) | −0.0096 (10) | 0.0641 (15) | −0.0082 (11) |
C71 | 0.137 (2) | 0.0584 (10) | 0.0853 (13) | −0.0222 (11) | 0.0591 (15) | −0.0110 (9) |
C81 | 0.1096 (15) | 0.0597 (10) | 0.0632 (10) | −0.0108 (9) | 0.0110 (10) | −0.0015 (8) |
C91 | 0.0640 (9) | 0.0587 (9) | 0.0651 (9) | −0.0004 (7) | 0.0103 (7) | −0.0025 (7) |
C101 | 0.0581 (9) | 0.0581 (8) | 0.0622 (9) | −0.0032 (7) | 0.0114 (7) | 0.0038 (7) |
O11—N1 | 1.1976 (18) | C21—H21B | 0.97 |
O12—N1 | 1.2071 (18) | C21—H21C | 0.96 |
O31—N3 | 1.200 (2) | C21—H21D | 0.96 |
O32—N3 | 1.203 (2) | C31—C41 | 1.493 (3) |
O51—N5 | 1.219 (2) | C31—H31A | 0.97 |
O52—N5 | 1.210 (2) | C31—H31B | 0.97 |
N1—C1 | 1.464 (2) | C31A—C41 | 1.490 (4) |
N3—C3 | 1.469 (2) | C31A—H31C | 0.97 |
N5—C5 | 1.4807 (19) | C31A—H31D | 0.97 |
C1—C6 | 1.378 (2) | C41—C101 | 1.503 (2) |
C1—C2 | 1.380 (2) | C41—H41A | 0.97 |
C2—C3 | 1.378 (2) | C41—H41B | 0.97 |
C2—H2 | 0.93 | C41—H41C | 0.96 |
C3—C4 | 1.382 (2) | C41—H41D | 0.96 |
C4—C5 | 1.376 (2) | C51—C61 | 1.376 (3) |
C4—H4 | 0.93 | C51—C101 | 1.381 (2) |
C5—C6 | 1.375 (2) | C51—H51 | 0.93 |
C6—H6 | 0.93 | C61—C71 | 1.379 (3) |
N11—C91 | 1.387 (2) | C61—H61 | 0.93 |
N11—C21 | 1.411 (3) | C71—C81 | 1.367 (3) |
N11—H11 | 0.83 (3) | C71—H71 | 0.93 |
C21—C31A | 1.471 (4) | C81—C91 | 1.396 (2) |
C21—C31 | 1.475 (3) | C81—H81 | 0.93 |
C21—H21A | 0.97 | C91—C101 | 1.398 (2) |
O11—N1—O12 | 123.46 (15) | H21C—C31—H31A | 75.2 |
O11—N1—C1 | 118.71 (14) | C21—C31—H31B | 109.2 |
O12—N1—C1 | 117.83 (13) | C41—C31—H31B | 109.2 |
O31—N3—O32 | 123.05 (17) | H21C—C31—H31B | 103.4 |
O31—N3—C3 | 118.13 (15) | H31A—C31—H31B | 107.9 |
O32—N3—C3 | 118.82 (16) | C21—C31—H41C | 143.6 |
O52—N5—O51 | 124.76 (15) | C41—C31—H41C | 37.5 |
O52—N5—C5 | 117.88 (15) | H21C—C31—H41C | 147.1 |
O51—N5—C5 | 117.36 (16) | H31A—C31—H41C | 77.4 |
C6—C1—C2 | 122.73 (14) | H31B—C31—H41C | 101.9 |
C6—C1—N1 | 118.51 (14) | C21—C31A—C41 | 112.3 (4) |
C2—C1—N1 | 118.74 (13) | C21—C31A—H31C | 109.1 |
C3—C2—C1 | 116.99 (13) | C41—C31A—H31C | 109.1 |
C3—C2—H2 | 121.5 | C21—C31A—H31D | 109.1 |
C1—C2—H2 | 121.5 | C41—C31A—H31D | 109.1 |
C2—C3—C4 | 123.08 (14) | H31C—C31A—H31D | 107.9 |
C2—C3—N3 | 118.71 (14) | C31A—C41—C31 | 41.2 (4) |
C4—C3—N3 | 118.21 (14) | C31A—C41—C101 | 116.1 (3) |
C5—C4—C3 | 116.79 (14) | C31—C41—C101 | 111.38 (18) |
C5—C4—H4 | 121.6 | C31A—C41—H41A | 132.5 |
C3—C4—H4 | 121.6 | C31—C41—H41A | 109.4 |
C6—C5—C4 | 123.10 (13) | C101—C41—H41A | 109.4 |
C6—C5—N5 | 118.29 (14) | C31A—C41—H41B | 69.5 |
C4—C5—N5 | 118.61 (14) | C31—C41—H41B | 109.4 |
C5—C6—C1 | 117.30 (14) | C101—C41—H41B | 109.4 |
C5—C6—H6 | 121.4 | H41A—C41—H41B | 108.0 |
C1—C6—H6 | 121.4 | C31A—C41—H41C | 107.5 |
C91—N11—C21 | 122.77 (18) | C31—C41—H41C | 71.4 |
C91—N11—H11 | 113.6 (18) | C101—C41—H41C | 109.4 |
C21—N11—H11 | 123.6 (18) | H41A—C41—H41C | 41.4 |
N11—C21—C31A | 117.6 (3) | H41B—C41—H41C | 137.4 |
N11—C21—C31 | 113.0 (2) | C31A—C41—H41D | 106.6 |
C31A—C21—C31 | 41.8 (4) | C31—C41—H41D | 137.2 |
N11—C21—H21A | 109.0 | C101—C41—H41D | 108.9 |
C31A—C21—H21A | 131.9 | H41A—C41—H41D | 69.1 |
C31—C21—H21A | 109.0 | H41B—C41—H41D | 41.7 |
N11—C21—H21B | 109.0 | H41C—C41—H41D | 107.9 |
C31A—C21—H21B | 68.6 | C61—C51—C101 | 122.11 (19) |
C31—C21—H21B | 109.0 | C61—C51—H51 | 118.9 |
H21A—C21—H21B | 107.8 | C101—C51—H51 | 118.9 |
N11—C21—H21C | 108.2 | C51—C61—C71 | 119.03 (18) |
C31A—C21—H21C | 104.2 | C51—C61—H61 | 120.5 |
C31—C21—H21C | 66.4 | C71—C61—H61 | 120.5 |
H21A—C21—H21C | 47.1 | C81—C71—C61 | 120.18 (18) |
H21B—C21—H21C | 140.7 | C81—C71—H71 | 119.9 |
N11—C21—H21D | 107.3 | C61—C71—H71 | 119.9 |
C31A—C21—H21D | 111.8 | C71—C81—C91 | 121.16 (19) |
C31—C21—H21D | 139.1 | C71—C81—H81 | 119.4 |
H21A—C21—H21D | 61.9 | C91—C81—H81 | 119.4 |
H21B—C21—H21D | 49.2 | N11—C91—C81 | 121.35 (17) |
H21C—C21—H21D | 107.1 | N11—C91—C101 | 119.76 (16) |
C21—C31—C41 | 111.9 (2) | C81—C91—C101 | 118.90 (16) |
C21—C31—H21C | 38.9 | C51—C101—C91 | 118.61 (16) |
C41—C31—H21C | 143.2 | C51—C101—C41 | 121.94 (15) |
C21—C31—H31A | 109.2 | C91—C101—C41 | 119.45 (15) |
C41—C31—H31A | 109.2 | ||
O11—N1—C1—C6 | −15.4 (2) | N11—C21—C31—C41 | 50.6 (4) |
O12—N1—C1—C6 | 163.78 (17) | C31A—C21—C31—C41 | −55.6 (4) |
O11—N1—C1—C2 | 166.06 (17) | N11—C21—C31A—C41 | −38.4 (9) |
O12—N1—C1—C2 | −14.7 (2) | C31—C21—C31A—C41 | 56.1 (5) |
C6—C1—C2—C3 | −0.5 (2) | C21—C31A—C41—C31 | −55.9 (4) |
N1—C1—C2—C3 | 177.92 (13) | C21—C31A—C41—C101 | 37.3 (9) |
C1—C2—C3—C4 | −0.2 (2) | C21—C31—C41—C31A | 55.5 (4) |
C1—C2—C3—N3 | 179.38 (13) | C21—C31—C41—C101 | −50.2 (4) |
O31—N3—C3—C2 | −2.8 (3) | C101—C51—C61—C71 | −0.1 (3) |
O32—N3—C3—C2 | 177.93 (17) | C51—C61—C71—C81 | 0.3 (3) |
O31—N3—C3—C4 | 176.77 (17) | C61—C71—C81—C91 | −0.7 (3) |
O32—N3—C3—C4 | −2.5 (2) | C21—N11—C91—C81 | 179.5 (2) |
C2—C3—C4—C5 | 1.0 (2) | C21—N11—C91—C101 | −0.5 (3) |
N3—C3—C4—C5 | −178.58 (14) | C71—C81—C91—N11 | −179.07 (17) |
C3—C4—C5—C6 | −1.1 (2) | C71—C81—C91—C101 | 1.0 (2) |
C3—C4—C5—N5 | 178.88 (13) | C61—C51—C101—C91 | 0.4 (2) |
O52—N5—C5—C6 | 1.2 (2) | C61—C51—C101—C41 | 179.59 (16) |
O51—N5—C5—C6 | −178.86 (15) | N11—C91—C101—C51 | 179.27 (17) |
O52—N5—C5—C4 | −178.77 (16) | C81—C91—C101—C51 | −0.8 (2) |
O51—N5—C5—C4 | 1.1 (2) | N11—C91—C101—C41 | 0.0 (2) |
C4—C5—C6—C1 | 0.5 (2) | C81—C91—C101—C41 | 179.99 (15) |
N5—C5—C6—C1 | −179.56 (12) | C31A—C41—C101—C51 | 161.4 (5) |
C2—C1—C6—C5 | 0.4 (2) | C31—C41—C101—C51 | −153.7 (2) |
N1—C1—C6—C5 | −178.04 (13) | C31A—C41—C101—C91 | −19.4 (5) |
C91—N11—C21—C31A | 20.9 (6) | C31—C41—C101—C91 | 25.6 (3) |
C91—N11—C21—C31 | −25.3 (4) |
D—H···A | D—H | H···A | D···A | D—H···A |
N11—H11···O31 | 0.83 (3) | 2.37 (3) | 3.170 (3) | 163 (3) |
C61—H61···O12i | 0.93 | 2.56 | 3.432 (3) | 156 |
Symmetry code: (i) x+1, y, z. |
Experimental details
Crystal data | |
Chemical formula | C9H11N·C6H3N3O6 |
Mr | 346.30 |
Crystal system, space group | Monoclinic, P21/c |
Temperature (K) | 293 |
a, b, c (Å) | 13.8474 (12), 6.8830 (6), 16.8328 (15) |
β (°) | 99.273 (3) |
V (Å3) | 1583.4 (2) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 0.12 |
Crystal size (mm) | 0.45 × 0.40 × 0.24 |
Data collection | |
Diffractometer | Bruker SMART CCD area detector diffractometer |
Absorption correction | – |
No. of measured, independent and observed [I > 2σ(I)] reflections | 9501, 3583, 2519 |
Rint | 0.055 |
(sin θ/λ)max (Å−1) | 0.650 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.055, 0.174, 1.07 |
No. of reflections | 3583 |
No. of parameters | 240 |
No. of restraints | 6 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 0.21, −0.24 |
Computer programs: SMART (Bruker, 2000), SMART, SAINT (Bruker, 1999), SHELXTL (Bruker, 1997), SHELXTL, PLATON (Spek, 1999).
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2,4,6-Trinitrobenzoic acid (TNBA) is a relatively strong organic acid (pKa = 0.65) which has proved useful in the preparation of proton-transfer compounds with Lewis bases, a small number of which have been characterized crystallographically, e.g. with 2-aminopyrimidine (2-AP), [(2-AP)+(TNBA)−] (Byriel et al., 1992), with 3-hydroxypyridine (3-HP) [(3-HP)+(TNBA)−] (Lynch et al., 1992a), with 2,6-diaminopyridine (DAP), the modulated structure [(DAP)+(TNBA)−] (Smith et al., 2000), and with 4-aminobenzoic acid (PABA), three forms, [(PABA)+(TNBA)−] (Lynch et al., 1994), the hydrate [(PABA)+(TNBA)−. (H2O] (Lynch et al., 1992a) and the unusual tri-heteromolecular crystal adduct [(PABA)+(TNBA)−. 2(PABA)·(TNB)] (where TNB = 1,3,5-trinitrobenzene) (Lynch et al., 1992b). Non-transfer (1:1) compounds with triphenylphosphine oxide (Lynch et al., 1993) and phenylurea (Bott et al., 2000) are also known. As shown in the structure of the tri-crystal compound (Lynch et al., 1992b), which was prepared from the reaction of PABA with TNBA, the latter compound has a tendency to undergo facile decarboxylation (Coffey, 1977) often at a temperature lower than that of the usually employed refluxing conditions in 95% ethanol/water. The co-crystalline reaction products are stable 1:1 adducts involving 1,3,5-trinitrobenzene which associates with the companion molecule through π–π stacking together with weak N—H···O or C—H···O hydrogen bonds between the stacks. Examples of this type of compound are the (1:1) adducts with anthracene (Brown et al., 1964), skatole (Hanson, 1964), indole (Hanson, 1964), azulene (Hanson, 1965), acepleiadylene (Hanson, 1966), 2,4,6-tri(dimethylamino)-1,3,5-triazine (Williams & Wallwork, 1966), 1,3,5-triaminobenzene (Iwasaki & Saito, 1970), 8-hydroxyquinoline (oxine) (Castellano & Prout, 1971), pyrene (Prout & Tickle, 1973), azulene (Mariezcurrena et al.,1999) and with indole-3-acetic acid (Lynch et al., 1991). Adducts with (2:1) stoichiometry are also known [with trans-azobenzene and N-benzylideneaniline (Bar & Bernstein, 1981)].
Reported here is the crystal structure of the 1:1 adduct of 1,2,3,4-tetrahydroquinoline (THQ) with 1,3,5-trinitrobenzene [(THQ)(TNB)], (I), formed as the sole product in the reaction of THQ with 2,4,6-trinitrobenzoic acid (with decarboxylation). The cell dimensions and space group for this compound were reported by Herbstein et al. (1976), who indicated that it was one of an isomorphous set (Herbstein, 1971; Herbstein & Kaftory, 1975) which included the azulene–TNB adduct (Hanson, 1965). The isomorphism is confirmed in the present study [comparative cell data for (I) from Herbstein et al. (1976) are a = 17.02, b = 6.80, c = 14.05 Å, β = 100°, space group P21/a, cf. azulene:TNB (Hanson, 1965): a = 16.39, b = 6.66, c = 13.77 Å, β = 100°, space group P21/a].
Molecular conformation and atom numbering scheme for the individual molecules of (I) are shown in Fig. 1. These alternating TNB and THQ molecules give stacks down the b cell axis, involving π–π interaction between the aromatic ring systems of both molecules as well as the aromatic nitro substituents of TNB (Fig. 2). The aromatic rings are stacked alternatively at centroid–centroid distances of 3.676 (1) and 3.728 (1) Å, respectively. The stacks are linked by N—H (THQ) to O (TNB) and weaker C—H (THQ) to O (TNB) hydrogen bonds [N11···O31, 3.170 (3) Å, N11—H11···O31, 163 (3)°; C61···O12i, 3.432 (3) Å, C61—H61···O12i, 156°; symmetry code: (i) = 1 + x, y, z].
Only minor deviations from planarity in TNB due to rotation of the nitro group is observed [torsion angles C6—C1—N1—O12, C2—C3—N3—O32, C4—C5—N5—O52 being 163.8 (2), 177.9 (2) and −178.8 (2)°, respectively], the largest being with the only unassociated nitro group. The THQ molecule is similar to that found in its 1:1 proton-transfer compound with 3,5-dinitrosalicylic acid (Smith et al., 2002). However, there is significant vibrational disorder in the carbon atoms of the saturated ring of THQ (particularly C21, C31 and C41), largely in the direction of the molecular stacks. The worst of these, C31 was therefore modelled over two disorder sites [C31 (SOF = 0.733) and C31A (SOF = 0.267)]. This phenomenon is probably due to the presence of two possible conformational orientations of this ring, although similar disorder is also present in the isomorphous azulene–TNB adduct (Hansen, 1965) and in other adducts which involve π–π stacking (Herbstein & Kaftory, 1975).