Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270101007028/gg1054sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S0108270101007028/gg1054Isup2.hkl |
CCDC reference: 170185
Urotropine and sebacic acid were purchased from Fluka. Stoichiometric amounts were dissolved in ethanol, which was then removed by rotary evaporation. The resulting white powder was recrystallized by slow evaporation from acetonitrile at room temperature. The glossy colourless (010) platelets of (I) were very often twinned according to (101) or (101) and had to be cut to obtain single-domain crystals. Query 2 x (101).
H atoms bonded to the O atoms of the acid-chain end-groups were located in electron-density maps and refined isotropically. H atoms bonded to C atoms (in both U and S) were placed in calculated positions and treated as riding atoms, with C—H = 0.98 Å and Uiso(H) = 1.2Ueq(C). Query constraints.
Data collection: EXPOSE (Stoe & Cie, 1997); cell refinement: CELL (Stoe & Cie, 1997); data reduction: INTEGRATE (Stoe & Cie, 1997) and XPREP (Siemens, 1996); program(s) used to solve structure: SIR97 (Altomare et al., 1998); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: XP (Siemens, 1996) and Cerius2 (MSI, 1997); software used to prepare material for publication: SHELXL97.
C10H18O4·C6H12N4 | Dx = 1.220 Mg m−3 |
Mr = 342.44 | Melting point: 440 K |
Monoclinic, P21/c | Mo Kα radiation, λ = 0.71073 Å |
a = 5.9030 (12) Å | Cell parameters from 6009 reflections |
b = 27.549 (6) Å | θ = 1.9–26.1° |
c = 23.371 (5) Å | µ = 0.09 mm−1 |
β = 101.22 (3)° | T = 215 K |
V = 3728.0 (13) Å3 | Wedge, colourless |
Z = 8 | 0.36 × 0.24 × 0.08 mm |
F(000) = 1488 |
Stoe IPDS diffractometer | 3916 reflections with I > 2σ(I) |
Radiation source: fine-focus sealed tube | Rint = 0.065 |
Graphite monochromator | θmax = 26.2°, θmin = 1.9° |
Detector resolution: 6.7 pixels mm-1 | h = −7→5 |
ϕ scans | k = −34→34 |
18263 measured reflections | l = −28→23 |
6652 independent reflections |
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)] = 0.057 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.064 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.63 | Weighting scheme based on measured s.u.'s |
6652 reflections | (Δ/σ)max = 0.003 |
449 parameters | Δρmax = 0.29 e Å−3 |
0 restraints | Δρmin = −0.29 e Å−3 |
C10H18O4·C6H12N4 | V = 3728.0 (13) Å3 |
Mr = 342.44 | Z = 8 |
Monoclinic, P21/c | Mo Kα radiation |
a = 5.9030 (12) Å | µ = 0.09 mm−1 |
b = 27.549 (6) Å | T = 215 K |
c = 23.371 (5) Å | 0.36 × 0.24 × 0.08 mm |
β = 101.22 (3)° |
Stoe IPDS diffractometer | 3916 reflections with I > 2σ(I) |
18263 measured reflections | Rint = 0.065 |
6652 independent reflections |
R[F2 > 2σ(F2)] = 0.057 | 0 restraints |
wR(F2) = 0.064 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.63 | Δρmax = 0.29 e Å−3 |
6652 reflections | Δρmin = −0.29 e Å−3 |
449 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. Least-squares planes (x,y,z in crystal coordinates) and deviations from them (* indicates atom used to define plane) - 3.0185(0.0076) x + 22.4324(0.0235) y - 3.9722(0.0336) z = 5.6855(0.0178) * -0.0005 (0.0006) O1A * -0.0006 (0.0008) O2A * 0.0015 (0.0020) C1A * -0.0004 (0.0006) C2A Rms deviation of fitted atoms = 0.0009 - 2.4409(0.0063) x + 22.1942(0.0214) y - 7.8445(0.0254) z = 3.3989(0.0286) Angle to previous plane (with approximate e.s.d.) = 10.26 (0.17) * -0.0029 (0.0006) O3A * -0.0035 (0.0007) O4A * -0.0027 (0.0005) C9A * 0.0091 (0.0018) C10A Rms deviation of fitted atoms = 0.0053 - 3.9594(0.0072) x - 7.4203(0.0442) y + 18.8929(0.0272) z = 9.5294(0.0330) Angle to previous plane (with approximate e.s.d.) = 76.54 (0.11) * 0.0036 (0.0007) O1B * 0.0045 (0.0009) O2B * -0.0112 (0.0022) C1B * 0.0032 (0.0006) C2B Rms deviation of fitted atoms = 0.0065 - 3.6531(0.0072) x - 5.1723(0.0404) y + 20.3003(0.0215) z = 12.1040(0.0461) Angle to previous plane (with approximate e.s.d.) = 6.90 (0.21) * -0.0041 (0.0006) O3B * -0.0051 (0.0008) O4B * -0.0037 (0.0006) C9B * 0.0129 (0.0020) C10B Rms deviation of fitted atoms = 0.0075 |
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 | ||
O1A | 0.4310 (3) | 0.38433 (6) | 0.41174 (8) | 0.0610 (5) | |
H1A | 0.318 (6) | 0.3584 (9) | 0.4008 (15) | 0.116 (12)* | |
O2A | 0.3061 (5) | 0.38206 (8) | 0.49384 (9) | 0.1096 (10) | |
O3A | 1.6231 (3) | 0.63986 (5) | 0.87239 (7) | 0.0517 (4) | |
H3A | 1.764 (6) | 0.6645 (9) | 0.8727 (14) | 0.117 (11)* | |
O4A | 1.7561 (4) | 0.62607 (6) | 0.79205 (8) | 0.0736 (6) | |
C1A | 0.4435 (4) | 0.39582 (7) | 0.46662 (11) | 0.0452 (6) | |
C2A | 0.6508 (4) | 0.42783 (7) | 0.49035 (10) | 0.0483 (6) | |
H2A1 | 0.7920 | 0.4103 | 0.4869 | 0.058* | |
H2A2 | 0.6429 | 0.4570 | 0.4661 | 0.058* | |
C3A | 0.6675 (5) | 0.44305 (7) | 0.55326 (11) | 0.0528 (7) | |
H3A1 | 0.6747 | 0.4140 | 0.5778 | 0.063* | |
H3A2 | 0.5283 | 0.4612 | 0.5569 | 0.063* | |
C4A | 0.8804 (5) | 0.47457 (7) | 0.57498 (11) | 0.0576 (7) | |
H4A1 | 1.0193 | 0.4560 | 0.5719 | 0.069* | |
H4A2 | 0.8747 | 0.5031 | 0.5496 | 0.069* | |
C5A | 0.8992 (5) | 0.49152 (7) | 0.63792 (11) | 0.0592 (7) | |
H5A1 | 0.9020 | 0.4632 | 0.6634 | 0.071* | |
H5A2 | 0.7630 | 0.5109 | 0.6410 | 0.071* | |
C6A | 1.1177 (5) | 0.52195 (7) | 0.65862 (11) | 0.0578 (8) | |
H6A1 | 1.2532 | 0.5021 | 0.6559 | 0.069* | |
H6A2 | 1.1159 | 0.5497 | 0.6322 | 0.069* | |
C7A | 1.1428 (5) | 0.54069 (7) | 0.72040 (10) | 0.0516 (7) | |
H7A1 | 1.1375 | 0.5132 | 0.7468 | 0.062* | |
H7A2 | 1.0123 | 0.5621 | 0.7228 | 0.062* | |
C8A | 1.3687 (4) | 0.56859 (7) | 0.74039 (10) | 0.0485 (7) | |
H8A1 | 1.4988 | 0.5467 | 0.7394 | 0.058* | |
H8A2 | 1.3767 | 0.5951 | 0.7129 | 0.058* | |
C9A | 1.3937 (4) | 0.58964 (6) | 0.80164 (10) | 0.0431 (6) | |
H9A1 | 1.2575 | 0.6095 | 0.8034 | 0.052* | |
H9A2 | 1.3969 | 0.5629 | 0.8294 | 0.052* | |
C10A | 1.6070 (4) | 0.62026 (6) | 0.82039 (10) | 0.0395 (6) | |
O1B | 0.2419 (4) | 0.37515 (5) | 0.70261 (9) | 0.0899 (8) | |
H1B | 0.187 (6) | 0.3422 (10) | 0.6843 (15) | 0.116 (11)* | |
O2B | 0.5454 (3) | 0.33640 (5) | 0.75104 (8) | 0.0652 (6) | |
O3B | 1.7832 (3) | 0.64191 (5) | 1.08048 (9) | 0.0849 (7) | |
H3B | 1.841 (7) | 0.6790 (11) | 1.0991 (17) | 0.156 (14)* | |
O4B | 1.4671 (3) | 0.67686 (4) | 1.03246 (8) | 0.0613 (5) | |
C1B | 0.4350 (5) | 0.37264 (7) | 0.74131 (11) | 0.0484 (7) | |
C2B | 0.4909 (5) | 0.41978 (7) | 0.77232 (13) | 0.0752 (10) | |
H2B1 | 0.3672 | 0.4272 | 0.7935 | 0.090* | |
H2B2 | 0.4890 | 0.4452 | 0.7429 | 0.090* | |
C3B | 0.7162 (4) | 0.42281 (6) | 0.81452 (11) | 0.0509 (7) | |
H3B1 | 0.8420 | 0.4150 | 0.7942 | 0.061* | |
H3B2 | 0.7180 | 0.3987 | 0.8454 | 0.061* | |
C4B | 0.7578 (5) | 0.47293 (6) | 0.84195 (11) | 0.0543 (7) | |
H4B1 | 0.7562 | 0.4967 | 0.8106 | 0.065* | |
H4B2 | 0.6283 | 0.4807 | 0.8610 | 0.065* | |
C5B | 0.9790 (4) | 0.47937 (6) | 0.88600 (10) | 0.0473 (7) | |
H5B1 | 1.1093 | 0.4709 | 0.8675 | 0.057* | |
H5B2 | 0.9793 | 0.4566 | 0.9182 | 0.057* | |
C6B | 1.0157 (4) | 0.53029 (6) | 0.91069 (10) | 0.0430 (6) | |
H6B1 | 1.0144 | 0.5531 | 0.8784 | 0.052* | |
H6B2 | 0.8860 | 0.5386 | 0.9294 | 0.052* | |
C7B | 1.2379 (4) | 0.53692 (6) | 0.95453 (10) | 0.0464 (6) | |
H7B1 | 1.3664 | 0.5266 | 0.9364 | 0.056* | |
H7B2 | 1.2349 | 0.5152 | 0.9876 | 0.056* | |
C8B | 1.2866 (4) | 0.58798 (6) | 0.97774 (10) | 0.0428 (6) | |
H8B1 | 1.1628 | 0.5981 | 0.9977 | 0.051* | |
H8B2 | 1.2861 | 0.6101 | 0.9449 | 0.051* | |
C9B | 1.5163 (4) | 0.59211 (6) | 1.01979 (11) | 0.0565 (8) | |
H9B1 | 1.5146 | 0.5696 | 1.0522 | 0.068* | |
H9B2 | 1.6379 | 0.5812 | 0.9996 | 0.068* | |
C10B | 1.5809 (4) | 0.64106 (6) | 1.04471 (10) | 0.0402 (6) | |
N1A | 0.1191 (3) | 0.31485 (5) | 0.37116 (7) | 0.0333 (4) | |
N2A | 0.0733 (3) | 0.22691 (5) | 0.37270 (8) | 0.0344 (4) | |
N3A | −0.2700 (3) | 0.27944 (5) | 0.35035 (8) | 0.0355 (4) | |
N4A | −0.0117 (3) | 0.27073 (5) | 0.28026 (7) | 0.0353 (4) | |
C11A | 0.1259 (4) | 0.31166 (6) | 0.30884 (9) | 0.0378 (5) | |
H11A | 0.2865 | 0.3079 | 0.3043 | 0.045* | |
H11B | 0.0667 | 0.3420 | 0.2896 | 0.045* | |
C12A | −0.1247 (4) | 0.31966 (6) | 0.37756 (10) | 0.0400 (6) | |
H12A | −0.1307 | 0.3210 | 0.4191 | 0.048* | |
H12B | −0.1871 | 0.3503 | 0.3598 | 0.048* | |
C13A | 0.2085 (4) | 0.26880 (6) | 0.39936 (9) | 0.0355 (5) | |
H13A | 0.3701 | 0.2647 | 0.3959 | 0.043* | |
H13B | 0.2030 | 0.2702 | 0.4410 | 0.043* | |
C14A | 0.0811 (4) | 0.22604 (6) | 0.30992 (9) | 0.0408 (6) | |
H14A | 0.2414 | 0.2218 | 0.3053 | 0.049* | |
H14B | −0.0084 | 0.1983 | 0.2916 | 0.049* | |
C15A | −0.2525 (4) | 0.27693 (6) | 0.28879 (9) | 0.0362 (5) | |
H15A | −0.3164 | 0.3068 | 0.2692 | 0.043* | |
H15B | −0.3460 | 0.2497 | 0.2704 | 0.043* | |
C16A | −0.1710 (4) | 0.23407 (6) | 0.37799 (10) | 0.0394 (5) | |
H16A | −0.2630 | 0.2066 | 0.3598 | 0.047* | |
H16B | −0.1804 | 0.2346 | 0.4194 | 0.047* | |
N1B | 0.0892 (3) | 0.29935 (5) | 0.63674 (8) | 0.0352 (4) | |
N2B | 0.0763 (3) | 0.21431 (5) | 0.60727 (8) | 0.0342 (4) | |
N3B | −0.2844 (3) | 0.26064 (5) | 0.59947 (8) | 0.0376 (5) | |
N4B | −0.0181 (3) | 0.27815 (5) | 0.53380 (8) | 0.0367 (4) | |
C11B | 0.1032 (4) | 0.31303 (6) | 0.57610 (9) | 0.0419 (6) | |
H11C | 0.0354 | 0.3453 | 0.5675 | 0.050* | |
H11D | 0.2657 | 0.3146 | 0.5725 | 0.050* | |
C12B | −0.1595 (4) | 0.29595 (7) | 0.64061 (10) | 0.0387 (5) | |
H12C | −0.1716 | 0.2866 | 0.6804 | 0.046* | |
H12D | −0.2316 | 0.3279 | 0.6326 | 0.046* | |
C13B | 0.1952 (4) | 0.25100 (6) | 0.64865 (10) | 0.0381 (5) | |
H13C | 0.1877 | 0.2412 | 0.6886 | 0.046* | |
H13D | 0.3582 | 0.2526 | 0.6456 | 0.046* | |
C14B | 0.0883 (4) | 0.23040 (6) | 0.54782 (9) | 0.0382 (5) | |
H14C | 0.2504 | 0.2318 | 0.5439 | 0.046* | |
H14D | 0.0099 | 0.2065 | 0.5197 | 0.046* | |
C15B | −0.2615 (4) | 0.27521 (7) | 0.54073 (9) | 0.0388 (5) | |
H15C | −0.3347 | 0.3070 | 0.5319 | 0.047* | |
H15D | −0.3435 | 0.2518 | 0.5126 | 0.047* | |
C16B | −0.1716 (4) | 0.21315 (6) | 0.61205 (10) | 0.0404 (6) | |
H16C | −0.2527 | 0.1890 | 0.5847 | 0.048* | |
H16D | −0.1834 | 0.2031 | 0.6516 | 0.048* |
U11 | U22 | U33 | U12 | U13 | U23 | |
O1A | 0.0598 (13) | 0.0730 (10) | 0.0511 (13) | −0.0264 (9) | 0.0131 (11) | −0.0212 (8) |
O2A | 0.142 (2) | 0.1387 (17) | 0.0529 (14) | −0.1029 (16) | 0.0300 (15) | −0.0222 (11) |
O3A | 0.0498 (12) | 0.0585 (9) | 0.0503 (12) | −0.0168 (8) | 0.0185 (9) | −0.0176 (8) |
O4A | 0.0827 (16) | 0.0994 (13) | 0.0427 (12) | −0.0423 (11) | 0.0220 (12) | −0.0118 (9) |
C1A | 0.0535 (17) | 0.0400 (11) | 0.0402 (17) | −0.0085 (10) | 0.0047 (14) | 0.0042 (10) |
C2A | 0.0502 (17) | 0.0410 (11) | 0.0501 (16) | −0.0089 (10) | 0.0011 (14) | −0.0022 (10) |
C3A | 0.0603 (18) | 0.0409 (11) | 0.0524 (17) | −0.0067 (11) | −0.0007 (15) | −0.0065 (10) |
C4A | 0.0607 (19) | 0.0500 (13) | 0.0558 (18) | −0.0067 (11) | −0.0043 (15) | −0.0082 (11) |
C5A | 0.0592 (18) | 0.0522 (12) | 0.0591 (18) | −0.0087 (11) | −0.0061 (16) | −0.0122 (12) |
C6A | 0.060 (2) | 0.0535 (13) | 0.0531 (18) | −0.0051 (11) | −0.0062 (16) | −0.0100 (11) |
C7A | 0.0575 (18) | 0.0427 (12) | 0.0505 (17) | −0.0020 (10) | 0.0006 (15) | −0.0070 (10) |
C8A | 0.0570 (17) | 0.0422 (11) | 0.0412 (16) | −0.0010 (10) | −0.0030 (14) | 0.0010 (9) |
C9A | 0.0423 (15) | 0.0375 (10) | 0.0473 (15) | 0.0004 (9) | 0.0036 (13) | 0.0012 (9) |
C10A | 0.0457 (16) | 0.0403 (11) | 0.0332 (15) | −0.0030 (10) | 0.0092 (13) | 0.0044 (10) |
O1B | 0.0939 (17) | 0.0503 (10) | 0.0977 (16) | 0.0136 (10) | −0.0501 (14) | −0.0278 (9) |
O2B | 0.0669 (14) | 0.0410 (8) | 0.0747 (14) | 0.0097 (8) | −0.0183 (11) | −0.0139 (7) |
O3B | 0.0718 (14) | 0.0372 (9) | 0.1186 (17) | 0.0079 (8) | −0.0483 (13) | −0.0232 (9) |
O4B | 0.0638 (13) | 0.0372 (8) | 0.0709 (13) | 0.0092 (7) | −0.0162 (11) | −0.0133 (7) |
C1B | 0.0446 (16) | 0.0438 (12) | 0.0484 (16) | −0.0009 (11) | −0.0120 (14) | −0.0085 (10) |
C2B | 0.065 (2) | 0.0480 (13) | 0.093 (2) | 0.0082 (12) | −0.0331 (18) | −0.0250 (13) |
C3B | 0.0452 (16) | 0.0435 (11) | 0.0549 (17) | 0.0006 (10) | −0.0128 (14) | −0.0113 (10) |
C4B | 0.0542 (18) | 0.0423 (11) | 0.0579 (18) | −0.0008 (10) | −0.0100 (15) | −0.0084 (10) |
C5B | 0.0485 (17) | 0.0402 (11) | 0.0469 (16) | −0.0027 (10) | −0.0066 (13) | −0.0087 (10) |
C6B | 0.0435 (16) | 0.0370 (10) | 0.0445 (16) | −0.0037 (9) | −0.0011 (13) | −0.0047 (9) |
C7B | 0.0494 (16) | 0.0363 (11) | 0.0484 (16) | −0.0047 (9) | −0.0032 (14) | −0.0043 (9) |
C8B | 0.0482 (16) | 0.0300 (10) | 0.0460 (15) | −0.0039 (9) | −0.0012 (13) | −0.0031 (9) |
C9B | 0.0554 (17) | 0.0341 (11) | 0.0678 (18) | 0.0012 (10) | −0.0183 (15) | −0.0118 (10) |
C10B | 0.0417 (16) | 0.0352 (11) | 0.0405 (14) | −0.0011 (10) | −0.0001 (12) | −0.0049 (9) |
N1A | 0.0350 (11) | 0.0356 (8) | 0.0288 (11) | 0.0003 (7) | 0.0049 (9) | 0.0008 (7) |
N2A | 0.0300 (11) | 0.0359 (8) | 0.0346 (11) | 0.0019 (7) | −0.0001 (9) | 0.0068 (7) |
N3A | 0.0286 (11) | 0.0442 (9) | 0.0337 (11) | 0.0045 (7) | 0.0062 (9) | 0.0053 (7) |
N4A | 0.0372 (12) | 0.0406 (9) | 0.0282 (11) | 0.0028 (8) | 0.0070 (9) | −0.0005 (7) |
C11A | 0.0373 (14) | 0.0434 (10) | 0.0337 (14) | −0.0047 (9) | 0.0091 (11) | 0.0058 (9) |
C12A | 0.0425 (15) | 0.0453 (11) | 0.0325 (14) | 0.0104 (9) | 0.0080 (12) | −0.0020 (9) |
C13A | 0.0307 (13) | 0.0432 (11) | 0.0315 (13) | 0.0008 (9) | 0.0036 (11) | 0.0035 (9) |
C14A | 0.0414 (15) | 0.0394 (10) | 0.0414 (15) | 0.0076 (9) | 0.0076 (12) | −0.0068 (9) |
C15A | 0.0318 (13) | 0.0425 (10) | 0.0314 (13) | 0.0027 (9) | −0.0012 (11) | 0.0038 (9) |
C16A | 0.0314 (14) | 0.0536 (12) | 0.0331 (14) | −0.0053 (10) | 0.0064 (11) | 0.0119 (9) |
N1B | 0.0337 (12) | 0.0417 (9) | 0.0289 (11) | −0.0045 (7) | 0.0033 (9) | −0.0017 (7) |
N2B | 0.0312 (11) | 0.0401 (8) | 0.0313 (11) | 0.0009 (7) | 0.0061 (9) | 0.0021 (7) |
N3B | 0.0323 (11) | 0.0435 (9) | 0.0363 (12) | 0.0003 (7) | 0.0054 (10) | 0.0011 (7) |
N4B | 0.0373 (12) | 0.0437 (9) | 0.0290 (11) | 0.0023 (8) | 0.0065 (9) | 0.0047 (7) |
C11B | 0.0404 (15) | 0.0432 (10) | 0.0421 (15) | −0.0067 (9) | 0.0079 (12) | 0.0090 (9) |
C12B | 0.0388 (15) | 0.0470 (11) | 0.0312 (13) | 0.0063 (9) | 0.0093 (12) | −0.0021 (9) |
C13B | 0.0301 (14) | 0.0530 (11) | 0.0302 (14) | 0.0030 (9) | 0.0034 (12) | 0.0041 (9) |
C14B | 0.0381 (14) | 0.0485 (11) | 0.0288 (13) | 0.0046 (9) | 0.0088 (11) | 0.0005 (9) |
C15B | 0.0342 (14) | 0.0465 (11) | 0.0324 (14) | 0.0031 (9) | −0.0014 (11) | −0.0006 (9) |
C16B | 0.0372 (15) | 0.0449 (11) | 0.0399 (15) | −0.0075 (9) | 0.0099 (12) | 0.0035 (9) |
O1A—C1A | 1.309 (3) | C7B—H7B2 | 0.9800 |
O1A—H1A | 0.98 (3) | C8B—C9B | 1.516 (3) |
O2A—C1A | 1.186 (3) | C8B—H8B1 | 0.9800 |
O3A—C10A | 1.316 (3) | C8B—H8B2 | 0.9800 |
O3A—H3A | 1.07 (3) | C9B—C10B | 1.489 (3) |
O4A—C10A | 1.211 (3) | C9B—H9B1 | 0.9800 |
C1A—C2A | 1.523 (3) | C9B—H9B2 | 0.9800 |
C2A—C3A | 1.514 (3) | N1A—C11A | 1.467 (3) |
C2A—H2A1 | 0.9800 | N1A—C13A | 1.479 (2) |
C2A—H2A2 | 0.9800 | N1A—C12A | 1.482 (3) |
C3A—C4A | 1.531 (3) | N2A—C13A | 1.471 (2) |
C3A—H3A1 | 0.9800 | N2A—C14A | 1.477 (3) |
C3A—H3A2 | 0.9800 | N2A—C16A | 1.484 (3) |
C4A—C5A | 1.527 (3) | N3A—C15A | 1.464 (3) |
C4A—H4A1 | 0.9800 | N3A—C12A | 1.468 (3) |
C4A—H4A2 | 0.9800 | N3A—C16A | 1.474 (2) |
C5A—C6A | 1.536 (3) | N4A—C14A | 1.466 (2) |
C5A—H5A1 | 0.9800 | N4A—C11A | 1.472 (2) |
C5A—H5A2 | 0.9800 | N4A—C15A | 1.483 (3) |
C6A—C7A | 1.513 (3) | C11A—H11A | 0.9800 |
C6A—H6A1 | 0.9800 | C11A—H11B | 0.9800 |
C6A—H6A2 | 0.9800 | C12A—H12A | 0.9800 |
C7A—C8A | 1.532 (3) | C12A—H12B | 0.9800 |
C7A—H7A1 | 0.9800 | C13A—H13A | 0.9800 |
C7A—H7A2 | 0.9800 | C13A—H13B | 0.9800 |
C8A—C9A | 1.525 (3) | C14A—H14A | 0.9800 |
C8A—H8A1 | 0.9800 | C14A—H14B | 0.9800 |
C8A—H8A2 | 0.9800 | C15A—H15A | 0.9800 |
C9A—C10A | 1.508 (3) | C15A—H15B | 0.9800 |
C9A—H9A1 | 0.9800 | C16A—H16A | 0.9800 |
C9A—H9A2 | 0.9800 | C16A—H16B | 0.9800 |
O1B—C1B | 1.312 (3) | N1B—C13B | 1.475 (2) |
O1B—H1B | 1.03 (3) | N1B—C11B | 1.484 (3) |
O2B—C1B | 1.190 (2) | N1B—C12B | 1.491 (3) |
O3B—C10B | 1.318 (3) | N2B—C14B | 1.473 (3) |
O3B—H3B | 1.14 (3) | N2B—C13B | 1.478 (3) |
O4B—C10B | 1.196 (2) | N2B—C16B | 1.490 (3) |
C1B—C2B | 1.493 (3) | N3B—C15B | 1.462 (3) |
C2B—C3B | 1.496 (3) | N3B—C12B | 1.462 (3) |
C2B—H2B1 | 0.9800 | N3B—C16B | 1.472 (2) |
C2B—H2B2 | 0.9800 | N4B—C11B | 1.462 (2) |
C3B—C4B | 1.522 (2) | N4B—C14B | 1.467 (2) |
C3B—H3B1 | 0.9800 | N4B—C15B | 1.479 (3) |
C3B—H3B2 | 0.9800 | C11B—H11C | 0.9800 |
C4B—C5B | 1.508 (3) | C11B—H11D | 0.9800 |
C4B—H4B1 | 0.9800 | C12B—H12C | 0.9800 |
C4B—H4B2 | 0.9800 | C12B—H12D | 0.9800 |
C5B—C6B | 1.516 (2) | C13B—H13C | 0.9800 |
C5B—H5B1 | 0.9800 | C13B—H13D | 0.9800 |
C5B—H5B2 | 0.9800 | C14B—H14C | 0.9800 |
C6B—C7B | 1.510 (3) | C14B—H14D | 0.9800 |
C6B—H6B1 | 0.9800 | C15B—H15C | 0.9800 |
C6B—H6B2 | 0.9800 | C15B—H15D | 0.9800 |
C7B—C8B | 1.515 (2) | C16B—H16C | 0.9800 |
C7B—H7B1 | 0.9800 | C16B—H16D | 0.9800 |
C1A—O1A—H1A | 109.7 (19) | C10B—C9B—H9B1 | 108.1 |
C10A—O3A—H3A | 100.5 (18) | C8B—C9B—H9B1 | 108.1 |
O2A—C1A—O1A | 122.3 (2) | C10B—C9B—H9B2 | 108.1 |
O2A—C1A—C2A | 125.1 (2) | C8B—C9B—H9B2 | 108.1 |
O1A—C1A—C2A | 112.6 (2) | H9B1—C9B—H9B2 | 107.3 |
C3A—C2A—C1A | 114.2 (2) | O4B—C10B—O3B | 122.32 (18) |
C3A—C2A—H2A1 | 108.7 | O4B—C10B—C9B | 124.3 (2) |
C1A—C2A—H2A1 | 108.7 | O3B—C10B—C9B | 113.31 (18) |
C3A—C2A—H2A2 | 108.7 | C11A—N1A—C13A | 108.35 (15) |
C1A—C2A—H2A2 | 108.7 | C11A—N1A—C12A | 108.67 (18) |
H2A1—C2A—H2A2 | 107.6 | C13A—N1A—C12A | 107.52 (16) |
C2A—C3A—C4A | 111.9 (2) | C13A—N2A—C14A | 108.30 (16) |
C2A—C3A—H3A1 | 109.2 | C13A—N2A—C16A | 108.44 (16) |
C4A—C3A—H3A1 | 109.2 | C14A—N2A—C16A | 107.66 (17) |
C2A—C3A—H3A2 | 109.2 | C15A—N3A—C12A | 108.33 (16) |
C4A—C3A—H3A2 | 109.2 | C15A—N3A—C16A | 107.04 (16) |
H3A1—C3A—H3A2 | 107.9 | C12A—N3A—C16A | 107.57 (17) |
C5A—C4A—C3A | 113.2 (2) | C14A—N4A—C11A | 107.84 (17) |
C5A—C4A—H4A1 | 108.9 | C14A—N4A—C15A | 108.25 (16) |
C3A—C4A—H4A1 | 108.9 | C11A—N4A—C15A | 108.03 (15) |
C5A—C4A—H4A2 | 108.9 | N1A—C11A—N4A | 112.15 (16) |
C3A—C4A—H4A2 | 108.9 | N1A—C11A—H11A | 109.2 |
H4A1—C4A—H4A2 | 107.8 | N4A—C11A—H11A | 109.2 |
C4A—C5A—C6A | 111.7 (2) | N1A—C11A—H11B | 109.2 |
C4A—C5A—H5A1 | 109.3 | N4A—C11A—H11B | 109.2 |
C6A—C5A—H5A1 | 109.3 | H11A—C11A—H11B | 107.9 |
C4A—C5A—H5A2 | 109.3 | N3A—C12A—N1A | 112.68 (15) |
C6A—C5A—H5A2 | 109.3 | N3A—C12A—H12A | 109.1 |
H5A1—C5A—H5A2 | 107.9 | N1A—C12A—H12A | 109.1 |
C7A—C6A—C5A | 114.0 (2) | N3A—C12A—H12B | 109.1 |
C7A—C6A—H6A1 | 108.8 | N1A—C12A—H12B | 109.1 |
C5A—C6A—H6A1 | 108.8 | H12A—C12A—H12B | 107.8 |
C7A—C6A—H6A2 | 108.8 | N2A—C13A—N1A | 111.55 (17) |
C5A—C6A—H6A2 | 108.8 | N2A—C13A—H13A | 109.3 |
H6A1—C6A—H6A2 | 107.6 | N1A—C13A—H13A | 109.3 |
C6A—C7A—C8A | 112.3 (2) | N2A—C13A—H13B | 109.3 |
C6A—C7A—H7A1 | 109.1 | N1A—C13A—H13B | 109.3 |
C8A—C7A—H7A1 | 109.1 | H13A—C13A—H13B | 108.0 |
C6A—C7A—H7A2 | 109.1 | N4A—C14A—N2A | 112.04 (15) |
C8A—C7A—H7A2 | 109.1 | N4A—C14A—H14A | 109.2 |
H7A1—C7A—H7A2 | 107.9 | N2A—C14A—H14A | 109.2 |
C9A—C8A—C7A | 113.4 (2) | N4A—C14A—H14B | 109.2 |
C9A—C8A—H8A1 | 108.9 | N2A—C14A—H14B | 109.2 |
C7A—C8A—H8A1 | 108.9 | H14A—C14A—H14B | 107.9 |
C9A—C8A—H8A2 | 108.9 | N3A—C15A—N4A | 112.96 (17) |
C7A—C8A—H8A2 | 108.9 | N3A—C15A—H15A | 109.0 |
H8A1—C8A—H8A2 | 107.7 | N4A—C15A—H15A | 109.0 |
C10A—C9A—C8A | 114.1 (2) | N3A—C15A—H15B | 109.0 |
C10A—C9A—H9A1 | 108.7 | N4A—C15A—H15B | 109.0 |
C8A—C9A—H9A1 | 108.7 | H15A—C15A—H15B | 107.8 |
C10A—C9A—H9A2 | 108.7 | N3A—C16A—N2A | 112.63 (16) |
C8A—C9A—H9A2 | 108.7 | N3A—C16A—H16A | 109.1 |
H9A1—C9A—H9A2 | 107.6 | N2A—C16A—H16A | 109.1 |
O4A—C10A—O3A | 121.4 (2) | N3A—C16A—H16B | 109.1 |
O4A—C10A—C9A | 124.7 (2) | N2A—C16A—H16B | 109.1 |
O3A—C10A—C9A | 113.8 (2) | H16A—C16A—H16B | 107.8 |
C1B—O1B—H1B | 113.7 (18) | C13B—N1B—C11B | 108.01 (16) |
C10B—O3B—H3B | 115.2 (19) | C13B—N1B—C12B | 108.57 (15) |
O2B—C1B—O1B | 123.10 (19) | C11B—N1B—C12B | 108.20 (18) |
O2B—C1B—C2B | 125.2 (2) | C14B—N2B—C13B | 107.92 (15) |
O1B—C1B—C2B | 111.7 (2) | C14B—N2B—C16B | 107.77 (18) |
C1B—C2B—C3B | 116.93 (19) | C13B—N2B—C16B | 108.28 (17) |
C1B—C2B—H2B1 | 108.1 | C15B—N3B—C12B | 107.93 (16) |
C3B—C2B—H2B1 | 108.1 | C15B—N3B—C16B | 108.11 (16) |
C1B—C2B—H2B2 | 108.1 | C12B—N3B—C16B | 108.03 (17) |
C3B—C2B—H2B2 | 108.1 | C11B—N4B—C14B | 107.84 (17) |
H2B1—C2B—H2B2 | 107.3 | C11B—N4B—C15B | 108.67 (17) |
C2B—C3B—C4B | 112.22 (17) | C14B—N4B—C15B | 108.00 (15) |
C2B—C3B—H3B1 | 109.2 | N4B—C11B—N1B | 111.58 (15) |
C4B—C3B—H3B1 | 109.2 | N4B—C11B—H11C | 109.3 |
C2B—C3B—H3B2 | 109.2 | N1B—C11B—H11C | 109.3 |
C4B—C3B—H3B2 | 109.2 | N4B—C11B—H11D | 109.3 |
H3B1—C3B—H3B2 | 107.9 | N1B—C11B—H11D | 109.3 |
C5B—C4B—C3B | 116.21 (17) | H11C—C11B—H11D | 108.0 |
C5B—C4B—H4B1 | 108.2 | N3B—C12B—N1B | 112.21 (17) |
C3B—C4B—H4B1 | 108.2 | N3B—C12B—H12C | 109.2 |
C5B—C4B—H4B2 | 108.2 | N1B—C12B—H12C | 109.2 |
C3B—C4B—H4B2 | 108.2 | N3B—C12B—H12D | 109.2 |
H4B1—C4B—H4B2 | 107.4 | N1B—C12B—H12D | 109.2 |
C4B—C5B—C6B | 114.16 (16) | H12C—C12B—H12D | 107.9 |
C4B—C5B—H5B1 | 108.7 | N1B—C13B—N2B | 111.35 (17) |
C6B—C5B—H5B1 | 108.7 | N1B—C13B—H13C | 109.4 |
C4B—C5B—H5B2 | 108.7 | N2B—C13B—H13C | 109.4 |
C6B—C5B—H5B2 | 108.7 | N1B—C13B—H13D | 109.4 |
H5B1—C5B—H5B2 | 107.6 | N2B—C13B—H13D | 109.4 |
C7B—C6B—C5B | 114.26 (16) | H13C—C13B—H13D | 108.0 |
C7B—C6B—H6B1 | 108.7 | N4B—C14B—N2B | 112.55 (16) |
C5B—C6B—H6B1 | 108.7 | N4B—C14B—H14C | 109.1 |
C7B—C6B—H6B2 | 108.7 | N2B—C14B—H14C | 109.1 |
C5B—C6B—H6B2 | 108.7 | N4B—C14B—H14D | 109.1 |
H6B1—C6B—H6B2 | 107.6 | N2B—C14B—H14D | 109.1 |
C6B—C7B—C8B | 115.75 (16) | H14C—C14B—H14D | 107.8 |
C6B—C7B—H7B1 | 108.3 | N3B—C15B—N4B | 112.80 (17) |
C8B—C7B—H7B1 | 108.3 | N3B—C15B—H15C | 109.0 |
C6B—C7B—H7B2 | 108.3 | N4B—C15B—H15C | 109.0 |
C8B—C7B—H7B2 | 108.3 | N3B—C15B—H15D | 109.0 |
H7B1—C7B—H7B2 | 107.4 | N4B—C15B—H15D | 109.0 |
C7B—C8B—C9B | 112.65 (16) | H15C—C15B—H15D | 107.8 |
C7B—C8B—H8B1 | 109.1 | N3B—C16B—N2B | 112.27 (15) |
C9B—C8B—H8B1 | 109.1 | N3B—C16B—H16C | 109.2 |
C7B—C8B—H8B2 | 109.1 | N2B—C16B—H16C | 109.2 |
C9B—C8B—H8B2 | 109.1 | N3B—C16B—H16D | 109.2 |
H8B1—C8B—H8B2 | 107.8 | N2B—C16B—H16D | 109.2 |
C10B—C9B—C8B | 116.75 (17) | H16C—C16B—H16D | 107.9 |
O2A—C1A—C2A—C3A | −1.9 (4) | C15A—N4A—C14A—N2A | −57.8 (2) |
O1A—C1A—C2A—C3A | 178.4 (2) | C13A—N2A—C14A—N4A | −58.9 (2) |
C1A—C2A—C3A—C4A | 179.26 (19) | C16A—N2A—C14A—N4A | 58.2 (2) |
C2A—C3A—C4A—C5A | 178.66 (19) | C12A—N3A—C15A—N4A | 57.35 (19) |
C3A—C4A—C5A—C6A | 178.60 (19) | C16A—N3A—C15A—N4A | −58.39 (19) |
C4A—C5A—C6A—C7A | 178.74 (19) | C14A—N4A—C15A—N3A | 58.57 (19) |
C5A—C6A—C7A—C8A | 177.05 (19) | C11A—N4A—C15A—N3A | −57.95 (19) |
C6A—C7A—C8A—C9A | 177.64 (18) | C15A—N3A—C16A—N2A | 58.9 (2) |
C7A—C8A—C9A—C10A | −175.83 (18) | C12A—N3A—C16A—N2A | −57.4 (2) |
C8A—C9A—C10A—O4A | −4.3 (3) | C13A—N2A—C16A—N3A | 57.9 (2) |
C8A—C9A—C10A—O3A | 177.52 (17) | C14A—N2A—C16A—N3A | −59.1 (2) |
O2B—C1B—C2B—C3B | 6.6 (4) | C14B—N4B—C11B—N1B | −59.2 (2) |
O1B—C1B—C2B—C3B | −175.6 (3) | C15B—N4B—C11B—N1B | 57.6 (2) |
C1B—C2B—C3B—C4B | 178.2 (2) | C13B—N1B—C11B—N4B | 59.7 (2) |
C2B—C3B—C4B—C5B | 179.0 (3) | C12B—N1B—C11B—N4B | −57.6 (2) |
C3B—C4B—C5B—C6B | 178.3 (2) | C15B—N3B—C12B—N1B | −58.3 (2) |
C4B—C5B—C6B—C7B | −179.6 (2) | C16B—N3B—C12B—N1B | 58.4 (2) |
C5B—C6B—C7B—C8B | 176.9 (2) | C13B—N1B—C12B—N3B | −58.7 (2) |
C6B—C7B—C8B—C9B | −177.9 (2) | C11B—N1B—C12B—N3B | 58.28 (19) |
C7B—C8B—C9B—C10B | 179.5 (2) | C11B—N1B—C13B—N2B | −59.0 (2) |
C8B—C9B—C10B—O4B | −2.1 (4) | C12B—N1B—C13B—N2B | 58.1 (2) |
C8B—C9B—C10B—O3B | −179.5 (2) | C14B—N2B—C13B—N1B | 58.3 (2) |
C13A—N1A—C11A—N4A | 58.7 (2) | C16B—N2B—C13B—N1B | −58.1 (2) |
C12A—N1A—C11A—N4A | −57.8 (2) | C11B—N4B—C14B—N2B | 59.2 (2) |
C14A—N4A—C11A—N1A | −58.9 (2) | C15B—N4B—C14B—N2B | −58.1 (2) |
C15A—N4A—C11A—N1A | 57.8 (2) | C13B—N2B—C14B—N4B | −58.7 (2) |
C15A—N3A—C12A—N1A | −56.7 (2) | C16B—N2B—C14B—N4B | 58.1 (2) |
C16A—N3A—C12A—N1A | 58.6 (2) | C12B—N3B—C15B—N4B | 58.4 (2) |
C11A—N1A—C12A—N3A | 57.3 (2) | C16B—N3B—C15B—N4B | −58.2 (2) |
C13A—N1A—C12A—N3A | −59.8 (2) | C11B—N4B—C15B—N3B | −58.53 (19) |
C14A—N2A—C13A—N1A | 58.1 (2) | C14B—N4B—C15B—N3B | 58.2 (2) |
C16A—N2A—C13A—N1A | −58.5 (2) | C15B—N3B—C16B—N2B | 58.0 (2) |
C11A—N1A—C13A—N2A | −58.2 (2) | C12B—N3B—C16B—N2B | −58.6 (2) |
C12A—N1A—C13A—N2A | 59.1 (2) | C14B—N2B—C16B—N3B | −57.9 (2) |
C11A—N4A—C14A—N2A | 58.8 (2) | C13B—N2B—C16B—N3B | 58.6 (2) |
D—H···A | D—H | H···A | D···A | D—H···A |
O1A—H1A···N1A | 0.98 (3) | 1.73 (3) | 2.697 (2) | 172 (3) |
O3A—H3A···N2Bi | 1.07 (3) | 1.68 (3) | 2.693 (2) | 156 (3) |
O1B—H1B···N1B | 1.03 (3) | 1.65 (3) | 2.646 (2) | 163 (3) |
O3B—H3B···N2Ai | 1.14 (3) | 1.52 (3) | 2.653 (2) | 176 (3) |
C13A—H13A···N3Aii | 0.98 | 2.59 | 3.500 (3) | 155 |
C13B—H13C···N4Aiii | 0.98 | 2.66 | 3.574 (3) | 156 |
C13B—H13D···N3Bii | 0.98 | 2.56 | 3.493 (3) | 160 |
C13A—H13B···N4B | 0.98 | 2.75 | 3.656 (3) | 154 |
C11B—H11D···O2A | 0.98 | 2.66 | 3.105 (3) | 108 |
C11A—H11B···O4Aiv | 0.98 | 2.51 | 3.103 (3) | 119 |
C15A—H15B···O2Bv | 0.98 | 2.48 | 3.397 (2) | 157 |
C15B—H15D···O4Bvi | 0.98 | 2.37 | 3.306 (2) | 161 |
Symmetry codes: (i) −x+2, y+1/2, −z+3/2; (ii) x+1, y, z; (iii) x, −y+1/2, z+1/2; (iv) −x+2, −y+1, −z+1; (v) x−1, −y+1/2, z−1/2; (vi) −x+1, y−1/2, −z+3/2. |
Experimental details
Crystal data | |
Chemical formula | C10H18O4·C6H12N4 |
Mr | 342.44 |
Crystal system, space group | Monoclinic, P21/c |
Temperature (K) | 215 |
a, b, c (Å) | 5.9030 (12), 27.549 (6), 23.371 (5) |
β (°) | 101.22 (3) |
V (Å3) | 3728.0 (13) |
Z | 8 |
Radiation type | Mo Kα |
µ (mm−1) | 0.09 |
Crystal size (mm) | 0.36 × 0.24 × 0.08 |
Data collection | |
Diffractometer | Stoe IPDS diffractometer |
Absorption correction | – |
No. of measured, independent and observed [I > 2σ(I)] reflections | 18263, 6652, 3916 |
Rint | 0.065 |
(sin θ/λ)max (Å−1) | 0.621 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.057, 0.064, 1.63 |
No. of reflections | 6652 |
No. of parameters | 449 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 0.29, −0.29 |
Computer programs: EXPOSE (Stoe & Cie, 1997), CELL (Stoe & Cie, 1997), INTEGRATE (Stoe & Cie, 1997) and XPREP (Siemens, 1996), SIR97 (Altomare et al., 1998), SHELXL97 (Sheldrick, 1997), XP (Siemens, 1996) and Cerius2 (MSI, 1997), SHELXL97.
O1A—C1A | 1.309 (3) | O1B—C1B | 1.312 (3) |
O2A—C1A | 1.186 (3) | O2B—C1B | 1.190 (2) |
O3A—C10A | 1.316 (3) | O3B—C10B | 1.318 (3) |
O4A—C10A | 1.211 (3) | O4B—C10B | 1.196 (2) |
O2A—C1A—O1A | 122.3 (2) | O2B—C1B—O1B | 123.10 (19) |
O4A—C10A—O3A | 121.4 (2) | O4B—C10B—O3B | 122.32 (18) |
D—H···A | D—H | H···A | D···A | D—H···A |
O1A—H1A···N1A | 0.98 (3) | 1.73 (3) | 2.697 (2) | 172 (3) |
O3A—H3A···N2Bi | 1.07 (3) | 1.68 (3) | 2.693 (2) | 156 (3) |
O1B—H1B···N1B | 1.03 (3) | 1.65 (3) | 2.646 (2) | 163 (3) |
O3B—H3B···N2Ai | 1.14 (3) | 1.52 (3) | 2.653 (2) | 176 (3) |
C13A—H13A···N3Aii | 0.98 | 2.59 | 3.500 (3) | 155 |
C13B—H13C···N4Aiii | 0.98 | 2.66 | 3.574 (3) | 156 |
C13B—H13D···N3Bii | 0.98 | 2.56 | 3.493 (3) | 160 |
C13A—H13B···N4B | 0.98 | 2.75 | 3.656 (3) | 154 |
C11B—H11D···O2A | 0.98 | 2.66 | 3.105 (3) | 108 |
C11A—H11B···O4Aiv | 0.98 | 2.51 | 3.103 (3) | 119 |
C15A—H15B···O2Bv | 0.98 | 2.48 | 3.397 (2) | 157 |
C15B—H15D···O4Bvi | 0.98 | 2.37 | 3.306 (2) | 161 |
Symmetry codes: (i) −x+2, y+1/2, −z+3/2; (ii) x+1, y, z; (iii) x, −y+1/2, z+1/2; (iv) −x+2, −y+1, −z+1; (v) x−1, −y+1/2, z−1/2; (vi) −x+1, y−1/2, −z+3/2. |
In the urotropine-sebacic acid system, US, (I), an incommensurate phase has been observed at 295 K (Bussien Gaillard et al., 1998). Its structure, characterized by the modulation vector [-0.02 (5), 0, 0.24 (5)], comprises two very distinct moieties: slightly modulated layers of urotropine, U, and strongly modulated layers of sebacic acid, S. In the S layers, the planes of the two independent chains are almost at right angles to each other. The modulation requires a high number of harmonic terms or crenel functions. Another striking feature of this structure lies in its pseudo-centrosymmetric nature: both E-statistics and systematic absences point to the superspace group P21/m(α0γ)0 s. Indeed, all atoms except those of the carboxy groups fulfil the superspace symmetry s. However, a better model requires the non-centrosymmetric superspace group P21(α0γ)0. Owing to the exceptionally large stability range of the incommensurate phase of the analogous compound urotropine suberate (Bussien Gaillard et al., 1996), it was believed that the incommensurate phase of (I) persists down to liquid nitrogen temperatures. \sch
In this communication we show that this is not the case. Despite the absence of all but the faintest signals in the differential scanning calorimetry curve, a lock-in phase does exist below 291 K: the oxygen disorder no longer exists and the centrosymmetric space group P21/c is realised for the whole structure. Interestingly, the systematic absence h0lm (m = 2n) of the incommensurate phase anticipates the absence h0l (l = 2n) in the lock-in phase. This lock-in occurs at (0,0,1/4) and the transition shows mixed displacive-OD type character. OD is? Its enthalpy is exceedingly small and reveals the transition to be only weakly of first order. In the light of its complex nature it has to be described by at least two order parameters. As a conclusion, we must advise that it is of crucial importance to scrutinize the calorimetric results to the fullest extent and to analyse the temperature evolution of the wavevector carefully before classifying an incommensurate phase. This is especially true for such a strongly anharmonic modulation, which can too easily be enhanced or biased by the vicinity of the lock-in phase (soliton regime).
The structure of (I) consists of (010) layers of U alternating with layers of S. The inter- and intralayer forces are due to hydrogen bonds of varying strength (Table 2 and Fig. 2). The following hydrogen-bond scheme is observed: strong O—H···N bonds link S to U and weak C—H···O bonds link U to S. Each U molecule is connected to its four U neighbours by C—H···N hydrogen bonds. The chain packing is further stabilized by van der Waals forces. The U layer in (I) closely resembles the (110) layer of pure U at 200 K (Kampermann et al., 1995), except that the layer in (I) is slightly contracted along [110] and elongated along [100], and that the C—H···N hydrogen bonds (c.f. 152° and 2.84 Å for H···N in pure U) are somewhat stronger.
It is noteworthy that one of the threefold axes of U is parallel to the a axis in (I). In the S layers of (I), there are two chains with different orientations, A and B (Fig. 1). One of the zigzag planes of the chains lies roughly perpendicular to the (104) plane, while the other is nearly parallel [the (104) plane of this lock-in phase corresponds to the (101) plane of the incommensurate structure]. The interplane angle is 80°, whereas in the incommensurate phase a wide variation of this angle has been observed. In all urotropine-alkanedioic-acid compounds there is a wide variation of this angle. One is led to believe that it represents one of the order parameters of this system. Quite surprisingly, the two chain axes are not parallel but span an angle of 10°. They also form an angle of 30° with the [401] direction and they pack according to an AABB··· sequence. The body of each chain lies in an almost perfect plane: the r.m.s. deviations are 0.003 and 0.007 Å for A and B, respectively. The AABB··· sequence, the angle between the chain axes and especially the acute angle with respect to the (010) layer clearly demonstrate that the chains do not adopt as compact a packing as possible [20.5 Å2, compared with 19.5 Å2 in pure S (Bond et al., 2001)]. The AABB··· sequence is not only observed in the chain conformation but also in the C—H···O hydrogen-bonding scheme (Fig. 2). This feature is intrinsic to the modulated character of the structure, and therefore the asymmetric unit contains two molecules of both moieties.
Examination of Tables 1 and 2 confirms the acid character of the chain end-groups. This acidity of the sebacic moiety will serve as a possible order parameter for many of the phase transitions in this and analogous compounds. Indeed, Bussien Gaillard et al. (1998) pointed out for the incommensurate phase that on one side of a chain the acid proton was clearly attached to the chain end-group, whereas on the opposite end it was rather associated with the nearest N atom. In addition, the hydrogen bond was shared between the two O atoms. We found that during the lock-in transition, the carboxy groups reconstitute and steer towards a new potential well. Each H atom is associated with one O atom, but with a slight delocalization towards the corresponding N atom. This results in rather long O—H distances (Table 2). The carboxy groups themselves are almost planar, from analysis of the refinement, but subtend dihedral angles with the zigzag planes of between 3° and 8°. These dihedral angles are of the same order as those observed in pure S (Bond et al., 2001).
The C—C and C—N bond lengths range from 1.489 (3) to 1.536 (3) Å and 1.462 (3) to 1.491 (3) Å, respectively. These values are in good agreement with those published in the International Tables for Crystallography (1992?, Vol. C). In conclusion, we may say that both moieties retain the main features of their single-phase character, except for some (110) distortion for U and a marginally looser chain packing for S. The lock-in phase may thus be regarded as a co-crystal.