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organic compounds
5-[(1R,2R,4R)-2-Methoxy-1,7,7-trimethylbicyclo[2.2.1]hept-2-yl]-1H-tetrazole
aInstitut für Organische Chemie und Chemische Biologie, Universität Frankfurt, Max-von-Laue-Strasse 7, D-60438 Frankfurt am Main, Germany
*Correspondence e-mail: bats@chemie.uni-frankfurt.de
The title compound, C12H20N4O, undergoes a on cooling. The room-temperature structure is tetragonal (P43212, Z′ = 1), with the methoxybornyl group being extremely disordered. Below 213 K the structure is orthorhombic (P212121, Z′ = 2), with ordered molecules. The two independent molecules (A and B) have very similar conformations; significant differences only occur for the torsion angles about the Cbornyl—Ctetrazole bonds. The independent molecules are approximately related by the pseudo-symmetry relation: xB = −1/4 + yA, yB = 3/4 - xA and zB = 1/4 + zA. In the crystal, molecules are connected by N—H⋯N hydrogen bonds between the tetrazole groups, forming a pseudo-43 helix parallel to the c-axis direction. The crystal studied was a twin with a refined twin fraction value of 0.231 (2).
Related literature
For the chemical background and synthesis of the title compound, see: Schell & Engels (1997, 1998
). For related structures, see: Ohno et al. (1999
).
Experimental
Crystal data
|
|
Data collection: SMART (Siemens, 1995); cell SMART; data reduction: SAINT (Siemens, 1995
); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008
); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008
); molecular graphics: SHELXTL (Sheldrick, 2008
); software used to prepare material for publication: SHELXL97.
Supporting information
https://doi.org/10.1107/S1600536813014700/su2603sup1.cif
contains datablocks global, I. DOI:Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S1600536813014700/su2603Isup2.hkl
Supporting information file. DOI: https://doi.org/10.1107/S1600536813014700/su2603Isup3.cml
The synthesis of the title compound, starting from (+)-camphor, has been reported by Schell & Engels (1997). The final product was recrystallized from tetrachloromethane/n-hexane (1:1), resulting in colourless needles.
Friedel opposites were merged. C-bound H atoms were positioned geometrically and treated as riding: C—H = 0.98 - 1.00 Å, with Uiso(H)=1.5Ueq(C-methyl) and 1.2Ueq(C) for other H atoms. N-bound H atoms were located from a difference Fourier synthesis. Their fractional coordinates were refined using a N—H bond length constraint of 0.88 (1) Å with Uiso(H) = 1.2Ueq(N). The crystal was found to be twinned. The twin relations are: htwin = k, ktwin = -h and ltwin = l. Reflections were integrated using a large profile width. Thus the observed intensities contain the contributions of both the main and the twin reflections.
of the twin fraction resulted in the value 0.231 (2).The title compound has been prepared as a chiral catalyst for the diastereoselective synthesis of dinucleoside methylphosphonates (Schell & Engels, 1997; Schell & Engels, 1998). An initial
determination of the title compound at room temperature revealed a tetragonal with a = b = 13.452 (2) Å, c = 14.642 (2) Å and P43212. There is one molecule in the but the atoms, especially of the methoxybornyl group show very large displacement parameters. The average Ueq values of the non-H atoms is 0.080 Å2 for the tetrazole group, 0.136 Å2 for the bornyl group and 0.243 Å2 for the methoxy group. Thus the molecule is heavily disordered. On cooling the crystal, weak incommensurate reflections were observed in the temperature range 223 - 213 K, while below 213 K an orthorhombic with P212121 was found. Herein, we report on the of the orthorhombic phase measured at 194 K.The
contains two independent molecules, A and B (Figs. 1 and 2). The only significant difference between the molecules is found for the torsion angles about the Cbornyl—Ctetrazole bond [e.g. corresponding torsion angles C2—C1—C11—N4: -5.0 (7)° and C14—C13—C23—N8: -21.9 (7)°]. The methoxy group is in the exo-position and the tetrazole group in the endo-position with respect to the bicyclo[2.2.1]heptane group. The tetrazole rings are planar (r.m.s. deviations: 0.004 Å for molecule A and 0.005 Å for molecule B). The C—N bond distances in the tetrazole rings range from 1.318 (6) - 1.352 (6) Å and the N—N bond distances from 1.315 (6) - 1.353 (6) Å, thus showing a considerable degree of delocalization of the double bonds in the ring. Resonance has also been reported for tetrazole rings in other crystal structures (Ohno et al., 1999).The
from the room temperature P43212 structure to the low temperature P212121 structure results in the doubling of the number of molecules in the from Z'=1 to Z'=2. Thus the two molecules, A and B, are expected to be related by tetragonal pseudo-symmetry. A close inspection of the fractional coordinates shows the molecules to be approximately related by the pseudo-relation: xB = -1/4 + yA, yB = 3/4 - xA and zB = 1/4 + zA. This is a of a 43 screw-axis.In the crystal, molecules are connected by N—H···N hydrogen bonds (Table 1 and Fig. 3) to form a helix along the pseudo-43 screw-axis parallel to the c axis direction. There are no short intermolecular contacts between neighboring helices, the shortest contact has a H···N distance of 2.71 Å. Thus the
is a [001] needle.For the chemical background and synthesis of the title compound, see: Schell & Engels (1997, 1998). For related structures, see: Ohno et al. (1999).
Data collection: SMART (Siemens, 1995); cell
SMART (Siemens, 1995); data reduction: SAINT (Siemens, 1995); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).C12H20N4O | Dx = 1.208 Mg m−3 |
Mr = 236.32 | Melting point: 446 K |
Orthorhombic, P212121 | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: P 2ac 2ab | Cell parameters from 76 reflections |
a = 13.298 (3) Å | θ = 3–23° |
b = 13.608 (4) Å | µ = 0.08 mm−1 |
c = 14.356 (3) Å | T = 194 K |
V = 2597.9 (11) Å3 | Rod, colourless |
Z = 8 | 0.65 × 0.24 × 0.20 mm |
F(000) = 1024 |
Siemens SMART 1K CCD diffractometer | 2259 reflections with I > 2σ(I) |
Radiation source: normal-focus sealed tube | Rint = 0.109 |
Graphite monochromator | θmax = 27.5°, θmin = 2.1° |
ω scans | h = −17→16 |
31860 measured reflections | k = −17→17 |
3283 independent reflections | l = −18→18 |
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)] = 0.069 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.138 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.08 | w = 1/[σ2(Fo2) + (0.07P)2] where P = (Fo2 + 2Fc2)/3 |
3283 reflections | (Δ/σ)max < 0.001 |
322 parameters | Δρmax = 0.20 e Å−3 |
2 restraints | Δρmin = −0.21 e Å−3 |
C12H20N4O | V = 2597.9 (11) Å3 |
Mr = 236.32 | Z = 8 |
Orthorhombic, P212121 | Mo Kα radiation |
a = 13.298 (3) Å | µ = 0.08 mm−1 |
b = 13.608 (4) Å | T = 194 K |
c = 14.356 (3) Å | 0.65 × 0.24 × 0.20 mm |
Siemens SMART 1K CCD diffractometer | 2259 reflections with I > 2σ(I) |
31860 measured reflections | Rint = 0.109 |
3283 independent reflections |
R[F2 > 2σ(F2)] = 0.069 | 2 restraints |
wR(F2) = 0.138 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.08 | Δρmax = 0.20 e Å−3 |
3283 reflections | Δρmin = −0.21 e Å−3 |
322 parameters |
Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes. |
Refinement. Refinement of F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > σ(F2) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2 are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger. |
x | y | z | Uiso*/Ueq | ||
O1 | 0.6305 (3) | 0.5594 (3) | 0.3157 (2) | 0.0447 (9) | |
O2 | 0.2964 (3) | 0.1694 (3) | 0.6297 (2) | 0.0489 (10) | |
N1 | 0.4154 (3) | 0.5552 (3) | 0.3153 (3) | 0.0345 (9) | |
H1A | 0.435 (4) | 0.502 (2) | 0.344 (3) | 0.041* | |
N2 | 0.3246 (3) | 0.5527 (3) | 0.2727 (3) | 0.0466 (11) | |
N3 | 0.3298 (3) | 0.6241 (3) | 0.2111 (3) | 0.0471 (11) | |
N4 | 0.4180 (4) | 0.6711 (4) | 0.2151 (3) | 0.0509 (12) | |
N5 | 0.3253 (3) | 0.3587 (3) | 0.5745 (2) | 0.0309 (9) | |
H5C | 0.269 (2) | 0.357 (4) | 0.606 (3) | 0.037* | |
N6 | 0.3365 (3) | 0.4372 (3) | 0.5209 (3) | 0.0413 (10) | |
N7 | 0.4046 (4) | 0.4110 (3) | 0.4588 (3) | 0.0456 (11) | |
N8 | 0.4374 (3) | 0.3188 (3) | 0.4730 (3) | 0.0426 (11) | |
C1 | 0.5766 (4) | 0.6494 (4) | 0.3131 (3) | 0.0364 (11) | |
C2 | 0.6290 (4) | 0.7309 (5) | 0.2547 (4) | 0.0547 (16) | |
H2A | 0.6921 | 0.7063 | 0.2266 | 0.066* | |
H2B | 0.5843 | 0.7551 | 0.2046 | 0.066* | |
C3 | 0.6506 (5) | 0.8127 (4) | 0.3267 (5) | 0.0589 (16) | |
H3A | 0.7019 | 0.8617 | 0.3059 | 0.071* | |
C4 | 0.5507 (5) | 0.8572 (5) | 0.3526 (7) | 0.085 (2) | |
H4A | 0.5094 | 0.8705 | 0.2966 | 0.102* | |
H4B | 0.5596 | 0.9191 | 0.3879 | 0.102* | |
C5 | 0.5031 (4) | 0.7775 (4) | 0.4133 (5) | 0.0591 (17) | |
H5A | 0.4908 | 0.8020 | 0.4772 | 0.071* | |
H5B | 0.4386 | 0.7548 | 0.3864 | 0.071* | |
C6 | 0.5800 (4) | 0.6954 (4) | 0.4136 (3) | 0.0419 (12) | |
C7 | 0.6814 (4) | 0.7541 (4) | 0.4126 (4) | 0.0443 (13) | |
C8 | 0.7776 (4) | 0.6940 (4) | 0.4010 (4) | 0.0526 (14) | |
H8A | 0.8355 | 0.7384 | 0.3971 | 0.079* | |
H8B | 0.7733 | 0.6547 | 0.3439 | 0.079* | |
H8C | 0.7858 | 0.6502 | 0.4547 | 0.079* | |
C9 | 0.6968 (5) | 0.8181 (5) | 0.5005 (5) | 0.0683 (19) | |
H9A | 0.7494 | 0.8670 | 0.4886 | 0.102* | |
H9B | 0.7170 | 0.7762 | 0.5528 | 0.102* | |
H9C | 0.6338 | 0.8517 | 0.5159 | 0.102* | |
C10 | 0.5666 (5) | 0.6200 (5) | 0.4921 (3) | 0.0581 (18) | |
H10A | 0.5834 | 0.6506 | 0.5519 | 0.087* | |
H10B | 0.6112 | 0.5639 | 0.4812 | 0.087* | |
H10C | 0.4966 | 0.5975 | 0.4933 | 0.087* | |
C11 | 0.4718 (4) | 0.6263 (4) | 0.2813 (3) | 0.0358 (11) | |
C12 | 0.6516 (5) | 0.5179 (5) | 0.2245 (4) | 0.0641 (17) | |
H12A | 0.5905 | 0.5196 | 0.1864 | 0.096* | |
H12B | 0.6740 | 0.4497 | 0.2316 | 0.096* | |
H12C | 0.7045 | 0.5563 | 0.1941 | 0.096* | |
C13 | 0.3936 (3) | 0.1902 (4) | 0.5947 (3) | 0.0337 (11) | |
C14 | 0.4411 (5) | 0.1082 (4) | 0.5341 (4) | 0.0549 (16) | |
H14A | 0.3939 | 0.0525 | 0.5265 | 0.066* | |
H14B | 0.4593 | 0.1337 | 0.4717 | 0.066* | |
C15 | 0.5344 (5) | 0.0766 (4) | 0.5875 (4) | 0.0558 (16) | |
H15A | 0.5603 | 0.0102 | 0.5696 | 0.067* | |
C16 | 0.6124 (5) | 0.1578 (5) | 0.5818 (4) | 0.0659 (18) | |
H16A | 0.6209 | 0.1811 | 0.5169 | 0.079* | |
H16B | 0.6782 | 0.1355 | 0.6060 | 0.079* | |
C17 | 0.5673 (4) | 0.2382 (4) | 0.6436 (4) | 0.0456 (13) | |
H17A | 0.5544 | 0.2988 | 0.6074 | 0.055* | |
H17B | 0.6127 | 0.2539 | 0.6962 | 0.055* | |
C18 | 0.4685 (3) | 0.1927 (4) | 0.6786 (3) | 0.0317 (10) | |
C19 | 0.4982 (4) | 0.0841 (4) | 0.6911 (3) | 0.0399 (12) | |
C20 | 0.4155 (5) | 0.0138 (4) | 0.7167 (4) | 0.0573 (15) | |
H20A | 0.3924 | 0.0277 | 0.7802 | 0.086* | |
H20B | 0.4408 | −0.0538 | 0.7134 | 0.086* | |
H20C | 0.3592 | 0.0216 | 0.6732 | 0.086* | |
C21 | 0.5845 (5) | 0.0671 (5) | 0.7623 (4) | 0.0567 (15) | |
H21A | 0.5573 | 0.0695 | 0.8257 | 0.085* | |
H21B | 0.6355 | 0.1185 | 0.7548 | 0.085* | |
H21C | 0.6151 | 0.0027 | 0.7512 | 0.085* | |
C22 | 0.4253 (5) | 0.2447 (4) | 0.7636 (3) | 0.0468 (14) | |
H22A | 0.4756 | 0.2455 | 0.8135 | 0.070* | |
H22B | 0.3652 | 0.2097 | 0.7851 | 0.070* | |
H22C | 0.4073 | 0.3123 | 0.7470 | 0.070* | |
C23 | 0.3845 (3) | 0.2864 (4) | 0.5473 (3) | 0.0300 (10) | |
C24 | 0.2217 (5) | 0.1422 (5) | 0.5634 (5) | 0.080 (2) | |
H24A | 0.2365 | 0.1735 | 0.5034 | 0.121* | |
H24B | 0.1555 | 0.1639 | 0.5853 | 0.121* | |
H24C | 0.2216 | 0.0707 | 0.5557 | 0.121* |
U11 | U22 | U33 | U12 | U13 | U23 | |
O1 | 0.056 (2) | 0.054 (2) | 0.0242 (15) | 0.0130 (18) | −0.0103 (15) | −0.0055 (16) |
O2 | 0.044 (2) | 0.051 (2) | 0.052 (2) | −0.0146 (18) | −0.0080 (17) | 0.0216 (18) |
N1 | 0.035 (2) | 0.035 (2) | 0.033 (2) | 0.002 (2) | −0.0031 (18) | 0.0015 (18) |
N2 | 0.046 (3) | 0.053 (3) | 0.041 (2) | −0.002 (2) | 0.002 (2) | 0.001 (2) |
N3 | 0.046 (3) | 0.053 (3) | 0.042 (2) | 0.000 (2) | −0.004 (2) | 0.010 (2) |
N4 | 0.049 (3) | 0.066 (3) | 0.038 (2) | 0.001 (2) | −0.008 (2) | 0.025 (2) |
N5 | 0.035 (2) | 0.029 (2) | 0.0285 (19) | −0.0009 (19) | −0.0028 (17) | 0.0040 (18) |
N6 | 0.052 (3) | 0.033 (2) | 0.039 (2) | −0.002 (2) | −0.005 (2) | 0.007 (2) |
N7 | 0.065 (3) | 0.042 (3) | 0.029 (2) | −0.012 (2) | −0.003 (2) | 0.0046 (19) |
N8 | 0.060 (3) | 0.044 (3) | 0.0239 (19) | 0.002 (2) | 0.0066 (19) | 0.0010 (19) |
C1 | 0.039 (3) | 0.046 (3) | 0.024 (2) | 0.003 (2) | 0.002 (2) | 0.006 (2) |
C2 | 0.044 (3) | 0.070 (4) | 0.049 (3) | −0.001 (3) | 0.000 (3) | 0.029 (3) |
C3 | 0.050 (4) | 0.040 (3) | 0.087 (4) | −0.005 (3) | 0.006 (3) | 0.020 (3) |
C4 | 0.058 (4) | 0.047 (4) | 0.150 (7) | 0.003 (3) | 0.005 (4) | 0.012 (4) |
C5 | 0.044 (3) | 0.051 (4) | 0.082 (4) | −0.006 (3) | 0.020 (3) | −0.011 (3) |
C6 | 0.058 (3) | 0.038 (3) | 0.030 (2) | −0.014 (3) | 0.011 (2) | −0.006 (2) |
C7 | 0.053 (3) | 0.034 (3) | 0.046 (3) | −0.007 (3) | 0.001 (3) | −0.001 (2) |
C8 | 0.061 (4) | 0.047 (3) | 0.050 (3) | 0.004 (3) | −0.005 (3) | 0.000 (3) |
C9 | 0.072 (4) | 0.047 (4) | 0.086 (5) | −0.014 (3) | 0.009 (4) | −0.026 (3) |
C10 | 0.087 (5) | 0.067 (4) | 0.021 (2) | −0.022 (3) | −0.001 (3) | −0.002 (2) |
C11 | 0.036 (3) | 0.037 (3) | 0.034 (2) | −0.001 (2) | 0.008 (2) | 0.004 (2) |
C12 | 0.062 (4) | 0.088 (5) | 0.042 (3) | 0.010 (4) | 0.001 (3) | −0.029 (3) |
C13 | 0.036 (3) | 0.034 (3) | 0.032 (2) | −0.011 (2) | −0.008 (2) | 0.000 (2) |
C14 | 0.091 (5) | 0.040 (3) | 0.034 (3) | 0.008 (3) | −0.008 (3) | −0.008 (2) |
C15 | 0.078 (4) | 0.048 (3) | 0.042 (3) | 0.026 (3) | 0.007 (3) | −0.009 (3) |
C16 | 0.051 (4) | 0.087 (5) | 0.060 (3) | 0.013 (4) | 0.021 (3) | 0.009 (4) |
C17 | 0.041 (3) | 0.047 (3) | 0.049 (3) | −0.005 (3) | −0.008 (2) | 0.007 (2) |
C18 | 0.033 (2) | 0.038 (3) | 0.025 (2) | 0.005 (2) | −0.0033 (19) | 0.001 (2) |
C19 | 0.038 (3) | 0.043 (3) | 0.038 (3) | 0.010 (2) | −0.003 (2) | −0.001 (2) |
C20 | 0.066 (4) | 0.046 (3) | 0.061 (3) | −0.014 (3) | −0.021 (3) | 0.017 (3) |
C21 | 0.053 (3) | 0.053 (4) | 0.063 (4) | 0.003 (3) | −0.012 (3) | 0.008 (3) |
C22 | 0.069 (4) | 0.053 (3) | 0.018 (2) | 0.017 (3) | −0.004 (2) | −0.002 (2) |
C23 | 0.038 (3) | 0.035 (3) | 0.0172 (19) | −0.005 (2) | −0.0053 (18) | 0.0019 (19) |
C24 | 0.071 (5) | 0.072 (5) | 0.099 (5) | −0.034 (4) | −0.044 (4) | 0.023 (4) |
O1—C1 | 1.420 (6) | C9—H9B | 0.9800 |
O1—C12 | 1.453 (6) | C9—H9C | 0.9800 |
O2—C13 | 1.416 (6) | C10—H10A | 0.9800 |
O2—C24 | 1.425 (7) | C10—H10B | 0.9800 |
N1—C11 | 1.318 (6) | C10—H10C | 0.9800 |
N1—N2 | 1.353 (6) | C12—H12A | 0.9800 |
N1—H1A | 0.877 (10) | C12—H12B | 0.9800 |
N2—N3 | 1.315 (6) | C12—H12C | 0.9800 |
N3—N4 | 1.337 (6) | C13—C23 | 1.479 (7) |
N4—C11 | 1.337 (6) | C13—C14 | 1.549 (7) |
N5—C23 | 1.320 (6) | C13—C18 | 1.564 (6) |
N5—N6 | 1.325 (5) | C14—C15 | 1.520 (8) |
N5—H5C | 0.879 (10) | C14—H14A | 0.9900 |
N6—N7 | 1.319 (6) | C14—H14B | 0.9900 |
N7—N8 | 1.344 (6) | C15—C16 | 1.518 (9) |
N8—C23 | 1.352 (6) | C15—C19 | 1.567 (7) |
C1—C11 | 1.499 (7) | C15—H15A | 1.0000 |
C1—C2 | 1.555 (7) | C16—C17 | 1.530 (8) |
C1—C6 | 1.574 (7) | C16—H16A | 0.9900 |
C2—C3 | 1.546 (9) | C16—H16B | 0.9900 |
C2—H2A | 0.9900 | C17—C18 | 1.537 (7) |
C2—H2B | 0.9900 | C17—H17A | 0.9900 |
C3—C4 | 1.507 (9) | C17—H17B | 0.9900 |
C3—C7 | 1.524 (8) | C18—C22 | 1.523 (7) |
C3—H3A | 1.0000 | C18—C19 | 1.540 (7) |
C4—C5 | 1.529 (9) | C19—C20 | 1.504 (7) |
C4—H4A | 0.9900 | C19—C21 | 1.554 (7) |
C4—H4B | 0.9900 | C20—H20A | 0.9800 |
C5—C6 | 1.515 (8) | C20—H20B | 0.9800 |
C5—H5A | 0.9900 | C20—H20C | 0.9800 |
C5—H5B | 0.9900 | C21—H21A | 0.9800 |
C6—C10 | 1.534 (7) | C21—H21B | 0.9800 |
C6—C7 | 1.567 (7) | C21—H21C | 0.9800 |
C7—C8 | 1.527 (8) | C22—H22A | 0.9800 |
C7—C9 | 1.548 (8) | C22—H22B | 0.9800 |
C8—H8A | 0.9800 | C22—H22C | 0.9800 |
C8—H8B | 0.9800 | C24—H24A | 0.9800 |
C8—H8C | 0.9800 | C24—H24B | 0.9800 |
C9—H9A | 0.9800 | C24—H24C | 0.9800 |
C1—O1—C12 | 114.1 (4) | N4—C11—C1 | 128.2 (4) |
C13—O2—C24 | 116.8 (4) | O1—C12—H12A | 109.5 |
C11—N1—N2 | 111.1 (4) | O1—C12—H12B | 109.5 |
C11—N1—H1A | 128 (3) | H12A—C12—H12B | 109.5 |
N2—N1—H1A | 117 (3) | O1—C12—H12C | 109.5 |
N3—N2—N1 | 103.8 (4) | H12A—C12—H12C | 109.5 |
N2—N3—N4 | 111.8 (4) | H12B—C12—H12C | 109.5 |
N3—N4—C11 | 106.3 (4) | O2—C13—C23 | 105.4 (4) |
C23—N5—N6 | 111.3 (4) | O2—C13—C14 | 115.3 (4) |
C23—N5—H5C | 130 (3) | C23—C13—C14 | 114.4 (4) |
N6—N5—H5C | 114 (3) | O2—C13—C18 | 108.2 (4) |
N7—N6—N5 | 104.5 (4) | C23—C13—C18 | 112.8 (4) |
N6—N7—N8 | 111.9 (4) | C14—C13—C18 | 100.9 (4) |
N7—N8—C23 | 104.8 (4) | C15—C14—C13 | 104.7 (4) |
O1—C1—C11 | 107.2 (4) | C15—C14—H14A | 110.8 |
O1—C1—C2 | 113.8 (4) | C13—C14—H14A | 110.8 |
C11—C1—C2 | 113.7 (4) | C15—C14—H14B | 110.8 |
O1—C1—C6 | 107.7 (4) | C13—C14—H14B | 110.8 |
C11—C1—C6 | 113.0 (4) | H14A—C14—H14B | 108.9 |
C2—C1—C6 | 101.3 (4) | C16—C15—C14 | 108.9 (5) |
C3—C2—C1 | 103.7 (4) | C16—C15—C19 | 102.3 (5) |
C3—C2—H2A | 111.0 | C14—C15—C19 | 102.1 (4) |
C1—C2—H2A | 111.0 | C16—C15—H15A | 114.1 |
C3—C2—H2B | 111.0 | C14—C15—H15A | 114.1 |
C1—C2—H2B | 111.0 | C19—C15—H15A | 114.1 |
H2A—C2—H2B | 109.0 | C15—C16—C17 | 102.8 (4) |
C4—C3—C7 | 104.4 (6) | C15—C16—H16A | 111.2 |
C4—C3—C2 | 106.9 (6) | C17—C16—H16A | 111.2 |
C7—C3—C2 | 102.3 (4) | C15—C16—H16B | 111.2 |
C4—C3—H3A | 114.0 | C17—C16—H16B | 111.2 |
C7—C3—H3A | 114.0 | H16A—C16—H16B | 109.1 |
C2—C3—H3A | 114.0 | C16—C17—C18 | 103.7 (4) |
C3—C4—C5 | 102.7 (5) | C16—C17—H17A | 111.0 |
C3—C4—H4A | 111.2 | C18—C17—H17A | 111.0 |
C5—C4—H4A | 111.2 | C16—C17—H17B | 111.0 |
C3—C4—H4B | 111.2 | C18—C17—H17B | 111.0 |
C5—C4—H4B | 111.2 | H17A—C17—H17B | 109.0 |
H4A—C4—H4B | 109.1 | C22—C18—C17 | 113.4 (4) |
C6—C5—C4 | 104.2 (5) | C22—C18—C19 | 116.7 (4) |
C6—C5—H5A | 110.9 | C17—C18—C19 | 101.8 (4) |
C4—C5—H5A | 110.9 | C22—C18—C13 | 112.8 (4) |
C6—C5—H5B | 110.9 | C17—C18—C13 | 107.5 (4) |
C4—C5—H5B | 110.9 | C19—C18—C13 | 103.5 (4) |
H5A—C5—H5B | 108.9 | C20—C19—C18 | 116.8 (4) |
C5—C6—C10 | 114.6 (5) | C20—C19—C21 | 106.6 (4) |
C5—C6—C7 | 101.9 (4) | C18—C19—C21 | 114.1 (4) |
C10—C6—C7 | 116.6 (5) | C20—C19—C15 | 114.5 (5) |
C5—C6—C1 | 105.7 (5) | C18—C19—C15 | 91.8 (4) |
C10—C6—C1 | 113.9 (4) | C21—C19—C15 | 112.8 (4) |
C7—C6—C1 | 102.7 (4) | C19—C20—H20A | 109.5 |
C3—C7—C8 | 114.7 (5) | C19—C20—H20B | 109.5 |
C3—C7—C9 | 113.6 (4) | H20A—C20—H20B | 109.5 |
C8—C7—C9 | 106.2 (5) | C19—C20—H20C | 109.5 |
C3—C7—C6 | 92.5 (4) | H20A—C20—H20C | 109.5 |
C8—C7—C6 | 116.6 (4) | H20B—C20—H20C | 109.5 |
C9—C7—C6 | 113.2 (5) | C19—C21—H21A | 109.5 |
C7—C8—H8A | 109.5 | C19—C21—H21B | 109.5 |
C7—C8—H8B | 109.5 | H21A—C21—H21B | 109.5 |
H8A—C8—H8B | 109.5 | C19—C21—H21C | 109.5 |
C7—C8—H8C | 109.5 | H21A—C21—H21C | 109.5 |
H8A—C8—H8C | 109.5 | H21B—C21—H21C | 109.5 |
H8B—C8—H8C | 109.5 | C18—C22—H22A | 109.5 |
C7—C9—H9A | 109.5 | C18—C22—H22B | 109.5 |
C7—C9—H9B | 109.5 | H22A—C22—H22B | 109.5 |
H9A—C9—H9B | 109.5 | C18—C22—H22C | 109.5 |
C7—C9—H9C | 109.5 | H22A—C22—H22C | 109.5 |
H9A—C9—H9C | 109.5 | H22B—C22—H22C | 109.5 |
H9B—C9—H9C | 109.5 | N5—C23—N8 | 107.5 (4) |
C6—C10—H10A | 109.5 | N5—C23—C13 | 125.0 (4) |
C6—C10—H10B | 109.5 | N8—C23—C13 | 127.5 (5) |
H10A—C10—H10B | 109.5 | O2—C24—H24A | 109.5 |
C6—C10—H10C | 109.5 | O2—C24—H24B | 109.5 |
H10A—C10—H10C | 109.5 | H24A—C24—H24B | 109.5 |
H10B—C10—H10C | 109.5 | O2—C24—H24C | 109.5 |
N1—C11—N4 | 107.0 (4) | H24A—C24—H24C | 109.5 |
N1—C11—C1 | 124.8 (4) | H24B—C24—H24C | 109.5 |
C11—N1—N2—N3 | 0.9 (5) | O1—C1—C11—N4 | −131.7 (5) |
N1—N2—N3—N4 | −1.2 (5) | C2—C1—C11—N4 | −5.0 (7) |
N2—N3—N4—C11 | 1.1 (6) | C6—C1—C11—N4 | 109.8 (6) |
C23—N5—N6—N7 | 0.4 (5) | C24—O2—C13—C23 | 72.8 (5) |
N5—N6—N7—N8 | −1.1 (5) | C24—O2—C13—C14 | −54.3 (6) |
N6—N7—N8—C23 | 1.3 (5) | C24—O2—C13—C18 | −166.3 (5) |
C12—O1—C1—C11 | 70.1 (5) | O2—C13—C14—C15 | −117.3 (5) |
C12—O1—C1—C2 | −56.6 (6) | C23—C13—C14—C15 | 120.3 (5) |
C12—O1—C1—C6 | −168.1 (4) | C18—C13—C14—C15 | −1.1 (5) |
O1—C1—C2—C3 | −117.8 (5) | C13—C14—C15—C16 | −71.0 (5) |
C11—C1—C2—C3 | 119.0 (5) | C13—C14—C15—C19 | 36.7 (6) |
C6—C1—C2—C3 | −2.5 (6) | C14—C15—C16—C17 | 70.9 (6) |
C1—C2—C3—C4 | −70.5 (6) | C19—C15—C16—C17 | −36.6 (5) |
C1—C2—C3—C7 | 38.9 (6) | C15—C16—C17—C18 | 0.6 (5) |
C7—C3—C4—C5 | −34.8 (7) | C16—C17—C18—C22 | 162.5 (4) |
C2—C3—C4—C5 | 73.1 (7) | C16—C17—C18—C19 | 36.3 (5) |
C3—C4—C5—C6 | −1.2 (7) | C16—C17—C18—C13 | −72.1 (5) |
C4—C5—C6—C10 | 162.2 (5) | O2—C13—C18—C22 | −41.4 (6) |
C4—C5—C6—C7 | 35.4 (6) | C23—C13—C18—C22 | 74.7 (5) |
C4—C5—C6—C1 | −71.6 (6) | C14—C13—C18—C22 | −162.8 (4) |
O1—C1—C6—C5 | −167.4 (4) | O2—C13—C18—C17 | −167.2 (4) |
C11—C1—C6—C5 | −49.1 (5) | C23—C13—C18—C17 | −51.0 (5) |
C2—C1—C6—C5 | 72.9 (5) | C14—C13—C18—C17 | 71.4 (5) |
O1—C1—C6—C10 | −40.7 (6) | O2—C13—C18—C19 | 85.6 (4) |
C11—C1—C6—C10 | 77.5 (6) | C23—C13—C18—C19 | −158.3 (4) |
C2—C1—C6—C10 | −160.5 (5) | C14—C13—C18—C19 | −35.8 (5) |
O1—C1—C6—C7 | 86.2 (4) | C22—C18—C19—C20 | 61.6 (6) |
C11—C1—C6—C7 | −155.5 (4) | C17—C18—C19—C20 | −174.3 (4) |
C2—C1—C6—C7 | −33.5 (5) | C13—C18—C19—C20 | −62.9 (5) |
C4—C3—C7—C8 | 175.1 (5) | C22—C18—C19—C21 | −63.6 (6) |
C2—C3—C7—C8 | 63.8 (6) | C17—C18—C19—C21 | 60.4 (5) |
C4—C3—C7—C9 | −62.5 (7) | C13—C18—C19—C21 | 171.9 (4) |
C2—C3—C7—C9 | −173.8 (5) | C22—C18—C19—C15 | −179.6 (5) |
C4—C3—C7—C6 | 54.2 (5) | C17—C18—C19—C15 | −55.6 (4) |
C2—C3—C7—C6 | −57.1 (5) | C13—C18—C19—C15 | 55.9 (4) |
C5—C6—C7—C3 | −53.7 (5) | C16—C15—C19—C20 | 177.4 (5) |
C10—C6—C7—C3 | −179.2 (5) | C14—C15—C19—C20 | 64.7 (6) |
C1—C6—C7—C3 | 55.6 (5) | C16—C15—C19—C18 | 56.7 (5) |
C5—C6—C7—C8 | −173.1 (5) | C14—C15—C19—C18 | −56.0 (5) |
C10—C6—C7—C8 | 61.5 (6) | C16—C15—C19—C21 | −60.5 (6) |
C1—C6—C7—C8 | −63.7 (6) | C14—C15—C19—C21 | −173.2 (5) |
C5—C6—C7—C9 | 63.3 (6) | N6—N5—C23—N8 | 0.4 (5) |
C10—C6—C7—C9 | −62.2 (6) | N6—N5—C23—C13 | 177.2 (4) |
C1—C6—C7—C9 | 172.6 (5) | N7—N8—C23—N5 | −1.0 (5) |
N2—N1—C11—N4 | −0.3 (5) | N7—N8—C23—C13 | −177.7 (4) |
N2—N1—C11—C1 | 179.9 (4) | O2—C13—C23—N5 | 34.3 (6) |
N3—N4—C11—N1 | −0.4 (5) | C14—C13—C23—N5 | 162.0 (4) |
N3—N4—C11—C1 | 179.4 (5) | C18—C13—C23—N5 | −83.5 (6) |
O1—C1—C11—N1 | 48.0 (6) | O2—C13—C23—N8 | −149.5 (4) |
C2—C1—C11—N1 | 174.8 (5) | C14—C13—C23—N8 | −21.9 (7) |
C6—C1—C11—N1 | −70.4 (6) | C18—C13—C23—N8 | 92.7 (5) |
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1A···N7 | 0.88 (1) | 2.09 (3) | 2.850 (6) | 144 (5) |
N5—H5C···N3i | 0.88 (1) | 2.02 (2) | 2.857 (6) | 160 (5) |
Symmetry code: (i) −x+1/2, −y+1, z+1/2. |
Experimental details
Crystal data | |
Chemical formula | C12H20N4O |
Mr | 236.32 |
Crystal system, space group | Orthorhombic, P212121 |
Temperature (K) | 194 |
a, b, c (Å) | 13.298 (3), 13.608 (4), 14.356 (3) |
V (Å3) | 2597.9 (11) |
Z | 8 |
Radiation type | Mo Kα |
µ (mm−1) | 0.08 |
Crystal size (mm) | 0.65 × 0.24 × 0.20 |
Data collection | |
Diffractometer | Siemens SMART 1K CCD |
Absorption correction | – |
No. of measured, independent and observed [I > 2σ(I)] reflections | 31860, 3283, 2259 |
Rint | 0.109 |
(sin θ/λ)max (Å−1) | 0.649 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.069, 0.138, 1.08 |
No. of reflections | 3283 |
No. of parameters | 322 |
No. of restraints | 2 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 0.20, −0.21 |
Computer programs: SMART (Siemens, 1995), SAINT (Siemens, 1995), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), SHELXTL (Sheldrick, 2008).
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1A···N7 | 0.877 (10) | 2.09 (3) | 2.850 (6) | 144 (5) |
N5—H5C···N3i | 0.879 (10) | 2.02 (2) | 2.857 (6) | 160 (5) |
Symmetry code: (i) −x+1/2, −y+1, z+1/2. |
References
Ohno, Y., Akutsu, Y., Arai, M., Tamura, M. & Matsunaga, T. (1999). Acta Cryst. C55, 1014–1016. Web of Science CSD CrossRef CAS IUCr Journals Google Scholar
Schell, P. & Engels, J. W. (1997). Nucleosides Nucleotides, 16, 769–772. CrossRef CAS Google Scholar
Schell, P. & Engels, J. W. (1998). Tetrahedron Lett. 39, 8629–8632. Web of Science CrossRef CAS Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Siemens (1995). SMART and SAINT. Siemens Analytical X-ray Instruments Inc., Madison, Wisconsin, USA. Google Scholar
This is an open-access article distributed under the terms of the Creative Commons Attribution (CC-BY) Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are cited.
The title compound has been prepared as a chiral catalyst for the diastereoselective synthesis of dinucleoside methylphosphonates (Schell & Engels, 1997; Schell & Engels, 1998). An initial crystal structure determination of the title compound at room temperature revealed a tetragonal unit cell with a = b = 13.452 (2) Å, c = 14.642 (2) Å and space group P43212. There is one molecule in the asymmetric unit, but the atoms, especially of the methoxybornyl group show very large displacement parameters. The average Ueq values of the non-H atoms is 0.080 Å2 for the tetrazole group, 0.136 Å2 for the bornyl group and 0.243 Å2 for the methoxy group. Thus the molecule is heavily disordered. On cooling the crystal, weak incommensurate reflections were observed in the temperature range 223 - 213 K, while below 213 K an orthorhombic unit cell with space group P212121 was found. Herein, we report on the crystal structure of the orthorhombic phase measured at 194 K.
The asymmetric unit contains two independent molecules, A and B (Figs. 1 and 2). The only significant difference between the molecules is found for the torsion angles about the Cbornyl—Ctetrazole bond [e.g. corresponding torsion angles C2—C1—C11—N4: -5.0 (7)° and C14—C13—C23—N8: -21.9 (7)°]. The methoxy group is in the exo-position and the tetrazole group in the endo-position with respect to the bicyclo[2.2.1]heptane group. The tetrazole rings are planar (r.m.s. deviations: 0.004 Å for molecule A and 0.005 Å for molecule B). The C—N bond distances in the tetrazole rings range from 1.318 (6) - 1.352 (6) Å and the N—N bond distances from 1.315 (6) - 1.353 (6) Å, thus showing a considerable degree of delocalization of the double bonds in the ring. Resonance has also been reported for tetrazole rings in other crystal structures (Ohno et al., 1999).
The phase transition from the room temperature P43212 structure to the low temperature P212121 structure results in the doubling of the number of molecules in the asymmetric unit from Z'=1 to Z'=2. Thus the two molecules, A and B, are expected to be related by tetragonal pseudo-symmetry. A close inspection of the fractional coordinates shows the molecules to be approximately related by the pseudo-relation: xB = -1/4 + yA, yB = 3/4 - xA and zB = 1/4 + zA. This is a symmetry element of a 43 screw-axis.
In the crystal, molecules are connected by N—H···N hydrogen bonds (Table 1 and Fig. 3) to form a helix along the pseudo-43 screw-axis parallel to the c axis direction. There are no short intermolecular contacts between neighboring helices, the shortest contact has a H···N distance of 2.71 Å. Thus the crystal habit is a [001] needle.