In the title structure, C
18H
18N
2O
2, the piperazine ring adopts a chair conformation and the two phenyl rings are parallel. The molecule possesses a crystallographically imposed inversion centre. In the crystal structure, weak intermolecular C—H
O hydrogen bonds link the molecules into ribbons along the
b axis.
Supporting information
CCDC reference: 282304
Key indicators
- Single-crystal X-ray study
- T = 294 K
- Mean (C-C)= 0.002 Å
- R factor = 0.038
- wR factor = 0.106
- Data-to-parameter ratio = 15.6
checkCIF/PLATON results
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Data collection: SMART (Bruker, 1997); cell refinement: SAINT (Bruker, 1997); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL (Bruker, 1997); software used to prepare material for publication: SHELXTL.
N,
N'-dibenzoylpiperazine
top
Crystal data top
C18H18N2O2 | Dx = 1.268 Mg m−3 |
Mr = 294.34 | Melting point: 471(1) K |
Orthorhombic, Pbca | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -P 2ac2ab | Cell parameters from 2532 reflections |
a = 7.8486 (13) Å | θ = 2.8–26.4° |
b = 6.8254 (12) Å | µ = 0.08 mm−1 |
c = 28.771 (5) Å | T = 294 K |
V = 1541.3 (5) Å3 | Block, colourless |
Z = 4 | 0.26 × 0.24 × 0.20 mm |
F(000) = 624 | |
Data collection top
Bruker SMART CCD area-detector diffractometer | 1580 independent reflections |
Radiation source: fine-focus sealed tube | 1168 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.037 |
φ and ω scans | θmax = 26.4°, θmin = 1.4° |
Absorption correction: multi-scan (SADABS; Sheldrick, 1996) | h = −9→5 |
Tmin = 0.930, Tmax = 0.983 | k = −8→8 |
7944 measured reflections | l = −35→35 |
Refinement top
Refinement on F2 | Secondary atom site location: difference Fourier map |
Least-squares matrix: full | Hydrogen site location: inferred from neighbouring sites |
R[F2 > 2σ(F2)] = 0.038 | H-atom parameters constrained |
wR(F2) = 0.106 | w = 1/[σ2(Fo2) + (0.0513P)2 + 0.3539P] where P = (Fo2 + 2Fc2)/3 |
S = 1.02 | (Δ/σ)max = 0.004 |
1580 reflections | Δρmax = 0.17 e Å−3 |
101 parameters | Δρmin = −0.14 e Å−3 |
0 restraints | Extinction correction: SHELXL |
Primary atom site location: structure-invariant direct methods | Extinction coefficient: 0.060 (4) |
Special details top
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. |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top | x | y | z | Uiso*/Ueq | |
O1 | 0.52685 (16) | 0.43277 (15) | 0.43666 (4) | 0.0542 (4) | |
N1 | 0.54459 (15) | 0.11883 (16) | 0.46140 (4) | 0.0345 (3) | |
C1 | 0.6320 (2) | 0.0725 (2) | 0.35815 (5) | 0.0453 (4) | |
H1 | 0.7214 | 0.0240 | 0.3760 | 0.054* | |
C2 | 0.6215 (2) | 0.0266 (3) | 0.31129 (6) | 0.0561 (5) | |
H2 | 0.7040 | −0.0528 | 0.2978 | 0.067* | |
C3 | 0.4901 (3) | 0.0976 (3) | 0.28478 (6) | 0.0597 (5) | |
H3 | 0.4834 | 0.0662 | 0.2534 | 0.072* | |
C4 | 0.3690 (3) | 0.2147 (3) | 0.30467 (6) | 0.0601 (5) | |
H4 | 0.2793 | 0.2618 | 0.2867 | 0.072* | |
C5 | 0.3787 (2) | 0.2638 (2) | 0.35123 (6) | 0.0485 (4) | |
H5 | 0.2973 | 0.3462 | 0.3643 | 0.058* | |
C6 | 0.50911 (18) | 0.1906 (2) | 0.37843 (5) | 0.0355 (4) | |
C7 | 0.52542 (18) | 0.2566 (2) | 0.42795 (5) | 0.0356 (4) | |
C8 | 0.59471 (19) | 0.1745 (2) | 0.50852 (4) | 0.0369 (4) | |
H8A | 0.5964 | 0.3163 | 0.5109 | 0.044* | |
H8B | 0.7091 | 0.1272 | 0.5146 | 0.044* | |
C9 | 0.52503 (19) | −0.0927 (2) | 0.45522 (5) | 0.0354 (4) | |
H9A | 0.6353 | −0.1559 | 0.4579 | 0.043* | |
H9B | 0.4804 | −0.1196 | 0.4244 | 0.043* | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
O1 | 0.0912 (9) | 0.0294 (6) | 0.0420 (6) | 0.0043 (5) | 0.0034 (6) | 0.0016 (5) |
N1 | 0.0470 (7) | 0.0287 (6) | 0.0278 (6) | −0.0032 (5) | 0.0007 (5) | 0.0006 (5) |
C1 | 0.0521 (9) | 0.0478 (9) | 0.0360 (8) | 0.0085 (7) | 0.0038 (7) | 0.0034 (7) |
C2 | 0.0751 (13) | 0.0538 (10) | 0.0394 (9) | 0.0067 (9) | 0.0151 (8) | −0.0023 (8) |
C3 | 0.0881 (14) | 0.0598 (11) | 0.0313 (8) | −0.0079 (10) | −0.0015 (9) | −0.0017 (8) |
C4 | 0.0701 (13) | 0.0673 (12) | 0.0427 (10) | 0.0020 (9) | −0.0150 (9) | 0.0098 (8) |
C5 | 0.0529 (10) | 0.0487 (9) | 0.0438 (9) | 0.0089 (7) | −0.0006 (7) | 0.0059 (7) |
C6 | 0.0446 (8) | 0.0312 (7) | 0.0307 (7) | −0.0011 (6) | 0.0031 (6) | 0.0058 (6) |
C7 | 0.0415 (8) | 0.0326 (8) | 0.0326 (8) | 0.0018 (6) | 0.0054 (6) | 0.0020 (6) |
C8 | 0.0469 (9) | 0.0319 (7) | 0.0319 (8) | −0.0056 (6) | −0.0040 (6) | −0.0006 (6) |
C9 | 0.0477 (9) | 0.0291 (7) | 0.0295 (7) | 0.0005 (6) | −0.0001 (6) | −0.0015 (6) |
Geometric parameters (Å, º) top
O1—C7 | 1.2284 (18) | C4—C5 | 1.383 (2) |
N1—C7 | 1.3539 (18) | C4—H4 | 0.9300 |
N1—C8 | 1.4619 (17) | C5—C6 | 1.382 (2) |
N1—C9 | 1.4629 (17) | C5—H5 | 0.9300 |
C1—C6 | 1.386 (2) | C6—C7 | 1.500 (2) |
C1—C2 | 1.387 (2) | C8—C9i | 1.511 (2) |
C1—H1 | 0.9300 | C8—H8A | 0.9700 |
C2—C3 | 1.371 (3) | C8—H8B | 0.9700 |
C2—H2 | 0.9300 | C9—C8i | 1.511 (2) |
C3—C4 | 1.368 (3) | C9—H9A | 0.9700 |
C3—H3 | 0.9300 | C9—H9B | 0.9700 |
| | | |
C7—N1—C8 | 120.56 (12) | C5—C6—C1 | 119.16 (14) |
C7—N1—C9 | 125.98 (12) | C5—C6—C7 | 119.53 (13) |
C8—N1—C9 | 113.43 (11) | C1—C6—C7 | 121.01 (13) |
C6—C1—C2 | 119.97 (15) | O1—C7—N1 | 122.27 (13) |
C6—C1—H1 | 120.0 | O1—C7—C6 | 119.23 (13) |
C2—C1—H1 | 120.0 | N1—C7—C6 | 118.45 (12) |
C3—C2—C1 | 120.37 (16) | N1—C8—C9i | 112.13 (12) |
C3—C2—H2 | 119.8 | N1—C8—H8A | 109.2 |
C1—C2—H2 | 119.8 | C9i—C8—H8A | 109.2 |
C4—C3—C2 | 119.77 (16) | N1—C8—H8B | 109.2 |
C4—C3—H3 | 120.1 | C9i—C8—H8B | 109.2 |
C2—C3—H3 | 120.1 | H8A—C8—H8B | 107.9 |
C3—C4—C5 | 120.57 (17) | N1—C9—C8i | 110.26 (11) |
C3—C4—H4 | 119.7 | N1—C9—H9A | 109.6 |
C5—C4—H4 | 119.7 | C8i—C9—H9A | 109.6 |
C6—C5—C4 | 120.13 (16) | N1—C9—H9B | 109.6 |
C6—C5—H5 | 119.9 | C8i—C9—H9B | 109.6 |
C4—C5—H5 | 119.9 | H9A—C9—H9B | 108.1 |
| | | |
C6—C1—C2—C3 | 0.0 (3) | C8—N1—C7—C6 | 167.75 (12) |
C1—C2—C3—C4 | 0.2 (3) | C9—N1—C7—C6 | −10.1 (2) |
C2—C3—C4—C5 | 0.6 (3) | C5—C6—C7—O1 | −51.6 (2) |
C3—C4—C5—C6 | −1.6 (3) | C1—C6—C7—O1 | 122.11 (17) |
C4—C5—C6—C1 | 1.8 (2) | C5—C6—C7—N1 | 130.92 (15) |
C4—C5—C6—C7 | 175.55 (15) | C1—C6—C7—N1 | −55.42 (19) |
C2—C1—C6—C5 | −1.0 (2) | C7—N1—C8—C9i | 127.61 (13) |
C2—C1—C6—C7 | −174.70 (15) | C9—N1—C8—C9i | −54.29 (17) |
C8—N1—C7—O1 | −9.7 (2) | C7—N1—C9—C8i | −128.72 (14) |
C9—N1—C7—O1 | 172.45 (14) | C8—N1—C9—C8i | 53.31 (17) |
Symmetry code: (i) −x+1, −y, −z+1. |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
C8—H8A···O1ii | 0.97 | 2.48 | 3.253 (3) | 137 |
Symmetry code: (ii) −x+1, −y+1, −z+1. |