Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536807037956/bg2085sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S1600536807037956/bg2085Isup2.hkl |
CCDC reference: 660243
A mixture of 1-methyl-3,5-bis[(E)-(4methylphenyl)methylidene]tetrahydro-4(1H)-pyridinone (1 g, 3 mmol), cyanogen bromide (0.33 g, 3 mmol) and potassium carbonate (3 mmol) in acetone (20 ml) was refluxed for 30 min. After completion of the reaction as seen from TLC (4:1 v/v petroleum ether:ethyl acetate), the mixture was poured into water (50 ml) and the precipitated 1-cyano-3,5-bis[(E)-(4methylphenyl)methylidene]tetrahydro-4(1H)- pyridinone was filtered, washed with water and recrystallized from ethanol.
H atoms were positioned geometrically and refined using a riding model with C—H = 0.95–0.99 Å and with Uiso(H) = 1.2 (1.5 for methyl groups) times Ueq(C).
Piperidinones are regarded as precursors of a host of biologically active compounds and natural alkaloids prior to their conversion to piperidines and also possess cytotoxic and anticancer properties (Dimmock et al., 1990, 2001). In addition, precise X-ray crystallographic investigations of the molecular and crystal structures of symmetrically shaped molecules are expected to provide insights into the nature and strength of the competition between inter- and intramolecular forces and their role in effecting symmetry carry-over from the free state to the solid. The crystal structure of the title compound is a good example of a symmetrically shaped molecule loosing its molecular symmetry upon crystallization. In this context, we have already elucidated the crystal structures of cyano substituted (Suresh et al., 2006) and nitroso substituted (Suresh et al., 2005a; 2005b; Natarajan et al., 2005) piperidinone derivatives. The present paper reports the crystal structure of 1-cyano-3,5-bis[(4-methylphenyl)methylidene]-piperidin-4-one.
The piperidinone ring adopts the envelope conformation. Atom N1 deviates by 0.655 (2) Å from the least-squares plane defined by atoms C2, C3, C4, C5 and C6. The envelope conformation is also evident from the puckering amplitudes [Q = 0.492 (1) Å, θ = 57.9 (2) °, φ = 349.8 (2) °] (Cremer & Pople, 1975). As expected, the N—Cτp-N bond is linear. The 3- and 5- substituted 4-methylphenyl rings are twisted with respect to the plane defined by the piperidinone ring (excluding N1) and the methylidene C atoms by 15.7 (1) ° and 35.7 (1) °, respectively. This unequal twists of the rings may be attributed to the fact that atoms C52 and C57 take part in intermolecular interactions (Table 1). Thus the present structure is a good example of a molecule where competition between intra- and intermolecular interactions is apparent.
The molecular aggregation in the crystal is characterized by H-bonded bilayered structures parallel to (-101) plane, with the molecules themselves aligned along the [1–11] direction. Figures 2 and 3 present two views (at 90° from one another) of these two-dimensional structures, where the internal link between layers can be appeciated. This is due to weak non conventional H-bonding (Table 1) as well as π···π interactions between symmetrically related 4-methylphenyl rings substituted at 3, [with and interplanar distance of 3.973 (1) Å] and at 5 [4.082 (1) Å] (See Fig. 3).
Interactions connecting bilayers are mainly van der Waal's
For related literature, see Cremer & Pople (1975); Dimmock et al. (1990, 2001); Suresh et al. (2005a, 2005b, 2006); Natarajan et al. (2005).
Data collection: APEX2 (Bruker, 2004a); cell refinement: SAINT (Bruker, 2004b); data reduction: SAINT; program(s) used to solve structure: SHELXS86 (Sheldrick, 1990); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: PLUTON (Spek, 2003); software used to prepare material for publication: SHELXL97.
C22H20N2O | Z = 2 |
Mr = 328.40 | F(000) = 348 |
Triclinic, P1 | Dx = 1.262 Mg m−3 |
Hall symbol: -P 1 | Mo Kα radiation, λ = 0.71073 Å |
a = 9.1976 (2) Å | Cell parameters from 5233 reflections |
b = 9.5012 (2) Å | θ = 3–29° |
c = 10.9418 (3) Å | µ = 0.08 mm−1 |
α = 104.03 (2)° | T = 298 K |
β = 95.080 (1)° | Needle, colourless |
γ = 108.73 (1)° | 0.28 × 0.14 × 0.12 mm |
V = 864.01 (12) Å3 |
Bruker Kappa-APEXII CCD diffractometer | 5753 independent reflections |
Radiation source: fine-focus sealed tube | 3427 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.031 |
ω and φ scans | θmax = 31.5°, θmin = 2.4° |
Absorption correction: multi-scan (SADABS; Sheldrick, 2004) | h = −13→13 |
Tmin = 0.88, Tmax = 0.99 | k = −13→13 |
23388 measured reflections | l = −15→16 |
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)] = 0.050 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.150 | H-atom parameters constrained |
S = 1.04 | w = 1/[σ2(Fo2) + (0.0677P)2 + 0.0757P] where P = (Fo2 + 2Fc2)/3 |
5753 reflections | (Δ/σ)max = 0.012 |
228 parameters | Δρmax = 0.21 e Å−3 |
0 restraints | Δρmin = −0.20 e Å−3 |
C22H20N2O | γ = 108.73 (1)° |
Mr = 328.40 | V = 864.01 (12) Å3 |
Triclinic, P1 | Z = 2 |
a = 9.1976 (2) Å | Mo Kα radiation |
b = 9.5012 (2) Å | µ = 0.08 mm−1 |
c = 10.9418 (3) Å | T = 298 K |
α = 104.03 (2)° | 0.28 × 0.14 × 0.12 mm |
β = 95.080 (1)° |
Bruker Kappa-APEXII CCD diffractometer | 5753 independent reflections |
Absorption correction: multi-scan (SADABS; Sheldrick, 2004) | 3427 reflections with I > 2σ(I) |
Tmin = 0.88, Tmax = 0.99 | Rint = 0.031 |
23388 measured reflections |
R[F2 > 2σ(F2)] = 0.050 | 0 restraints |
wR(F2) = 0.150 | H-atom parameters constrained |
S = 1.04 | Δρmax = 0.21 e Å−3 |
5753 reflections | Δρmin = −0.20 e Å−3 |
228 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 | 0.48410 (14) | 0.53238 (12) | 0.31301 (10) | 0.0690 (3) | |
N1 | 0.30550 (12) | 0.11155 (12) | 0.05535 (10) | 0.0460 (3) | |
N2 | 0.07443 (16) | −0.00446 (16) | 0.14716 (13) | 0.0643 (3) | |
C1 | 0.18139 (16) | 0.05283 (15) | 0.10693 (12) | 0.0460 (3) | |
C2 | 0.30506 (16) | 0.23774 (15) | −0.00010 (13) | 0.0461 (3) | |
H2A | 0.2005 | 0.2149 | −0.0447 | 0.055* | |
H2B | 0.3740 | 0.2431 | −0.0624 | 0.055* | |
C3 | 0.35695 (14) | 0.39263 (15) | 0.10000 (12) | 0.0426 (3) | |
C4 | 0.45051 (15) | 0.41260 (15) | 0.22607 (13) | 0.0461 (3) | |
C5 | 0.50289 (14) | 0.28455 (14) | 0.24356 (12) | 0.0430 (3) | |
C6 | 0.45772 (15) | 0.14170 (16) | 0.13125 (13) | 0.0482 (3) | |
H6A | 0.5365 | 0.1551 | 0.0774 | 0.058* | |
H6B | 0.4534 | 0.0531 | 0.1620 | 0.058* | |
C30 | 0.32067 (15) | 0.51409 (15) | 0.08403 (13) | 0.0465 (3) | |
H30 | 0.3595 | 0.6021 | 0.1542 | 0.056* | |
C31 | 0.23114 (15) | 0.53174 (15) | −0.02403 (13) | 0.0448 (3) | |
C32 | 0.17379 (16) | 0.65369 (16) | −0.00096 (14) | 0.0507 (3) | |
H32 | 0.1971 | 0.7214 | 0.0812 | 0.061* | |
C33 | 0.08403 (16) | 0.67599 (16) | −0.09644 (14) | 0.0519 (3) | |
H33 | 0.0478 | 0.7582 | −0.0774 | 0.062* | |
C34 | 0.04622 (15) | 0.57891 (16) | −0.22043 (14) | 0.0482 (3) | |
C35 | 0.10540 (19) | 0.45993 (17) | −0.24448 (14) | 0.0563 (4) | |
H35 | 0.0831 | 0.3935 | −0.3271 | 0.068* | |
C36 | 0.19605 (18) | 0.43723 (17) | −0.14985 (14) | 0.0543 (4) | |
H36 | 0.2349 | 0.3570 | −0.1702 | 0.065* | |
C37 | −0.05332 (19) | 0.6022 (2) | −0.32468 (16) | 0.0635 (4) | |
H37A | −0.1565 | 0.5257 | −0.3424 | 0.095* | |
H37B | −0.0083 | 0.5917 | −0.4007 | 0.095* | |
H37C | −0.0589 | 0.7040 | −0.2976 | 0.095* | |
C50 | 0.58049 (14) | 0.30007 (15) | 0.35805 (13) | 0.0476 (3) | |
H50 | 0.5946 | 0.3909 | 0.4215 | 0.057* | |
C51 | 0.64599 (14) | 0.19288 (15) | 0.39650 (13) | 0.0452 (3) | |
C52 | 0.65606 (16) | 0.18862 (16) | 0.52345 (13) | 0.0515 (3) | |
H52 | 0.6261 | 0.2574 | 0.5826 | 0.062* | |
C53 | 0.70973 (17) | 0.08408 (17) | 0.56235 (13) | 0.0532 (3) | |
H53 | 0.7151 | 0.0835 | 0.6475 | 0.064* | |
C54 | 0.75601 (15) | −0.02031 (16) | 0.47766 (13) | 0.0501 (3) | |
C55 | 0.75351 (16) | −0.01031 (18) | 0.35349 (14) | 0.0548 (4) | |
H55 | 0.7890 | −0.0755 | 0.2958 | 0.066* | |
C56 | 0.70000 (15) | 0.09333 (17) | 0.31296 (13) | 0.0511 (3) | |
H56 | 0.6999 | 0.0970 | 0.2288 | 0.061* | |
C57 | 0.8060 (2) | −0.1408 (2) | 0.51771 (16) | 0.0676 (4) | |
H57A | 0.7203 | −0.2381 | 0.4921 | 0.101* | |
H57B | 0.8379 | −0.1088 | 0.6091 | 0.101* | |
H57C | 0.8918 | −0.1525 | 0.4776 | 0.101* |
U11 | U22 | U33 | U12 | U13 | U23 | |
O1 | 0.0862 (8) | 0.0512 (6) | 0.0606 (7) | 0.0354 (6) | −0.0140 (6) | −0.0056 (5) |
N1 | 0.0521 (6) | 0.0369 (6) | 0.0455 (6) | 0.0155 (5) | −0.0001 (5) | 0.0090 (5) |
N2 | 0.0627 (8) | 0.0644 (8) | 0.0548 (8) | 0.0108 (6) | 0.0026 (6) | 0.0161 (6) |
C1 | 0.0550 (7) | 0.0362 (7) | 0.0391 (7) | 0.0143 (5) | −0.0048 (6) | 0.0043 (5) |
C2 | 0.0543 (7) | 0.0398 (7) | 0.0437 (7) | 0.0176 (6) | 0.0051 (5) | 0.0113 (6) |
C3 | 0.0436 (6) | 0.0391 (6) | 0.0451 (7) | 0.0151 (5) | 0.0075 (5) | 0.0112 (5) |
C4 | 0.0463 (6) | 0.0396 (7) | 0.0486 (7) | 0.0168 (5) | 0.0026 (5) | 0.0057 (6) |
C5 | 0.0404 (6) | 0.0395 (7) | 0.0468 (7) | 0.0149 (5) | 0.0046 (5) | 0.0089 (5) |
C6 | 0.0507 (7) | 0.0445 (7) | 0.0498 (8) | 0.0229 (6) | 0.0033 (6) | 0.0080 (6) |
C30 | 0.0497 (7) | 0.0400 (7) | 0.0497 (8) | 0.0172 (5) | 0.0085 (6) | 0.0112 (6) |
C31 | 0.0495 (7) | 0.0384 (7) | 0.0514 (8) | 0.0181 (5) | 0.0131 (6) | 0.0170 (6) |
C32 | 0.0580 (8) | 0.0397 (7) | 0.0537 (8) | 0.0203 (6) | 0.0075 (6) | 0.0088 (6) |
C33 | 0.0574 (8) | 0.0410 (7) | 0.0616 (9) | 0.0249 (6) | 0.0095 (6) | 0.0127 (6) |
C34 | 0.0488 (7) | 0.0451 (7) | 0.0546 (8) | 0.0174 (6) | 0.0112 (6) | 0.0197 (6) |
C35 | 0.0792 (10) | 0.0518 (8) | 0.0455 (8) | 0.0326 (7) | 0.0138 (7) | 0.0137 (6) |
C36 | 0.0766 (9) | 0.0500 (8) | 0.0514 (8) | 0.0375 (7) | 0.0198 (7) | 0.0183 (7) |
C37 | 0.0645 (9) | 0.0658 (10) | 0.0648 (10) | 0.0282 (8) | 0.0047 (7) | 0.0224 (8) |
C50 | 0.0462 (7) | 0.0419 (7) | 0.0495 (8) | 0.0152 (5) | 0.0021 (6) | 0.0067 (6) |
C51 | 0.0407 (6) | 0.0435 (7) | 0.0468 (7) | 0.0131 (5) | 0.0007 (5) | 0.0098 (6) |
C52 | 0.0565 (8) | 0.0498 (8) | 0.0416 (7) | 0.0209 (6) | 0.0005 (6) | 0.0015 (6) |
C53 | 0.0625 (8) | 0.0554 (8) | 0.0400 (7) | 0.0227 (7) | 0.0022 (6) | 0.0103 (6) |
C54 | 0.0480 (7) | 0.0511 (8) | 0.0481 (8) | 0.0192 (6) | −0.0022 (6) | 0.0103 (6) |
C55 | 0.0574 (8) | 0.0660 (9) | 0.0459 (8) | 0.0350 (7) | 0.0058 (6) | 0.0086 (7) |
C56 | 0.0519 (7) | 0.0656 (9) | 0.0413 (7) | 0.0279 (7) | 0.0078 (5) | 0.0159 (6) |
C57 | 0.0794 (11) | 0.0675 (10) | 0.0622 (10) | 0.0380 (9) | −0.0005 (8) | 0.0181 (8) |
O1—C4 | 1.2218 (16) | C34—C37 | 1.502 (2) |
N1—C1 | 1.3381 (18) | C35—C36 | 1.373 (2) |
N1—C6 | 1.4673 (16) | C35—H35 | 0.9300 |
N1—C2 | 1.4700 (16) | C36—H36 | 0.9300 |
N2—C1 | 1.1431 (18) | C37—H37A | 0.9600 |
C2—C3 | 1.5060 (18) | C37—H37B | 0.9600 |
C2—H2A | 0.9700 | C37—H37C | 0.9600 |
C2—H2B | 0.9700 | C50—C51 | 1.4609 (18) |
C3—C30 | 1.3448 (17) | C50—H50 | 0.9300 |
C3—C4 | 1.4957 (19) | C51—C56 | 1.3928 (18) |
C4—C5 | 1.4906 (18) | C51—C52 | 1.3952 (19) |
C5—C50 | 1.3360 (18) | C52—C53 | 1.3763 (19) |
C5—C6 | 1.5046 (18) | C52—H52 | 0.9300 |
C6—H6A | 0.9700 | C53—C54 | 1.385 (2) |
C6—H6B | 0.9700 | C53—H53 | 0.9300 |
C30—C31 | 1.4548 (19) | C54—C55 | 1.383 (2) |
C30—H30 | 0.9300 | C54—C57 | 1.503 (2) |
C31—C36 | 1.393 (2) | C55—C56 | 1.3759 (19) |
C31—C32 | 1.3997 (18) | C55—H55 | 0.9300 |
C32—C33 | 1.373 (2) | C56—H56 | 0.9300 |
C32—H32 | 0.9300 | C57—H57A | 0.9600 |
C33—C34 | 1.384 (2) | C57—H57B | 0.9600 |
C33—H33 | 0.9300 | C57—H57C | 0.9600 |
C34—C35 | 1.3856 (19) | ||
C1—N1—C6 | 115.53 (11) | C36—C35—C34 | 121.90 (14) |
C1—N1—C2 | 116.42 (10) | C36—C35—H35 | 119.1 |
C6—N1—C2 | 112.59 (10) | C34—C35—H35 | 119.1 |
N2—C1—N1 | 176.60 (14) | C35—C36—C31 | 121.46 (12) |
N1—C2—C3 | 112.30 (11) | C35—C36—H36 | 119.3 |
N1—C2—H2A | 109.1 | C31—C36—H36 | 119.3 |
C3—C2—H2A | 109.1 | C34—C37—H37A | 109.5 |
N1—C2—H2B | 109.1 | C34—C37—H37B | 109.5 |
C3—C2—H2B | 109.1 | H37A—C37—H37B | 109.5 |
H2A—C2—H2B | 107.9 | C34—C37—H37C | 109.5 |
C30—C3—C4 | 117.59 (12) | H37A—C37—H37C | 109.5 |
C30—C3—C2 | 123.71 (12) | H37B—C37—H37C | 109.5 |
C4—C3—C2 | 118.68 (11) | C5—C50—C51 | 128.41 (12) |
O1—C4—C5 | 120.60 (12) | C5—C50—H50 | 115.8 |
O1—C4—C3 | 120.45 (12) | C51—C50—H50 | 115.8 |
C5—C4—C3 | 118.95 (11) | C56—C51—C52 | 117.42 (12) |
C50—C5—C4 | 118.73 (12) | C56—C51—C50 | 123.55 (12) |
C50—C5—C6 | 124.05 (12) | C52—C51—C50 | 119.03 (12) |
C4—C5—C6 | 117.15 (11) | C53—C52—C51 | 120.95 (12) |
N1—C6—C5 | 111.28 (10) | C53—C52—H52 | 119.5 |
N1—C6—H6A | 109.4 | C51—C52—H52 | 119.5 |
C5—C6—H6A | 109.4 | C52—C53—C54 | 121.54 (13) |
N1—C6—H6B | 109.4 | C52—C53—H53 | 119.2 |
C5—C6—H6B | 109.4 | C54—C53—H53 | 119.2 |
H6A—C6—H6B | 108.0 | C55—C54—C53 | 117.29 (13) |
C3—C30—C31 | 131.19 (13) | C55—C54—C57 | 120.90 (13) |
C3—C30—H30 | 114.4 | C53—C54—C57 | 121.80 (13) |
C31—C30—H30 | 114.4 | C56—C55—C54 | 121.84 (13) |
C36—C31—C32 | 116.34 (13) | C56—C55—H55 | 119.1 |
C36—C31—C30 | 125.85 (12) | C54—C55—H55 | 119.1 |
C32—C31—C30 | 117.81 (12) | C55—C56—C51 | 120.79 (13) |
C33—C32—C31 | 121.72 (13) | C55—C56—H56 | 119.6 |
C33—C32—H32 | 119.1 | C51—C56—H56 | 119.6 |
C31—C32—H32 | 119.1 | C54—C57—H57A | 109.5 |
C32—C33—C34 | 121.50 (12) | C54—C57—H57B | 109.5 |
C32—C33—H33 | 119.2 | H57A—C57—H57B | 109.5 |
C34—C33—H33 | 119.2 | C54—C57—H57C | 109.5 |
C33—C34—C35 | 117.04 (13) | H57A—C57—H57C | 109.5 |
C33—C34—C37 | 121.56 (13) | H57B—C57—H57C | 109.5 |
C35—C34—C37 | 121.39 (13) | ||
C1—N1—C2—C3 | 81.35 (14) | C31—C32—C33—C34 | −0.2 (2) |
C6—N1—C2—C3 | −55.37 (14) | C32—C33—C34—C35 | −1.2 (2) |
N1—C2—C3—C30 | −157.65 (12) | C32—C33—C34—C37 | 179.36 (13) |
N1—C2—C3—C4 | 20.61 (16) | C33—C34—C35—C36 | 0.8 (2) |
C30—C3—C4—O1 | 4.15 (19) | C37—C34—C35—C36 | −179.76 (14) |
C2—C3—C4—O1 | −174.21 (12) | C34—C35—C36—C31 | 1.0 (2) |
C30—C3—C4—C5 | −175.46 (11) | C32—C31—C36—C35 | −2.2 (2) |
C2—C3—C4—C5 | 6.17 (18) | C30—C31—C36—C35 | 177.47 (13) |
O1—C4—C5—C50 | 3.3 (2) | C4—C5—C50—C51 | −178.33 (12) |
C3—C4—C5—C50 | −177.08 (11) | C6—C5—C50—C51 | 4.6 (2) |
O1—C4—C5—C6 | −179.45 (13) | C5—C50—C51—C56 | 29.9 (2) |
C3—C4—C5—C6 | 0.16 (17) | C5—C50—C51—C52 | −150.15 (14) |
C1—N1—C6—C5 | −75.18 (14) | C56—C51—C52—C53 | −3.3 (2) |
C2—N1—C6—C5 | 61.93 (14) | C50—C51—C52—C53 | 176.74 (12) |
C50—C5—C6—N1 | 144.17 (13) | C51—C52—C53—C54 | 0.2 (2) |
C4—C5—C6—N1 | −32.92 (16) | C52—C53—C54—C55 | 3.1 (2) |
C4—C3—C30—C31 | −179.02 (12) | C52—C53—C54—C57 | −176.43 (14) |
C2—C3—C30—C31 | −0.7 (2) | C53—C54—C55—C56 | −3.2 (2) |
C3—C30—C31—C36 | −18.2 (2) | C57—C54—C55—C56 | 176.34 (14) |
C3—C30—C31—C32 | 161.51 (13) | C54—C55—C56—C51 | 0.0 (2) |
C36—C31—C32—C33 | 1.8 (2) | C52—C51—C56—C55 | 3.3 (2) |
C30—C31—C32—C33 | −177.90 (12) | C50—C51—C56—C55 | −176.84 (13) |
D—H···A | D—H | H···A | D···A | D—H···A |
C2—H2A···N2i | 0.97 | 2.61 | 3.4630 (19) | 147 |
C52—H52···O1ii | 0.93 | 2.59 | 3.4921 (17) | 163 |
C57—H57B···N2iii | 0.96 | 2.57 | 3.524 (2) | 174 |
Symmetry codes: (i) −x, −y, −z; (ii) −x+1, −y+1, −z+1; (iii) −x+1, −y, −z+1. |
Experimental details
Crystal data | |
Chemical formula | C22H20N2O |
Mr | 328.40 |
Crystal system, space group | Triclinic, P1 |
Temperature (K) | 298 |
a, b, c (Å) | 9.1976 (2), 9.5012 (2), 10.9418 (3) |
α, β, γ (°) | 104.03 (2), 95.080 (1), 108.73 (1) |
V (Å3) | 864.01 (12) |
Z | 2 |
Radiation type | Mo Kα |
µ (mm−1) | 0.08 |
Crystal size (mm) | 0.28 × 0.14 × 0.12 |
Data collection | |
Diffractometer | Bruker Kappa-APEXII CCD |
Absorption correction | Multi-scan (SADABS; Sheldrick, 2004) |
Tmin, Tmax | 0.88, 0.99 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 23388, 5753, 3427 |
Rint | 0.031 |
(sin θ/λ)max (Å−1) | 0.736 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.050, 0.150, 1.04 |
No. of reflections | 5753 |
No. of parameters | 228 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.21, −0.20 |
Computer programs: APEX2 (Bruker, 2004a), SAINT (Bruker, 2004b), SAINT, SHELXS86 (Sheldrick, 1990), SHELXL97 (Sheldrick, 1997), PLUTON (Spek, 2003), SHELXL97.
D—H···A | D—H | H···A | D···A | D—H···A |
C2—H2A···N2i | 0.97 | 2.61 | 3.4630 (19) | 147 |
C52—H52···O1ii | 0.93 | 2.59 | 3.4921 (17) | 163 |
C57—H57B···N2iii | 0.96 | 2.57 | 3.524 (2) | 174 |
Symmetry codes: (i) −x, −y, −z; (ii) −x+1, −y+1, −z+1; (iii) −x+1, −y, −z+1. |
Piperidinones are regarded as precursors of a host of biologically active compounds and natural alkaloids prior to their conversion to piperidines and also possess cytotoxic and anticancer properties (Dimmock et al., 1990, 2001). In addition, precise X-ray crystallographic investigations of the molecular and crystal structures of symmetrically shaped molecules are expected to provide insights into the nature and strength of the competition between inter- and intramolecular forces and their role in effecting symmetry carry-over from the free state to the solid. The crystal structure of the title compound is a good example of a symmetrically shaped molecule loosing its molecular symmetry upon crystallization. In this context, we have already elucidated the crystal structures of cyano substituted (Suresh et al., 2006) and nitroso substituted (Suresh et al., 2005a; 2005b; Natarajan et al., 2005) piperidinone derivatives. The present paper reports the crystal structure of 1-cyano-3,5-bis[(4-methylphenyl)methylidene]-piperidin-4-one.
The piperidinone ring adopts the envelope conformation. Atom N1 deviates by 0.655 (2) Å from the least-squares plane defined by atoms C2, C3, C4, C5 and C6. The envelope conformation is also evident from the puckering amplitudes [Q = 0.492 (1) Å, θ = 57.9 (2) °, φ = 349.8 (2) °] (Cremer & Pople, 1975). As expected, the N—Cτp-N bond is linear. The 3- and 5- substituted 4-methylphenyl rings are twisted with respect to the plane defined by the piperidinone ring (excluding N1) and the methylidene C atoms by 15.7 (1) ° and 35.7 (1) °, respectively. This unequal twists of the rings may be attributed to the fact that atoms C52 and C57 take part in intermolecular interactions (Table 1). Thus the present structure is a good example of a molecule where competition between intra- and intermolecular interactions is apparent.
The molecular aggregation in the crystal is characterized by H-bonded bilayered structures parallel to (-101) plane, with the molecules themselves aligned along the [1–11] direction. Figures 2 and 3 present two views (at 90° from one another) of these two-dimensional structures, where the internal link between layers can be appeciated. This is due to weak non conventional H-bonding (Table 1) as well as π···π interactions between symmetrically related 4-methylphenyl rings substituted at 3, [with and interplanar distance of 3.973 (1) Å] and at 5 [4.082 (1) Å] (See Fig. 3).
Interactions connecting bilayers are mainly van der Waal's