[2.2]Basketenopara­cyclo­phane 18,20-dicarbo­nitrile

The title compound, C₂₂H₁₈N₂, displays some release of the usual strain in [2.2]­para­cyclo­phanes (e.g. the bridge bonds are no longer lengthened), associated with the lengthening of the bridgehead contact C3...C14. However, the effect is not uniform; the basketene ring system introduces strain of its own (e.g. lengthened single bonds, wide angles at the corresponding bridge atoms).

Key indicators

• Single-crystal X-ray study
• T = 293 K
• Mean [sigma](C-C) = 0.002 Å
• R factor = 0.040
• wR factor = 0.117
• Data-to-parameter ratio = 12.7

checkCIF results

No syntax errors found

ADDSYM reports no extra symmetry


 Alert Level C:



PLAT_320  Alert C Check Hybridisation of  C(18)  in main residue          ?

PLAT_320  Alert C Check Hybridisation of  C(19)  in main residue          ?

PLAT_320  Alert C Check Hybridisation of  C(20)  in main residue          ?


 0 Alert Level A = Potentially serious problem

 0 Alert Level B = Potential problem

 3 Alert Level C = Please check

---

Computing details

Data collection: P3 (Nicolet, 1987); cell refinement: P3; data reduction: XDISK (Nicolet, 1987); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: XP (Siemens, 1994); software used to prepare material for publication: SHELXL97.

[2.2]basketenoparacyclophane 18,20-dicarbonitrile

Crystal data

C22H18N2	F(000) = 656
Mr = 310.38	Dx = 1.310 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
a = 6.6094 (14) Å	Cell parameters from 50 reflections
b = 17.251 (3) Å	θ = 10–11.5°
c = 13.910 (3) Å	µ = 0.08 mm^−1
β = 97.272 (16)°	T = 293 K
V = 1573.3 (5) Å^3	Plate, colourless
Z = 4	0.6 × 0.6 × 0.08 mm

Data collection

Nicolet R3 diffractometer	Rint = 0.024
Radiation source: fine-focus sealed tube	θmax = 25.0°, θmin = 3.1°
Graphite monochromator	h = −7→7
ω scans	k = −20→20
5639 measured reflections	l = −16→0
2760 independent reflections	3 standard reflections every 147 reflections
2175 reflections with I > 2σ(I)	intensity decay: none

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.040	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.117	H-atom parameters constrained
S = 1.03	w = 1/[σ^2(Fo^2) + (0.0592P)^2 + 0.3931P] where P = (Fo^2 + 2Fc^2)/3
2760 reflections	(Δ/σ)max < 0.001
217 parameters	Δρmax = 0.22 e Å^−3
0 restraints	Δρmin = −0.21 e Å^−3

Special details

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)

- 1.1042 (0.0051) x + 16.8350 (0.0064) y + 2.2328 (0.0164) z = 11.9081 (0.0050)

* -0.0045 (0.0008) C12 * 0.0045 (0.0008) C13 * -0.0045 (0.0008) C15 * 0.0045 (0.0008) C16 - 0.1541 (0.0025) C11 - 0.1420 (0.0025) C14

Rms deviation of fitted atoms = 0.0045

Non-bonded distances: 3.0227 (0.0023) C3 - C14 2.7980 (0.0022) C6 - C11

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 (Ų)

	x	y	z	Uiso*/Ueq
C1	0.4122 (3)	0.64203 (11)	0.40469 (14)	0.0524 (5)
H1A	0.3024	0.6667	0.4334	0.065*
H1B	0.5333	0.6431	0.4520	0.065*
C2	0.3542 (3)	0.55730 (10)	0.38012 (13)	0.0438 (4)
H2A	0.3605	0.5290	0.4407	0.055*
H2B	0.2129	0.5567	0.3509	0.055*
C3	0.4785 (2)	0.51175 (9)	0.31326 (11)	0.0352 (4)
C4	0.3869 (2)	0.49151 (9)	0.20535 (12)	0.0368 (4)
H4	0.2393	0.4831	0.1998	0.045*
C5	0.4425 (2)	0.54168 (9)	0.12594 (11)	0.0382 (4)
H5	0.3441	0.5606	0.0780	0.045*
C6	0.6389 (2)	0.55832 (9)	0.12644 (11)	0.0360 (4)
C7	0.7718 (2)	0.52073 (9)	0.20871 (11)	0.0341 (4)
H7	0.9161	0.5332	0.2073	0.040*
C8	0.7110 (2)	0.52785 (9)	0.31314 (11)	0.0340 (4)
H8	0.7785	0.5667	0.3575	0.040*
C9	0.7301 (3)	0.61092 (10)	0.05539 (13)	0.0472 (4)
H9A	0.7236	0.5842	−0.0063	0.055*
H9B	0.8730	0.6190	0.0790	0.055*
C10	0.6266 (3)	0.69141 (11)	0.03779 (13)	0.0565 (5)
H10A	0.7228	0.7285	0.0173	0.067*
H10B	0.5113	0.6876	−0.0126	0.067*
C11	0.5563 (3)	0.71725 (9)	0.13142 (13)	0.0459 (4)
C12	0.3532 (3)	0.71087 (10)	0.14603 (15)	0.0534 (5)
H12	0.2511	0.7167	0.0940	0.065*
C13	0.3017 (3)	0.69586 (10)	0.23777 (15)	0.0523 (5)
H13	0.1651	0.6919	0.2469	0.065*
C14	0.4521 (3)	0.68664 (9)	0.31608 (13)	0.0445 (4)
C15	0.6482 (3)	0.70927 (9)	0.30399 (13)	0.0438 (4)
H15	0.7464	0.7138	0.3578	0.050*
C16	0.6994 (3)	0.72524 (9)	0.21295 (13)	0.0441 (4)
H16	0.8309	0.7415	0.2061	0.050*
C17	0.5057 (2)	0.41391 (9)	0.21873 (12)	0.0374 (4)
H17	0.4461	0.3665	0.1883	0.045*
C18	0.7378 (2)	0.43105 (9)	0.21861 (11)	0.0358 (4)
C19	0.5277 (3)	0.42301 (9)	0.33029 (12)	0.0393 (4)
H19	0.4664	0.3890	0.3751	0.047*
C20	0.7591 (2)	0.43934 (9)	0.33238 (11)	0.0374 (4)
C21	0.8551 (3)	0.37897 (10)	0.16549 (13)	0.0438 (4)
C22	0.9261 (3)	0.40857 (10)	0.39827 (13)	0.0469 (4)
N1	0.9479 (3)	0.33944 (11)	0.12212 (14)	0.0675 (5)
N2	1.0577 (3)	0.38472 (11)	0.45089 (14)	0.0715 (5)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.0646 (12)	0.0466 (11)	0.0491 (10)	0.0010 (9)	0.0194 (9)	−0.0102 (8)
C2	0.0477 (10)	0.0419 (9)	0.0438 (9)	0.0006 (7)	0.0140 (8)	−0.0025 (7)
C3	0.0389 (9)	0.0310 (8)	0.0362 (8)	0.0003 (6)	0.0060 (7)	0.0006 (6)
C4	0.0330 (8)	0.0332 (8)	0.0432 (9)	−0.0015 (6)	0.0014 (7)	−0.0038 (7)
C5	0.0467 (10)	0.0295 (8)	0.0357 (8)	0.0036 (6)	−0.0051 (7)	−0.0022 (6)
C6	0.0483 (10)	0.0275 (8)	0.0320 (8)	0.0024 (7)	0.0040 (7)	−0.0022 (6)
C7	0.0352 (8)	0.0288 (8)	0.0386 (8)	−0.0006 (6)	0.0061 (6)	0.0014 (6)
C8	0.0381 (8)	0.0297 (8)	0.0334 (8)	0.0001 (6)	0.0009 (6)	0.0006 (6)
C9	0.0678 (12)	0.0375 (9)	0.0380 (9)	0.0000 (8)	0.0130 (8)	0.0051 (7)
C10	0.0854 (15)	0.0409 (10)	0.0428 (10)	0.0014 (9)	0.0069 (9)	0.0111 (8)
C11	0.0664 (12)	0.0238 (8)	0.0464 (10)	0.0041 (7)	0.0032 (8)	0.0056 (7)
C12	0.0587 (12)	0.0363 (9)	0.0602 (12)	0.0119 (8)	−0.0117 (9)	0.0032 (8)
C13	0.0444 (10)	0.0404 (10)	0.0726 (13)	0.0088 (8)	0.0094 (9)	−0.0047 (9)
C14	0.0572 (11)	0.0295 (8)	0.0480 (10)	0.0068 (7)	0.0108 (8)	−0.0093 (7)
C15	0.0554 (11)	0.0296 (8)	0.0446 (9)	0.0013 (7)	−0.0012 (8)	−0.0082 (7)
C16	0.0510 (10)	0.0274 (8)	0.0538 (10)	−0.0021 (7)	0.0065 (8)	−0.0026 (7)
C17	0.0437 (9)	0.0267 (8)	0.0416 (9)	−0.0034 (6)	0.0048 (7)	−0.0025 (6)
C18	0.0433 (9)	0.0279 (8)	0.0368 (8)	0.0039 (6)	0.0067 (7)	0.0016 (6)
C19	0.0478 (10)	0.0313 (8)	0.0401 (9)	−0.0011 (7)	0.0102 (7)	0.0041 (7)
C20	0.0433 (9)	0.0324 (8)	0.0364 (8)	0.0044 (7)	0.0045 (7)	0.0039 (7)
C21	0.0497 (10)	0.0338 (9)	0.0492 (10)	0.0044 (7)	0.0116 (8)	0.0024 (7)
C22	0.0491 (10)	0.0438 (10)	0.0469 (10)	0.0054 (8)	0.0023 (8)	0.0085 (8)
N1	0.0761 (12)	0.0546 (10)	0.0775 (12)	0.0146 (9)	0.0317 (10)	−0.0060 (9)
N2	0.0664 (11)	0.0720 (12)	0.0715 (12)	0.0135 (9)	−0.0087 (10)	0.0198 (10)

Geometric parameters (Å, º)

C1—C14	1.505 (3)	C9—H9B	0.9700
C1—C2	1.539 (2)	C10—C11	1.505 (3)
C1—H1A	0.9700	C10—H10A	0.9700
C1—H1B	0.9700	C10—H10B	0.9700
C2—C3	1.534 (2)	C11—C12	1.388 (3)
C2—H2A	0.9700	C11—C16	1.388 (3)
C2—H2B	0.9700	C12—C13	1.386 (3)
C3—C8	1.562 (2)	C12—H12	0.9300
C3—C19	1.577 (2)	C13—C14	1.388 (3)
C3—C4	1.585 (2)	C13—H13	0.9300
C4—C5	1.485 (2)	C14—C15	1.384 (3)
C4—C17	1.551 (2)	C15—C16	1.379 (3)
C4—H4	0.9800	C15—H15	0.9300
C5—C6	1.329 (2)	C16—H16	0.9300
C5—H5	0.9300	C17—C19	1.548 (2)
C6—C7	1.499 (2)	C17—C18	1.562 (2)
C6—C9	1.521 (2)	C17—H17	0.9800
C7—C8	1.560 (2)	C18—C21	1.449 (2)
C7—C18	1.572 (2)	C18—C20	1.578 (2)
C7—H7	0.9800	C19—C20	1.552 (2)
C8—C20	1.576 (2)	C19—H19	0.9800
C8—H8	0.9800	C20—C22	1.444 (2)
C9—C10	1.554 (2)	C21—N1	1.140 (2)
C9—H9A	0.9700	C22—N2	1.140 (2)
C14—C1—C2	111.63 (14)	C11—C10—H10A	110.1
C14—C1—H1A	109.3	C9—C10—H10A	110.1
C2—C1—H1A	109.3	C11—C10—H10B	110.1
C14—C1—H1B	109.3	C9—C10—H10B	110.1
C2—C1—H1B	109.3	H10A—C10—H10B	108.5
H1A—C1—H1B	108.0	C12—C11—C16	117.37 (17)
C3—C2—C1	118.93 (14)	C12—C11—C10	120.91 (17)
C3—C2—H2A	107.6	C16—C11—C10	118.93 (18)
C1—C2—H2A	107.6	C13—C12—C11	120.30 (17)
C3—C2—H2B	107.6	C13—C12—H12	119.8
C1—C2—H2B	107.6	C11—C12—H12	119.8
H2A—C2—H2B	107.0	C12—C13—C14	120.60 (18)
C2—C3—C8	120.83 (13)	C12—C13—H13	119.7
C2—C3—C19	121.49 (13)	C14—C13—H13	119.7
C8—C3—C19	89.36 (11)	C15—C14—C13	117.46 (17)
C2—C3—C4	121.15 (14)	C15—C14—C1	120.52 (17)
C8—C3—C4	107.23 (12)	C13—C14—C1	121.28 (17)
C19—C3—C4	88.58 (11)	C16—C15—C14	120.67 (16)
C5—C4—C17	115.02 (13)	C16—C15—H15	119.7
C5—C4—C3	118.37 (13)	C14—C15—H15	119.7
C17—C4—C3	87.10 (11)	C15—C16—C11	120.63 (17)
C5—C4—H4	111.4	C15—C16—H16	119.7
C17—C4—H4	111.4	C11—C16—H16	119.7
C3—C4—H4	111.4	C19—C17—C4	90.84 (12)
C6—C5—C4	117.09 (14)	C19—C17—C18	90.82 (12)
C6—C5—H5	121.5	C4—C17—C18	108.58 (12)
C4—C5—H5	121.5	C19—C17—H17	119.9
C5—C6—C7	112.85 (14)	C4—C17—H17	119.9
C5—C6—C9	126.36 (15)	C18—C17—H17	119.9
C7—C6—C9	120.78 (14)	C21—C18—C17	118.16 (14)
C6—C7—C8	118.79 (13)	C21—C18—C7	118.29 (14)
C6—C7—C18	114.59 (13)	C17—C18—C7	109.73 (12)
C8—C7—C18	86.52 (11)	C21—C18—C20	125.62 (14)
C6—C7—H7	111.6	C17—C18—C20	88.79 (12)
C8—C7—H7	111.6	C7—C18—C20	90.18 (11)
C18—C7—H7	111.6	C17—C19—C20	90.25 (12)
C7—C8—C3	110.88 (12)	C17—C19—C3	87.50 (11)
C7—C8—C20	90.68 (11)	C20—C19—C3	90.59 (12)
C3—C8—C20	90.27 (11)	C17—C19—H19	125.6
C7—C8—H8	119.4	C20—C19—H19	125.6
C3—C8—H8	119.4	C3—C19—H19	125.6
C20—C8—H8	119.4	C22—C20—C19	128.15 (14)
C6—C9—C10	115.64 (15)	C22—C20—C8	125.85 (14)
C6—C9—H9A	108.4	C19—C20—C8	89.76 (11)
C10—C9—H9A	108.4	C22—C20—C18	124.57 (14)
C6—C9—H9B	108.4	C19—C20—C18	90.13 (12)
C10—C9—H9B	108.4	C8—C20—C18	85.81 (11)
H9A—C9—H9B	107.4	N1—C21—C18	178.31 (19)
C11—C10—C9	107.84 (14)	N2—C22—C20	179.4 (2)
C14—C1—C2—C3	44.9 (2)	C3—C4—C17—C19	18.48 (12)
C1—C2—C3—C8	32.4 (2)	C5—C4—C17—C18	47.44 (17)
C1—C2—C3—C19	142.94 (16)	C3—C4—C17—C18	−72.66 (13)
C1—C2—C3—C4	−107.40 (19)	C19—C17—C18—C21	131.05 (14)
C2—C3—C4—C5	98.29 (18)	C4—C17—C18—C21	−137.79 (15)
C8—C3—C4—C5	−46.26 (18)	C19—C17—C18—C7	−89.20 (13)
C19—C3—C4—C5	−135.15 (15)	C4—C17—C18—C7	1.96 (17)
C2—C3—C4—C17	−144.70 (14)	C19—C17—C18—C20	0.55 (11)
C8—C3—C4—C17	70.75 (13)	C4—C17—C18—C20	91.71 (13)
C19—C3—C4—C17	−18.14 (11)	C6—C7—C18—C21	88.66 (18)
C17—C4—C5—C6	−52.95 (19)	C8—C7—C18—C21	−151.15 (14)
C3—C4—C5—C6	47.9 (2)	C6—C7—C18—C17	−51.03 (17)
C4—C5—C6—C7	1.2 (2)	C8—C7—C18—C17	69.16 (13)
C4—C5—C6—C9	−177.29 (14)	C6—C7—C18—C20	−139.80 (13)
C5—C6—C7—C8	−48.82 (19)	C8—C7—C18—C20	−19.61 (11)
C9—C6—C7—C8	129.74 (15)	C4—C17—C19—C20	−109.16 (12)
C5—C6—C7—C18	51.28 (18)	C18—C17—C19—C20	−0.56 (11)
C9—C6—C7—C18	−130.16 (15)	C4—C17—C19—C3	−18.58 (12)
C6—C7—C8—C3	45.34 (18)	C18—C17—C19—C3	90.02 (12)
C18—C7—C8—C3	−70.90 (13)	C2—C3—C19—C17	144.45 (15)
C6—C7—C8—C20	135.89 (14)	C8—C3—C19—C17	−89.08 (12)
C18—C7—C8—C20	19.64 (11)	C4—C3—C19—C17	18.17 (12)
C2—C3—C8—C7	−143.30 (14)	C2—C3—C19—C20	−125.32 (15)
C19—C3—C8—C7	89.70 (13)	C8—C3—C19—C20	1.14 (11)
C4—C3—C8—C7	1.38 (16)	C4—C3—C19—C20	108.40 (12)
C2—C3—C8—C20	125.87 (15)	C17—C19—C20—C22	−135.78 (17)
C19—C3—C8—C20	−1.13 (11)	C3—C19—C20—C22	136.72 (17)
C4—C3—C8—C20	−89.45 (12)	C17—C19—C20—C8	86.36 (11)
C5—C6—C9—C10	49.2 (2)	C3—C19—C20—C8	−1.13 (11)
C7—C6—C9—C10	−129.17 (17)	C17—C19—C20—C18	0.55 (11)
C6—C9—C10—C11	34.3 (2)	C3—C19—C20—C18	−86.94 (11)
C9—C10—C11—C12	−101.56 (19)	C7—C8—C20—C22	110.88 (17)
C9—C10—C11—C16	59.0 (2)	C3—C8—C20—C22	−138.24 (17)
C16—C11—C12—C13	−13.9 (2)	C7—C8—C20—C19	−109.74 (12)
C10—C11—C12—C13	146.98 (18)	C3—C8—C20—C19	1.14 (11)
C11—C12—C13—C14	−0.3 (3)	C7—C8—C20—C18	−19.59 (11)
C12—C13—C14—C15	13.7 (2)	C3—C8—C20—C18	91.29 (11)
C12—C13—C14—C1	−156.48 (17)	C21—C18—C20—C22	13.8 (3)
C2—C1—C14—C15	−109.31 (19)	C17—C18—C20—C22	138.20 (16)
C2—C1—C14—C13	60.6 (2)	C7—C18—C20—C22	−112.07 (17)
C13—C14—C15—C16	−12.8 (2)	C21—C18—C20—C19	−124.99 (17)
C1—C14—C15—C16	157.42 (16)	C17—C18—C20—C19	−0.55 (11)
C14—C15—C16—C11	−1.5 (2)	C7—C18—C20—C19	109.18 (11)
C12—C11—C16—C15	14.8 (2)	C21—C18—C20—C8	145.26 (16)
C10—C11—C16—C15	−146.44 (16)	C17—C18—C20—C8	−90.30 (11)
C5—C4—C17—C19	138.58 (14)	C7—C18—C20—C8	19.43 (11)