(E)-Azulene-1-carbox­aldehyde oxime

In the title compound, C₁₁H₉NO, the azulene moiety is planar with a delocalized 10π-electron perimeter. In the crystal structure, the mol­ecules are connected by hydrogen bonds to form centrosymmetric dimers.

Key indicators

• Powder X-ray study
• T = 293 K
• Mean [sigma](C-C) = 0.004 Å
• R factor = 0.052
• wR factor = 0.149
• Data-to-parameter ratio = 14.9

checkCIF results

No syntax errors found

ADDSYM reports no extra symmetry

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S1. Comment

Azulene-1-carboxaldehyde oxime was first obtained by Hafner (Hafner & Bernhard, 1959) as cystalline derivative of azulene-1-carbaldehyde. To determine the configuration of the oxime, the synthesis was optimized. The (E)-azulene-1-carboxaldehyde oxime, (I), could be separated from the isomer (Z)-azulene-1-carboxaldehyde and crystallized. No isomerization could be observed in solution in the absence of acids. The (E)-azulene-1-carboxaldehyde oxime shows the expected molecular geometry (see Fig. 1), viz. a planar azulene moiety with a delocalized 10π-electron perimeter [mean C—C distance 1.392 (4) Å] and a central bond length of 1.489 (4) Å. The crystal packing is determined by intermolecular hydrogen bonds and π-stacking as shown in Fig. 2. Hydrogen bonded centrosymmetric dimers are stacked along the z axis.

S2. Experimental

To a mixture of hydroxylammoniumchloride (460 mg, 6.6 mmol) and potassium acetate (668 mg, 6.8 mmol) in 40 ml e thanol azulene-1-carbaldehyde (1.0 g, 6.5 mmol) was added and heated to 323 K. After 1.5 h, the solvent was evaporated. Chromatography with silica gel (hexane/ethyl acetate 4:1) yielded the isomer oximes. Dark green crystals of (I) were obtained from a toluene solution by evaporation. (E)-Azulene-1-carboxaldehyde oxime, (I), m.p. 393–394 K; ¹H NMR (500 MHz, [D₆]DMSO): δ = 10.94 (s, 1H, H11O), 8.92 (d, 1H, H8), 8.72 (s, 1H, H11), 8.42 (d, 1H, H4), 8.13 (d, 1H, H2), 7.74 (app.t, 1H, H6), 7.43 (d, 1H, H3), 7.32 (app. q, 2H, H5,H7); J_2,3 = 4.0, J_4,5 = 9.3, J_7,8 = 9.8, J_5,6 = J_6,7=9.8 Hz. ¹³C NMR (125.75 MHz, [D₆]DMSO): δ = 144.9 (C11), 143.2 (C10), 139.6 (C6), 138.2 (C4), 136.4 (C2), 136.3 (C9), 136.1 (C8), 125.4 (C5), 125.1 (C7), 121.8 (C1), 119.2 (C3).

S3. Refinement

H atoms of (I) are treated as riding atoms. The position of the hydroyxl H atom was found in a difference Fourier map and refined.

Computing details

Data collection: CrysAlis CCD (Oxford Diffraction, 2001); cell refinement: CrysAlis CCD; data reduction: CrysAlis RED (Oxford Diffraction, 2001); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: PLATON (Spek, 2001) and ORTEPIII (Johnson & Burnett, 1998); software used to prepare material for publication: SHELXL97 CIF and IUCr SHELXL97 template.

Figures

	Fig. 1. A view of (I). Displacement ellipsoids are drawn at the 30% probability level.
	Fig. 2. A packing plot of (I), viewed along the b axis.

E-azulenecarboxaldehyde oxime

Crystal data

C11H9NO	Dx = 1.281 Mg m^−3
Mr = 171.19	Melting point = 120–121 K
Monoclinic, C2/c	Mo Kα radiation, λ = 0.71073 Å
a = 16.931 (3) Å	Cell parameters from 5481 reflections
b = 6.174 (2) Å	θ = 3.5–26.4°
c = 17.028 (5) Å	µ = 0.08 mm^−1
β = 94.00 (2)°	T = 293 K
V = 1775.6 (8) Å^3	Needle, dark green
Z = 8	0.52 × 0.28 × 0.14 mm
F(000) = 720

Data collection

Oxford Diffraction Excalibur (TM) single-crystal X-ray diffractometer with Sapphire CCD detector	815 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.066
Graphite monochromator	θmax = 26.4°, θmin = 3.5°
Rotation method data acquisition using ω and θ scans	h = −21→21
5481 measured reflections	k = −7→5
1803 independent reflections	l = −21→21

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)] = 0.052	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.149	H atoms treated by a mixture of independent and constrained refinement
S = 0.98	w = 1/[σ^2(Fo^2) + (0.0524P)^2] where P = (Fo^2 + 2Fc^2)/3
1803 reflections	(Δ/σ)max < 0.001
121 parameters	Δρmax = 0.13 e Å^−3
1 restraint	Δρmin = −0.14 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.

Mean-plane data from final SHELXL refinement run:

Least-squares planes (x,y,z in crystal coordinates) and deviations from them (* indicates atom used to define plane)

2.9924 (0.0090) x + 2.8321 (0.0046) y + 14.5824 (0.0084) z = 10.5556 (0.0085)

* −0.0070 (0.0022) C1 * −0.0130 (0.0024) C2 * 0.0078 (0.0025) C3 * 0.0068 (0.0024) C4 * −0.0034 (0.0025) C5 * −0.0134 (0.0026) C6 * 0.0017 (0.0024) C7 * 0.0095 (0.0023) C8 * 0.0092 (0.0023) C9 * 0.0018 (0.0024) C10 − 0.0039 (0.0036) C11 − 0.0506 (0.0036) N11 − 0.0125 (0.0047) O11

Rms deviation of fitted atoms = 0.0084

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	0.81777 (15)	−0.2035 (4)	0.59510 (16)	0.0523 (8)
C2	0.86254 (17)	−0.3869 (5)	0.62111 (19)	0.0678 (9)
H2	0.9158	−0.4081	0.6132	0.081*
C3	0.81635 (18)	−0.5287 (5)	0.65957 (19)	0.0684 (9)
H3	0.8335	−0.6588	0.6824	0.082*
C4	0.67554 (19)	−0.5457 (5)	0.69167 (17)	0.0639 (9)
H4	0.6868	−0.6782	0.7159	0.077*
C5	0.59747 (18)	−0.4760 (5)	0.69347 (19)	0.0717 (10)
H5	0.5635	−0.5680	0.7183	0.086*
C6	0.56442 (18)	−0.2881 (6)	0.66306 (19)	0.0718 (9)
H6	0.5107	−0.2719	0.6696	0.086*
C7	0.59873 (17)	−0.1188 (5)	0.62419 (19)	0.0705 (9)
H7	0.5648	−0.0052	0.6095	0.085*
C8	0.67591 (16)	−0.0935 (5)	0.60397 (16)	0.0584 (8)
H8	0.6865	0.0338	0.5775	0.070*
C9	0.73988 (15)	−0.2334 (4)	0.61798 (15)	0.0473 (7)
C10	0.73862 (16)	−0.4461 (5)	0.65905 (16)	0.0531 (8)
C11	0.84635 (16)	−0.0184 (5)	0.55349 (16)	0.0566 (8)
H11	0.8120	0.0959	0.5409	0.068*
N11	0.91781 (13)	−0.0081 (4)	0.53362 (14)	0.0616 (7)
O11	0.93267 (11)	0.1898 (4)	0.49475 (14)	0.0763 (7)
H11O	0.9787 (12)	0.168 (5)	0.4808 (19)	0.092*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.0514 (17)	0.0573 (18)	0.0485 (18)	0.0087 (15)	0.0053 (14)	−0.0002 (15)
C2	0.0526 (19)	0.076 (2)	0.075 (2)	0.0178 (17)	0.0090 (16)	0.003 (2)
C3	0.072 (2)	0.061 (2)	0.073 (2)	0.0147 (18)	0.0120 (17)	0.0080 (18)
C4	0.080 (2)	0.0551 (19)	0.057 (2)	−0.0070 (17)	0.0051 (16)	−0.0009 (16)
C5	0.062 (2)	0.078 (2)	0.076 (2)	−0.0146 (19)	0.0142 (17)	0.003 (2)
C6	0.0479 (18)	0.089 (3)	0.079 (2)	−0.0009 (19)	0.0069 (16)	0.003 (2)
C7	0.0509 (19)	0.077 (2)	0.084 (2)	0.0124 (17)	0.0064 (17)	0.009 (2)
C8	0.0533 (18)	0.0608 (18)	0.061 (2)	0.0034 (15)	0.0051 (14)	0.0022 (17)
C9	0.0496 (17)	0.0505 (17)	0.0418 (17)	0.0070 (14)	0.0034 (13)	−0.0044 (14)
C10	0.0576 (19)	0.0542 (18)	0.0477 (19)	0.0038 (15)	0.0041 (14)	−0.0025 (15)
C11	0.0504 (18)	0.062 (2)	0.058 (2)	0.0106 (15)	0.0076 (15)	−0.0015 (16)
N11	0.0511 (15)	0.0637 (17)	0.0714 (19)	0.0034 (12)	0.0137 (12)	0.0062 (14)
O11	0.0603 (14)	0.0758 (15)	0.0952 (18)	0.0054 (12)	0.0239 (12)	0.0206 (13)

Geometric parameters (Å, º)

C1—C9	1.413 (3)	C6—C7	1.386 (4)
C1—C2	1.416 (3)	C6—H6	0.9300
C1—C11	1.446 (3)	C7—C8	1.383 (4)
C2—C3	1.371 (4)	C7—H7	0.9300
C2—H2	0.9300	C8—C9	1.393 (3)
C3—C10	1.411 (3)	C8—H8	0.9300
C3—H3	0.9300	C9—C10	1.489 (4)
C4—C10	1.382 (3)	C11—N11	1.281 (3)
C4—C5	1.392 (4)	C11—H11	0.9300
C4—H4	0.9300	N11—O11	1.420 (3)
C5—C6	1.374 (4)	O11—H11O	0.840 (17)
C5—H5	0.9300
C9—C1—C2	107.4 (3)	C8—C7—C6	129.7 (3)
C9—C1—C11	126.1 (2)	C8—C7—H7	115.2
C2—C1—C11	126.5 (3)	C6—C7—H7	115.2
C3—C2—C1	110.5 (3)	C7—C8—C9	128.6 (3)
C3—C2—H2	124.8	C7—C8—H8	115.7
C1—C2—H2	124.8	C9—C8—H8	115.7
C2—C3—C10	109.2 (3)	C8—C9—C1	127.0 (3)
C2—C3—H3	125.4	C8—C9—C10	126.2 (2)
C10—C3—H3	125.4	C1—C9—C10	106.8 (2)
C10—C4—C5	129.3 (3)	C4—C10—C3	125.7 (3)
C10—C4—H4	115.4	C4—C10—C9	128.2 (3)
C5—C4—H4	115.4	C3—C10—C9	106.1 (2)
C6—C5—C4	128.0 (3)	N11—C11—C1	121.6 (3)
C6—C5—H5	116.0	N11—C11—H11	119.2
C4—C5—H5	116.0	C1—C11—H11	119.2
C5—C6—C7	130.0 (3)	C11—N11—O11	111.6 (2)
C5—C6—H6	115.0	N11—O11—H11O	101 (2)
C7—C6—H6	115.0
C9—C1—C2—C3	−0.4 (3)	C11—C1—C9—C10	−179.9 (2)
C11—C1—C2—C3	179.0 (3)	C5—C4—C10—C3	−179.7 (3)
C1—C2—C3—C10	1.1 (4)	C5—C4—C10—C9	1.2 (5)
C10—C4—C5—C6	−0.4 (6)	C2—C3—C10—C4	179.4 (3)
C4—C5—C6—C7	−1.0 (6)	C2—C3—C10—C9	−1.4 (3)
C5—C6—C7—C8	1.2 (6)	C8—C9—C10—C4	−0.7 (4)
C6—C7—C8—C9	−0.3 (5)	C1—C9—C10—C4	−179.7 (3)
C7—C8—C9—C1	178.8 (3)	C8—C9—C10—C3	−179.9 (3)
C7—C8—C9—C10	−0.1 (5)	C1—C9—C10—C3	1.1 (3)
C2—C1—C9—C8	−179.5 (3)	C9—C1—C11—N11	−178.4 (3)
C11—C1—C9—C8	1.1 (5)	C2—C1—C11—N11	2.3 (5)
C2—C1—C9—C10	−0.4 (3)	C1—C11—N11—O11	−178.9 (2)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O11—H11O···N11^i	0.84 (2)	2.04 (2)	2.841 (3)	158 (3)

Symmetry code: (i) −x+2, −y, −z+1.