(Z)-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 and π-stacking to form chains running along the a axis.

Key indicators

• Powder X-ray study
• T = 293 K
• Mean [sigma](C-C) = 0.009 Å
• R factor = 0.058
• wR factor = 0.157
• Data-to-parameter ratio = 9.9

checkCIF results

No syntax errors found

ADDSYM reports no extra symmetry


 Alert Level C:



RINTA_01  Alert C The value of Rint is greater than 0.10
          Rint given   0.134

General Notes



REFLT_03
         From the CIF: _diffrn_reflns_theta_max           27.06
         From the CIF: _reflns_number_total               1176
         Count of symmetry unique reflns         1180
         Completeness (_total/calc)             99.66%
         TEST3: Check Friedels for noncentro structure
         Estimate of Friedel pairs measured         0
         Fraction of Friedel pairs measured     0.000
         Are heavy atom types Z>Si present           no
          Please check that the estimate of the number of Friedel pairs is
          correct. If it is not, please give the correct count in the
          _publ_section_exptl_refinement section of the submitted CIF.


 0 Alert Level A = Potentially serious problem

 0 Alert Level B = Potential problem

 1 Alert Level C = Please check

---

S1. Comment

Azulene-1-carboxaldehyde oxime was first obtained by Hafner (Hafner & Bernhard, 1959) as a crystalline derivative of azulene-1-carbaldehyde. To determine the configuration of the oxime, the synthesis was optimized. (Z)-Azulene-1-carboxaldehyde oxime, (I), was separated from the (E)-azulene-1-carboxaldehyde oxime and crystallized. No isomerization could be observed in solution in the absence of acids. Compound (I) shows the expected molecular geometry (see Fig. 1), viz. a planar azulene moietiy with a delocalized 10π-electron perimeter [mean C—C distance 1.383 (8) Å] and a central bond length of 1.459 (7) Å. The aldoxime group deviates significantly from the azulene plane with a C2—C1—C11—N11 torsion angle of −17.1 (9)°. The crystal packing is determined by intermolecular hydrogen bond (Table 1) and π-stacking as shown in Fig. 2. Hydrogen bonds connect the molecules into π-stacked chains running along the a axis.

S2. Experimental

To a mixture of hydroxylammonium chloride (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. Compound (II) crystallized as dark green needles from hexane/ethyl acetate. (Z)-Azulene-1-carboxaldehyde oxime, (I), m.p. 391–392 K; ¹H NMR (500 MHz, [D₆]DMSO): δ 11.28 (s, 1H, H11O), 8.84 (d, 1H, H8), 8.80 (d, 1H, H2), 8.51 (d, 1H, H4), 8.17 (s, 1H, H11), 7.82 (app.t, 1H, H6), 7.48 (d, 1H, H3), 7.40 (app.q, 2H, H5, H7); J_2,3 = 4.1, J_4,5 = 9.6, J_7,8 = 9.7, J_5,6 = J_6,7 = 9.8 Hz. ¹³C NMR (125.75 MHz, [D₆]DMSO): δ 140.7 (C10), 140.2 (C2), 138.9 (C6), 138.4 (C11), 137.8 (C9), 137.7 (C4), 134.1 (C8), 125.2 (C5), 124.7 (C7), 118.6 (C1), 118.7 (C3).

S3. Refinement

H atoms of (I) are treated as riding atoms. The position of the hydroxyl H atom was found in difference Fourier maps 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), view along the a axis.

(Z)-Azulene-1-carboxaldehyde oxime

Crystal data

C11H9NO	Dx = 1.269 Mg m^−3
Mr = 171.19	Melting point = 118–119 K
Orthorhombic, P212121	Mo Kα radiation, λ = 0.71073 Å
a = 4.631 (5) Å	Cell parameters from 6381 reflections
b = 11.068 (5) Å	θ = 3.9–27.1°
c = 17.487 (8) Å	µ = 0.08 mm^−1
V = 896.3 (11) Å^3	T = 293 K
Z = 4	Needle, dark green
F(000) = 360	0.55 × 0.10 × 0.08 mm

Data collection

Oxford Diffraction Excalibur (TM) single-crystal X-ray diffractometer with Sapphire CCD detector	459 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.134
Graphite monochromator	θmax = 27.1°, θmin = 3.9°
Rotation method data acquisition using ω and θ scans	h = −3→5
6381 measured reflections	k = −7→14
1176 independent reflections	l = −22→22

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)] = 0.058	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.157	H-atom parameters constrained
S = 0.93	w = 1/[σ^2(Fo^2) + (0.0502P)^2] where P = (Fo^2 + 2Fc^2)/3
1176 reflections	(Δ/σ)max < 0.001
119 parameters	Δρmax = 0.19 e Å^−3
0 restraints	Δρmin = −0.17 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)

3.4810 (0.0054) x − 6.7005 (0.0152) y − 4.5764 (0.0214) z = 1.0394 (0.0064)

* −0.0079 (0.0039) C1 * 0.0222 (0.0042) C2 * 0.0190 (0.0048) C3 * −0.0022 (0.0048) C4 * −0.0011 (0.0051) C5 * 0.0127 (0.0051) C6 * 0.0131 (0.0049) C7 * −0.0029 (0.0043) C8 * −0.0161 (0.0044) C9 * −0.0369 (0.0047) C10 − 0.0782 (0.0069) C11 0.1522 (0.0072) N11 0.5798 (0.0071) O11

Rms deviation of fitted atoms = 0.0170

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	−0.2130 (11)	−0.1303 (5)	−0.1966 (3)	0.0576 (13)
C2	−0.0167 (14)	−0.0345 (5)	−0.1942 (3)	0.0738 (16)
H2	0.0903	−0.0107	−0.1518	0.089*
C3	−0.0091 (15)	0.0186 (5)	−0.2655 (3)	0.0808 (17)
H3	0.1077	0.0837	−0.2787	0.097*
C4	−0.2364 (14)	−0.0106 (5)	−0.3910 (3)	0.0822 (19)
H4	−0.1282	0.0541	−0.4091	0.099*
C5	−0.4097 (17)	−0.0651 (7)	−0.4432 (3)	0.095 (2)
H5	−0.4094	−0.0304	−0.4916	0.114*
C6	−0.5845 (16)	−0.1637 (8)	−0.4348 (3)	0.095 (2)
H6	−0.6842	−0.1872	−0.4785	0.113*
C7	−0.6334 (13)	−0.2323 (6)	−0.3717 (4)	0.091 (2)
H7	−0.7615	−0.2961	−0.3785	0.109*
C8	−0.5193 (12)	−0.2209 (5)	−0.2981 (3)	0.0711 (15)
H8	−0.5825	−0.2776	−0.2626	0.085*
C9	−0.3277 (11)	−0.1375 (5)	−0.2715 (3)	0.0584 (14)
C10	−0.1989 (12)	−0.0382 (5)	−0.3145 (3)	0.0664 (15)
C11	−0.3038 (11)	−0.2088 (5)	−0.1353 (3)	0.0685 (15)
H11	−0.4729	−0.2513	−0.1452	0.082*
N11	−0.1930 (10)	−0.2305 (4)	−0.0697 (2)	0.0713 (13)
O11	0.0622 (9)	−0.1690 (4)	−0.0590 (2)	0.0807 (12)
H11O	0.1402	−0.1929	−0.0197	0.097*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.074 (3)	0.054 (3)	0.044 (3)	0.016 (3)	0.007 (3)	0.001 (3)
C2	0.104 (5)	0.060 (4)	0.057 (3)	−0.001 (4)	−0.001 (4)	−0.004 (3)
C3	0.108 (5)	0.056 (4)	0.079 (4)	−0.005 (4)	0.009 (4)	0.011 (3)
C4	0.125 (5)	0.068 (4)	0.053 (4)	0.017 (4)	0.006 (4)	0.011 (3)
C5	0.140 (7)	0.095 (6)	0.051 (4)	0.017 (5)	0.003 (4)	0.015 (4)
C6	0.119 (6)	0.106 (6)	0.059 (4)	0.016 (5)	−0.016 (4)	−0.004 (4)
C7	0.110 (5)	0.094 (5)	0.070 (4)	−0.008 (4)	−0.017 (4)	0.001 (4)
C8	0.082 (4)	0.077 (4)	0.055 (3)	0.000 (4)	−0.003 (3)	0.007 (3)
C9	0.074 (4)	0.055 (3)	0.046 (3)	0.007 (3)	0.004 (3)	0.007 (3)
C10	0.092 (4)	0.052 (3)	0.055 (3)	0.014 (3)	0.006 (3)	0.004 (3)
C11	0.082 (4)	0.068 (4)	0.055 (3)	0.004 (3)	0.009 (3)	0.001 (3)
N11	0.092 (3)	0.078 (3)	0.044 (3)	0.012 (3)	0.006 (3)	0.003 (2)
O11	0.102 (3)	0.092 (3)	0.049 (2)	0.006 (3)	−0.008 (2)	0.005 (2)

Geometric parameters (Å, º)

C1—C2	1.397 (7)	C6—C7	1.357 (9)
C1—C9	1.415 (7)	C6—H6	0.9300
C1—C11	1.443 (7)	C7—C8	1.397 (7)
C2—C3	1.379 (7)	C7—H7	0.9300
C2—H2	0.9300	C8—C9	1.362 (7)
C3—C10	1.379 (7)	C8—H8	0.9300
C3—H3	0.9300	C9—C10	1.459 (7)
C4—C5	1.357 (8)	C11—N11	1.279 (6)
C4—C10	1.383 (7)	C11—H11	0.9300
C4—H4	0.9300	N11—O11	1.376 (5)
C5—C6	1.367 (8)	O11—H11O	0.8200
C5—H5	0.9300
C2—C1—C9	108.4 (5)	C6—C7—C8	129.4 (7)
C2—C1—C11	128.6 (5)	C6—C7—H7	115.3
C9—C1—C11	123.0 (5)	C8—C7—H7	115.3
C3—C2—C1	108.2 (5)	C9—C8—C7	128.5 (5)
C3—C2—H2	125.9	C9—C8—H8	115.8
C1—C2—H2	125.9	C7—C8—H8	115.8
C10—C3—C2	110.5 (5)	C8—C9—C1	126.8 (5)
C10—C3—H3	124.7	C8—C9—C10	126.9 (5)
C2—C3—H3	124.7	C1—C9—C10	106.3 (5)
C5—C4—C10	128.9 (6)	C3—C10—C4	125.5 (6)
C5—C4—H4	115.6	C3—C10—C9	106.5 (5)
C10—C4—H4	115.6	C4—C10—C9	127.8 (6)
C4—C5—C6	129.2 (6)	N11—C11—C1	131.5 (5)
C4—C5—H5	115.4	N11—C11—H11	114.3
C6—C5—H5	115.4	C1—C11—H11	114.3
C7—C6—C5	129.2 (6)	C11—N11—O11	112.0 (5)
C7—C6—H6	115.4	N11—O11—H11O	109.5
C5—C6—H6	115.4
C9—C1—C2—C3	0.6 (5)	C11—C1—C9—C10	175.7 (4)
C11—C1—C2—C3	−176.9 (5)	C2—C3—C10—C4	−177.3 (5)
C1—C2—C3—C10	1.1 (6)	C2—C3—C10—C9	−2.3 (6)
C10—C4—C5—C6	−2.5 (12)	C5—C4—C10—C3	177.2 (6)
C4—C5—C6—C7	0.9 (12)	C5—C4—C10—C9	3.2 (10)
C5—C6—C7—C8	0.1 (12)	C8—C9—C10—C3	−177.3 (5)
C6—C7—C8—C9	−0.4 (11)	C1—C9—C10—C3	2.6 (6)
C7—C8—C9—C1	−178.8 (6)	C8—C9—C10—C4	−2.4 (9)
C7—C8—C9—C10	1.0 (9)	C1—C9—C10—C4	177.4 (5)
C2—C1—C9—C8	177.9 (5)	C2—C1—C11—N11	−17.1 (9)
C11—C1—C9—C8	−4.5 (7)	C9—C1—C11—N11	165.7 (5)
C2—C1—C9—C10	−1.9 (5)	C1—C11—N11—O11	−2.3 (7)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O11—H11O···N11^i	0.82	1.94	2.756 (5)	173

Symmetry code: (i) x+1/2, −y−1/2, −z.