(E)-1-(4-Meth­oxy­anthracen-1-yl)-2-phenyl­diazene

Crochet, A.; Fromm, K.M.; Kurteva, V.; Antonov, L.

doi:10.1107/S1600536811010932

organic compounds

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ISSN: 2056-9890

Volume 67| Part 4| April 2011| Page o993

doi:10.1107/S1600536811010932

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(E)-1-(4-Methoxyanthracen-1-yl)-2-phenyldiazene

Aurelien Crochet,^a Katharina M. Fromm,^a ^* Vanya Kurteva ^b and Liudmil Antonov ^b ^*

^aUniversity of Fribourg, Department of Chemistry, Chemin du Musee 9, CH-1700 Fribourg, Switzerland, and ^bInstitute of Organic Chemistry, Bulgarian Academy of Sciences, Acad. G. Bonchev str., bdg 9, Sofia 1113, Bulgaria
^*Correspondence e-mail: katharina.fromm@unifr.ch, lantonov@orgchm.bas.bg

(Received 10 February 2011; accepted 23 March 2011; online 31 March 2011)

The title compound, C₂₁H₁₆N₂O, has an E-conformation about the diazene N=N bond. It is reasonably planar with the phenyl ring being inclined to the mean plane of the anthracene moiety [planar to within 0.077 (3) Å] by 6.43 (10)°. The crystal structure is stabilized by C—H⋯π and weak π–π interactions [centroid–centroid distances of 3.7192 (16) and 3.8382 (15) Å], leading to the formation of two-dimensional networks stacking along [001] and lying parallel to (110).

Related literature

For background to sensing molecules based on tautomeric switches, see: Nedeltcheva et al. (2009 ); Antonov et al. (2009 , 2010 ). For investigations of the tautomerism of azodyes, see: Kelemen (1981 ). For the synthesis of the title compound, see: Nedeltcheva et al. (2010 ).

Experimental

Crystal data

C₂₁H₁₆N₂O
M_r = 312.36
Orthorhombic, P 2₁ 2₁ 2₁
a = 6.3021 (3) Å
b = 9.0481 (4) Å
c = 27.3935 (17) Å
V = 1562.03 (14) Å³
Z = 4
Mo Kα radiation
μ = 0.08 mm⁻¹
T = 150 K
0.54 × 0.32 × 0.12 mm

Data collection

STOE IPDS 2T diffractometer
12181 measured reflections
2584 independent reflections
2096 reflections with I > 2σ(I)
R_int = 0.072

Refinement

R[F² > 2σ(F²)] = 0.047
wR(F²) = 0.086
S = 1.10
2584 reflections
218 parameters
H-atom parameters constrained
Δρ_max = 0.13 e Å⁻³
Δρ_min = −0.15 e Å⁻³

Table 1
C—H⋯π interactions (Å, °)

Cg1, Cg2 and Cg3 are the centroids of the C1–C6, C7,C8,C17–C20 and C8–C10,C15–C17) rings, respectively.

C—H⋯Cg	C—H	H⋯Cg	C⋯Cg	C—H⋯Cg
C21—H21A⋯Cg1ⁱ	0.98	2.83	3.646 (4)	141
C12—H12⋯Cg2ⁱⁱ	0.95	2.80	3.681 (4)	154
C11—H11⋯Cg3ⁱⁱ	0.95	2.83	3.543 (3)	132
Symmetry codes: (i) x+1, y+1, z; (ii) $[-x+2, y+{\script{1\over 2}}, -z+{\script{1\over 2}}]$ .

Data collection: X-AREA (Stoe & Cie, 2009 ); cell refinement: X-AREA; data reduction: X-RED32 (Stoe & Cie, 2009); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: PLATON (Spek, 2009 ) and Mercury (Macrae et al., 2006 ); software used to prepare material for publication: SHELXL97, PLATON and publCIF (Westrip, 2010 ).

Supporting information

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536811010932/nc2221sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536811010932/nc2221Isup2.hkl

checkCIF report

Comment top

More than 90% of the existing commercial azodyes are tautomeric ones, which makes the investigation of their tautomerism of substantial practical interest (Kelemen, 1981). However, in most of the tautomeric dyes the tautomeric equilibrium cannot be shifted to the pure, end tautomeric forms. In such cases model compounds, possessing the characteristics of the corresponding end-structures, are usually applied. As a part of our interest in sensing molecules based on tautomeric switches (Nedeltcheva et al., 2009, Antonov et al., 2009, 2010), the equilibrium in 4-phenylazo-antracene-1-ol was studied in the gas phase by mass spectrometry, and in solution by flash photolysis (Nedeltcheva et al., 2010). The corresponding O-methyl and N-methyl derivatives were used as model enol and keto tautomers, respectively, and the tautomeric constant was estimated. Herein, we report on the crystal structure of the title compound, the model enol analogue of 4-phenylazo-antracene-1-ol.

The molecular structure of the title molecule is shown in Fig. 1. The molecule, which has the E-conformation about the diazene N1═N2 bond, is relatively planar, with phenyl ring (C1—C6) being inclined to the mean plane of the anthracene moiety (C7—C20) by 6.43 (10) °.

In the crystal the molecules are linked by C—H···π interactions (Table 1). There are also weak π···π interactions involving the phenyl ring (C1—C6) with rings (C7,C8,C17—C20)ⁱ and (C8—C10,C15—C17)ⁱ [symmetry code (i) x - 1, y - 1, z]; the centroid-centroid distances are 3.7192 (16) and 3.8382 (15) Å, respectively. These interactions lead to the formation of two-dimensional sheet-like networks that stack along the c axis, lying parallel to the ab-plane (Fig. 2).

Related literature top

For backgroung to sensing molecules based on tautomeric switches, see: Nedeltcheva et al. (2009); Antonov et al. (2009, 2010). For investigations of the tautomerism of azodyes, see: Kelemen (1981). For the synthesis of the title compound, see: Nedeltcheva et al. (2010).

Experimental top

Simple methylation of (E)-4-(phenyldiazenyl)anthracen-1-ol in basic media gave an easy separable mixture of the title compound and the corresponding N-methyl derivative, with yields of 32% and 43%, respectively (Nedeltcheva et al., 2010). Dark red block-like crystals of the title compound, suitable for X-ray diffraction analysis, were grown by slow diffusion of hexane into a chloroform solution of the title compound.

Computing details top

Data collection: X-AREA (Stoe & Cie, 2009); cell refinement: X-AREA (Stoe & Cie, 2009); data reduction: X-RED32 (Stoe & Cie, 2009); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: PLATON (Spek, 2009) and Mercury (Macrae et al., 2006); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008), PLATON (Spek, 2009) and publCIF (Westrip, 2010).

Figures top

	Fig. 1. A view of the molecular structure of the title compound with labeling and displacement ellipsoids drawn at the 50% probability level.
	Fig. 2. A view along the a-axis of the crystal structure of the title compound. The π···π and C—H···π and interactions are shown as dashed cyan lines [see Table 1 for details; H-atoms not involved in these interactions have been omitted for clarity].

(E)-1-(4-Methoxyanthracen-1-yl)-2-phenyldiazene top

Crystal data top

C₂₁H₁₆N₂O	F(000) = 656
M_r = 312.36	D_x = 1.328 Mg m⁻³
Orthorhombic, P2₁2₁2₁	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2ac 2ab	Cell parameters from 8137 reflections
a = 6.3021 (3) Å	θ = 1.5–25.1°
b = 9.0481 (4) Å	µ = 0.08 mm⁻¹
c = 27.3935 (17) Å	T = 150 K
V = 1562.03 (14) Å³	Block, red
Z = 4	0.54 × 0.32 × 0.12 mm

Data collection top

STOE IPDS 2T diffractometer	2096 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	R_int = 0.072
Graphite monochromator	θ_max = 24.6°, θ_min = 1.5°
Detector resolution: 6.67 pixels mm^-1	h = −6→7
rotation method scans	k = −9→10
12181 measured reflections	l = −32→32
2584 independent reflections

Refinement top

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)] = 0.047	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.086	H-atom parameters constrained
S = 1.10	w = 1/[σ²(F_o²) + (0.0342P)² + 0.1352P] where P = (F_o² + 2F_c²)/3
2584 reflections	(Δ/σ)_max < 0.001
218 parameters	Δρ_max = 0.13 e Å⁻³
0 restraints	Δρ_min = −0.15 e Å⁻³

Crystal data top

C₂₁H₁₆N₂O	V = 1562.03 (14) Å³
M_r = 312.36	Z = 4
Orthorhombic, P2₁2₁2₁	Mo Kα radiation
a = 6.3021 (3) Å	µ = 0.08 mm⁻¹
b = 9.0481 (4) Å	T = 150 K
c = 27.3935 (17) Å	0.54 × 0.32 × 0.12 mm

Data collection top

STOE IPDS 2T diffractometer	2096 reflections with I > 2σ(I)
12181 measured reflections	R_int = 0.072
2584 independent reflections

Refinement top

R[F² > 2σ(F²)] = 0.047	0 restraints
wR(F²) = 0.086	H-atom parameters constrained
S = 1.10	Δρ_max = 0.13 e Å⁻³
2584 reflections	Δρ_min = −0.15 e Å⁻³
218 parameters

Special details top

Geometry. All s.u.'s (except the s.u. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell s.u.'s are taken into account individually in the estimation of s.u.'s in distances, angles and torsion angles; correlations between s.u.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell s.u.'s is used for estimating s.u.'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 > 2σ(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	U_iso*/U_eq
C1	0.3714 (4)	−0.0729 (3)	0.41632 (8)	0.0295 (6)
C2	0.2333 (4)	−0.0908 (3)	0.45491 (10)	0.0390 (7)
H2	0.2609	−0.0433	0.4852	0.047*
C3	0.0531 (5)	−0.1787 (3)	0.44947 (11)	0.0459 (8)
H3	−0.0422	−0.1911	0.4760	0.055*
C4	0.0136 (5)	−0.2471 (3)	0.40569 (10)	0.0428 (8)
H4	−0.1105	−0.3056	0.4018	0.051*
C5	0.1533 (5)	−0.2314 (3)	0.36735 (11)	0.0410 (7)
H5	0.1260	−0.2802	0.3373	0.049*
C6	0.3333 (4)	−0.1448 (3)	0.37242 (9)	0.0343 (6)
H6	0.4300	−0.1348	0.3460	0.041*
C7	0.8346 (4)	0.1413 (3)	0.39361 (8)	0.0279 (6)
C8	0.9818 (4)	0.1429 (3)	0.35326 (8)	0.0278 (6)
C9	0.9493 (4)	0.0641 (3)	0.31029 (8)	0.0308 (6)
H9	0.8233	0.0075	0.3067	0.037*
C10	1.0975 (4)	0.0660 (3)	0.27227 (8)	0.0287 (6)
C11	1.0656 (5)	−0.0128 (3)	0.22788 (8)	0.0335 (6)
H11	0.9396	−0.0689	0.2235	0.040*
C12	1.2126 (5)	−0.0087 (3)	0.19165 (8)	0.0352 (7)
H12	1.1875	−0.0608	0.1621	0.042*
C13	1.4030 (4)	0.0725 (3)	0.19757 (9)	0.0355 (7)
H13	1.5051	0.0736	0.1721	0.043*
C14	1.4408 (4)	0.1487 (3)	0.23939 (8)	0.0328 (6)
H14	1.5688	0.2032	0.2428	0.039*
C15	1.2913 (4)	0.1479 (3)	0.27795 (8)	0.0280 (6)
C16	1.3235 (4)	0.2270 (3)	0.32118 (8)	0.0290 (6)
H16	1.4516	0.2808	0.3253	0.035*
C17	1.1728 (4)	0.2290 (3)	0.35837 (8)	0.0258 (6)
C18	1.2018 (4)	0.3159 (3)	0.40158 (8)	0.0284 (6)
C19	1.0512 (4)	0.3180 (3)	0.43775 (8)	0.0302 (6)
H19	1.0691	0.3792	0.4656	0.036*
C20	0.8696 (4)	0.2281 (3)	0.43313 (8)	0.0322 (7)
H20	0.7677	0.2285	0.4587	0.039*
C21	1.4285 (5)	0.4842 (3)	0.44324 (8)	0.0410 (7)
H21A	1.3165	0.5585	0.4470	0.061*
H21B	1.5656	0.5337	0.4390	0.061*
H21C	1.4333	0.4217	0.4724	0.061*
N1	0.5491 (4)	0.0227 (3)	0.42517 (7)	0.0329 (5)
N2	0.6573 (3)	0.0465 (2)	0.38713 (7)	0.0301 (5)
O1	1.3851 (3)	0.3951 (2)	0.40156 (6)	0.0347 (5)

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
C1	0.0235 (15)	0.0275 (16)	0.0375 (13)	0.0038 (13)	0.0023 (11)	0.0052 (11)
C2	0.0385 (18)	0.0367 (19)	0.0418 (14)	−0.0030 (14)	0.0075 (13)	−0.0038 (13)
C3	0.0361 (18)	0.044 (2)	0.0573 (17)	−0.0027 (16)	0.0182 (15)	−0.0014 (15)
C4	0.0335 (19)	0.0329 (18)	0.0620 (19)	0.0001 (14)	0.0059 (15)	−0.0030 (14)
C5	0.0377 (18)	0.0352 (18)	0.0500 (16)	−0.0040 (15)	−0.0016 (14)	−0.0009 (13)
C6	0.0330 (16)	0.0341 (16)	0.0359 (13)	0.0017 (14)	0.0032 (12)	0.0043 (12)
C7	0.0220 (15)	0.0298 (16)	0.0319 (12)	0.0031 (13)	−0.0034 (11)	0.0060 (11)
C8	0.0294 (15)	0.0280 (15)	0.0260 (12)	0.0022 (13)	−0.0010 (11)	0.0037 (10)
C9	0.0253 (14)	0.0341 (16)	0.0330 (13)	−0.0021 (13)	−0.0042 (12)	0.0013 (11)
C10	0.0272 (15)	0.0274 (15)	0.0314 (12)	0.0005 (13)	−0.0018 (11)	0.0003 (11)
C11	0.0357 (16)	0.0324 (16)	0.0322 (13)	−0.0038 (13)	−0.0045 (12)	−0.0007 (11)
C12	0.0410 (17)	0.0361 (17)	0.0285 (12)	−0.0008 (14)	−0.0017 (12)	−0.0026 (12)
C13	0.0365 (17)	0.0337 (17)	0.0363 (14)	0.0002 (15)	0.0047 (12)	−0.0013 (12)
C14	0.0291 (16)	0.0315 (16)	0.0378 (13)	−0.0024 (13)	0.0033 (12)	0.0005 (11)
C15	0.0314 (15)	0.0253 (15)	0.0273 (12)	0.0023 (12)	−0.0010 (12)	0.0025 (11)
C16	0.0247 (15)	0.0283 (16)	0.0341 (13)	0.0011 (12)	−0.0026 (12)	0.0021 (10)
C17	0.0254 (15)	0.0260 (15)	0.0259 (12)	0.0007 (12)	−0.0028 (11)	0.0013 (10)
C18	0.0265 (15)	0.0275 (16)	0.0312 (12)	−0.0005 (12)	−0.0048 (12)	0.0023 (11)
C19	0.0316 (16)	0.0314 (16)	0.0276 (12)	0.0030 (13)	−0.0025 (12)	−0.0038 (11)
C20	0.0312 (16)	0.0368 (17)	0.0285 (13)	0.0060 (14)	0.0018 (12)	0.0003 (11)
C21	0.0461 (18)	0.0429 (18)	0.0340 (13)	−0.0091 (15)	−0.0066 (13)	−0.0066 (12)
N1	0.0315 (13)	0.0331 (13)	0.0342 (11)	0.0031 (11)	0.0053 (10)	0.0021 (9)
N2	0.0246 (12)	0.0333 (14)	0.0325 (11)	0.0033 (11)	0.0005 (10)	0.0042 (9)
O1	0.0350 (12)	0.0380 (11)	0.0311 (9)	−0.0086 (9)	−0.0036 (8)	−0.0065 (8)

Geometric parameters (Å, º) top

C1—C2	1.379 (3)	C11—H11	0.9500
C1—C6	1.389 (3)	C12—C13	1.416 (4)
C1—N1	1.435 (3)	C12—H12	0.9500
C2—C3	1.394 (4)	C13—C14	1.358 (3)
C2—H2	0.9500	C13—H13	0.9500
C3—C4	1.373 (4)	C14—C15	1.415 (3)
C3—H3	0.9500	C14—H14	0.9500
C4—C5	1.378 (4)	C15—C16	1.398 (3)
C4—H4	0.9500	C16—C17	1.393 (3)
C5—C6	1.386 (4)	C16—H16	0.9500
C5—H5	0.9500	C17—C18	1.433 (3)
C6—H6	0.9500	C18—O1	1.359 (3)
C7—C20	1.356 (3)	C18—C19	1.372 (3)
C7—N2	1.420 (3)	C19—C20	1.409 (4)
C7—C8	1.443 (3)	C19—H19	0.9500
C8—C9	1.391 (3)	C20—H20	0.9500
C8—C17	1.441 (4)	C21—O1	1.424 (3)
C9—C10	1.399 (3)	C21—H21A	0.9800
C9—H9	0.9500	C21—H21B	0.9800
C10—C11	1.423 (3)	C21—H21C	0.9800
C10—C15	1.437 (4)	N1—N2	1.264 (3)
C11—C12	1.358 (4)

C2—C1—C6	120.0 (3)	C13—C12—H12	119.7
C2—C1—N1	115.7 (2)	C14—C13—C12	120.6 (2)
C6—C1—N1	124.3 (2)	C14—C13—H13	119.7
C1—C2—C3	120.0 (3)	C12—C13—H13	119.7
C1—C2—H2	120.0	C13—C14—C15	120.7 (3)
C3—C2—H2	120.0	C13—C14—H14	119.7
C4—C3—C2	119.9 (3)	C15—C14—H14	119.7
C4—C3—H3	120.1	C16—C15—C14	122.2 (2)
C2—C3—H3	120.1	C16—C15—C10	118.6 (2)
C3—C4—C5	120.2 (3)	C14—C15—C10	119.2 (2)
C3—C4—H4	119.9	C17—C16—C15	121.8 (2)
C5—C4—H4	119.9	C17—C16—H16	119.1
C4—C5—C6	120.3 (3)	C15—C16—H16	119.1
C4—C5—H5	119.8	C16—C17—C18	121.6 (2)
C6—C5—H5	119.8	C16—C17—C8	119.4 (2)
C5—C6—C1	119.6 (3)	C18—C17—C8	118.9 (2)
C5—C6—H6	120.2	O1—C18—C19	125.5 (2)
C1—C6—H6	120.2	O1—C18—C17	113.4 (2)
C20—C7—N2	125.3 (2)	C19—C18—C17	121.0 (2)
C20—C7—C8	120.1 (2)	C18—C19—C20	119.3 (2)
N2—C7—C8	114.6 (2)	C18—C19—H19	120.4
C9—C8—C17	118.8 (2)	C20—C19—H19	120.4
C9—C8—C7	123.2 (2)	C7—C20—C19	122.5 (2)
C17—C8—C7	117.9 (2)	C7—C20—H20	118.7
C8—C9—C10	121.7 (2)	C19—C20—H20	118.7
C8—C9—H9	119.2	O1—C21—H21A	109.5
C10—C9—H9	119.2	O1—C21—H21B	109.5
C9—C10—C11	122.4 (2)	H21A—C21—H21B	109.5
C9—C10—C15	119.5 (2)	O1—C21—H21C	109.5
C11—C10—C15	118.1 (2)	H21A—C21—H21C	109.5
C12—C11—C10	121.0 (3)	H21B—C21—H21C	109.5
C12—C11—H11	119.5	N2—N1—C1	112.59 (19)
C10—C11—H11	119.5	N1—N2—C7	115.1 (2)
C11—C12—C13	120.5 (2)	C18—O1—C21	117.5 (2)
C11—C12—H12	119.7

C6—C1—C2—C3	−1.3 (4)	C11—C10—C15—C14	0.7 (4)
N1—C1—C2—C3	178.4 (3)	C14—C15—C16—C17	178.1 (2)
C1—C2—C3—C4	0.0 (4)	C10—C15—C16—C17	−0.4 (4)
C2—C3—C4—C5	1.1 (4)	C15—C16—C17—C18	−176.9 (2)
C3—C4—C5—C6	−0.9 (4)	C15—C16—C17—C8	2.5 (4)
C4—C5—C6—C1	−0.5 (4)	C9—C8—C17—C16	−2.4 (3)
C2—C1—C6—C5	1.6 (4)	C7—C8—C17—C16	176.7 (2)
N1—C1—C6—C5	−178.2 (3)	C9—C8—C17—C18	177.0 (2)
C20—C7—C8—C9	−175.8 (3)	C7—C8—C17—C18	−3.9 (3)
N2—C7—C8—C9	3.0 (4)	C16—C17—C18—O1	1.0 (3)
C20—C7—C8—C17	5.1 (4)	C8—C17—C18—O1	−178.4 (2)
N2—C7—C8—C17	−176.1 (2)	C16—C17—C18—C19	179.4 (2)
C17—C8—C9—C10	0.3 (4)	C8—C17—C18—C19	0.0 (4)
C7—C8—C9—C10	−178.8 (2)	O1—C18—C19—C20	−179.1 (2)
C8—C9—C10—C11	−179.3 (3)	C17—C18—C19—C20	2.7 (4)
C8—C9—C10—C15	1.7 (4)	N2—C7—C20—C19	178.8 (2)
C9—C10—C11—C12	−180.0 (3)	C8—C7—C20—C19	−2.6 (4)
C15—C10—C11—C12	−1.0 (4)	C18—C19—C20—C7	−1.5 (4)
C10—C11—C12—C13	0.9 (4)	C2—C1—N1—N2	−173.3 (2)
C11—C12—C13—C14	−0.6 (4)	C6—C1—N1—N2	6.5 (3)
C12—C13—C14—C15	0.4 (4)	C1—N1—N2—C7	179.6 (2)
C13—C14—C15—C16	−179.0 (3)	C20—C7—N2—N1	−13.9 (4)
C13—C14—C15—C10	−0.4 (4)	C8—C7—N2—N1	167.4 (2)
C9—C10—C15—C16	−1.7 (4)	C19—C18—O1—C21	2.2 (4)
C11—C10—C15—C16	179.3 (2)	C17—C18—O1—C21	−179.5 (2)
C9—C10—C15—C14	179.7 (2)

Hydrogen-bond geometry (Å, º) top

Cg1, Cg2 and Cg3 are the centroids of the C1–C6, C7,C8,C17–C20 and C8–C10,C15–C17) rings, respectively.

D—H···A	D—H	H···A	D···A	D—H···A
C21—H21A···Cg1ⁱ	0.98	2.83	3.646 (4)	141
C12—H12···Cg2ⁱⁱ	0.95	2.80	3.681 (4)	154
C11—H11···Cg3ⁱⁱ	0.95	2.83	3.543 (3)	132

Symmetry codes: (i) x+1, y+1, z; (ii) −x+2, y+1/2, −z+1/2.

Experimental details

Crystal data
Chemical formula	C₂₁H₁₆N₂O
M_r	312.36
Crystal system, space group	Orthorhombic, P2₁2₁2₁
Temperature (K)	150
a, b, c (Å)	6.3021 (3), 9.0481 (4), 27.3935 (17)
V (Å³)	1562.03 (14)
Z	4
Radiation type	Mo Kα
µ (mm⁻¹)	0.08
Crystal size (mm)	0.54 × 0.32 × 0.12

Data collection
Diffractometer	STOE IPDS 2T diffractometer
Absorption correction	–
No. of measured, independent and observed [I > 2σ(I)] reflections	12181, 2584, 2096
R_int	0.072
(sin θ/λ)_max (Å⁻¹)	0.586

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.047, 0.086, 1.10
No. of reflections	2584
No. of parameters	218
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.13, −0.15

Computer programs: X-AREA (Stoe & Cie, 2009), X-RED32 (Stoe & Cie, 2009), SHELXS97 (Sheldrick, 2008), PLATON (Spek, 2009) and Mercury (Macrae et al., 2006), SHELXL97 (Sheldrick, 2008), PLATON (Spek, 2009) and publCIF (Westrip, 2010).

Hydrogen-bond geometry (Å, º) top

Cg1, Cg2 and Cg3 are the centroids of the C1–C6, C7,C8,C17–C20 and C8–C10,C15–C17) rings, respectively.

D—H···A	D—H	H···A	D···A	D—H···A
C21—H21A···Cg1ⁱ	0.98	2.83	3.646 (4)	141
C12—H12···Cg2ⁱⁱ	0.95	2.80	3.681 (4)	154
C11—H11···Cg3ⁱⁱ	0.95	2.83	3.543 (3)	132

Symmetry codes: (i) x+1, y+1, z; (ii) −x+2, y+1/2, −z+1/2.

Acknowledgements

The authors thank the Bulgarian National Science Fund (Project TK–X-1716), the SCOPES program of the Swiss National Science Foundation and FriMat for generous funding. They also thank Professor Helen Stoekli-Evans for valuable advice and assistance.

References

Antonov, L., Deneva, V., Simeonov, S., Kurteva, V., Nedeltcheva, D. & Wirz, J. (2009). Angew. Chem. Int. Ed. 48, 7875–7878. CrossRef CAS Google Scholar
Antonov, L. M., Kurteva, V. B., Simeonov, S. P., Deneva, V. V., Crochet, A. & Fromm, K. (2010). Tetrahedron, 66, 4292–4297. CrossRef CAS Google Scholar
Kelemen, J. (1981). J. Dyes Pigm. 2, 73–91. CrossRef CAS Google Scholar
Macrae, C. F., Edgington, P. R., McCabe, P., Pidcock, E., Shields, G. P., Taylor, R., Towler, M. & van de Streek, J. (2006). J. Appl. Cryst. 39, 453–457. Web of Science CrossRef CAS IUCr Journals Google Scholar
Nedeltcheva, D., Antonov, L., Lycka, A., Damyanova, B. & Popov, S. (2009). Curr. Org. Chem. 13, 217–240. CrossRef CAS Google Scholar
Nedeltcheva, D., Kurteva, V. & Topalova, I. (2010). Rapid Commun. Mass Spectrom. 24, 714–720. Web of Science CrossRef CAS PubMed Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Spek, A. L. (2009). Acta Cryst. D65, 148–155. Web of Science CrossRef CAS IUCr Journals Google Scholar
Stoe & Cie (2009). X-AREA and X-RED32. Stoe & Cie GmbH, Darmstadt, Germany. Google Scholar
Westrip, S. P. (2010). J. Appl. Cryst. 43, 920–925. Web of Science CrossRef CAS IUCr Journals Google Scholar

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Volume 67| Part 4| April 2011| Page o993

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