Reinvestigation of 5,12-di­hydro-5,12-di­methyl­quino­[2,3-b]­acridine-7,4-dione

The structure of the title compound, C₂₂H₁₆N₂O₂ commonly called trans-N,N'-di­methyl­quinacridone, has been reinvestigated at 223 K [the original determination was by Zavodnik, Chetkina & Val'kova (1981). Zh. Struckt. Khim. 22, 188-190; and also by Ohmasa & Susse (1976). Naturwissenschaften, 63, 387-388]. The structure, in space group P2₁/c, is basically in good agreement with those reported earlier, but is determined with higher precision. The entirely planar centrosymmetric mol­ecules are arranged with major overlap of the acridine skeleton along the stacking axis.

Key indicators

• Single-crystal X-ray study
• T = 223 K
• Mean [sigma](C-C) = 0.002 Å
• R factor = 0.044
• wR factor = 0.126
• Data-to-parameter ratio = 14.8

checkCIF results

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ADDSYM reports no extra symmetry


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CRYSS_02  Alert B The value of _exptl_crystal_size_max is > 1.0
 Maximum crystal size given =   1.180


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S1. Comment

The crystal structure of the title compound, (I), was reported not only by Zavodnik et al. (1981) but also by Ohmasa & Susse (1976). The present paper provides some additional results at 223 K with higher precision. We have been conducting a series of investigations on the correlation between the color in the solid state and crystal structures in quinacridone pigments. Special attention has been focused on the effect of N—H···O intermolecular hydrogen bonds on the color as well as on the stability of the compounds. For this reason, we have tackled three representative quinacridone compounds with various hydrogen bonds, namely unsubstituted quinacridone with two NH groups (four hydrogen bonds per molecule; Mizuguchi, Sasaki & Tojo, 2002), the monomethyl derivative with one NH group (two hydrogen bonds per molecule; Zambounis & Mizuguchi, 1996; Mizuguchi & Senju, 2002) and the dimethyl derivative with no NH group (i.e. the title compound; no hydrogen bonds per molecule). Compound (I) has also recently attracted attention as a doping material for electroluminescence applications (Shi & Tang, 1997). In this connection, the present reinvestigation has been carried out.

Our results are basically in good agreement with those of Zavodnik et al. (1981). The molecule is entirely planar, as shown in Fig. 1, and belongs to the point group of C_i. The molecules are stacked with major overlap of the acridine skeleton along the a axis. Our result is R_gt = 0.044 for 1747 reflections (reflection/parameter ratio = 14.8), while R = 0.047 for 532 reflections with I greater than 3σ in Zavodnik's study. Since the measurement temperatures were different (at 223 K in our case but room temperature in Zavodnik's study), direct comparison of the structural parameters seems rather difficult. However, the s.u. values of the bond parameters have been improved significantly in the present investigation: the values in (I) are 0.002 Å for the bond lengths C—C, C—N and C—O, whereas the values were in the range 0.005–0.007 Å in Zavodnik's study. As for the bond angles C—C—C, C—C—N, C—N—C and C—C—O, our s.u. values are 0.1°, while a range of 0.4–0.6° was reported for Zavodnik's study. Our results also include displacement displacement parameters for non-H atoms.

S2. Experimental

The title compound, (I), was prepared according to a method described in the literature (Zambounis et al., 1996). The sample was purified by sublimation at about 623 K, using a two zone furnace (Mizuguchi, 1981). Single crystals of (I) were then grown from a solution in dimethylformamide. The present material is quite fragile, so that cutting of the crystal using a safety razor impairs the quality of the crystal. For this reason, we used the single-crystal as grown.

S3. Refinement

All H atoms were positioned by calculation but were not refined. Special caution was taken to the position of H atoms of the methyl group on the basis of the difference Fourier maps.

Computing details

Data collection: PROCESS-AUTO (Rigaku, 1998); cell refinement: PROCESS-AUTO; data reduction: TEXSAN (Molecular Structure Corporation, 2001); program(s) used to solve structure: SIR88 (Burla et al., 1989); program(s) used to refine structure: TEXSAN; molecular graphics: ORTEPIII (Burnett & Johnson, 1996); software used to prepare material for publication: TEXSAN.

Figures

Fig. 1. A view of the molecular structure of (I), showing 50% displacement ellipsoids for the non-H atoms.

(I)

Crystal data

C22H16N2O2	F(000) = 356
Mr = 340.38	Dx = 1.444 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.7107 Å
a = 4.928 (3) Å	Cell parameters from 25 reflections
b = 11.103 (3) Å	θ = 14.7–14.9°
c = 14.462 (2) Å	µ = 0.09 mm^−1
β = 98.39 (2)°	T = 223 K
V = 782.8 (4) Å^3	Platelet, red
Z = 2	1.18 × 0.17 × 0.07 mm

Data collection

Rigaku AFC-7R diffractometer	Rint = 0.013
ω–2θ scans	θmax = 27.5°
Absorption correction: ψ scan (North et al., 1968)	h = −6→0
Tmin = 0.947, Tmax = 0.998	k = 0→14
2107 measured reflections	l = −18→18
1797 independent reflections	3 standard reflections every 150 reflections
1349 reflections with F^2 > 2σ(F^2)	intensity decay: 1.3%

Refinement

Refinement on F^2	H-atom parameters not refined
R[F^2 > 2σ(F^2)] = 0.044	w = 1/[σ^2(Fo^2) + {0.05[Max(Fo^2,0) + 2Fc^2]/3}^2]
wR(F^2) = 0.126	(Δ/σ)max = 0.001
S = 1.59	Δρmax = 0.21 e Å^−3
1747 reflections	Δρmin = −0.17 e Å^−3
118 parameters

Special details

Refinement. Refinement using reflections with F² > −3.0 σ(F²). The weighted R-factor (wR) and goodness of fit (S) are based on F². R-factor (gt) are based on F. The threshold expression of F² > 2.0 σ(F²) is used only for calculating R-factor (gt).

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
O1	0.3115 (3)	0.7365 (1)	−0.12444 (7)	0.0480 (3)
N1	0.4143 (2)	0.58724 (9)	0.13854 (7)	0.0237 (2)
C1	0.7310 (3)	0.8262 (1)	0.01053 (10)	0.0338 (3)
C2	0.9407 (3)	0.8648 (1)	0.0773 (1)	0.0358 (3)
C3	0.9722 (3)	0.8110 (1)	0.16559 (9)	0.0317 (3)
C4	0.7988 (3)	0.7214 (1)	0.18705 (8)	0.0273 (3)
C5	0.5848 (2)	0.6794 (1)	0.11876 (8)	0.0226 (3)
C6	0.5536 (2)	0.7332 (1)	0.02929 (8)	0.0260 (3)
C7	0.3424 (3)	0.6922 (1)	−0.04536 (9)	0.0296 (3)
C8	0.1689 (2)	0.5933 (1)	−0.02056 (8)	0.0231 (3)
C9	0.2095 (2)	0.5436 (1)	0.07058 (7)	0.0217 (3)
C10	0.0369 (2)	0.4500 (1)	0.08876 (8)	0.0241 (3)
C11	0.4437 (3)	0.5355 (1)	0.23233 (9)	0.0384 (4)
H1	0.7050	0.8634	−0.0492	0.0405*
H2	1.0619	0.9267	0.0637	0.0425*
H3	1.1173	0.8367	0.2120	0.0377*
H4	0.8226	0.6877	0.2480	0.0327*
H5	0.0570	0.4141	0.1491	0.0287*
H6	0.5907	0.5734	0.2710	0.0458*
H7	0.2784	0.5468	0.2578	0.0458*
H8	0.4802	0.4514	0.2289	0.0458*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.0575 (7)	0.0550 (7)	0.0267 (5)	−0.0296 (6)	−0.0096 (4)	0.0124 (5)
N1	0.0256 (5)	0.0249 (5)	0.0189 (4)	−0.0038 (4)	−0.0025 (3)	−0.0004 (4)
C1	0.0369 (7)	0.0327 (7)	0.0303 (6)	−0.0106 (5)	−0.0002 (5)	0.0024 (5)
C2	0.0362 (7)	0.0331 (7)	0.0368 (7)	−0.0132 (5)	0.0006 (5)	−0.0028 (5)
C3	0.0291 (6)	0.0320 (6)	0.0319 (6)	−0.0067 (5)	−0.0020 (5)	−0.0083 (5)
C4	0.0268 (6)	0.0290 (6)	0.0245 (5)	−0.0020 (4)	−0.0019 (4)	−0.0054 (4)
C5	0.0220 (5)	0.0218 (5)	0.0230 (5)	−0.0002 (4)	−0.0003 (4)	−0.0040 (4)
C6	0.0270 (6)	0.0261 (6)	0.0238 (5)	−0.0046 (5)	0.0000 (4)	−0.0011 (4)
C7	0.0318 (6)	0.0324 (6)	0.0233 (5)	−0.0088 (5)	−0.0008 (5)	0.0019 (5)
C8	0.0238 (5)	0.0243 (5)	0.0204 (5)	−0.0027 (4)	0.0008 (4)	−0.0015 (4)
C9	0.0220 (5)	0.0222 (5)	0.0197 (5)	−0.0001 (4)	−0.0012 (4)	−0.0030 (4)
C10	0.0255 (5)	0.0260 (6)	0.0197 (5)	−0.0023 (4)	−0.0008 (4)	−0.0003 (4)
C11	0.0460 (8)	0.0417 (8)	0.0231 (6)	−0.0140 (6)	−0.0092 (5)	0.0060 (5)

Geometric parameters (Å, º)

O1—C7	1.234 (2)	C4—H4	0.949
N1—C5	1.380 (2)	C5—C6	1.413 (2)
N1—C9	1.389 (1)	C6—C7	1.459 (2)
N1—C11	1.461 (2)	C7—C8	1.468 (2)
C1—C2	1.376 (2)	C8—C9	1.416 (2)
C1—C6	1.405 (2)	C8—C10^i	1.393 (2)
C1—H1	0.950	C9—C10	1.392 (2)
C2—C3	1.398 (2)	C10—H5	0.951
C2—H2	0.949	C11—H6	0.947
C3—C4	1.376 (2)	C11—H7	0.950
C3—H3	0.950	C11—H8	0.953
C4—C5	1.414 (2)
O1···C3^ii	3.288 (2)	C2···C8^vi	3.581 (2)
O1···C11^iii	3.394 (2)	C3···C5^vi	3.507 (2)
O1···C4^ii	3.468 (2)	C3···C9^vi	3.541 (2)
N1···C3^iv	3.364 (2)	C4···C9^vi	3.439 (2)
N1···C8^v	3.489 (2)	C5···C10^vi	3.453 (2)
N1···C4^iv	3.540 (2)	C5···C9^vi	3.587 (2)
N1···C10^vi	3.592 (2)	C6···C10^v	3.482 (2)
C1···C8^vi	3.439 (2)	C6···C8^vi	3.572 (2)
C1···C7^vi	3.557 (2)	C7···C9^v	3.478 (2)
C2···C7^vi	3.430 (2)	C7···C10^v	3.578 (2)
C2···C6^vi	3.515 (2)	C8···C9^v	3.586 (2)
C5—N1—C9	120.89 (10)	C5—C6—C7	121.1 (1)
C5—N1—C11	120.21 (10)	O1—C7—C6	122.7 (1)
C9—N1—C11	118.9 (1)	O1—C7—C8	121.8 (1)
C2—C1—C6	121.2 (1)	C6—C7—C8	115.5 (1)
C2—C1—H1	119.4	C7—C8—C9	120.7 (1)
C6—C1—H1	119.4	C7—C8—C10^i	118.3 (1)
C1—C2—C3	118.7 (1)	C9—C8—C10^i	120.9 (1)
C1—C2—H2	120.8	N1—C9—C8	120.8 (1)
C3—C2—H2	120.6	N1—C9—C10	121.9 (1)
C2—C3—C4	121.7 (1)	C8—C9—C10	117.4 (1)
C2—C3—H3	119.2	C8^i—C10—C9	121.7 (1)
C4—C3—H3	119.1	C8^i—C10—H5	118.2
C3—C4—C5	120.3 (1)	C9—C10—H5	120.1
C3—C4—H4	119.8	N1—C11—H6	109.7
C5—C4—H4	119.8	N1—C11—H7	109.5
N1—C5—C4	120.9 (1)	N1—C11—H8	109.3
N1—C5—C6	120.98 (10)	H6—C11—H7	109.7
C4—C5—C6	118.1 (1)	H6—C11—H8	109.4
C1—C6—C5	120.0 (1)	H7—C11—H8	109.2
C1—C6—C7	118.9 (1)

Symmetry codes: (i) −x, −y+1, −z; (ii) x−1, −y+3/2, z−1/2; (iii) x, −y+3/2, z−1/2; (iv) x−1, y, z; (v) −x+1, −y+1, −z; (vi) x+1, y, z.