3,10-Dichloro-5,12-dihydro­quino[2,3-b]acridine-7,14-dione

The title compound, C₂₀H₁₀Cl₂N₂O₂, is one of the quinacridone derivatives known as red pigments. The mol­ecule has inversion symmetry. The quinacridone mol­ecules are connected by N—H...O hydrogen bonds along the [10] direction to form a ribbon structure.

Key indicators

• Single-crystal X-ray study
• T = 93 K
• Mean [sigma](C-C) = 0.004 Å
• R factor = 0.057
• wR factor = 0.172
• Data-to-parameter ratio = 10.5

checkCIF/PLATON results

No syntax errors found



Alert level A
PLAT029_ALERT_3_A _diffrn_measured_fraction_theta_full Low .......       0.93

Author Response: A two-dimensional detector (IP) was used in combination with Cu as radiation.

Alert level C
REFLT03_ALERT_3_C  Reflection count < 95% complete
           From the CIF: _diffrn_reflns_theta_max           68.22
           From the CIF: _diffrn_reflns_theta_full          68.22
           From the CIF: _reflns_number_total               1254
           TEST2: Reflns within _diffrn_reflns_theta_max
           Count of symmetry unique reflns         1347
           Completeness (_total/calc)             93.10%
PLAT022_ALERT_3_C Ratio Unique / Expected Reflections too Low ....       0.93

   1 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
   2 ALERT level C = Check and explain
   0 ALERT level G = General alerts; check

   0 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   0 ALERT type 2 Indicator that the structure model may be wrong or deficient
   3 ALERT type 3 Indicator that the structure quality may be low
   0 ALERT type 4 Improvement, methodology, query or suggestion

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S1. Comment

The title compound, (I), abbreviated to 3,10-DClQA, is one of the quinacridone derivatives on the market which are known as red pigments (Pigment Red 209; Herbst & Hunger, 1997) and typically characterized by N—H···O intermolecular hydrogen bonds. 3,10-DClQA exhibits a yellowish–red shade in the solid state, while the colour is bluish–red in 2,9-dichloroquinacridone (2,9-DClQA; Senju et al., 2005), although the solution spectra of both compounds are practically the same. This suggests that intermolecular interactions in the solid state are responsible for the difference in colour. In this connection, the structure analysis of (I) has been undertaken.

Fig. 1 shows a plot of the molecule of (I). The molecule has inversion symmetry. The quinacridine skeleton is entirely planar, as indicated by a small deviation [For which atom?] of about 0.02 Å from the least-squares plane of the rings defined by atoms C1–C10 and N1. However, the carbonyl O atom deviates by 0.140 (3) Å from the least-squares plane of the ring system towards the NH group of the neighbouring molecule, enabling the formation of an N—H···O intermolecular hydrogen bond (Table 2). This tendency was also found in 2,9-DClQA (Senju et al., 2005).

As shown in Fig. 2(a), there are chains of N—H···O intermolecular hydrogen bonds along the [110] direction. One molecule is bonded to two neighbouring molecules through four hydrogen bonds. There is a small step of about 0.55 Å between the two molecular planes of the hydrogen-bonded molecules, as shown in Fig. 2(b). In commercial hydrogen-bonded pigments, there are normally no steps between molecules (Mizuguchi et al., 1992, 1993) and this is a good criterion for strong hydrogen bonds. The existence of the step in (I) indicates a somewhat weaker hydrogen bond. This kind of step has also been found in the following pigments: 2,9-dimethylquinacridone (Mizuguchi et al., 2002), modifications I and II of dithioketopyrrolopyrrole (Mizuguchi et al., 1990), thiazine-indigo (Senju & Mizuguchi, 2003) and 2,9-DClQA (Senju et al., 2005). In the present investigation, no significant difference in structure has been observed between 3,10-DClQA [(I)] and 2,9-DClQA, contrary to our expectation. Further investigation is now in progress in order to elucidate the origin of the difference in colour in the solid state.

S2. Experimental

Compound (I) was purchased form Dainippon Ink & Chemicals Inc. and purified twice by sublimation using a two-zone furnace (Mizuguchi, 1981). Single crystals were grown from the vapour phase in a closed system at about 743 K. After 24 h, a number of red platelet [Needle below?] single crystals were obtained.

S3. Refinement

The H atom of the NH group was found in a difference density map and fixed during the refinement [U_iso(H) = 0.021 Ų]. All other H atoms were positioned geometrically and constrained to ride on their parent atoms, with C—H = 0.95 Å and U_iso(H) = 1.2U_eq(C).

Computing details

Data collection: PROCESS-AUTO (Rigaku, 1998); cell refinement: PROCESS-AUTO; data reduction: CrystalStructure (Rigaku/MSC & Rigaku, 2005); program(s) used to solve structure: SHELXS86 (Sheldrick, 1986); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEPIII (Burnett & Johnson, 1996); software used to prepare material for publication: CrystalStructure.

Figures

	Fig. 1. A view of the molecular structure of (I), showing 50% probability displacement ellipsoids. Unlabelled atoms are related by the symmetry code (−x, 1 − y, 1 − z).
	Fig. 2. (a) Top view of the two hydrogen-bonded molecules. The dotted lines denote hydrogen bonds. [Symmetry code: (i) 1 + x, y − 1, z.] (b) Side view of the two hydrogen-bonded molecules, showing a small step of ca 0.55 Å between the molecular planes.

3,10-Dichloro-5,12-dihydroquino[2,3-b]acridine-7,14-dione

Crystal data

C20H10Cl2N2O2	Z = 1
Mr = 381.20	F(000) = 194.00
Triclinic, P1	Dx = 1.732 Mg m^−3
Hall symbol: -P 1	Cu Kα radiation, λ = 1.5418 Å
a = 3.7635 (13) Å	Cell parameters from 2796 reflections
b = 5.853 (2) Å	θ = 10.7–136.4°
c = 16.746 (6) Å	µ = 4.17 mm^−1
α = 85.20 (2)°	T = 93 K
β = 83.79 (2)°	Needle, red
γ = 89.32 (2)°	0.10 × 0.05 × 0.02 mm
V = 365.4 (2) Å^3

Data collection

Rigaku R-AXIS RAPID imaging-plate diffractometer	1103 reflections with F^2 > 2σ(F^2)
Detector resolution: 10.00 pixels mm^-1	Rint = 0.046
72 frames, Δω = 10° scans	θmax = 68.2°
Absorption correction: multi-scan (ABSCOR; Higashi, 1995)	h = −4→4
Tmin = 0.681, Tmax = 0.921	k = −7→6
3173 measured reflections	l = −20→20
1254 independent reflections

Refinement

Refinement on F^2	H-atom parameters constrained
R[F^2 > 2σ(F^2)] = 0.057	w = 1/[σ^2(Fo^2) + (0.1114P)^2 + 0.1855P] where P = (Fo^2 + 2Fc^2)/3
wR(F^2) = 0.172	(Δ/σ)max < 0.001
S = 1.13	Δρmax = 0.60 e Å^−3
1254 reflections	Δρmin = −0.38 e Å^−3
119 parameters

Special details

Geometry. All standard uncertainties (s.u.s) 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 and angles; correlations between s.u.s in cell parameters are only used when they are defined by crystal symmetry.

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
Cl1	0.3744 (2)	0.20197 (14)	0.06111 (4)	0.0274 (4)
O1	−0.3270 (6)	0.8901 (4)	0.33978 (12)	0.0173 (6)
N1	0.2179 (7)	0.2827 (5)	0.36148 (15)	0.0160 (6)
C1	−0.0590 (8)	0.6790 (6)	0.19657 (18)	0.0164 (7)
H1	−0.1733	0.8234	0.1886	0.020*
C2	0.0589 (8)	0.5644 (6)	0.13156 (19)	0.0200 (7)
H2	0.0297	0.6276	0.0785	0.024*
C3	0.2245 (8)	0.3509 (6)	0.14436 (18)	0.0189 (7)
C4	0.2763 (8)	0.2534 (6)	0.21913 (18)	0.0175 (7)
H4	0.3878	0.1076	0.2259	0.021*
C5	0.1585 (8)	0.3764 (5)	0.28627 (18)	0.0164 (7)
C6	−0.0155 (8)	0.5880 (5)	0.27631 (18)	0.0153 (7)
C7	−0.1521 (8)	0.7105 (6)	0.34532 (18)	0.0167 (7)
C8	−0.0715 (8)	0.6025 (5)	0.42458 (18)	0.0150 (7)
C9	0.1095 (8)	0.3899 (5)	0.43037 (18)	0.0147 (7)
C10	−0.1758 (8)	0.7107 (6)	0.49436 (19)	0.0166 (7)
H10	−0.2938	0.8549	0.4906	0.020*
H1N	0.3272	0.1676	0.3677	0.021*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cl1	0.0322 (6)	0.0306 (6)	0.0200 (5)	0.0049 (4)	−0.0016 (3)	−0.0067 (3)
O1	0.0191 (11)	0.0152 (13)	0.0175 (11)	0.0045 (10)	−0.0031 (9)	−0.0003 (8)
N1	0.0177 (13)	0.0149 (14)	0.0158 (14)	0.0034 (11)	−0.0027 (10)	−0.0023 (10)
C1	0.0142 (15)	0.0175 (17)	0.0171 (15)	−0.0004 (13)	−0.0028 (12)	0.0017 (12)
C2	0.0183 (16)	0.0256 (19)	0.0158 (16)	−0.0039 (14)	−0.0035 (12)	0.0025 (12)
C3	0.0147 (15)	0.0249 (19)	0.0178 (16)	−0.0014 (14)	−0.0014 (12)	−0.0056 (13)
C4	0.0151 (15)	0.0183 (17)	0.0192 (16)	0.0016 (14)	−0.0009 (12)	−0.0037 (12)
C5	0.0133 (15)	0.0187 (18)	0.0173 (15)	−0.0028 (13)	−0.0020 (12)	−0.0013 (12)
C6	0.0126 (15)	0.0149 (17)	0.0186 (17)	0.0000 (13)	−0.0024 (12)	−0.0024 (12)
C7	0.0131 (15)	0.0188 (18)	0.0185 (16)	−0.0053 (13)	−0.0017 (12)	−0.0024 (12)
C8	0.0111 (15)	0.0142 (17)	0.0202 (16)	−0.0021 (13)	−0.0024 (12)	−0.0021 (12)
C9	0.0111 (14)	0.0134 (17)	0.0200 (16)	0.0000 (13)	−0.0018 (12)	−0.0031 (12)
C10	0.0147 (15)	0.0144 (16)	0.0214 (17)	−0.0015 (13)	−0.0036 (12)	−0.0028 (12)

Geometric parameters (Å, º)

Cl1—C3	1.744 (3)	C3—C4	1.365 (4)
O1—C7	1.236 (4)	C4—C5	1.414 (4)
N1—C5	1.371 (4)	C4—H4	0.9500
N1—C9	1.380 (4)	C5—C6	1.400 (5)
N1—H1N	0.7904	C6—C7	1.454 (4)
C1—C2	1.357 (5)	C7—C8	1.482 (4)
C1—C6	1.421 (4)	C8—C10	1.392 (4)
C1—H1	0.9500	C8—C9	1.413 (5)
C2—C3	1.400 (5)	C9—C10^i	1.392 (5)
C2—H2	0.9500	C10—H10	0.9500
C5—N1—C9	122.2 (3)	C6—C5—C4	120.9 (3)
C5—N1—H1N	121.8	C5—C6—C1	118.0 (3)
C9—N1—H1N	115.9	C5—C6—C7	121.2 (3)
C2—C1—C6	121.6 (3)	C1—C6—C7	120.7 (3)
C2—C1—H1	119.2	O1—C7—C6	123.5 (3)
C6—C1—H1	119.2	O1—C7—C8	121.4 (3)
C1—C2—C3	118.5 (3)	C6—C7—C8	115.1 (3)
C1—C2—H2	120.7	C10—C8—C9	119.4 (3)
C3—C2—H2	120.7	C10—C8—C7	119.9 (3)
C4—C3—C2	123.1 (3)	C9—C8—C7	120.7 (3)
C4—C3—Cl1	118.1 (3)	N1—C9—C10^i	120.4 (3)
C2—C3—Cl1	118.8 (2)	N1—C9—C8	119.8 (3)
C3—C4—C5	117.8 (3)	C10^i—C9—C8	119.7 (3)
C3—C4—H4	121.1	C9^i—C10—C8	120.9 (3)
C5—C4—H4	121.1	C9^i—C10—H10	119.6
N1—C5—C6	120.8 (3)	C8—C10—H10	119.6
N1—C5—C4	118.3 (3)

Symmetry code: (i) −x, −y+1, −z+1.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1N···O1^ii	0.79	2.12	2.873 (4)	159

Symmetry code: (ii) x+1, y−1, z.