3,3′-(Quinoxaline-2,3-diyldimethyl­ene)bis­(penta­ne-2,4-dione)

In the title compound, C₂₀H₂₄N₂O₄, the quinoxalinedi­yl bridging group separates two β-diketone groups, which are found to be in a pseudo-trans configuration. The major contributing packing forces are π–π inter­actions and weak but influential C—H...O hydrogen bonds.

Key indicators

• Single-crystal X-ray study
• T = 100 K
• Mean [sigma](C-C) = 0.002 Å
• R factor = 0.044
• wR factor = 0.116
• Data-to-parameter ratio = 17.3

checkCIF/PLATON results

No syntax errors found



Alert level G
REFLT03_ALERT_1_G ALERT: Expected hkl max differ from CIF values
           From the CIF: _diffrn_reflns_theta_max           28.28
           From the CIF: _reflns_number_total               4138
           From the CIF: _diffrn_reflns_limit_ max hkl   28.    9.   29.
           From the CIF: _diffrn_reflns_limit_ min hkl  -28.   -9.  -28.
           TEST1: Expected hkl limits for theta max
           Calculated maximum hkl   29.    9.   31.
           Calculated minimum hkl  -29.   -9.  -31.

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

   1 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
   0 ALERT type 3 Indicator that the structure quality may be low
   0 ALERT type 4 Improvement, methodology, query or suggestion

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Computing details

Data collection: SMART (Bruker, 2001); cell refinement: SAINT (Bruker, 2002); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: X-SEED (Atwood & Barbour, 2003; Barbour, 2001); software used to prepare material for publication: X-SEED.

3,3'-(Quinoxaline-2,3-diyldimethylene)bis(pentane-2,4-dione)

Crystal data

C20H22N2O4	F(000) = 1504
Mr = 354.41	Dx = 1.313 Mg m^−3
Monoclinic, C2/c	Melting point = 392–394 K
Hall symbol: -C2yc	Mo Kα radiation, λ = 0.71073 Å
a = 22.3830 (17) Å	Cell parameters from 3362 reflections
b = 7.4043 (6) Å	θ = 2.9–27.8°
c = 23.3675 (18) Å	µ = 0.09 mm^−1
β = 112.224 (1)°	T = 100 K
V = 3585.0 (5) Å^3	Needle, colourless
Z = 8	0.18 × 0.08 × 0.07 mm

Data collection

Bruker APEX CCD area-detector diffractometer	4138 independent reflections
Radiation source: fine-focus sealed tube	3320 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.023
ω scans	θmax = 28.3°, θmin = 1.9°
Absorption correction: multi-scan (SADABS; Sheldrick, 1997)	h = −28→28
Tmin = 0.944, Tmax = 0.994	k = −9→9
10931 measured reflections	l = −28→29

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)] = 0.044	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.117	H-atom parameters constrained
S = 1.00	w = 1/[σ^2(Fo^2) + (0.0706P)^2 + 1.0823P] where P = (Fo^2 + 2Fc^2)/3
4138 reflections	(Δ/σ)max = 0.008
239 parameters	Δρmax = 0.37 e Å^−3
0 restraints	Δρmin = −0.33 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.

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
O1	0.35985 (5)	0.15049 (13)	0.09655 (5)	0.0267 (2)
C1	0.56750 (6)	0.24858 (18)	0.08042 (6)	0.0195 (3)
H1	0.5726	0.2889	0.1206	0.023*
O2	0.25819 (5)	0.45129 (14)	0.08235 (5)	0.0305 (3)
C2	0.61806 (6)	0.16832 (19)	0.07058 (6)	0.0215 (3)
H2	0.6583	0.1538	0.1041	0.026*
O3	0.26564 (6)	0.2888 (2)	−0.28683 (5)	0.0517 (4)
C3	0.61083 (6)	0.10710 (18)	0.01106 (6)	0.0212 (3)
H3	0.6458	0.0484	0.0052	0.025*
O4	0.39903 (5)	0.46424 (15)	−0.20184 (5)	0.0289 (2)
C4	0.55380 (6)	0.13156 (18)	−0.03825 (6)	0.0199 (3)
H4	0.5496	0.0922	−0.0783	0.024*
C5	0.50108 (6)	0.21551 (17)	−0.02948 (6)	0.0171 (3)
C6	0.50782 (6)	0.27091 (17)	0.03049 (6)	0.0170 (3)
N7	0.44422 (5)	0.24078 (15)	−0.07877 (5)	0.0175 (2)
C8	0.39593 (6)	0.31242 (17)	−0.06780 (6)	0.0164 (3)
C9	0.40179 (6)	0.35863 (17)	−0.00612 (6)	0.0163 (3)
N10	0.45637 (5)	0.34151 (14)	0.04123 (5)	0.0173 (2)
C11	0.34396 (6)	0.42339 (18)	0.00645 (6)	0.0177 (3)
H11A	0.3101	0.3292	−0.0065	0.021*
H11B	0.3262	0.5333	−0.0183	0.021*
C12	0.36193 (6)	0.46578 (17)	0.07510 (6)	0.0170 (3)
H12	0.3977	0.5565	0.0885	0.020*
C13	0.38377 (6)	0.29597 (18)	0.11495 (6)	0.0197 (3)
C14	0.43420 (7)	0.3232 (2)	0.17849 (7)	0.0285 (3)
H14A	0.4440	0.2072	0.2003	0.043*
H14C	0.4181	0.4081	0.2015	0.043*
H14B	0.4735	0.3720	0.1752	0.043*
C15	0.30264 (6)	0.54624 (18)	0.08375 (6)	0.0186 (3)
C16	0.30234 (8)	0.7457 (2)	0.09205 (8)	0.0314 (4)
H15A	0.3043	0.8059	0.0554	0.047*
H15C	0.3399	0.7810	0.1286	0.047*
H15B	0.2627	0.7815	0.0976	0.047*
C17	0.33375 (6)	0.34427 (18)	−0.12202 (6)	0.0189 (3)
H17A	0.3283	0.4755	−0.1305	0.023*
H17B	0.2973	0.3023	−0.1114	0.023*
C18	0.33176 (6)	0.24634 (19)	−0.18046 (6)	0.0201 (3)
H18	0.3375	0.1144	−0.1707	0.024*
C19	0.26731 (7)	0.2704 (2)	−0.23483 (6)	0.0242 (3)
C20	0.20685 (7)	0.2688 (2)	−0.22213 (7)	0.0313 (4)
H20B	0.2046	0.3788	−0.1997	0.047*
H20A	0.2068	0.1629	−0.1970	0.047*
H20C	0.1695	0.2635	−0.2613	0.047*
C21	0.38618 (7)	0.3056 (2)	−0.20099 (6)	0.0237 (3)
C22	0.41942 (8)	0.1610 (2)	−0.22294 (8)	0.0363 (4)
H22A	0.3886	0.1061	−0.2607	0.054*
H22C	0.4361	0.0683	−0.1909	0.054*
H22B	0.4552	0.2142	−0.2315	0.054*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.0325 (6)	0.0203 (5)	0.0290 (5)	−0.0003 (4)	0.0136 (5)	0.0017 (4)
C1	0.0195 (6)	0.0194 (6)	0.0186 (6)	−0.0027 (5)	0.0063 (5)	0.0011 (5)
O2	0.0203 (5)	0.0276 (6)	0.0460 (7)	−0.0017 (4)	0.0154 (5)	−0.0009 (5)
C2	0.0165 (6)	0.0212 (7)	0.0248 (7)	−0.0011 (5)	0.0057 (5)	0.0050 (5)
O3	0.0303 (6)	0.1045 (12)	0.0181 (6)	0.0002 (7)	0.0066 (5)	0.0041 (6)
C3	0.0198 (7)	0.0171 (6)	0.0301 (7)	0.0009 (5)	0.0133 (6)	0.0041 (5)
O4	0.0300 (6)	0.0346 (6)	0.0243 (5)	−0.0024 (4)	0.0129 (4)	0.0054 (4)
C4	0.0223 (7)	0.0181 (6)	0.0227 (7)	−0.0022 (5)	0.0124 (6)	0.0004 (5)
C5	0.0171 (6)	0.0151 (6)	0.0202 (6)	−0.0026 (5)	0.0082 (5)	0.0012 (5)
C6	0.0174 (6)	0.0148 (6)	0.0193 (6)	−0.0024 (5)	0.0076 (5)	0.0013 (5)
N7	0.0187 (5)	0.0172 (5)	0.0178 (5)	−0.0017 (4)	0.0083 (4)	0.0015 (4)
C8	0.0170 (6)	0.0153 (6)	0.0173 (6)	−0.0029 (5)	0.0067 (5)	0.0009 (5)
C9	0.0171 (6)	0.0146 (6)	0.0177 (6)	−0.0025 (5)	0.0072 (5)	0.0009 (5)
N10	0.0179 (5)	0.0165 (5)	0.0177 (5)	−0.0012 (4)	0.0070 (4)	0.0008 (4)
C11	0.0165 (6)	0.0195 (6)	0.0166 (6)	0.0005 (5)	0.0058 (5)	0.0009 (5)
C12	0.0159 (6)	0.0176 (6)	0.0176 (6)	−0.0004 (5)	0.0065 (5)	−0.0009 (5)
C13	0.0188 (6)	0.0234 (7)	0.0196 (6)	0.0037 (5)	0.0103 (5)	0.0008 (5)
C14	0.0269 (8)	0.0364 (8)	0.0196 (7)	0.0049 (6)	0.0060 (6)	0.0030 (6)
C15	0.0188 (6)	0.0232 (7)	0.0136 (6)	0.0015 (5)	0.0061 (5)	0.0019 (5)
C16	0.0363 (9)	0.0241 (7)	0.0447 (9)	0.0022 (6)	0.0277 (8)	−0.0021 (7)
C17	0.0176 (6)	0.0219 (7)	0.0172 (6)	−0.0011 (5)	0.0065 (5)	−0.0008 (5)
C18	0.0198 (7)	0.0232 (7)	0.0166 (6)	−0.0002 (5)	0.0061 (5)	−0.0008 (5)
C19	0.0244 (7)	0.0266 (7)	0.0188 (7)	−0.0014 (6)	0.0052 (5)	−0.0018 (5)
C20	0.0206 (7)	0.0457 (9)	0.0240 (7)	−0.0026 (6)	0.0042 (6)	−0.0010 (7)
C21	0.0215 (7)	0.0337 (8)	0.0148 (6)	0.0002 (6)	0.0058 (5)	−0.0001 (5)
C22	0.0329 (9)	0.0460 (10)	0.0364 (9)	0.0001 (7)	0.0203 (7)	−0.0100 (7)

Geometric parameters (Å, º)

O1—C13	1.2074 (17)	C12—C15	1.5363 (17)
C1—C2	1.3726 (19)	C12—H12	1.0000
C1—C6	1.4121 (18)	C13—C14	1.500 (2)
C1—H1	0.9500	C14—H14A	0.9800
O2—C15	1.2084 (16)	C14—H14C	0.9800
C2—C3	1.413 (2)	C14—H14B	0.9800
C2—H2	0.9500	C15—C16	1.490 (2)
O3—C19	1.2092 (18)	C16—H15A	0.9800
C3—C4	1.3702 (19)	C16—H15C	0.9800
C3—H3	0.9500	C16—H15B	0.9800
O4—C21	1.2113 (18)	C17—C18	1.5317 (18)
C4—C5	1.4154 (18)	C17—H17A	0.9900
C4—H4	0.9500	C17—H17B	0.9900
C5—N7	1.3684 (17)	C18—C19	1.5298 (19)
C5—C6	1.4125 (18)	C18—C21	1.5326 (18)
C6—N10	1.3715 (16)	C18—H18	1.0000
N7—C8	1.3133 (17)	C19—C20	1.491 (2)
C8—C9	1.4383 (17)	C20—H20B	0.9800
C8—C17	1.5048 (18)	C20—H20A	0.9800
C9—N10	1.3077 (17)	C20—H20C	0.9800
C9—C11	1.5096 (17)	C21—C22	1.500 (2)
C11—C12	1.5316 (17)	C22—H22A	0.9800
C11—H11A	0.9900	C22—H22C	0.9800
C11—H11B	0.9900	C22—H22B	0.9800
C12—C13	1.5307 (18)
C2—C1—C6	119.64 (12)	H14A—C14—H14C	109.5
C2—C1—H1	120.2	C13—C14—H14B	109.5
C6—C1—H1	120.2	H14A—C14—H14B	109.5
C1—C2—C3	120.61 (12)	H14C—C14—H14B	109.5
C1—C2—H2	119.7	O2—C15—C16	122.42 (12)
C3—C2—H2	119.7	O2—C15—C12	120.94 (12)
C4—C3—C2	120.59 (12)	C16—C15—C12	116.62 (11)
C4—C3—H3	119.7	C15—C16—H15A	109.5
C2—C3—H3	119.7	C15—C16—H15C	109.5
C3—C4—C5	119.92 (12)	H15A—C16—H15C	109.5
C3—C4—H4	120.0	C15—C16—H15B	109.5
C5—C4—H4	120.0	H15A—C16—H15B	109.5
N7—C5—C6	120.77 (11)	H15C—C16—H15B	109.5
N7—C5—C4	119.94 (11)	C8—C17—C18	112.47 (11)
C6—C5—C4	119.29 (12)	C8—C17—H17A	109.1
N10—C6—C5	120.68 (11)	C18—C17—H17A	109.1
N10—C6—C1	119.40 (11)	C8—C17—H17B	109.1
C5—C6—C1	119.89 (12)	C18—C17—H17B	109.1
C8—N7—C5	117.59 (11)	H17A—C17—H17B	107.8
N7—C8—C9	121.45 (12)	C19—C18—C21	108.55 (11)
N7—C8—C17	117.80 (11)	C19—C18—C17	112.68 (11)
C9—C8—C17	120.74 (11)	C21—C18—C17	112.64 (11)
N10—C9—C8	121.79 (11)	C19—C18—H18	107.6
N10—C9—C11	117.48 (11)	C21—C18—H18	107.6
C8—C9—C11	120.70 (11)	C17—C18—H18	107.6
C9—N10—C6	117.55 (11)	O3—C19—C20	121.03 (13)
C9—C11—C12	111.35 (10)	O3—C19—C18	120.58 (13)
C9—C11—H11A	109.4	C20—C19—C18	118.38 (11)
C12—C11—H11A	109.4	C19—C20—H20B	109.5
C9—C11—H11B	109.4	C19—C20—H20A	109.5
C12—C11—H11B	109.4	H20B—C20—H20A	109.5
H11A—C11—H11B	108.0	C19—C20—H20C	109.5
C13—C12—C11	111.46 (10)	H20B—C20—H20C	109.5
C13—C12—C15	109.36 (10)	H20A—C20—H20C	109.5
C11—C12—C15	108.65 (10)	O4—C21—C22	122.33 (14)
C13—C12—H12	109.1	O4—C21—C18	120.30 (13)
C11—C12—H12	109.1	C22—C21—C18	117.28 (13)
C15—C12—H12	109.1	C21—C22—H22A	109.5
O1—C13—C14	122.58 (13)	C21—C22—H22C	109.5
O1—C13—C12	121.30 (12)	H22A—C22—H22C	109.5
C14—C13—C12	116.07 (12)	C21—C22—H22B	109.5
C13—C14—H14A	109.5	H22A—C22—H22B	109.5
C13—C14—H14C	109.5	H22C—C22—H22B	109.5
C6—C1—C2—C3	−0.33 (19)	C8—C9—C11—C12	−179.52 (11)
C1—C2—C3—C4	1.9 (2)	C9—C11—C12—C13	−64.30 (13)
C2—C3—C4—C5	−1.31 (19)	C9—C11—C12—C15	175.13 (10)
C3—C4—C5—N7	179.67 (12)	C11—C12—C13—O1	−35.01 (17)
C3—C4—C5—C6	−0.88 (18)	C15—C12—C13—O1	85.15 (15)
N7—C5—C6—N10	3.86 (18)	C11—C12—C13—C14	147.41 (11)
C4—C5—C6—N10	−175.59 (11)	C15—C12—C13—C14	−92.43 (13)
N7—C5—C6—C1	−178.09 (11)	C13—C12—C15—O2	−46.06 (16)
C4—C5—C6—C1	2.46 (18)	C11—C12—C15—O2	75.80 (15)
C2—C1—C6—N10	176.22 (12)	C13—C12—C15—C16	135.61 (12)
C2—C1—C6—C5	−1.85 (19)	C11—C12—C15—C16	−102.53 (14)
C6—C5—N7—C8	−2.22 (18)	N7—C8—C17—C18	13.50 (16)
C4—C5—N7—C8	177.22 (12)	C9—C8—C17—C18	−166.25 (11)
C5—N7—C8—C9	−1.57 (18)	C8—C17—C18—C19	177.08 (11)
C5—N7—C8—C17	178.69 (11)	C8—C17—C18—C21	−59.69 (15)
N7—C8—C9—N10	4.12 (19)	C21—C18—C19—O3	16.5 (2)
C17—C8—C9—N10	−176.14 (11)	C17—C18—C19—O3	141.96 (15)
N7—C8—C9—C11	−173.85 (11)	C21—C18—C19—C20	−164.08 (13)
C17—C8—C9—C11	5.89 (18)	C17—C18—C19—C20	−38.60 (18)
C8—C9—N10—C6	−2.44 (18)	C19—C18—C21—O4	80.73 (15)
C11—C9—N10—C6	175.60 (11)	C17—C18—C21—O4	−44.78 (17)
C5—C6—N10—C9	−1.37 (17)	C19—C18—C21—C22	−95.92 (15)
C1—C6—N10—C9	−179.43 (11)	C17—C18—C21—C22	138.57 (13)
N10—C9—C11—C12	2.42 (16)