2,3-Bis(pyrazin-2-yloxyimino)butane

Abstract

The title mol­ecule, C₁₂H₁₂N₆O₂, lies on a crystallographic inversion center with all non-H atoms essentially coplanar.

Related literature

For a related structure, see: Chen & Yang (2008 ▶).

Experimental

Crystal data

• C₁₂H₁₂N₆O₂

• M _r = 272.28

• Monoclinic,

• a = 4.7396 (15) Å

• b = 17.141 (5) Å

• c = 7.911 (3) Å

• β = 98.065 (5)°

• V = 636.3 (4) ų

• Z = 2

• Mo Kα radiation

• μ = 0.10 mm⁻¹

• T = 298 (2) K

• 0.43 × 0.10 × 0.06 mm

Data collection

• Bruker SMART APEX CCD diffractometer

• Absorption correction: multi-scan (SADABS; Sheldrick, 1996 ▶) T _min = 0.957, T _max = 0.994

• 3621 measured reflections

• 1368 independent reflections

• 872 reflections with I > 2σ(I)

• R _int = 0.036

Refinement

• R[F ² > 2σ(F ²)] = 0.057

• wR(F ²) = 0.142

• S = 1.03

• 1368 reflections

• 92 parameters

• H-atom parameters constrained

• Δρ_max = 0.19 e Å⁻³

• Δρ_min = −0.16 e Å⁻³

Data collection: SMART (Bruker, 2007 ▶); cell refinement: SAINT (Bruker, 2007 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL.

Supplementary Material

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

supplementary crystallographic information

Comment

We are interested in the design and synthesis of muliti-dentate ligands containing pyrazinyl and butane-2,3-dione dioxime and hence we have previously synthesized (2E,3E)-3-(pyrazin-2-yloxyimino)butane-2-one oxime (Chen et al., 2008) and now we report herein homologous title compound (I).

Fig. 1 shows the molecular structure with an inversion centre located in the middle of the C1-C1ⁱ bond [symmetry code: (i) -x+1, -y+1, -z]. All of the non-hydrogen atoms define a plane within 0.0652 Å with a maximum deviation of 0.1212 (16) Å for atom C4.

Experimental

A powder of the title compound (0.0473 g, 0.174 mmol) was dissolved into a mixture of solvents containing 20 ml dichloromethane and 10 ml methanol. The colorless single crystals were obtained after the solution was allowed to stand at room temperature for two days.

Refinement

All H atoms were placed in calculated positions and refined as riding with C—H = 0.96 Å, U_iso = 1.5U_eq(C) for methyl group and C—H = 0.93 Å, U_iso = 1.2U_eq(C) for pyrazinyl H atoms.

Figures

Fig. 1.

Molecular structure of the title compound with the atom-numbering scheme. Displacement ellipsoids are drawn at the 30% probability level [symmetry code: (i) -x+1, -y+1, -z].

Crystal data

C12H12N6O2	F(000) = 284
Mr = 272.28	Dx = 1.421 Mg m−3
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2yn	Cell parameters from 556 reflections
a = 4.7396 (15) Å	θ = 2.4–20.6°
b = 17.141 (5) Å	µ = 0.10 mm−1
c = 7.911 (3) Å	T = 298 K
β = 98.065 (5)°	Needle, colorless
V = 636.3 (4) Å3	0.43 × 0.10 × 0.06 mm
Z = 2

Data collection

Bruker SMART APEX CCD diffractometer	1368 independent reflections
Radiation source: fine-focus sealed tube	872 reflections with I > 2σ(I)
graphite	Rint = 0.036
φ and ω scans	θmax = 27.0°, θmin = 2.4°
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	h = −6→5
Tmin = 0.957, Tmax = 0.994	k = −21→17
3621 measured reflections	l = −9→10

Refinement

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)] = 0.057	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.142	H-atom parameters constrained
S = 1.03	w = 1/[σ2(Fo2) + (0.062P)2 + 0.0016P] where P = (Fo2 + 2Fc2)/3
1368 reflections	(Δ/σ)max < 0.001
92 parameters	Δρmax = 0.19 e Å−3
0 restraints	Δρmin = −0.16 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
C1	0.4107 (4)	0.53547 (11)	−0.0115 (3)	0.0380 (5)
C2	0.4063 (5)	0.58565 (13)	−0.1667 (3)	0.0555 (7)
H2A	0.2172	0.5864	−0.2290	0.083*
H2B	0.5364	0.5650	−0.2380	0.083*
H2C	0.4623	0.6378	−0.1326	0.083*
C3	−0.0460 (5)	0.63257 (12)	0.2132 (3)	0.0378 (5)
C4	−0.0315 (5)	0.58891 (14)	0.3610 (3)	0.0493 (6)
H4	0.0872	0.5455	0.3752	0.059*
C5	−0.3601 (5)	0.71330 (13)	0.3082 (3)	0.0507 (7)
H5	−0.4777	0.7569	0.2942	0.061*
C6	−0.3497 (5)	0.67050 (14)	0.4551 (3)	0.0550 (7)
H6	−0.4610	0.6856	0.5373	0.066*
N1	0.2691 (4)	0.54817 (9)	0.1113 (2)	0.0413 (5)
N2	−0.2076 (4)	0.69473 (10)	0.1842 (2)	0.0473 (5)
N3	−0.1848 (5)	0.60809 (12)	0.4829 (3)	0.0585 (6)
O1	0.1028 (3)	0.61679 (8)	0.07990 (19)	0.0447 (5)

Atomic displacement parameters (Ų)

	U11	U22	U33	U12	U13	U23
C1	0.0409 (14)	0.0379 (12)	0.0351 (12)	−0.0026 (9)	0.0053 (10)	−0.0015 (9)
C2	0.0700 (18)	0.0561 (15)	0.0443 (14)	0.0184 (13)	0.0213 (12)	0.0095 (11)
C3	0.0357 (13)	0.0368 (12)	0.0416 (13)	−0.0028 (10)	0.0084 (10)	−0.0026 (9)
C4	0.0509 (16)	0.0531 (14)	0.0453 (14)	0.0092 (11)	0.0116 (11)	0.0036 (11)
C5	0.0495 (15)	0.0371 (13)	0.0691 (18)	0.0028 (11)	0.0208 (13)	−0.0080 (11)
C6	0.0572 (17)	0.0602 (16)	0.0514 (16)	0.0023 (13)	0.0209 (12)	−0.0122 (12)
N1	0.0429 (12)	0.0382 (10)	0.0439 (11)	0.0056 (8)	0.0100 (9)	0.0015 (8)
N2	0.0504 (13)	0.0348 (11)	0.0594 (13)	0.0017 (9)	0.0176 (10)	0.0011 (8)
N3	0.0575 (14)	0.0742 (14)	0.0477 (13)	0.0163 (12)	0.0207 (10)	0.0036 (10)
O1	0.0499 (10)	0.0432 (9)	0.0441 (9)	0.0108 (7)	0.0175 (7)	0.0044 (6)

Geometric parameters (Å, °)

C1—N1	1.275 (3)	C4—N3	1.328 (3)
C1—C1i	1.478 (4)	C4—H4	0.9300
C1—C2	1.496 (3)	C5—N2	1.336 (3)
C2—H2A	0.9600	C5—C6	1.369 (3)
C2—H2B	0.9600	C5—H5	0.9300
C2—H2C	0.9600	C6—N3	1.325 (3)
C3—N2	1.314 (3)	C6—H6	0.9300
C3—O1	1.376 (3)	N1—O1	1.418 (2)
C3—C4	1.381 (3)
N1—C1—C1i	113.6 (2)	N3—C4—H4	119.6
N1—C1—C2	125.36 (19)	C3—C4—H4	119.6
C1i—C1—C2	121.1 (2)	N2—C5—C6	122.5 (2)
C1—C2—H2A	109.5	N2—C5—H5	118.8
C1—C2—H2B	109.5	C6—C5—H5	118.8
H2A—C2—H2B	109.5	N3—C6—C5	121.6 (2)
C1—C2—H2C	109.5	N3—C6—H6	119.2
H2A—C2—H2C	109.5	C5—C6—H6	119.2
H2B—C2—H2C	109.5	C1—N1—O1	110.30 (17)
N2—C3—O1	112.01 (18)	C3—N2—C5	115.3 (2)
N2—C3—C4	123.1 (2)	C6—N3—C4	116.7 (2)
O1—C3—C4	124.90 (19)	C3—O1—N1	111.15 (15)
N3—C4—C3	120.9 (2)
N2—C3—C4—N3	0.3 (4)	C6—C5—N2—C3	−0.2 (3)
O1—C3—C4—N3	−179.5 (2)	C5—C6—N3—C4	−0.3 (4)
N2—C5—C6—N3	0.5 (4)	C3—C4—N3—C6	0.0 (3)
C1i—C1—N1—O1	−179.78 (19)	N2—C3—O1—N1	−178.19 (15)
C2—C1—N1—O1	0.5 (3)	C4—C3—O1—N1	1.6 (3)
O1—C3—N2—C5	179.60 (18)	C1—N1—O1—C3	−178.45 (17)
C4—C3—N2—C5	−0.2 (3)

Symmetry codes: (i) −x+1, −y+1, −z.