5,5'-Di­methyl-2,2'-bi­pyrazine

The crystal structure of the title compound, C₁₀H₁₀N₄, a mol­ecule synthesized as a dye, was determined by X-ray diffraction at room temperature. The mol­ecule has a center of inversion located midway between the pyrazine units.

Key indicators

• Single-crystal X-ray study
• T = 298 K
• Mean [sigma](C-C) = 0.003 Å
• R factor = 0.048
• wR factor = 0.136
• Data-to-parameter ratio = 12.1

checkCIF/PLATON results

No syntax errors found



Alert level A
PLAT052_ALERT_1_A (Proper) Absorption Correction Method Missing ..          ?

Alert level B
PLAT027_ALERT_3_B _diffrn_reflns_theta_full (too) Low ............      24.97 Deg.

Alert level C
ABSTM02_ALERT_3_C  The ratio of expected to reported Tmax/Tmin(RR') is < 0.90
            Tmin and Tmax reported:      0.802     0.989
            Tmin' and Tmax expected:      0.966     0.991
            RR' =      0.833
            Please check that your absorption correction is appropriate.

   1 ALERT level A = In general: serious problem
   1 ALERT level B = Potentially serious problem
   1 ALERT level C = Check and explain
   0 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
   2 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: CAD-4 EXPRESS (Enraf-Nonius, 1994); cell refinement: CAD-4 EXPRESS; data reduction: XCAD4 (Harms & Wocadlo, 1995); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997); software used to prepare material for publication: WinGX (Farrugia, 1999).

(I)

Crystal data

C10H10N4	Z = 1
Mr = 186.14	F(000) = 98
Triclinic, P1	Dx = 1.334 Mg m^−3
Hall symbol: -P 1	Melting point: 147 K
a = 3.9580 (7) Å	Mo Kα radiation, λ = 0.71073 Å
b = 5.9476 (16) Å	Cell parameters from 24 reflections
c = 10.107 (2) Å	θ = 10–12°
α = 102.828 (19)°	µ = 0.09 mm^−1
β = 92.100 (17)°	T = 298 K
γ = 91.27 (2)°	Needle, white
V = 231.72 (9) Å^3	0.4 × 0.1 × 0.1 mm

Data collection

Enraf–Nonius CAD-4 diffractometer	Rint = 0.055
non–profiled ω/2θ scans	θmax = 25.0°, θmin = 2.1°
Absorption correction: ψ-scan (North et al., 1968)	h = −4→4
Tmin = 0.802, Tmax = 0.989	k = −7→7
1613 measured reflections	l = −11→11
811 independent reflections	3 standard reflections every 60 min
425 reflections with I > 2σ(I)	intensity decay: 10%

Refinement

Refinement on F^2	0 restraints
Least-squares matrix: full	H-atom parameters constrained
R[F^2 > 2σ(F^2)] = 0.048	w = 1/[σ^2(Fo^2) + (0.103P)^2] where P = (Fo^2 + 2Fc^2)/3
wR(F^2) = 0.136	(Δ/σ)max = 0.036
S = 0.96	Δρmax = 0.16 e Å^−3
811 reflections	Δρmin = −0.26 e Å^−3
67 parameters

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

	x	y	z	Uiso*/Ueq
N2	0.9089 (5)	0.0073 (4)	0.20068 (19)	0.0547 (6)
N1	0.7843 (5)	0.2425 (3)	0.46271 (18)	0.0489 (6)
C1	0.9443 (6)	0.0440 (4)	0.4407 (2)	0.0391 (5)
C2	0.6948 (6)	0.3227 (4)	0.3549 (2)	0.0513 (7)
H2	0.5885	0.4632	0.3678	0.058 (7)*
C3	0.7549 (6)	0.2072 (4)	0.2230 (2)	0.0464 (6)
C4	1.0010 (7)	−0.0700 (4)	0.3092 (2)	0.0514 (7)
H4	1.1084	−0.2102	0.2963	0.058 (7)*
C5	0.6486 (7)	0.3041 (5)	0.1031 (3)	0.0625 (8)
H5A	0.8175	0.2737	0.0361	0.094*
H5B	0.6236	0.4676	0.1321	0.094*
H5C	0.4368	0.2328	0.0644	0.094*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
N2	0.0665 (14)	0.0630 (14)	0.0349 (12)	0.0148 (11)	0.0038 (10)	0.0099 (10)
N1	0.0616 (14)	0.0472 (13)	0.0377 (12)	0.0131 (10)	0.0047 (9)	0.0078 (9)
C1	0.0386 (11)	0.0404 (12)	0.0384 (12)	0.0016 (9)	0.0030 (9)	0.0084 (9)
C2	0.0601 (16)	0.0472 (15)	0.0466 (14)	0.0129 (12)	0.0011 (12)	0.0098 (12)
C3	0.0452 (14)	0.0522 (15)	0.0431 (14)	0.0011 (11)	−0.0014 (11)	0.0140 (11)
C4	0.0625 (16)	0.0528 (15)	0.0389 (13)	0.0180 (12)	0.0061 (11)	0.0085 (11)
C5	0.0700 (18)	0.076 (2)	0.0457 (16)	0.0123 (15)	−0.0003 (13)	0.0222 (14)

Geometric parameters (Å, º)

N2—C4	1.323 (3)	C2—H2	0.9293
N2—C3	1.326 (3)	C3—C5	1.504 (3)
N1—C2	1.323 (3)	C4—H4	0.9299
N1—C1	1.331 (3)	C5—H5A	0.96
C1—C4	1.380 (3)	C5—H5B	0.96
C1—C1^i	1.467 (4)	C5—H5C	0.96
C2—C3	1.389 (3)
C4—N2—C3	116.5 (2)	C2—C3—C5	121.4 (2)
C2—N1—C1	117.1 (2)	N2—C4—C1	123.9 (2)
N1—C1—C4	119.5 (2)	N2—C4—H4	118.2
N1—C1—C1^i	117.9 (3)	C1—C4—H4	117.9
C4—C1—C1^i	122.6 (3)	C3—C5—H5A	109.5
N1—C2—C3	123.0 (2)	C3—C5—H5B	109.5
N1—C2—H2	118.7	H5A—C5—H5B	109.5
C3—C2—H2	118.3	C3—C5—H5C	109.5
N2—C3—C2	120.1 (2)	H5A—C5—H5C	109.5
N2—C3—C5	118.6 (2)	H5B—C5—H5C	109.5

Symmetry code: (i) −x+2, −y, −z+1.