(Z,Z)-N′′-[Amino­(pyrazin-2-yl)methyl­ene]pyrazine-2-carbohydrazonamide

The title compound, C₁₀H₁₀N₈, resides on a crystallographic symmetry center and features an essentially planar mol­ecule [r.m.s. deviation = 0.278 (1) Å]. In the C=N—N=C fragment, the C=N distance is 1.3017 (18) Å and the N—N distance is 1.403 (2) Å. In the crystal, adjacent mol­ecules are linked by N—H...N hydrogen bonds into a three-dimensional network.

Key indicators

• Single-crystal X-ray study
• T = 295 K
• Mean [sigma](C-C) = 0.002 Å
• R factor = 0.038
• wR factor = 0.108
• Data-to-parameter ratio = 10.5

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT029_ALERT_3_C _diffrn_measured_fraction_theta_full Low .......       0.98
PLAT417_ALERT_2_C Short Inter D-H..H-D       H3B    ..  H3C     ..       2.13 Ang.
PLAT790_ALERT_4_C Centre of Gravity not Within Unit Cell: Resd.  #          1
              C10 H10 N8

Alert level G
PLAT066_ALERT_1_G Predicted and Reported Transmissions Identical .          ?

   0 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
   3 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
   1 ALERT type 2 Indicator that the structure model may be wrong or deficient
   1 ALERT type 3 Indicator that the structure quality may be low
   1 ALERT type 4 Improvement, methodology, query or suggestion
   0 ALERT type 5 Informative message, check

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S1. Comment

The title compound can be regarded as a dihydrazidine with all atoms essentially coplanar and has now been shown to have trans geometry because of steric repulsion effect. In the C=N—N=C fragment, the C=N distance is 1.302 (2) Å, which is much shorter than the N—N distance of 1.403 (2) Å. All other C—N distances are 1.341 (2) Å, which are considered to have full double-bond character. Adjacent molecules are linked into a two-dimensional sheet by intermolecular N—H···N hydrogen bonds with the N···N distance of 3.054 (2) Å. Each molecule acts as double hydrogen-bond acceptors with the 2-positon N atoms of pyrazine rings and donors with the two amino groups.

Related literature

For related structures, see: Armstrong et al. (1998), Xu et al. (2006), Shi et al. (2008).

S2. Experimental

A mixture of pyrazine-2-carbonitrile (0.210 g, 2 mmol), MnSO₄.H₂O (0.169 g, 1 mmol), hydrazine hydrate (80%, 2 ml) and anhydrous ethanol (6 ml) was heated in a 15 ml Teflon-lined autoclave at 393 K for 3 days, followed by slow cooling (5 K h^-1) to room temperature. The resulting mixture was filtered and washed with 95% ethanol, and yellow block crystals were collected and dried in vacuum. Yield (0.32 g) 26.4%.

S3. Refinement

The H atom bonded to N were located in a difference map and freely refined. Other H atoms were positioned geometrically and refined using a riding model with C—H = 0.93 Å and with U_iso(H) = 1.2 U_eq(C).

Computing details

Data collection: SMART (Bruker, 2000); cell refinement: SAINT (Bruker, 2000); data reduction: SAINT (Bruker, 2000); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL97 (Sheldrick, 2008).

Figures

Fig. 1. Structure of the title compound with 30% displacement ellipsoids. [Symmetry code: (A) 2-x, -1-y, -z.]

(Z,Z)-N''-[Amino(pyrazin-2-yl)methylene]pyrazine-2-carbohydrazonamide

Crystal data

C10H10N8	F(000) = 252
Mr = 242.26	Dx = 1.462 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 651 reflections
a = 8.6576 (16) Å	θ = 3.9–26.5°
b = 6.6685 (12) Å	µ = 0.10 mm^−1
c = 9.6162 (18) Å	T = 295 K
β = 97.682 (4)°	Block, yellow
V = 550.19 (18) Å^3	0.30 × 0.19 × 0.16 mm
Z = 2

Data collection

Bruker SMART CCD diffractometer	946 independent reflections
Radiation source: fine-focus sealed tube	844 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.013
ϕ and ω scans	θmax = 25.0°, θmin = 2.4°
Absorption correction: multi-scan (SADABS; Sheldrick, 2000)	h = −10→4
Tmin = 0.970, Tmax = 0.984	k = −7→7
1946 measured reflections	l = −11→11

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)] = 0.038	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.108	H atoms treated by a mixture of independent and constrained refinement
S = 1.05	w = 1/[σ^2(Fo^2) + (0.0659P)^2 + 0.0834P] where P = (Fo^2 + 2Fc^2)/3
946 reflections	(Δ/σ)max < 0.001
90 parameters	Δρmax = 0.20 e Å^−3
0 restraints	Δρmin = −0.13 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	0.71263 (17)	−0.1470 (2)	−0.12888 (15)	0.0400 (4)
H1A	0.7177	−0.2641	−0.1806	0.048*
C2	0.61260 (19)	0.1595 (2)	−0.10119 (17)	0.0459 (4)
H2A	0.5502	0.2669	−0.1353	0.055*
C3	0.69636 (18)	0.1731 (2)	0.03029 (16)	0.0421 (4)
H3A	0.6851	0.2866	0.0842	0.050*
C4	0.80524 (15)	−0.1312 (2)	0.00078 (14)	0.0326 (4)
C5	0.92285 (16)	−0.2845 (2)	0.05271 (14)	0.0322 (4)
N1	0.61789 (15)	−0.0024 (2)	−0.18134 (13)	0.0462 (4)
N2	0.79325 (14)	0.02862 (18)	0.08288 (12)	0.0372 (4)
N3	1.00358 (16)	−0.2540 (2)	0.17988 (13)	0.0431 (4)
H3B	1.071 (2)	−0.351 (3)	0.2148 (18)	0.045 (4)*
H3C	0.974 (2)	−0.154 (3)	0.2320 (19)	0.050 (5)*
N4	0.94266 (14)	−0.43331 (17)	−0.03069 (11)	0.0356 (4)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.0420 (8)	0.0408 (8)	0.0350 (8)	0.0018 (6)	−0.0029 (6)	−0.0042 (7)
C2	0.0441 (9)	0.0435 (9)	0.0475 (9)	0.0069 (7)	−0.0038 (7)	0.0066 (7)
C3	0.0468 (9)	0.0355 (8)	0.0426 (9)	0.0047 (6)	0.0013 (7)	−0.0023 (7)
C4	0.0353 (8)	0.0329 (8)	0.0295 (7)	−0.0030 (6)	0.0039 (6)	0.0006 (6)
C5	0.0363 (8)	0.0316 (7)	0.0280 (7)	−0.0025 (6)	0.0017 (6)	0.0015 (6)
N1	0.0459 (8)	0.0486 (8)	0.0405 (8)	0.0040 (6)	−0.0078 (6)	0.0010 (6)
N2	0.0429 (7)	0.0339 (7)	0.0335 (7)	0.0024 (5)	−0.0002 (5)	−0.0018 (5)
N3	0.0534 (9)	0.0409 (8)	0.0317 (7)	0.0145 (6)	−0.0068 (6)	−0.0050 (6)
N4	0.0425 (7)	0.0312 (7)	0.0313 (7)	0.0042 (5)	−0.0016 (5)	−0.0001 (5)

Geometric parameters (Å, º)

C1—N1	1.3219 (19)	C4—N2	1.3386 (18)
C1—C4	1.393 (2)	C4—C5	1.4815 (19)
C1—H1A	0.9300	C5—N4	1.3017 (18)
C2—N1	1.331 (2)	C5—N3	1.3405 (18)
C2—C3	1.374 (2)	N3—H3B	0.906 (18)
C2—H2A	0.9300	N3—H3C	0.893 (19)
C3—N2	1.3318 (19)	N4—N4^i	1.403 (2)
C3—H3A	0.9300
N1—C1—C4	122.66 (14)	C1—C4—C5	122.46 (13)
N1—C1—H1A	118.7	N4—C5—N3	125.59 (13)
C4—C1—H1A	118.7	N4—C5—C4	117.36 (12)
N1—C2—C3	122.11 (14)	N3—C5—C4	117.01 (13)
N1—C2—H2A	118.9	C1—N1—C2	116.02 (13)
C3—C2—H2A	118.9	C3—N2—C4	116.52 (12)
N2—C3—C2	122.01 (14)	C5—N3—H3B	117.6 (10)
N2—C3—H3A	119.0	C5—N3—H3C	118.3 (11)
C2—C3—H3A	119.0	H3B—N3—H3C	123.0 (15)
N2—C4—C1	120.49 (13)	C5—N4—N4^i	111.61 (13)
N2—C4—C5	117.03 (12)

Symmetry code: (i) −x+2, −y−1, −z.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N3—H3B···N2^ii	0.906 (18)	2.280 (18)	3.0539 (18)	143.2 (14)
N3—H3C···N4^iii	0.892 (19)	2.405 (18)	3.1587 (18)	142.3 (16)

Symmetry codes: (ii) −x+2, y−1/2, −z+1/2; (iii) x, −y−1/2, z+1/2.