2,3,7,8-Tetra-2-pyridylpyrazino[2,3-g]quinoxaline dihydrate

The title compound, C₃₀H₁₈N₈·2H₂O, is a solvate of 2,3,7,8-tetra­(pyridin-2-yl)pyrazino[2,3-g]quinoxaline and, like the latter, is crystallographically centrosymmetric. The pyrazine ring makes dihedral angles of 54.95 (6) and 28.09 (6)° with the two independent pyridine rings. The two pyridine rings are inclined to one another by 56.77 (7)°, with their N atoms facing each other. In the crystal structure, adjacent mol­ecules are linked by O—H...N hydrogen bonds, forming a wide ribbon-like structure extending in the ac plane.

Key indicators

• Single-crystal X-ray study
• T = 153 K
• Mean [sigma](C-C) = 0.002 Å
• R factor = 0.032
• wR factor = 0.085
• Data-to-parameter ratio = 11.3

checkCIF/PLATON results

No syntax errors found



Alert level A
PLAT029_ALERT_3_A _diffrn_measured_fraction_theta_full Low .......       0.94

Author Response: ...For the triclinic system the Stoe IPDS-I diffractometer only allows one to collect ca. 93% of the available data in the Ewald sphere. This, however, does not have any significant effect on the final molecular dimensions of compound (II). The bond distances and angles are in fact more precise than those for the room temperature study of compound (I), see Fang, Y.-Y., Guo, Y.-M., Du, M., Liu, H., Leng, X.-B. & Zhang, R.-H. (2001). Acta Cryst. E57, o380-o382.

Alert level C
REFLT03_ALERT_3_C  Reflection count < 95% complete
           From the CIF: _diffrn_reflns_theta_max           25.25
           From the CIF: _diffrn_reflns_theta_full          25.25
           From the CIF: _reflns_number_total               2142
           TEST2: Reflns within _diffrn_reflns_theta_max
           Count of symmetry unique reflns         2284
           Completeness (_total/calc)             93.78%
PLAT022_ALERT_3_C Ratio Unique / Expected Reflections too Low ....       0.94

   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
   0 ALERT type 5 Informative message, check

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Computing details

Data collection: EXPOSE in IPDS-I (Stoe & Cie, 2000); cell refinement: CELL in IPDS-I (Stoe & Cie, 2000); data reduction: INTEGRATE in IPDS-I (Stoe & Cie, 2000); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: PLATON (Spek, 2003); software used to prepare material for publication: SHELXL97.

(II)

Crystal data

C30H18N8·2(H2O)	Z = 1
Mr = 526.56	F(000) = 274
Triclinic, P1	Dx = 1.386 Mg m^−3
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 5.9162 (8) Å	Cell parameters from 3947 reflections
b = 8.5485 (12) Å	θ = 2.2–25.1°
c = 13.6553 (18) Å	µ = 0.09 mm^−1
α = 76.734 (16)°	T = 153 K
β = 82.755 (16)°	Plate, yellow
γ = 70.068 (15)°	0.50 × 0.50 × 0.15 mm
V = 631.05 (15) Å^3

Data collection

STOE IPDS diffractometer	1637 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.024
Graphite monochromator	θmax = 25.3°, θmin = 2.6°
φ scans	h = −7→7
4660 measured reflections	k = −10→10
2142 independent reflections	l = −16→16

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)] = 0.032	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.085	H atoms treated by a mixture of independent and constrained refinement
S = 0.95	w = 1/[σ^2(Fo^2) + (0.0575P)^2] where P = (Fo^2 + 2Fc^2)/3
2142 reflections	(Δ/σ)max < 0.001
189 parameters	Δρmax = 0.18 e Å^−3
0 restraints	Δρmin = −0.18 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
N1	0.3982 (2)	−0.17191 (14)	0.12732 (8)	0.0305 (3)
N2	0.63908 (19)	−0.08701 (13)	0.31244 (7)	0.0249 (3)
N3	0.3180 (2)	−0.22470 (13)	0.44470 (7)	0.0257 (3)
N4	0.4720 (2)	−0.50219 (13)	0.27432 (8)	0.0289 (3)
C1	0.4352 (3)	−0.1891 (2)	0.03072 (10)	0.0388 (4)
H1	0.2990	−0.1596	−0.0081	0.047*
C2	0.6600 (3)	−0.2471 (2)	−0.01473 (10)	0.0447 (4)
H2	0.6777	−0.2614	−0.0825	0.054*
C3	0.8595 (3)	−0.28406 (19)	0.03929 (10)	0.0383 (4)
H3	1.0169	−0.3231	0.0091	0.046*
C4	0.8268 (3)	−0.26347 (17)	0.13820 (9)	0.0296 (3)
H4	0.9608	−0.2848	0.1768	0.036*
C5	0.5945 (2)	−0.21110 (16)	0.17945 (9)	0.0246 (3)
C6	0.5448 (2)	−0.18802 (15)	0.28627 (9)	0.0233 (3)
C7	0.3908 (2)	−0.26796 (15)	0.35724 (8)	0.0230 (3)
C8	0.3189 (2)	−0.40686 (15)	0.33565 (8)	0.0239 (3)
C9	0.1098 (2)	−0.43697 (16)	0.37983 (9)	0.0278 (3)
H9	0.0093	−0.3698	0.4251	0.033*
C10	0.0501 (3)	−0.56738 (17)	0.35664 (10)	0.0326 (3)
H10	−0.0930	−0.5903	0.3852	0.039*
C11	0.2021 (3)	−0.66308 (17)	0.29142 (10)	0.0344 (3)
H11	0.1639	−0.7511	0.2727	0.041*
C12	0.4114 (3)	−0.62786 (17)	0.25399 (10)	0.0325 (3)
H12	0.5185	−0.6971	0.2112	0.039*
C13	0.5774 (2)	−0.04828 (15)	0.40704 (8)	0.0230 (3)
C14	0.4023 (2)	−0.10927 (15)	0.47097 (9)	0.0235 (3)
C15	0.3249 (2)	−0.05848 (16)	0.56276 (9)	0.0254 (3)
H15	0.2056	−0.0968	0.6046	0.031*
O1W	−0.0318 (3)	0.08354 (16)	0.18967 (10)	0.0515 (3)
H1W	0.098 (5)	0.000 (3)	0.1658 (17)	0.089 (7)*
H2W	−0.126 (4)	0.029 (3)	0.2239 (16)	0.064 (6)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
N1	0.0365 (7)	0.0371 (6)	0.0238 (5)	−0.0188 (5)	−0.0009 (5)	−0.0071 (5)
N2	0.0289 (6)	0.0282 (6)	0.0208 (5)	−0.0127 (5)	0.0036 (4)	−0.0088 (4)
N3	0.0319 (6)	0.0287 (6)	0.0218 (5)	−0.0154 (5)	0.0015 (4)	−0.0081 (4)
N4	0.0347 (6)	0.0288 (6)	0.0271 (6)	−0.0129 (5)	0.0000 (5)	−0.0100 (4)
C1	0.0497 (9)	0.0546 (9)	0.0239 (7)	−0.0305 (8)	−0.0042 (6)	−0.0083 (6)
C2	0.0651 (11)	0.0626 (10)	0.0230 (7)	−0.0382 (9)	0.0078 (7)	−0.0193 (7)
C3	0.0450 (9)	0.0468 (8)	0.0323 (7)	−0.0246 (7)	0.0142 (6)	−0.0198 (6)
C4	0.0340 (7)	0.0344 (7)	0.0257 (6)	−0.0165 (6)	0.0037 (5)	−0.0107 (5)
C5	0.0332 (7)	0.0254 (6)	0.0205 (6)	−0.0156 (6)	0.0020 (5)	−0.0075 (5)
C6	0.0255 (7)	0.0240 (6)	0.0221 (6)	−0.0089 (5)	−0.0001 (5)	−0.0072 (5)
C7	0.0261 (6)	0.0256 (6)	0.0198 (6)	−0.0104 (5)	−0.0003 (5)	−0.0066 (5)
C8	0.0309 (7)	0.0252 (6)	0.0179 (6)	−0.0113 (6)	−0.0032 (5)	−0.0041 (5)
C9	0.0329 (7)	0.0302 (7)	0.0241 (6)	−0.0147 (6)	−0.0008 (5)	−0.0061 (5)
C10	0.0386 (8)	0.0357 (7)	0.0307 (7)	−0.0220 (7)	−0.0043 (6)	−0.0034 (6)
C11	0.0495 (9)	0.0280 (7)	0.0336 (7)	−0.0199 (7)	−0.0096 (6)	−0.0067 (6)
C12	0.0414 (8)	0.0286 (7)	0.0317 (7)	−0.0119 (6)	−0.0029 (6)	−0.0124 (6)
C13	0.0272 (7)	0.0247 (6)	0.0186 (6)	−0.0099 (5)	0.0021 (5)	−0.0066 (5)
C14	0.0280 (7)	0.0235 (6)	0.0214 (6)	−0.0106 (5)	−0.0016 (5)	−0.0057 (5)
C15	0.0292 (7)	0.0302 (6)	0.0219 (6)	−0.0166 (6)	0.0052 (5)	−0.0077 (5)
O1W	0.0538 (8)	0.0440 (6)	0.0638 (8)	−0.0278 (6)	0.0258 (6)	−0.0215 (6)

Geometric parameters (Å, º)

N1—C5	1.3421 (17)	C6—C7	1.4612 (18)
N1—C1	1.3430 (16)	C7—C8	1.4881 (18)
N2—C6	1.3055 (16)	C8—C9	1.3849 (19)
N2—C13	1.3808 (15)	C9—C10	1.3879 (18)
N3—C7	1.3087 (15)	C9—H9	0.9500
N3—C14	1.3763 (16)	C10—C11	1.379 (2)
N4—C12	1.3360 (17)	C10—H10	0.9500
N4—C8	1.3435 (16)	C11—C12	1.381 (2)
C1—C2	1.372 (2)	C11—H11	0.9500
C1—H1	0.9500	C12—H12	0.9500
C2—C3	1.377 (2)	C13—C15^i	1.3890 (18)
C2—H2	0.9500	C13—C14	1.4279 (18)
C3—C4	1.3829 (18)	C14—C15	1.3923 (17)
C3—H3	0.9500	C15—C13^i	1.3890 (18)
C4—C5	1.3812 (19)	C15—H15	0.9500
C4—H4	0.9500	O1W—H1W	0.94 (3)
C5—C6	1.4957 (16)	O1W—H2W	0.87 (2)
C5—N1—C1	116.86 (12)	N4—C8—C9	123.10 (12)
C6—N2—C13	118.39 (11)	N4—C8—C7	115.95 (11)
C7—N3—C14	118.27 (11)	C9—C8—C7	120.91 (11)
C12—N4—C8	117.00 (12)	C8—C9—C10	118.62 (12)
N1—C1—C2	123.31 (13)	C8—C9—H9	120.7
N1—C1—H1	118.3	C10—C9—H9	120.7
C2—C1—H1	118.3	C11—C10—C9	118.87 (13)
C1—C2—C3	119.08 (12)	C11—C10—H10	120.6
C1—C2—H2	120.5	C9—C10—H10	120.6
C3—C2—H2	120.5	C10—C11—C12	118.42 (12)
C2—C3—C4	118.86 (14)	C10—C11—H11	120.8
C2—C3—H3	120.6	C12—C11—H11	120.8
C4—C3—H3	120.6	N4—C12—C11	123.91 (12)
C5—C4—C3	118.35 (13)	N4—C12—H12	118.0
C5—C4—H4	120.8	C11—C12—H12	118.0
C3—C4—H4	120.8	N2—C13—C15^i	119.79 (11)
N1—C5—C4	123.45 (11)	N2—C13—C14	119.94 (11)
N1—C5—C6	115.06 (11)	C15^i—C13—C14	120.16 (11)
C4—C5—C6	121.45 (11)	N3—C14—C15	119.63 (11)
N2—C6—C7	121.16 (10)	N3—C14—C13	120.33 (11)
N2—C6—C5	116.57 (11)	C15—C14—C13	119.97 (11)
C7—C6—C5	122.22 (11)	C13^i—C15—C14	119.86 (12)
N3—C7—C6	121.10 (11)	C13^i—C15—H15	120.1
N3—C7—C8	117.05 (11)	C14—C15—H15	120.1
C6—C7—C8	121.79 (10)	H1W—O1W—H2W	105 (2)
C5—N1—C1—C2	1.4 (2)	C12—N4—C8—C7	179.90 (10)
N1—C1—C2—C3	−2.5 (2)	N3—C7—C8—N4	−150.08 (11)
C1—C2—C3—C4	0.8 (2)	C6—C7—C8—N4	27.22 (16)
C2—C3—C4—C5	1.8 (2)	N3—C7—C8—C9	27.82 (17)
C1—N1—C5—C4	1.42 (19)	C6—C7—C8—C9	−154.89 (11)
C1—N1—C5—C6	179.26 (11)	N4—C8—C9—C10	−2.68 (18)
C3—C4—C5—N1	−3.0 (2)	C7—C8—C9—C10	179.58 (11)
C3—C4—C5—C6	179.26 (12)	C8—C9—C10—C11	0.66 (19)
C13—N2—C6—C7	−4.14 (17)	C9—C10—C11—C12	1.75 (19)
C13—N2—C6—C5	173.37 (10)	C8—N4—C12—C11	0.58 (19)
N1—C5—C6—N2	−123.08 (13)	C10—C11—C12—N4	−2.5 (2)
C4—C5—C6—N2	54.81 (16)	C6—N2—C13—C15^i	179.84 (12)
N1—C5—C6—C7	54.40 (16)	C6—N2—C13—C14	−4.10 (16)
C4—C5—C6—C7	−127.71 (14)	C7—N3—C14—C15	178.89 (11)
C14—N3—C7—C6	−3.95 (17)	C7—N3—C14—C13	−4.31 (17)
C14—N3—C7—C8	173.36 (10)	N2—C13—C14—N3	8.68 (17)
N2—C6—C7—N3	8.64 (18)	C15^i—C13—C14—N3	−175.27 (11)
C5—C6—C7—N3	−168.72 (11)	N2—C13—C14—C15	−174.53 (11)
N2—C6—C7—C8	−168.54 (11)	C15^i—C13—C14—C15	1.52 (19)
C5—C6—C7—C8	14.09 (17)	N3—C14—C15—C13^i	175.30 (11)
C12—N4—C8—C9	2.05 (17)	C13—C14—C15—C13^i	−1.51 (19)

Symmetry code: (i) −x+1, −y, −z+1.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O1W—H1W···N1	0.94 (3)	1.98 (3)	2.9127 (18)	173 (2)
O1W—H2W···N2^ii	0.87 (2)	2.08 (2)	2.9526 (17)	175.5 (18)

Symmetry code: (ii) x−1, y, z.