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Journal logoCRYSTALLOGRAPHIC
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ISSN: 2056-9890
Volume 68| Part 5| May 2012| Page o1568

Bis(4-meth­­oxy­pyridin-3-yl)diazene

aInstitut für Organische Chemie, Universität Kiel, Otto-Hahn-Platz 4, 24118 Kiel, Germany, and bInstitut für Anorganische Chemie, Universität Kiel, Otto-Hahn-Platz 6/7, 24118 Kiel, Germany
*Correspondence e-mail: cnaether@ac.uni-kiel.de, rherges@ac.uni-kiel.de

(Received 20 April 2012; accepted 24 April 2012; online 28 April 2012)

The asymmetric unit of the title compound, C12H12N4O2, consists of one half-mol­ecule, which is located on a center of inversion. The molecule has a step-like shape; the azo group adopting a trans configuration, with the pyridine rings being parallel-displace.

Related literature

For background to this work, see: Thies et al. (2010[Thies, S., Bornholdt, C., Koehler, F., Sönnichsen, F. D., Naether, C., Tuczek, F. & Herges, R. (2010). Chem. Eur. J. 16, 10074-10083.], 2011[Thies, S., Sell, H., Schütt, C., Bornholdt, C., Näther, C., Tuczek, F. & Herges, R. (2011). J. Am. Chem. Soc. 133, 16243-16250.]); Venkataramani et al. (2011[Venkataramani, S., Jana, U., Dommaschk, M., Sönnichsen, F. D., Tuczek, F. & Herges, H. (2011). Science, 331, 445-448.]).

[Scheme 1]

Experimental

Crystal data
  • C12H12N4O2

  • Mr = 244.26

  • Orthorhombic, P b c a

  • a = 13.3976 (8) Å

  • b = 6.2101 (6) Å

  • c = 13.6079 (9) Å

  • V = 1132.18 (15) Å3

  • Z = 4

  • Mo Kα radiation

  • μ = 0.10 mm−1

  • T = 220 K

  • 0.3 × 0.2 × 0.2 mm

Data collection
  • Stoe IPDS-1 diffractometer

  • 5829 measured reflections

  • 1235 independent reflections

  • 1002 reflections with I > 2σ(I)

  • Rint = 0.045

Refinement
  • R[F2 > 2σ(F2)] = 0.039

  • wR(F2) = 0.105

  • S = 1.04

  • 1235 reflections

  • 84 parameters

  • H-atom parameters constrained

  • Δρmax = 0.26 e Å−3

  • Δρmin = −0.19 e Å−3

Data collection: X-AREA (Stoe & Cie, 2008[Stoe & Cie (2008). X-AREA and X-RED32. Stoe & Cie, Darmstadt, Germany.]); cell refinement: X-AREA; data reduction: X-RED32; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); molecular graphics: XP in SHELXTL (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); software used to prepare material for publication: SHELXL97.

Supporting information


Comment top

We recently reported about a change of the spin state by association/dissociation of photodissociable ligands (PDL's) at square planar Ni(II) porphyrine complexes (Thies et al. 2010, Thies et al. 2011, Venkataramani et al., 2011). Within this project the title compound was synthesized as potential PDL and its structure was determined by single-crystal X-ray diffraction.

In the crystal structure of the title compound, the azo group is in a trans configuration with an torsion angle C2—N2—N2i—C2i (i = -x + 1, -y + 2, -z + 1) of 180° due to symmetry. The pyridine rings are not coplanar with the central C—N—N—C unit with torsion angles of 32.9 (2)° for C1—C2—N2—N2i and 151.5 (2)° for C3—C2—N2—N2i (i = -x + 1, -y + 2, -z + 1).

Related literature top

For background to this work, see: Thies et al. (2010, 2011); Venkataramani et al. (2011).

Experimental top

3-Nitro-4-methoxypyridine (1.14 g, 7.41 mmol) was dissolved in ethanol (30 ml) and heated to 80°C. Barium hydroxide (3.50 g, 20.8 mmol) dissolved in 20 ml hot water was added. Zinc powder (6.00 g, 91,7 mmol) was added in small portions within 20 min. The reaction mixture was stirred at 80 °C for 3 h and filtered over celite®. 200 ml dichloromethane were added to the filtrate and air was bubbled through the solution for 2 h. The organic layer was dried over magnesium sulfate and the solvent was removed under reduced pressure. The crude product was dissolved in ethanol and two spoons of activated charcoal were added. After stirring at 80°C for 20 min the mixture was filtered over celite® and the product was crystallized from ethyl acetate. An orange solid (120 mg, 0.49 mmol, 13.2%) was afforded (mp: 218.4 °C). 1H-NMR (500 MHz, 300 K, CDCl3, TMS)): δ = 8.58 (s, 2H, 2-H), 8.55 (d, J = 5.8 Hz, 2H, 6-H), 7.02 (d, J = 5.8 Hz, 2H, 5-H), 4.08 (s, 6H, OCH3) p.p.m.. IR (KBr): ν (cm-1) = 2993, 2951, 1562, 1485, 1461, 1442, 1301, 1272, 1014, 817, 762. MS (EI): m/z (%) = 244 (100) [M]+, 136 (66) [M-PyrOMe]+, 108 (77) [M-NNPyrOMe]+. MS (CI): m/z (%) = 245 (100) [M+H]+. Anal. Calc.: C12H12N4O2 (244.10), ber. C 59.01, H 4.95, N 22.94, gef. C 59.72, H 4.58, N 22.64%.

Refinement top

All H atoms were positioned with idealized geometry (methyl H atoms allowed to rotate but not to tip) and were refined isotropically with Uiso(H) = 1.2 Ueq(C) for aromatic H atoms (1.5 for methyl H atoms) using a riding model.

Computing details top

Data collection: X-AREA (Stoe & Cie, 2008); cell refinement: X-AREA (Stoe & Cie, 2008); data reduction: X-RED32 (Stoe & Cie, 2008); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: XP in SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).

Figures top
[Figure 1] Fig. 1. : Crystal structure of the title compound with labeling and displacement ellipsoids drawn at the 50% probability level. Symmetry code: i = -x + 1, -y + 2, -z + 1.
Bis(4-methoxypyridin-3-yl)diazene top
Crystal data top
C12H12N4O2Dx = 1.433 Mg m3
Mr = 244.26Mo Kα radiation, λ = 0.71073 Å
Orthorhombic, PbcaCell parameters from 4972 reflections
a = 13.3976 (8) Åθ = 4.7–28.8°
b = 6.2101 (6) ŵ = 0.10 mm1
c = 13.6079 (9) ÅT = 220 K
V = 1132.18 (15) Å3Block, colourless
Z = 40.3 × 0.2 × 0.2 mm
F(000) = 512
Data collection top
Stoe IPDS-1
diffractometer
1002 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tubeRint = 0.045
Graphite monochromatorθmax = 27.1°, θmin = 3.0°
Phi scansh = 1712
5829 measured reflectionsk = 77
1235 independent reflectionsl = 1717
Refinement top
Refinement on F2Secondary atom site location: difference Fourier map
Least-squares matrix: fullHydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.039H-atom parameters constrained
wR(F2) = 0.105 w = 1/[σ2(Fo2) + (0.0625P)2 + 0.204P]
where P = (Fo2 + 2Fc2)/3
S = 1.04(Δ/σ)max < 0.001
1235 reflectionsΔρmax = 0.26 e Å3
84 parametersΔρmin = 0.19 e Å3
0 restraintsExtinction correction: SHELXL97 (Sheldrick, 2008), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
Primary atom site location: structure-invariant direct methodsExtinction coefficient: 0.030 (8)
Crystal data top
C12H12N4O2V = 1132.18 (15) Å3
Mr = 244.26Z = 4
Orthorhombic, PbcaMo Kα radiation
a = 13.3976 (8) ŵ = 0.10 mm1
b = 6.2101 (6) ÅT = 220 K
c = 13.6079 (9) Å0.3 × 0.2 × 0.2 mm
Data collection top
Stoe IPDS-1
diffractometer
1002 reflections with I > 2σ(I)
5829 measured reflectionsRint = 0.045
1235 independent reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0390 restraints
wR(F2) = 0.105H-atom parameters constrained
S = 1.04Δρmax = 0.26 e Å3
1235 reflectionsΔρmin = 0.19 e Å3
84 parameters
Special details top

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 (Å2) top
xyzUiso*/Ueq
N10.66974 (9)0.6358 (2)0.34371 (9)0.0314 (3)
C10.62249 (10)0.7907 (2)0.39360 (9)0.0263 (3)
H10.65910.91340.41190.032*
C20.52211 (9)0.7811 (2)0.42010 (8)0.0211 (3)
C30.46546 (10)0.60269 (19)0.38987 (8)0.0205 (3)
C40.51423 (10)0.4414 (2)0.33786 (9)0.0250 (3)
H40.47940.31900.31610.030*
C50.61506 (11)0.4644 (2)0.31870 (10)0.0301 (3)
H50.64750.35130.28570.036*
N20.47208 (8)0.94965 (17)0.47068 (7)0.0228 (3)
O10.36924 (7)0.60036 (15)0.41627 (7)0.0277 (3)
C60.30947 (11)0.4230 (2)0.38338 (11)0.0321 (4)
H6A0.30320.42840.31240.048*
H6B0.24380.43200.41300.048*
H6C0.34100.28880.40240.048*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
N10.0230 (6)0.0348 (6)0.0364 (7)0.0008 (5)0.0067 (5)0.0042 (5)
C10.0237 (7)0.0271 (7)0.0280 (6)0.0044 (5)0.0010 (5)0.0020 (5)
C20.0227 (6)0.0202 (6)0.0203 (5)0.0000 (5)0.0014 (4)0.0006 (4)
C30.0200 (6)0.0208 (6)0.0205 (6)0.0011 (5)0.0014 (4)0.0011 (4)
C40.0273 (7)0.0216 (6)0.0261 (6)0.0009 (5)0.0004 (5)0.0045 (5)
C50.0292 (7)0.0283 (7)0.0329 (7)0.0039 (6)0.0052 (5)0.0058 (5)
N20.0231 (5)0.0202 (5)0.0251 (5)0.0017 (4)0.0012 (4)0.0022 (4)
O10.0193 (5)0.0241 (5)0.0396 (6)0.0030 (4)0.0020 (4)0.0086 (4)
C60.0230 (7)0.0288 (7)0.0444 (8)0.0068 (6)0.0037 (6)0.0068 (6)
Geometric parameters (Å, º) top
N1—C51.3360 (19)C4—C51.3832 (19)
N1—C11.3369 (18)C4—H40.9400
C1—C21.3936 (18)C5—H50.9400
C1—H10.9400N2—N2i1.260 (2)
C2—C31.4044 (17)O1—C61.4333 (16)
C2—N21.4209 (16)C6—H6A0.9700
C3—O11.3384 (16)C6—H6B0.9700
C3—C41.3897 (17)C6—H6C0.9700
C5—N1—C1116.29 (12)C3—C4—H4120.6
N1—C1—C2123.89 (12)N1—C5—C4124.74 (13)
N1—C1—H1118.1N1—C5—H5117.6
C2—C1—H1118.1C4—C5—H5117.6
C1—C2—C3118.65 (11)N2i—N2—C2113.10 (14)
C1—C2—N2123.30 (11)C3—O1—C6117.56 (10)
C3—C2—N2117.91 (11)O1—C6—H6A109.5
O1—C3—C4125.58 (11)O1—C6—H6B109.5
O1—C3—C2116.77 (11)H6A—C6—H6B109.5
C4—C3—C2117.62 (12)O1—C6—H6C109.5
C5—C4—C3118.73 (12)H6A—C6—H6C109.5
C5—C4—H4120.6H6B—C6—H6C109.5
Symmetry code: (i) x+1, y+2, z+1.

Experimental details

Crystal data
Chemical formulaC12H12N4O2
Mr244.26
Crystal system, space groupOrthorhombic, Pbca
Temperature (K)220
a, b, c (Å)13.3976 (8), 6.2101 (6), 13.6079 (9)
V3)1132.18 (15)
Z4
Radiation typeMo Kα
µ (mm1)0.10
Crystal size (mm)0.3 × 0.2 × 0.2
Data collection
DiffractometerStoe IPDS1
diffractometer
Absorption correction
No. of measured, independent and
observed [I > 2σ(I)] reflections
5829, 1235, 1002
Rint0.045
(sin θ/λ)max1)0.641
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.039, 0.105, 1.04
No. of reflections1235
No. of parameters84
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å3)0.26, 0.19

Computer programs: X-AREA (Stoe & Cie, 2008), X-RED32 (Stoe & Cie, 2008), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), XP in SHELXTL (Sheldrick, 2008).

 

Acknowledgements

We gratefully acknowledge financial support by the Deutsche Forschungsgemeinschaft via SFB 677.

References

First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationStoe & Cie (2008). X-AREA and X-RED32. Stoe & Cie, Darmstadt, Germany.  Google Scholar
First citationThies, S., Bornholdt, C., Koehler, F., Sönnichsen, F. D., Naether, C., Tuczek, F. & Herges, R. (2010). Chem. Eur. J. 16, 10074-10083.  Web of Science CSD CrossRef CAS PubMed Google Scholar
First citationThies, S., Sell, H., Schütt, C., Bornholdt, C., Näther, C., Tuczek, F. & Herges, R. (2011). J. Am. Chem. Soc. 133, 16243-16250.  Web of Science CSD CrossRef CAS PubMed Google Scholar
First citationVenkataramani, S., Jana, U., Dommaschk, M., Sönnichsen, F. D., Tuczek, F. & Herges, H. (2011). Science, 331, 445-448.  Web of Science CrossRef CAS PubMed Google Scholar

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Journal logoCRYSTALLOGRAPHIC
COMMUNICATIONS
ISSN: 2056-9890
Volume 68| Part 5| May 2012| Page o1568
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