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organic compounds\(\def\hfill{\hskip 5em}\def\hfil{\hskip 3em}\def\eqno#1{\hfil {#1}}\)

Journal logoCRYSTALLOGRAPHIC
COMMUNICATIONS
ISSN: 2056-9890
Volume 65| Part 5| May 2009| Page o1168
doi:10.1107/S1600536809015591

N1,N2-Bis(6-methyl-2-pyrid­yl)formamidine

Chia-Jun Wu,a Chang-Wei Su,a Chun-Wei Yeh,a Jhy-Der Chena* and Ju-Chun Wangb

aDepartment of Chemistry, Chung-Yuan Christian University, Chung-Li, Taiwan, Republic of China, and bDepartment of Chemistry, Soochow University, Taipei, Taiwan, Republic of China
*Correspondence e-mail: jdchen@cycu.edu.tw

(Received 12 March 2009; accepted 27 April 2009; online 30 April 2009)

In the crystal structure of the title mol­ecule, C13H14N4, the two pyridyl rings are not coplanar but twisted about the C—N bond with an inter­planar angle of 71.1 (1)°. In the crystal, the mol­ecules form dimers, situated on crystallographic centres of inversion, which are connected via a pair of N—H⋯N hydrogen bonds. C—H⋯π-electron ring inter­actions are also present in the crystal structure. The title mol­ecule adopts an s–cis–anti–s–cis conformation in the solid state.

Related literature

For related structures, see: Wu et al. (2009[Wu, C.-J., Su, C.-W., Yeh, C.-W., Chen, J.-D. & Wang, J.-C. (2009). Acta Cryst. E65, o536.]); Liang et al. (2003[Liang, H.-C., Wu, Y.-Y., Chang, F.-C., Yang, P.-Y., Chen, J.-D. & Wang, J.-C. (2003). J. Organomet. Chem. 669, 182-188.]); Yang et al. (2000[Yang, P.-Y., Chang, F.-C., Suen, M.-C., Chen, J.-D., Feng, T.-C. & Wang, J.-C. (2000). J. Organomet. Chem. 596, 226-231.]); Radak et al. (2001[Radak, S., Ni, Y., Xu, G., Shaffer, K. L. & Ren, T. (2001). Inorg. Chim. Acta, 321, 200-204.]). For the synthesis, see: Roberts (1949[Roberts, R. M. (1949). J. Org. Chem. 14, 277-284.]).

[Scheme 1]

Experimental

Crystal data

  • C13H14N4

  • Mr = 226.28

  • Monoclinic, P 21 /c

  • a = 6.0364 (4) Å

  • b = 19.6697 (14) Å

  • c = 10.4040 (7) Å

  • β = 96.081 (1)°

  • V = 1228.36 (15) Å3

  • Z = 4

  • Mo Kα radiation

  • μ = 0.08 mm−1

  • T = 298 K

  • 0.5 × 0.5 × 0.3 mm
Data collection

  • Bruker SMART 1000 diffractometer

  • Absorption correction: multi-scan (SADABS; Bruker, 1997[Bruker (1997). SADABS ,SAINT and SMART. Bruker AXS Inc., Madison, Wisconsin, USA.]) Tmin = 0.683, Tmax = 0.792 (expected range = 0.842–0.977)

  • 7002 measured reflections

  • 2912 independent reflections

  • 2313 reflections with I > 2σ(I)

  • Rint = 0.110
Refinement

  • R[F2 > 2σ(F2)] = 0.060

  • wR(F2) = 0.148

  • S = 1.09

  • 2912 reflections

  • 161 parameters

  • H atoms treated by a mixture of independent and constrained refinement

  • Δρmax = 0.16 e Å−3

  • Δρmin = −0.21 e Å−3

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A D⋯A D—H⋯A
N3—H3N⋯N2i 0.89 (2) 2.09 (2) 2.9775 (19) 173 (2)
C1—H1B⋯Cg1ii 0.96 2.83 3.644 (2) 143
C11—H11A⋯Cg1iii 0.93 2.96 3.757 (2) 145
Symmetry codes: (i) -x+1, -y+1, -z+2; (ii) [-x, y+{\script{3\over 2}}, -z+{\script{3\over 2}}]; (iii) -x+1, -y, -z+1. Cg1 is the centroid of the N1,C2–C6 ring.

Data collection: SMART (Bruker, 1997[Bruker (1997). SADABS ,SAINT and SMART. Bruker AXS Inc., Madison, Wisconsin, USA.]); cell refinement: SAINT (Bruker, 1997[Bruker (1997). SADABS ,SAINT and SMART. Bruker AXS Inc., Madison, Wisconsin, USA.]); data reduction: SAINT and SHELXTL (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); 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: SHELXTL; software used to prepare material for publication: SHELXTL.

Supporting information

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536809015591/fb2144sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536809015591/fb2144Isup2.hkl

checkCIF report


Comment top

The title molecule as well as its anion have been used as bridging ligands in the coordination chemistry (Liang et al., 2003; Yang et al., 2000; Radak et al., 2001). In the present work, the structure of the title molecule (Fig. 1) has been determined to explore its ligand conformation.

The molecules form dimers that are interconnected via a pair of N—H···N hydrogen bonds (Tab. 1, Fig. 2). Moreover, there are also C—H···π-electron ring interactions (Tab. 1) in the structure. The conformation in the title molecule in the structure is s-cis-anti-s-cis. This conformation is in contrast to that one found in N1,N2-bis(2-pyridyl)formamidine, which is s-trans-syn-s-cis (Wu et al. , 2009).

Related literature top

For related structures, see: Wu et al. (2009); Liang et al. (2003); Yang et al. (2000); Radak et al. (2001). For the synthesis, see: Roberts (1949). Cg1 is the centroid of the N1,C2–C6 ring.

Experimental top

The title compound was prepared according to the procedure described by Roberts (1949). 2-Aminopyridine (12.96 g, 0.12 mol) and triethyl orthoformate (11.8 g, 0.06 mol) were placed under nitrogen into a flask. The mixture was then refluxed for 8 h to give a brown solid. Dichloromethane (10 ml) was then added to dissolve the solid and then hexane (25 ml) was added to induce the precipitation. The precipitate was filtered and dried under vacuum to give a light yellow solid with a yield of 83%. By dissolving the solid in dichloromethane, followed by allowing the solution to evaporate slowly under air, several yellow crystals suitable for X-ray crystallography were obtained. One block crystal with size of 0.5 x 0.5 x 0.3 mm was used for data collection.

Refinement top

All the hydrogen atoms were discernible in the difference Fourier maps. However, they were situated into the idealized positions and constrained by the riding atom approximation: C—Hmethyl = 0.96 Å while the methyls were allowed to rotate about their respective axes; C—Haryl = 0.93 Å; Uiso(Hmethyl) = 1.5Ueq(Cmethyl); Uiso(Haryl) = 1.2Ueq(Caryl). The amine hydrogen atom (H3N) that is involved in the N-H···N hydrogen bond was freely refined.

Computing details top

Data collection: SMART (Bruker, 1997); cell refinement: SAINT (Bruker, 1997); data reduction: SAINT (Bruker, 1997) and SHELXTL (Sheldrick, 2008); 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: SHELXTL (Sheldrick, 2008).

Figures top
[Figure 1] Fig. 1. The title molecule with the labelling scheme. The displacement ellipsoids are drawn at the 30% probability level.
[Figure 2] Fig. 2. View on the dimers bind by the hydrogen bonds, which are shown as dashed lines. Symmetry code: (i) -x+1, -y+1, -z+2.
N1,N2-Bis(6-methyl-2-pyridyl)formamidine top
Crystal data top
C13H14N4F(000) = 480
Mr = 226.28Dx = 1.224 Mg m−3
Monoclinic, P21/cMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybcCell parameters from 7002 reflections
a = 6.0364 (4) Åθ = 2.1–28.3°
b = 19.6697 (14) ŵ = 0.08 mm−1
c = 10.4040 (7) ÅT = 298 K
β = 96.081 (1)°Block, yellow
V = 1228.36 (15) Å30.5 × 0.5 × 0.3 mm
Z = 4
Data collection top
Bruker SMART 1000
diffractometer		2912 independent reflections
Radiation source: fine-focus sealed tube2313 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.110
ϕ and ω scansθmax = 28.3°, θmin = 2.1°
Absorption correction: multi-scan
(SADABS; Bruker, 1997)		h = −8→8
Tmin = 0.683, Tmax = 0.792k = −22→26
7002 measured reflectionsl = −13→8
Refinement top
Refinement on F2Secondary atom site location: difference Fourier map
Least-squares matrix: fullHydrogen site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.060H atoms treated by a mixture of independent and constrained refinement
wR(F2) = 0.148 w = 1/[σ2(Fo2) + (0.0514P)2 + 0.2913P]
where P = (Fo2 + 2Fc2)/3
S = 1.09(Δ/σ)max < 0.001
2912 reflectionsΔρmax = 0.16 e Å−3
161 parametersΔρmin = −0.21 e Å−3
0 restraintsExtinction correction: SHELXL97 (Sheldrick, 2008), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
50 constraintsExtinction coefficient: 0.050 (6)
Primary atom site location: structure-invariant direct methods
Crystal data top
C13H14N4V = 1228.36 (15) Å3
Mr = 226.28Z = 4
Monoclinic, P21/cMo Kα radiation
a = 6.0364 (4) ŵ = 0.08 mm−1
b = 19.6697 (14) ÅT = 298 K
c = 10.4040 (7) Å0.5 × 0.5 × 0.3 mm
β = 96.081 (1)°
Data collection top
Bruker SMART 1000
diffractometer		2912 independent reflections
Absorption correction: multi-scan
(SADABS; Bruker, 1997)		2313 reflections with I > 2σ(I)
Tmin = 0.683, Tmax = 0.792Rint = 0.110
7002 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0600 restraints
wR(F2) = 0.148H atoms treated by a mixture of independent and constrained refinement
S = 1.09Δρmax = 0.16 e Å−3
2912 reflectionsΔρmin = −0.21 e Å−3
161 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
N10.1831 (2)0.44487 (7)0.66067 (13)0.0459 (3)
N20.2674 (2)0.49243 (7)0.86759 (12)0.0470 (3)
N30.5357 (2)0.57705 (7)0.89283 (13)0.0497 (4)
N40.4953 (2)0.67233 (7)0.76126 (13)0.0481 (3)
C10.1286 (4)0.39836 (12)0.44484 (19)0.0733 (6)
H1B0.17750.43920.40590.110*
H1C0.01400.37720.38740.110*
H1D0.25210.36770.46130.110*
C20.0383 (3)0.41552 (8)0.56991 (16)0.0514 (4)
C3−0.1794 (3)0.40215 (10)0.5912 (2)0.0620 (5)
H3A−0.27800.38320.52620.074*
C4−0.2488 (3)0.41725 (10)0.7103 (2)0.0640 (5)
H4B−0.39470.40830.72630.077*
C5−0.1007 (3)0.44564 (9)0.80515 (18)0.0538 (4)
H5A−0.14230.45490.88690.065*
C60.1131 (3)0.46006 (8)0.77451 (15)0.0433 (3)
C70.3682 (3)0.54351 (8)0.82345 (15)0.0455 (4)
H7A0.32380.55810.73960.055*
C80.6236 (3)0.63789 (8)0.85033 (15)0.0457 (4)
C90.8327 (3)0.65966 (10)0.90180 (19)0.0627 (5)
H9A0.91870.63410.96350.075*
C100.9085 (4)0.72061 (12)0.8581 (2)0.0751 (6)
H10A1.04760.73700.89080.090*
C110.7783 (4)0.75724 (10)0.7662 (2)0.0684 (6)
H11A0.82770.79860.73670.082*
C120.5739 (3)0.73169 (9)0.71856 (17)0.0540 (4)
C130.4238 (4)0.76673 (12)0.6146 (2)0.0764 (6)
H13A0.27240.76400.63450.115*
H13B0.43670.74500.53300.115*
H13C0.46660.81360.60970.115*
H3N0.602 (3)0.5592 (11)0.966 (2)0.064 (6)*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
N10.0435 (7)0.0473 (7)0.0455 (7)0.0045 (5)−0.0024 (5)−0.0009 (5)
N20.0501 (7)0.0479 (7)0.0413 (7)−0.0025 (6)−0.0021 (5)0.0012 (5)
N30.0584 (8)0.0448 (7)0.0428 (7)−0.0054 (6)−0.0082 (6)0.0033 (6)
N40.0531 (7)0.0449 (7)0.0455 (7)0.0010 (6)0.0018 (6)0.0001 (6)
C10.0852 (14)0.0787 (14)0.0535 (10)0.0134 (12)−0.0042 (10)−0.0171 (10)
C20.0541 (9)0.0462 (9)0.0510 (9)0.0083 (7)−0.0082 (7)−0.0049 (7)
C30.0515 (9)0.0568 (10)0.0727 (12)−0.0009 (8)−0.0160 (8)−0.0071 (9)
C40.0404 (8)0.0656 (12)0.0847 (14)−0.0037 (8)−0.0002 (8)0.0039 (10)
C50.0466 (9)0.0583 (10)0.0567 (10)0.0035 (7)0.0068 (7)0.0021 (8)
C60.0425 (8)0.0403 (7)0.0457 (8)0.0032 (6)−0.0020 (6)0.0031 (6)
C70.0513 (9)0.0441 (8)0.0394 (7)0.0019 (7)−0.0033 (6)0.0004 (6)
C80.0529 (9)0.0426 (8)0.0406 (8)−0.0018 (6)0.0006 (6)−0.0041 (6)
C90.0642 (11)0.0625 (11)0.0569 (10)−0.0101 (9)−0.0145 (8)0.0035 (8)
C100.0751 (13)0.0725 (13)0.0732 (13)−0.0292 (11)−0.0123 (10)−0.0006 (10)
C110.0855 (14)0.0527 (10)0.0654 (12)−0.0207 (10)0.0010 (10)0.0008 (9)
C120.0693 (11)0.0423 (8)0.0506 (9)−0.0011 (8)0.0069 (8)−0.0017 (7)
C130.0903 (15)0.0602 (12)0.0768 (14)0.0066 (11)0.0008 (11)0.0175 (10)
Geometric parameters (Å, º) top
N1—C61.333 (2)C4—C51.378 (3)
N1—C21.347 (2)C4—H4B0.9300
N2—C71.285 (2)C5—C61.391 (2)
N2—C61.4212 (19)C5—H5A0.9300
N3—C71.350 (2)C7—H7A0.9300
N3—C81.400 (2)C8—C91.386 (2)
N3—H3N0.90 (2)C9—C101.377 (3)
N4—C81.329 (2)C9—H9A0.9300
N4—C121.353 (2)C10—C111.376 (3)
C1—C21.502 (3)C10—H10A0.9300
C1—H1B0.9600C11—C121.375 (3)
C1—H1C0.9600C11—H11A0.9300
C1—H1D0.9600C12—C131.503 (3)
C2—C31.380 (3)C13—H13A0.9600
C3—C41.382 (3)C13—H13B0.9600
C3—H3A0.9300C13—H13C0.9600
C6—N1—C2118.40 (14)C5—C6—N2119.49 (15)
C7—N2—C6114.08 (13)N2—C7—N3123.18 (14)
C7—N3—C8122.43 (14)N2—C7—H7A118.4
C7—N3—H3N120.3 (14)N3—C7—H7A118.4
C8—N3—H3N117.1 (14)N4—C8—C9123.49 (16)
C8—N4—C12118.06 (15)N4—C8—N3116.34 (14)
C2—C1—H1B109.5C9—C8—N3120.17 (15)
C2—C1—H1C109.5C10—C9—C8117.52 (18)
H1B—C1—H1C109.5C10—C9—H9A121.2
C2—C1—H1D109.5C8—C9—H9A121.2
H1B—C1—H1D109.5C11—C10—C9120.01 (18)
H1C—C1—H1D109.5C11—C10—H10A120.0
N1—C2—C3121.81 (16)C9—C10—H10A120.0
N1—C2—C1115.82 (17)C12—C11—C10118.93 (18)
C3—C2—C1122.37 (16)C12—C11—H11A120.5
C2—C3—C4119.16 (16)C10—C11—H11A120.5
C2—C3—H3A120.4N4—C12—C11121.97 (17)
C4—C3—H3A120.4N4—C12—C13115.27 (17)
C5—C4—C3119.60 (17)C11—C12—C13122.75 (17)
C5—C4—H4B120.2C12—C13—H13A109.5
C3—C4—H4B120.2C12—C13—H13B109.5
C4—C5—C6117.76 (17)H13A—C13—H13B109.5
C4—C5—H5A121.1C12—C13—H13C109.5
C6—C5—H5A121.1H13A—C13—H13C109.5
N1—C6—C5123.18 (15)H13B—C13—H13C109.5
N1—C6—N2117.34 (14)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N3—H3N···N2i0.89 (2)2.09 (2)2.9775 (19)173 (2)
C1—H1B···Cg1ii0.962.833.644 (2)143
C11—H11A···Cg1iii0.932.963.757 (2)145
Symmetry codes: (i) −x+1, −y+1, −z+2; (ii) −x, y+3/2, −z+3/2; (iii) −x+1, −y, −z+1.

Experimental details

Crystal data
Chemical formulaC13H14N4
Mr226.28
Crystal system, space groupMonoclinic, P21/c
Temperature (K)298
a, b, c (Å)6.0364 (4), 19.6697 (14), 10.4040 (7)
β (°) 96.081 (1)
V (Å3)1228.36 (15)
Z4
Radiation typeMo Kα
µ (mm−1)0.08
Crystal size (mm)0.5 × 0.5 × 0.3
Data collection
DiffractometerBruker SMART 1000
diffractometer
Absorption correctionMulti-scan
(SADABS; Bruker, 1997)
Tmin, Tmax0.683, 0.792
No. of measured, independent and
observed [I > 2σ(I)] reflections		7002, 2912, 2313
Rint0.110
(sin θ/λ)max (Å−1)0.666
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.060, 0.148, 1.09
No. of reflections2912
No. of parameters161
H-atom treatmentH atoms treated by a mixture of independent and constrained refinement
Δρmax, Δρmin (e Å−3)0.16, −0.21

Computer programs: SMART (Bruker, 1997), SAINT (Bruker, 1997) and SHELXTL (Sheldrick, 2008), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), SHELXTL (Sheldrick, 2008).

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N3—H3N···N2i0.89 (2)2.09 (2)2.9775 (19)173 (2)
C1—H1B···Cg1ii0.962.833.644 (2)143
C11—H11A···Cg1iii0.932.963.757 (2)145
Symmetry codes: (i) −x+1, −y+1, −z+2; (ii) −x, y+3/2, −z+3/2; (iii) −x+1, −y, −z+1.
 

Acknowledgements

We are grateful to the National Science Council of the Republic of China for the support. This research was also supported by the project of the specific research fields in Chung-Yuan Christian University, Taiwan, under grant CYCU-97-CR—CH.

References

First citationBruker (1997). SADABS ,SAINT and SMART. Bruker AXS Inc., Madison, Wisconsin, USA.  Google Scholar
 First citationLiang, H.-C., Wu, Y.-Y., Chang, F.-C., Yang, P.-Y., Chen, J.-D. & Wang, J.-C. (2003). J. Organomet. Chem. 669, 182–188.  Web of Science CSD CrossRef CAS Google Scholar
 First citationRadak, S., Ni, Y., Xu, G., Shaffer, K. L. & Ren, T. (2001). Inorg. Chim. Acta, 321, 200–204.  Web of Science CSD CrossRef CAS Google Scholar
 First citationRoberts, R. M. (1949). J. Org. Chem. 14, 277–284.  CrossRef PubMed CAS Web of Science Google Scholar
 First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals Google Scholar
 First citationWu, C.-J., Su, C.-W., Yeh, C.-W., Chen, J.-D. & Wang, J.-C. (2009). Acta Cryst. E65, o536.  Web of Science CSD CrossRef IUCr Journals Google Scholar
 First citationYang, P.-Y., Chang, F.-C., Suen, M.-C., Chen, J.-D., Feng, T.-C. & Wang, J.-C. (2000). J. Organomet. Chem. 596, 226–231.  Web of Science CSD CrossRef CAS Google Scholar

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Journal logoCRYSTALLOGRAPHIC
COMMUNICATIONS
ISSN: 2056-9890
Volume 65| Part 5| May 2009| Page o1168
doi:10.1107/S1600536809015591
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