supplementary materials


zs2225 scheme

Acta Cryst. (2012). E68, o2739    [ doi:10.1107/S1600536812035064 ]

N,N'-(4,5-Dimethyl-1,2-phenylene)bis(pyridine-2-carboxamide)

P. C. W. Van der Berg, H. G. Visser, A. Roodt and T. J. Muller

Abstract top

In the title compound, C20H18N4O2, the dihedral angles between the central benzene ring and the pyridine rings are 57.55 (6) and 22.05 (8)°. The molecular conformation is stabilized by intramolecular N-H...N interactions and in the crystal structure an intermolecular asymmetric cyclic hydrogen-bonding association involving both amide N-H donors and a common amide O-atom acceptor gives a chain extending along the c axis.

Comment top

The title compound C20H18N4O2 was synthesized as a ligand for potential use in medical and radiopharmaceutical applications. In this compound, which has one molecule in the asymmetric unit (Fig. 1), the dihedral angles between the central benzene ring and the pyridine rings are 57.55 (6) and 22.05 (8)°. The molecular conformation is stabilized by intramolecular N—H···N interactions and in the crystal structure an intermolecular asymmetric cyclic hydrogen-bonding association involving both amide N—H donors and a common amide O-atom acceptor (O2i) (Table 1), give a one-dimensional chain extending along c. The related structures from Roodt et al. (2011) and Schutte et al. (2011) also contribute to our studies in radiopharmaceutical design and reactivity.

Related literature top

For related structures, see: Jain et al. (2004); Lin et al. (2001); Roodt et al. (2011); Schutte et al. (2011); Van der Berg et al. (2011).

Experimental top

Under oxygen atmosphere, picolinic acid (5.73 g, 0.0465 mol) was added as a solid in one portion to a suspension of 4,5-dimethyl-1,2-phenylenediamine (3.00 g, 0.0220 mol) in pyridine (20 ml) and the mixture was stirred at 40 °C for 40 min. Triphenylphosphite (30 ml) was added dropwise over 10 minutes after which the temperature was increased to 90–100 °C and stirred for a further 24 h. On cooling the precipitate was filtered, washed with H2O (50 ml) and then MeOH (50 ml). The precipitate was recrystallized in chloroform to giving colourless crystals after five days

Refinement top

The amides, aromatic and methyl hydrogen atoms were positioned geometrically and allowed to ride on their parent atoms, N—H = 0.86 Å and Uiso(H) = 1.2Ueq, C—H (aromatic C) = 0.95 Å and Uiso(H) = 1.2Ueq and C—H (methyl C) = 0.98 Å and Uiso(H) = 1.5Ueq respectively. The methyl groups were allowed to rotate, giving six half-H sites.

Computing details top

Data collection: APEX2 (Bruker, 2010); cell refinement: SAINT-Plus (Bruker, 2004); data reduction: SAINT-Plus (Bruker, 2004); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: DIAMOND (Brandenburg & Putz, 2005); software used to prepare material for publication: WinGX (Farrugia, 1999).

Figures top
[Figure 1] Fig. 1. Molecular structure of the title compound, showing the atom numbering scheme, with displacement ellipsoids drawn at the 50% probability level.
N,N'-(4,5-Dimethyl-1,2-phenylene)bis(pyridine-2-carboxamide) top
Crystal data top
C20H18N4O2F(000) = 728
Mr = 346.38Dx = 1.313 Mg m3
Monoclinic, CcMo Kα radiation, λ = 0.71073 Å
Hall symbol: C -2ycCell parameters from 5487 reflections
a = 12.1299 (8) Åθ = 3.1–28.3°
b = 18.9418 (8) ŵ = 0.09 mm1
c = 7.7549 (4) ÅT = 100 K
β = 100.375 (4)°Needle, colourless
V = 1752.65 (17) Å30.78 × 0.08 × 0.07 mm
Z = 4
Data collection top
Bruker X8 APEXII KappaCCD
diffractometer
3860 independent reflections
Radiation source: sealed tube3529 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.031
φ and ω scansθmax = 28°, θmin = 3.1°
Absorption correction: multi-scan
(SADABS; Bruker, 2004)
h = 1616
Tmin = 0.990, Tmax = 0.994k = 2424
15674 measured reflectionsl = 1010
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.036Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.090H atoms treated by a mixture of independent and constrained refinement
S = 1.04 w = 1/[σ2(Fo2) + (0.0456P)2 + 0.7043P]
where P = (Fo2 + 2Fc2)/3
3860 reflections(Δ/σ)max = 0.001
237 parametersΔρmax = 0.26 e Å3
2 restraintsΔρmin = 0.20 e Å3
Crystal data top
C20H18N4O2V = 1752.65 (17) Å3
Mr = 346.38Z = 4
Monoclinic, CcMo Kα radiation
a = 12.1299 (8) ŵ = 0.09 mm1
b = 18.9418 (8) ÅT = 100 K
c = 7.7549 (4) Å0.78 × 0.08 × 0.07 mm
β = 100.375 (4)°
Data collection top
Bruker X8 APEXII KappaCCD
diffractometer
3860 independent reflections
Absorption correction: multi-scan
(SADABS; Bruker, 2004)
3529 reflections with I > 2σ(I)
Tmin = 0.990, Tmax = 0.994Rint = 0.031
15674 measured reflectionsθmax = 28°
Refinement top
R[F2 > 2σ(F2)] = 0.036H atoms treated by a mixture of independent and constrained refinement
wR(F2) = 0.090Δρmax = 0.26 e Å3
S = 1.04Δρmin = 0.20 e Å3
3860 reflectionsAbsolute structure: ?
237 parametersFlack parameter: ?
2 restraintsRogers parameter: ?
Special details top

Experimental. The intensity data was collected on a Bruker X8 ApexII 4 K Kappa CCD diffractometer using an exposure time of 30 s/frame. A total of 1895 frames was collected with a frame width of 0.5° covering up to θ = 28.29° with 99.9% completeness accomplished.

Geometry. All s.u.'s (except the s.u. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell s.u.'s are taken into account individually in the estimation of s.u.'s in distances, angles and torsion angles; correlations between s.u.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell s.u.'s is used for estimating s.u.'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 > 2σ(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*/UeqOcc. (<1)
C60.77131 (13)0.70520 (9)0.3849 (2)0.0204 (3)
C100.34827 (15)0.64314 (11)0.4195 (3)0.0336 (4)
H10A0.28570.61040.41930.050*0.5
H10B0.32460.68150.33610.050*0.5
H10C0.37130.66290.53730.050*0.5
H10D0.36880.69270.44240.050*0.5
H10E0.32980.62170.52570.050*0.5
H10F0.28310.64030.32450.050*0.5
C110.33503 (15)0.48994 (11)0.3373 (3)0.0313 (4)
H11A0.34590.44110.30250.047*0.5
H11B0.27030.51020.25920.047*0.5
H11C0.32180.49080.45830.047*0.5
H11D0.27940.52040.37750.047*0.5
H11E0.3550.45120.42080.047*0.5
H11F0.30350.47060.22170.047*0.5
C150.77150 (13)0.44582 (8)0.2917 (2)0.0202 (2)
N20.73461 (11)0.64533 (7)0.2985 (2)0.0221 (3)
N30.72056 (11)0.50299 (7)0.21172 (19)0.0190 (3)
O10.72183 (10)0.73844 (7)0.48200 (17)0.0277 (3)
O20.74071 (9)0.41395 (6)0.41242 (15)0.0202 (2)
H2'0.7803 (17)0.6283 (10)0.237 (3)0.027 (5)*
H3'0.7438 (16)0.5199 (10)0.122 (3)0.024 (5)*
C11.03548 (14)0.71236 (10)0.2222 (2)0.0283 (4)
H11.07310.68530.14740.034*
C21.08852 (15)0.77174 (10)0.3009 (2)0.0293 (4)
H21.16030.78520.27950.035*
C31.03552 (16)0.81103 (10)0.4107 (2)0.0289 (4)
H31.070.85210.46680.035*
C40.93064 (15)0.78956 (9)0.4380 (2)0.0249 (4)
H40.89180.81540.51340.03*
C50.88403 (13)0.72965 (9)0.3529 (2)0.0197 (3)
C70.63512 (12)0.60847 (8)0.3093 (2)0.0192 (3)
C80.54288 (15)0.64111 (9)0.3586 (2)0.0241 (3)
H80.54680.68990.38740.029*
C90.44549 (13)0.60415 (9)0.3667 (2)0.0243 (4)
C120.43827 (14)0.53253 (9)0.3249 (2)0.0235 (3)
C130.53017 (14)0.50011 (9)0.2728 (2)0.0215 (3)
H130.52580.45150.24210.026*
C140.62761 (12)0.53699 (8)0.2646 (2)0.0189 (3)
C160.87530 (13)0.42368 (9)0.2250 (2)0.0189 (3)
C170.93911 (15)0.36937 (9)0.3085 (2)0.0255 (4)
H170.91570.3440.40120.031*
C181.03894 (15)0.35268 (10)0.2530 (3)0.0295 (4)
H181.08590.3160.30790.035*
C191.06792 (15)0.39063 (10)0.1168 (2)0.0283 (4)
H191.13570.38060.07640.034*
C200.99767 (15)0.44332 (10)0.0395 (3)0.0301 (4)
H201.01810.46850.0560.036*
N10.93415 (12)0.69083 (8)0.2456 (2)0.0248 (3)
N40.90251 (12)0.46069 (8)0.09200 (19)0.0245 (3)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
C60.0205 (7)0.0210 (8)0.0200 (8)0.0032 (6)0.0050 (6)0.0032 (6)
C100.0211 (8)0.0387 (10)0.0437 (12)0.0041 (7)0.0132 (8)0.0001 (9)
C110.0227 (8)0.0378 (10)0.0351 (10)0.0060 (7)0.0102 (8)0.0020 (8)
C150.0209 (4)0.0201 (5)0.0205 (4)0.0022 (3)0.0064 (4)0.0014 (4)
N20.0184 (7)0.0206 (7)0.0304 (8)0.0008 (5)0.0124 (6)0.0027 (6)
N30.0181 (6)0.0214 (7)0.0192 (7)0.0007 (5)0.0081 (5)0.0004 (6)
O10.0252 (6)0.0322 (7)0.0283 (7)0.0007 (5)0.0117 (5)0.0061 (6)
O20.0209 (4)0.0201 (5)0.0205 (4)0.0022 (3)0.0064 (4)0.0014 (4)
C10.0238 (8)0.0362 (10)0.0265 (9)0.0018 (7)0.0088 (7)0.0063 (8)
C20.0253 (9)0.0384 (11)0.0253 (9)0.0092 (7)0.0078 (7)0.0008 (8)
C30.0343 (10)0.0279 (9)0.0243 (9)0.0102 (7)0.0043 (8)0.0031 (8)
C40.0291 (9)0.0253 (8)0.0215 (8)0.0022 (7)0.0079 (7)0.0008 (7)
C50.0196 (7)0.0191 (8)0.0213 (8)0.0005 (6)0.0061 (6)0.0034 (6)
C70.0168 (7)0.0215 (8)0.0202 (8)0.0008 (6)0.0060 (6)0.0027 (6)
C80.0212 (7)0.0253 (8)0.0268 (9)0.0037 (7)0.0072 (7)0.0020 (7)
C90.0196 (8)0.0314 (9)0.0232 (8)0.0047 (7)0.0070 (7)0.0027 (7)
C120.0174 (7)0.0329 (9)0.0205 (8)0.0024 (7)0.0041 (6)0.0035 (7)
C130.0217 (7)0.0238 (8)0.0196 (8)0.0022 (6)0.0055 (6)0.0005 (6)
C140.0173 (7)0.0240 (8)0.0158 (8)0.0020 (6)0.0044 (6)0.0014 (6)
C160.0188 (7)0.0188 (7)0.0190 (7)0.0015 (6)0.0035 (6)0.0040 (6)
C170.0262 (8)0.0248 (8)0.0274 (9)0.0022 (7)0.0097 (7)0.0020 (7)
C180.0271 (9)0.0278 (9)0.0346 (10)0.0079 (7)0.0079 (8)0.0012 (8)
C190.0210 (8)0.0356 (10)0.0302 (9)0.0049 (7)0.0096 (7)0.0046 (8)
C200.0274 (9)0.0375 (10)0.0282 (9)0.0030 (7)0.0128 (8)0.0046 (8)
N10.0218 (7)0.0269 (7)0.0275 (8)0.0029 (6)0.0089 (6)0.0051 (6)
N40.0231 (7)0.0290 (8)0.0227 (7)0.0031 (6)0.0080 (6)0.0027 (6)
Geometric parameters (Å, º) top
C6—O11.219 (2)C1—H10.95
C6—N21.351 (2)C2—C31.375 (3)
C6—C51.506 (2)C2—H20.95
C10—C91.509 (2)C3—C41.388 (2)
C10—H10A0.98C3—H30.95
C10—H10B0.98C4—C51.381 (2)
C10—H10C0.98C4—H40.95
C10—H10D0.98C5—N11.336 (2)
C10—H10E0.98C7—C81.391 (2)
C10—H10F0.98C7—C141.397 (2)
C11—C121.507 (2)C8—C91.384 (2)
C11—H11A0.98C8—H80.95
C11—H11B0.98C9—C121.394 (2)
C11—H11C0.98C12—C131.395 (2)
C11—H11D0.98C13—C141.384 (2)
C11—H11E0.98C13—H130.95
C11—H11F0.98C16—N41.336 (2)
C15—O21.2274 (19)C16—C171.377 (2)
C15—N31.342 (2)C17—C181.392 (2)
C15—C161.505 (2)C17—H170.95
N2—C71.410 (2)C18—C191.374 (3)
N2—H2'0.86 (2)C18—H180.95
N3—C141.421 (2)C19—C201.378 (3)
N3—H3'0.86 (2)C19—H190.95
C1—N11.338 (2)C20—N41.333 (2)
C1—C21.382 (3)C20—H200.95
O1—C6—N2125.78 (16)C15—N3—H3'119.0 (13)
O1—C6—C5120.35 (15)C14—N3—H3'117.3 (13)
N2—C6—C5113.87 (14)N1—C1—C2123.65 (17)
C9—C10—H10A109.5N1—C1—H1118.2
C9—C10—H10B109.5C2—C1—H1118.2
H10A—C10—H10B109.5C3—C2—C1118.80 (16)
C9—C10—H10C109.5C3—C2—H2120.6
H10A—C10—H10C109.5C1—C2—H2120.6
H10B—C10—H10C109.5C2—C3—C4118.66 (16)
C9—C10—H10D109.5C2—C3—H3120.7
H10A—C10—H10D141.1C4—C3—H3120.7
H10B—C10—H10D56.3C5—C4—C3118.40 (16)
H10C—C10—H10D56.3C5—C4—H4120.8
C9—C10—H10E109.5C3—C4—H4120.8
H10A—C10—H10E56.3N1—C5—C4123.82 (14)
H10B—C10—H10E141.1N1—C5—C6117.49 (14)
H10C—C10—H10E56.3C4—C5—C6118.67 (15)
H10D—C10—H10E109.5C8—C7—C14118.66 (14)
C9—C10—H10F109.5C8—C7—N2122.39 (15)
H10A—C10—H10F56.3C14—C7—N2118.93 (14)
H10B—C10—H10F56.3C9—C8—C7121.53 (15)
H10C—C10—H10F141.1C9—C8—H8119.2
H10D—C10—H10F109.5C7—C8—H8119.2
H10E—C10—H10F109.5C8—C9—C12120.01 (15)
C12—C11—H11A109.5C8—C9—C10118.66 (16)
C12—C11—H11B109.5C12—C9—C10121.33 (16)
H11A—C11—H11B109.5C9—C12—C13118.41 (15)
C12—C11—H11C109.5C9—C12—C11121.62 (16)
H11A—C11—H11C109.5C13—C12—C11119.96 (16)
H11B—C11—H11C109.5C14—C13—C12121.65 (15)
C12—C11—H11D109.5C14—C13—H13119.2
H11A—C11—H11D141.1C12—C13—H13119.2
H11B—C11—H11D56.3C13—C14—C7119.73 (14)
H11C—C11—H11D56.3C13—C14—N3120.85 (14)
C12—C11—H11E109.5C7—C14—N3119.42 (13)
H11A—C11—H11E56.3N4—C16—C17123.97 (15)
H11B—C11—H11E141.1N4—C16—C15117.22 (14)
H11C—C11—H11E56.3C17—C16—C15118.74 (14)
H11D—C11—H11E109.5C16—C17—C18118.08 (16)
C12—C11—H11F109.5C16—C17—H17121
H11A—C11—H11F56.3C18—C17—H17121
H11B—C11—H11F56.3C19—C18—C17118.40 (17)
H11C—C11—H11F141.1C19—C18—H18120.8
H11D—C11—H11F109.5C17—C18—H18120.8
H11E—C11—H11F109.5C18—C19—C20119.32 (16)
O2—C15—N3124.85 (15)C18—C19—H19120.3
O2—C15—C16120.91 (14)C20—C19—H19120.3
N3—C15—C16114.22 (14)N4—C20—C19123.20 (17)
C6—N2—C7126.56 (14)N4—C20—H20118.4
C6—N2—H2'113.8 (13)C19—C20—H20118.4
C7—N2—H2'119.5 (13)C5—N1—C1116.67 (14)
C15—N3—C14123.74 (14)C20—N4—C16117.01 (15)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N2—H2···N10.86 (2)2.20 (2)2.6698 (19)114.2 (16)
N2—H2···N30.86 (2)2.48 (2)2.777 (2)101.2 (15)
N2—H2···O2i0.86 (2)2.60 (2)3.2112 (19)129.0 (17)
N3—H3···O2i0.86 (2)2.05 (2)2.8508 (19)155.5 (18)
N3—H3···N40.86 (2)2.28 (2)2.6670 (19)107.8 (15)
C8—H8···O10.952.312.877 (2)118
C2—H2···O1ii0.952.593.195 (2)122
C3—H3···O2iii0.952.483.160 (2)128
Symmetry codes: (i) x, y+1, z1/2; (ii) x+1/2, y+3/2, z1/2; (iii) x+1/2, y+1/2, z.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N2—H2'···N10.86 (2)2.20 (2)2.6698 (19)114.2 (16)
N2—H2'···N30.86 (2)2.48 (2)2.777 (2)101.2 (15)
N2—H2'···O2i0.86 (2)2.60 (2)3.2112 (19)129.0 (17)
N3—H3'···O2i0.86 (2)2.05 (2)2.8508 (19)155.5 (18)
N3—H3'···N40.86 (2)2.28 (2)2.6670 (19)107.8 (15)
Symmetry code: (i) x, y+1, z1/2.
Acknowledgements top

The authors would like to thank the Department of Chemistry of the University of the Free State, the NRF, NTeMBI, THRIP and Sasol Ltd for funding.

references
References top

Brandenburg, K. & Putz, H. (2005). DIAMOND. Crystal Impact GbR, Bonn, Germany.

Bruker (2004). SAINT-Plus and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.

Bruker (2010). APEX2. Bruker AXS Inc., Madison, Wisconsin, USA.

Farrugia, L. J. (1999). J. Appl. Cryst. 32, 837–838.

Jain, S. L., Bhattacharyya, P., Milton, H. L., Slawin, A. M. Z., Crayston, J. A. & Woollins, J. D. (2004). Dalton Trans. pp. 862–871.

Lin, J., Zhang, J.-Y., Xu, Y., Ke, X.-K. & Guo, Z.-J. (2001). Acta Cryst. C57, 192–194.

Roodt, A., Visser, H. G. & Brink, A. (2011). Crystallogr. Rev. 17, 241–280.

Schutte, M., Kemp, G., Visser, H. G. & Roodt, A. (2011). Inorg. Chem. 50, 12486–12498.

Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122.

Van der Berg, P. C. W., Visser, H. G. & Roodt, A. (2011). Acta Cryst. E67, o3130.