N,N′-Bis[(E)-quinoxalin-2-ylmethyl­idene]­ethane-1,2-diamine

Varghese, D.; Arun, V.; Sebastian, M.; Leeju, P.; Varsha, G.; Yusuff, K.K.M.

doi:10.1107/S1600536809003006

organic compounds

CRYSTALLOGRAPHIC
COMMUNICATIONS

ISSN: 2056-9890

Volume 65| Part 2| February 2009| Page o435

doi:10.1107/S1600536809003006

Open

access

N,N′-Bis[(E)-quinoxalin-2-ylmethylidene]ethane-1,2-diamine

Digna Varghese,^a V. Arun,^a Manju Sebastian,^a P. Leeju,^a G. Varsha ^a and K. K. M. Yusuff ^a ^*

^aDepartment of Applied Chemistry, Cochin University of Science and Technology, Cochin 682 022, Kerala, India
^*Correspondence e-mail: yusuff@cusat.ac.in

(Received 16 December 2008; accepted 23 January 2009; online 31 January 2009)

In the molecule of the title compound, C₂₀H₁₆N₆, the central C—C bond lies on a crystallographic inversion centre. The quinoxalidine ring is nearly planar, with a maximum deviation of 0.021 (2) Å from the mean plane. The crystal structure is stabilized by intermolecular C—H⋯N interactions, leading to the formation of a layer-like structure, which extends along the a axis.

Related literature

For the synthesis of the Schiff base, see: Zolezzi et al. (1999 ). For the properties of Schiff base ligands, see: Gupta & Sutar (2008 ); Harmenberg et al. (1991 ); Mayadevi et al. (2003 ); Miller et al. (1999 ); Naylor et al. (1993 ); Sreekala & Yusuff (1994 ); Xavier et al. (2004 ); Yusuff & Sreekala (1991 ). For related structures, see: Habibi et al. (2006 ); Taylor & Kennard (1982 ).

Experimental

Crystal data

C₂₀H₁₆N₆
M_r = 340.39
Triclinic, $[P \overline 1]$
a = 6.888 (2) Å
b = 7.381 (3) Å
c = 9.638 (4) Å
α = 101.674 (6)°
β = 96.233 (6)°
γ = 116.046 (5)°
V = 420.1 (3) Å³
Z = 1
Mo Kα radiation
μ = 0.09 mm⁻¹
T = 298 (2) K
0.40 × 0.24 × 0.18 mm

Data collection

Bruker SMART CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 2001 ) T_min = 0.967, T_max = 0.995
3956 measured reflections
1465 independent reflections
1239 reflections with I > 2σ(I)
R_int = 0.025

Refinement

R[F² > 2σ(F²)] = 0.071
wR(F²) = 0.164
S = 1.27
1465 reflections
118 parameters
H-atom parameters constrained
Δρ_max = 0.13 e Å⁻³
Δρ_min = −0.21 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C1—H1⋯N2ⁱ	0.93	2.73	3.647 (4)	168
C9—H9⋯N1ⁱⁱ	0.93	2.67	3.593 (3)	169
Symmetry codes: (i) x+1, y, z; (ii) x-1, y, z.

Data collection: SMART (Bruker, 2000 ); cell refinement: SAINT (Bruker, 2000); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008) and/or ORTEP-3 (Farrugia, 1997 ); software used to prepare material for publication: SHELXL97 and PLATON (Spek, 2003 ).

Supporting information

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536809003006/fj2185sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536809003006/fj2185Isup2.hkl

checkCIF report

Comment top

Schiff bases derived from aldehydes and diamines constitute one of the most relevant synthetic ligand systems. They find application in a broad range of transition metal catalyzed reactions including lactide polymerization, epoxidation of olefins, hydroxylation and asymmetric ring opening of epoxides (Gupta & Sutar, 2008). Many drug candidates bearing quinoxaline core structures are in clinical trials in antiviral (Harmenberg et al., 1991), anticancer and central nervous system therapeutic areas (Naylor et al., 1993). Catalytic and antibacterial activities have been observed for the Schiff base complexes derived from Quinoxaline-2-carboxaldehyde (Yusuff & Sreekala, 1991; Sreekala & Yusuff, 1994; Mayadevi et al., 2003). Ethylenediamine groups appear to be of importance for various transition metal catalysis (Miller et al., 1999; Xavier et al., 2004). We have recently prepared the title compound (1), and report here its structure.

The single-crystal X-ray structure determination of (1) was carried out at 298 (2) K. The structure analysis showed that the compound to form in triclinic space group P-1 with a =6.888 (2) A°, b=7.381 (3) A°, c=9.638 (4) A° and α = 101.674 (6)°, β = 96.233 (6)°, γ = 116.046 (5)° with z=1. A perspective drawing is depicted in figure 1 with the atomic numbering scheme. The C10—N3—C9, N3—C9—C8 angles are 117.9 (2)° and 121.5 (2)° respectively. The N3—C10 and N3—C9 bond lengths are 1.455 (3) A° and 1.260 (3) A° respectively. In this compound (1), the short (C–)H···N contacts are responsible for the stability of layer structure (figure 3) which extends along the a axis (Taylor & Kennard, 1982). The (C–)H···N distances and C—H—N angles are given in table 1.

Related literature top

For the synthesis of the Schiff base, see: Zolezzi et al. (1999). For the properties of Schiff base ligands, see: Gupta & Sutar (2008); Harmenberg et al. (1991); Mayadevi et al. (2003); Miller et al. (1999); Naylor et al. (1993); Sreekala & Yusuff (1994); Xavier et al. (2004); Yusuff & Sreekala (1991). For related structures, see: Habibi et al. (2006); Taylor & Kennard (1982).

Experimental top

A hot solution of ethylenediamine (1 mmol) in methanol (25 ml) was slowly added over a hot solution of quinoxaline-2-carboxaldehyde (2 mmol) in the same solvent (50 ml). The resulting mixture on cooling yielded the crude product. The precipitated diimine was filtered off and washed with cold methanol. Light yellow single crystals of (1) were obtained from a solution of dichloromethane by slow evaporation.

Computing details top

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 (Farrugia, 1997); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008) and PLATON (Spek, 2003).

Figures top

	Fig. 1. An ORTEP-3 (Farrugia, 1997) plot of the (I) compound, with the atomic labelling scheme. The shapes of the ellipsoids correspond to 50% probability contours of atomic displacement.
	Fig. 2. Unit cell packing diagram of N,N'-bis[(E)-quinoxalin-2-ylmethylidene]ethane-1,2-diamine.
	Fig. 3. Pairs of (C–)H···N interactions lead to a layer structure along the a axis.

N,N'-Bis[(E)-quinoxalin-2-ylmethylidene]ethane-1,2-diamine top

Crystal data top

C₂₀H₁₆N₆	Z = 1
M_r = 340.39	F(000) = 178
Triclinic, P1	D_x = 1.345 Mg m⁻³
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 6.888 (2) Å	Cell parameters from 1465 reflections
b = 7.381 (3) Å	θ = 2.3–25.0°
c = 9.638 (4) Å	µ = 0.09 mm⁻¹
α = 101.674 (6)°	T = 298 K
β = 96.233 (6)°	Plate, yellow
γ = 116.046 (5)°	0.40 × 0.24 × 0.18 mm
V = 420.1 (3) Å³

Data collection top

Bruker SMART CCD area-detector diffractometer	1465 independent reflections
Radiation source: fine-focus sealed tube	1239 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.025
ϕ and ω scans	θ_max = 25.0°, θ_min = 2.2°
Absorption correction: multi-scan (SADABS; Sheldrick, 2001)	h = −8→8
T_min = 0.967, T_max = 0.995	k = −8→8
3956 measured reflections	l = −11→11

Refinement top

Refinement on F²	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F² > 2σ(F²)] = 0.071	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.164	H-atom parameters constrained
S = 1.27	w = 1/[σ²(F_o²) + (0.0542P)² + 0.1572P] where P = (F_o² + 2F_c²)/3
1465 reflections	(Δ/σ)_max < 0.001
118 parameters	Δρ_max = 0.13 e Å⁻³
0 restraints	Δρ_min = −0.21 e Å⁻³

Crystal data top

C₂₀H₁₆N₆	γ = 116.046 (5)°
M_r = 340.39	V = 420.1 (3) Å³
Triclinic, P1	Z = 1
a = 6.888 (2) Å	Mo Kα radiation
b = 7.381 (3) Å	µ = 0.09 mm⁻¹
c = 9.638 (4) Å	T = 298 K
α = 101.674 (6)°	0.40 × 0.24 × 0.18 mm
β = 96.233 (6)°

Data collection top

Bruker SMART CCD area-detector diffractometer	1465 independent reflections
Absorption correction: multi-scan (SADABS; Sheldrick, 2001)	1239 reflections with I > 2σ(I)
T_min = 0.967, T_max = 0.995	R_int = 0.025
3956 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.071	0 restraints
wR(F²) = 0.164	H-atom parameters constrained
S = 1.27	Δρ_max = 0.13 e Å⁻³
1465 reflections	Δρ_min = −0.21 e Å⁻³
118 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

	x	y	z	U_iso*/U_eq
N1	0.4604 (3)	0.2446 (3)	0.5782 (2)	0.0439 (6)
N2	0.0673 (3)	0.2571 (3)	0.4735 (2)	0.0405 (6)
N3	0.0679 (3)	0.3587 (3)	0.8476 (2)	0.0425 (6)
C1	0.5203 (4)	0.1943 (4)	0.3355 (3)	0.0482 (7)
H1	0.6488	0.1881	0.3682	0.058*
C2	0.4561 (5)	0.1772 (4)	0.1921 (3)	0.0518 (8)
H2	0.5425	0.1608	0.1280	0.062*
C3	0.2624 (5)	0.1841 (4)	0.1406 (3)	0.0522 (8)
H3	0.2216	0.1735	0.0429	0.063*
C4	0.1338 (4)	0.2062 (4)	0.2329 (3)	0.0473 (7)
H4	0.0032	0.2070	0.1975	0.057*
C5	0.1963 (4)	0.2279 (4)	0.3820 (3)	0.0374 (6)
C6	0.3918 (4)	0.2210 (4)	0.4334 (3)	0.0381 (6)
C7	0.3349 (4)	0.2733 (4)	0.6617 (3)	0.0429 (7)
H7	0.3764	0.2897	0.7604	0.051*
C8	0.1382 (4)	0.2813 (4)	0.6116 (3)	0.0371 (6)
C9	0.0064 (4)	0.3217 (4)	0.7124 (3)	0.0419 (6)
H9	−0.1251	0.3198	0.6754	0.050*
C10	−0.0707 (4)	0.3998 (4)	0.9395 (3)	0.0438 (7)
H10A	−0.1415	0.2835	0.9804	0.053*
H10B	−0.1857	0.4133	0.8820	0.053*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
N1	0.0419 (12)	0.0551 (14)	0.0405 (12)	0.0272 (11)	0.0095 (10)	0.0150 (10)
N2	0.0409 (12)	0.0465 (13)	0.0350 (12)	0.0231 (11)	0.0064 (9)	0.0084 (10)
N3	0.0463 (13)	0.0504 (13)	0.0342 (12)	0.0257 (11)	0.0108 (9)	0.0113 (10)
C1	0.0440 (15)	0.0514 (17)	0.0495 (16)	0.0233 (14)	0.0136 (13)	0.0113 (13)
C2	0.0565 (18)	0.0512 (17)	0.0433 (16)	0.0210 (14)	0.0221 (13)	0.0093 (13)
C3	0.0596 (18)	0.0568 (18)	0.0332 (14)	0.0228 (15)	0.0095 (13)	0.0101 (13)
C4	0.0497 (16)	0.0554 (18)	0.0345 (14)	0.0243 (14)	0.0039 (12)	0.0122 (12)
C5	0.0375 (14)	0.0327 (13)	0.0385 (14)	0.0138 (11)	0.0077 (11)	0.0098 (11)
C6	0.0380 (13)	0.0377 (14)	0.0372 (13)	0.0173 (12)	0.0074 (11)	0.0096 (11)
C7	0.0448 (15)	0.0524 (16)	0.0313 (13)	0.0233 (13)	0.0052 (11)	0.0127 (12)
C8	0.0368 (13)	0.0367 (14)	0.0357 (14)	0.0173 (11)	0.0061 (11)	0.0071 (11)
C9	0.0414 (15)	0.0457 (16)	0.0406 (15)	0.0229 (13)	0.0076 (12)	0.0113 (12)
C10	0.0443 (15)	0.0528 (17)	0.0368 (14)	0.0235 (13)	0.0139 (11)	0.0139 (12)

Geometric parameters (Å, º) top

N1—C7	1.298 (3)	C3—H3	0.9300
N1—C6	1.373 (3)	C4—C5	1.410 (3)
N2—C8	1.315 (3)	C4—H4	0.9300
N2—C5	1.369 (3)	C5—C6	1.409 (3)
N3—C9	1.260 (3)	C7—C8	1.418 (3)
N3—C10	1.455 (3)	C7—H7	0.9300
C1—C2	1.367 (4)	C8—C9	1.472 (3)
C1—C6	1.404 (3)	C9—H9	0.9300
C1—H1	0.9300	C10—C10ⁱ	1.512 (5)
C2—C3	1.398 (4)	C10—H10A	0.9700
C2—H2	0.9300	C10—H10B	0.9700
C3—C4	1.357 (4)

C7—N1—C6	115.8 (2)	N1—C6—C1	119.7 (2)
C8—N2—C5	116.2 (2)	N1—C6—C5	120.9 (2)
C9—N3—C10	117.9 (2)	C1—C6—C5	119.4 (2)
C2—C1—C6	119.9 (3)	N1—C7—C8	124.0 (2)
C2—C1—H1	120.1	N1—C7—H7	118.0
C6—C1—H1	120.1	C8—C7—H7	118.0
C1—C2—C3	121.0 (3)	N2—C8—C7	121.6 (2)
C1—C2—H2	119.5	N2—C8—C9	116.9 (2)
C3—C2—H2	119.5	C7—C8—C9	121.5 (2)
C4—C3—C2	120.1 (3)	N3—C9—C8	121.5 (2)
C4—C3—H3	120.0	N3—C9—H9	119.3
C2—C3—H3	120.0	C8—C9—H9	119.3
C3—C4—C5	120.7 (3)	N3—C10—C10	109.5 (3)
C3—C4—H4	119.7	N3—C10—H10A	109.8
C5—C4—H4	119.7	C10—C10—H10A	109.8
N2—C5—C6	121.6 (2)	N3—C10—H10B	109.8
N2—C5—C4	119.4 (2)	C10—C10—H10B	109.8
C6—C5—C4	119.0 (2)	H10A—C10—H10B	108.2

Symmetry code: (i) −x, −y+1, −z+2.

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C1—H1···N2ⁱⁱ	0.93	2.73	3.647 (4)	168
C9—H9···N1ⁱⁱⁱ	0.93	2.67	3.593 (3)	169

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

Experimental details

Crystal data
Chemical formula	C₂₀H₁₆N₆
M_r	340.39
Crystal system, space group	Triclinic, P1
Temperature (K)	298
a, b, c (Å)	6.888 (2), 7.381 (3), 9.638 (4)
α, β, γ (°)	101.674 (6), 96.233 (6), 116.046 (5)
V (Å³)	420.1 (3)
Z	1
Radiation type	Mo Kα
µ (mm⁻¹)	0.09
Crystal size (mm)	0.40 × 0.24 × 0.18

Data collection
Diffractometer	Bruker SMART CCD area-detector diffractometer
Absorption correction	Multi-scan (SADABS; Sheldrick, 2001)
T_min, T_max	0.967, 0.995
No. of measured, independent and observed [I > 2σ(I)] reflections	3956, 1465, 1239
R_int	0.025
(sin θ/λ)_max (Å⁻¹)	0.595

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.071, 0.164, 1.27
No. of reflections	1465
No. of parameters	118
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.13, −0.21

Computer programs: SMART (Bruker, 2000), SAINT (Bruker, 2000), SHELXS97 (Sheldrick, 2008), SHELXTL (Farrugia, 1997), SHELXL97 (Sheldrick, 2008) and PLATON (Spek, 2003).

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C1—H1···N2ⁱ	0.93	2.73	3.647 (4)	168
C9—H9···N1ⁱⁱ	0.93	2.67	3.593 (3)	169

Symmetry codes: (i) x+1, y, z; (ii) x−1, y, z.

Acknowledgements

The authors thank Professor M. V. Rajasekharan, School of Chemistry, University of Hyderabad, for kind help and useful discussions. The X-ray data were collected on the diffractometer facilities at the University of Hyderabad provided by the Department of Science and Technology. DV gratefully acknowledges financial support from the Council of Scientific and Industrial Research (CSIR), India. MS thanks KSCSTE, Trivandrum, Kerala, for financial assistance.

References

Bruker (2000). SMART and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Farrugia, L. J. (1997). J. Appl. Cryst. 30, 565. CrossRef IUCr Journals Google Scholar
Gupta, K. C. & Sutar, A. K. (2008). Coord. Chem. Rev. 252, 1420–1450. Web of Science CrossRef CAS Google Scholar
Habibi, M. H., Montazerozohori, M., Lalegani, A., Harrington, R. W. & Clegg, W. (2006). J. Fluorine Chem. 127, 769–773. Web of Science CSD CrossRef CAS Google Scholar
Harmenberg, J., Akesson-Johansson, A., Graslund, A., Malmfors, T., Bergman, J., Wahren, B., Akerfeldt, S., Lundblad, L. & Cox, S. (1991). Antiviral Res. 15, 193–204. CrossRef PubMed CAS Web of Science Google Scholar
Mayadevi, S., Prasad, P. G. & Yusuff, K. K. M. (2003). Synth. React. Inorg. Met. Org. Chem. 33, 481–496. Web of Science CrossRef CAS Google Scholar
Miller, J. K., Baag, J. H. & Abu-Omar, M. M. (1999). Inorg. Chem. 38, 4510–4514. Web of Science CSD CrossRef PubMed CAS Google Scholar
Naylor, M. A., Stephen, M. A., Nolan, J., Sutton, B., Tocher, J. H., Fielden, E. M., Adams, G. E. & Strafford, I. J. (1993). Anticancer Drug. Des. 8, 439–461. CAS PubMed Web of Science Google Scholar
Sheldrick, G. M. (2001). SADABS. University of Göttingen, Germany. Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Spek, A. L. (2003). J. Appl. Cryst. 36, 7–13. Web of Science CrossRef CAS IUCr Journals Google Scholar
Sreekala, R. & Yusuff, K. K. M. (1994). Synth. React. Inorg. Met. Org. Chem. 24, 1773–1788. CrossRef CAS Web of Science Google Scholar
Taylor, R. & Kennard, O. (1982). J. Am. Chem. Soc. 104, 5063–5070. CrossRef CAS Web of Science Google Scholar
Xavier, K. O., Chacko, J. & Yusuff, K. K. M. (2004). Appl. Catal. A Gen. 258, 251–259. Web of Science CrossRef CAS Google Scholar
Yusuff, K. K. M. & Sreekala, R. (1991). Synth. React. Inorg. Met. Org. Chem. 21, 553–568. CrossRef CAS Web of Science Google Scholar
Zolezzi, S., Decinti, A. & Spodine, E. (1999). Polyhedron, 18, 897–904. Web of Science CrossRef CAS Google Scholar