(1E,3E,5E,7E)-4,4′-(Octa-1,3,5,7-tetra­ene-1,8-di­yl)dipyridine

Arshad, M.N.; Bader, M.M.; Pham, P.-T.T.; Holman, K.T.

doi:10.1107/S160053681000317X

organic compounds

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ISSN: 2056-9890

Volume 66| Part 3| March 2010| Page o508

doi:10.1107/S160053681000317X

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(1E,3E,5E,7E)-4,4′-(Octa-1,3,5,7-tetraene-1,8-diyl)dipyridine

Muhammad Nadeem Arshad,^a ‡ Mamoun M. Bader,^b Phuong-Truc T. Pham ^c and K. Travis Holman ^d ^*

^aDepartment of Chemistry, GC University Lahore 54000, Pakistan, ^bDepartment of Chemistry, Pennsylvania State University, Hazleton, PA 18202, USA, ^cDepartment of Chemistry, Pennsylvania State University, Worthington Scranton, PA 18512, USA, and ^dDepartment of Chemistry, Georgetown University, 37th and O St. NW, Washington, DC 20057, USA
^*Correspondence e-mail: kth7@georgetown.edu

(Received 9 December 2009; accepted 25 January 2010; online 3 February 2010)

The title compound, C₁₈H₁₆N₂, crystallizes with one and a half independent molecules in the asymmetric unit, with the half-molecule being completed by crystallographic inversion symmetry. Both independent molecules are almost planar, with the non-H atoms exhibiting r.m.s. deviations from the least-squares molecular plane of 0.175 and 0.118 Å, respectively.

Related literature

For the synthesis, see: Woitellier et al. (1989 ). For the use of the diene and the triene in the synthesis of ladderanes via template-directed photochemistry, see: Gao et al. (2004 ). For a related structure, see: Bader (2009 ).

Experimental

Crystal data

C₁₈H₁₆N₂
M_r = 260.33
Monoclinic, P 2₁ /c
a = 5.5565 (12) Å
b = 17.950 (4) Å
c = 21.542 (5) Å
β = 94.809 (5)°
V = 2141.0 (8) Å³
Z = 6
Mo Kα radiation
μ = 0.07 mm⁻¹
T = 173 K
0.50 × 0.23 × 0.20 mm

Data collection

Siemens SMART 1K diffractometer
Absorption correction: multi-scan (SADABS; Bruker 2001 ) T_min = 0.979, T_max = 0.986
13659 measured reflections
4727 independent reflections
2195 reflections with I > 2σ(I)
R_int = 0.061

Refinement

R[F² > 2σ(F²)] = 0.045
wR(F²) = 0.102
S = 0.87
4727 reflections
343 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.15 e Å⁻³
Δρ_min = −0.17 e Å⁻³

Data collection: SMART (Bruker, 2001); cell refinement: SAINT (Bruker, 2001); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997 ), PLATON (Spek, 2009 ) and X-SEED (Barbour, 2001 )'; software used to prepare material for publication: WinGX (Farrugia, 1999 ) and PLATON.

Supporting information

Crystal structure: contains datablocks I, global. DOI: 10.1107/S160053681000317X/ng2706sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S160053681000317X/ng2706Isup2.hkl

checkCIF report

Comment top

The present bispyridyl tetraene is in continuation to our previously reported crystal structure of the bispyridyl triene analog (Bader, 2009). The diene and triene have been used in the synthesis of ladderanes via template directed photochemistry (Gao et al., 2004). The electron transfer properties of metal complexes of bispyridyl polyenes have also been studied and the crystal structure of a metal complex of the title compound was reported (Woitellier et al., 1989).

The title compound crystallizes in the monoclinic crystal system such that there are one and one-half molecules in the asymmetric unit, molecules A and B, respectively. Molecule B resides about an inverison center. The bond lengths of molecules A and B are comparable to the previously published structure of the triene derivative, namely 4-[(1E,3E,5E)-6-(4-pyridyl)hexa-1,3,5-trienyl]pyridine (Bader, 2009) and also the previously reported metal complex of the title compound (Woitellier et al., 1989). Molecules A and B both deviate significantly from planarity (Fig. 3). The root mean square deviation of the carbon and nitrogen atoms from the least squares plane defined by such atoms in molecule A measures 0.175 Å, with N3 deviating from the plane by as much as 0.33 Å. The dihedral angle between the two planar pyridine rings of molecule A measures 7.53(0.11)°. Similarly, the root mean square deviation of the carbon and nitrogen atoms from the least squares plane defined by such atoms in molecule B measures 0.118 Å, with C25 being located 0.17 Å from the plane.

Related literature top

For the synthesis, see: Woitellier et al. (1989). For the use of the diene and the triene in the synthesis of ladderanes via template-directed photochemistry, see: Gao et al. (2004). For a related structure, see: Bader (2009).

Experimental top

The compound was synthesized following the literature method (Woitellier et al., 1989).

Computing details top

Data collection: SMART (Bruker, 2001); cell refinement: SAINT (Bruker, 2001); data reduction: SAINT (Bruker, 2001); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997), PLATON (Spek, 2009) and X-SEED (Barbour, 2001)'; software used to prepare material for publication: WinGX (Farrugia, 1999) and PLATON (Spek, 2009).

Figures top

	Fig. 1. The labelled thermal ellipsoids plot with 50% probability level.
	Fig. 2. Unit cell packing for the title compound. Hydrogen atoms have been omitted for clarity.
	Fig. 3. Planarity comparison for unique molecules A and B.

(1E,3E,5E,7E)-4,4'-(Octa-1,3,5,7-tetraene-1,8- diyl)dipyridine top

Crystal data top

C₁₈H₁₆N₂	F(000) = 828
M_r = 260.33	D_x = 1.211 Mg m⁻³
Monoclinic, P2₁/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 1908 reflections
a = 5.5565 (12) Å	θ = 2.3–24.0°
b = 17.950 (4) Å	µ = 0.07 mm⁻¹
c = 21.542 (5) Å	T = 173 K
β = 94.809 (5)°	Needle, brown
V = 2141.0 (8) Å³	0.50 × 0.23 × 0.20 mm
Z = 6

Data collection top

Siemens SMART 1K diffractometer	2195 reflections with I > 2σ(I)
ω scans	R_int = 0.061
Absorption correction: multi-scan (SADABS; Bruker 2001)	θ_max = 27.2°, θ_min = 1.9°
T_min = 0.979, T_max = 0.986	h = −5→7
13659 measured reflections	k = −20→23
4727 independent reflections	l = −27→21

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)] = 0.045	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.102	H atoms treated by a mixture of independent and constrained refinement
S = 0.87	w = 1/[σ²(F_o²) + (0.0357P)²] where P = (F_o² + 2F_c²)/3
4727 reflections	(Δ/σ)_max < 0.001
343 parameters	Δρ_max = 0.15 e Å⁻³
0 restraints	Δρ_min = −0.17 e Å⁻³

Crystal data top

C₁₈H₁₆N₂	V = 2141.0 (8) Å³
M_r = 260.33	Z = 6
Monoclinic, P2₁/c	Mo Kα radiation
a = 5.5565 (12) Å	µ = 0.07 mm⁻¹
b = 17.950 (4) Å	T = 173 K
c = 21.542 (5) Å	0.50 × 0.23 × 0.20 mm
β = 94.809 (5)°

Data collection top

Siemens SMART 1K diffractometer	4727 independent reflections
Absorption correction: multi-scan (SADABS; Bruker 2001)	2195 reflections with I > 2σ(I)
T_min = 0.979, T_max = 0.986	R_int = 0.061
13659 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.045	0 restraints
wR(F²) = 0.102	H atoms treated by a mixture of independent and constrained refinement
S = 0.87	Δρ_max = 0.15 e Å⁻³
4727 reflections	Δρ_min = −0.17 e Å⁻³
343 parameters

Special details top

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

	x	y	z	U_iso*/U_eq
N1	−0.3021 (3)	0.65494 (9)	0.12504 (7)	0.0448 (4)
N2	1.1856 (3)	0.05066 (10)	0.59878 (8)	0.0536 (5)
N3	0.7464 (3)	0.29359 (9)	0.24722 (7)	0.0469 (4)
C1	−0.4416 (4)	0.59659 (12)	0.13700 (9)	0.0436 (5)
C2	−0.3757 (3)	0.54235 (11)	0.18034 (9)	0.0384 (5)
C3	−0.1522 (3)	0.54509 (10)	0.21419 (8)	0.0343 (5)
C4	−0.0079 (3)	0.60627 (11)	0.20284 (8)	0.0376 (5)
C5	−0.0885 (4)	0.65812 (12)	0.15892 (9)	0.0433 (5)
C6	−0.0763 (4)	0.48508 (11)	0.25731 (9)	0.0385 (5)
C7	0.1333 (4)	0.47926 (11)	0.29196 (8)	0.0385 (5)
C8	0.2023 (4)	0.41530 (11)	0.32953 (8)	0.0381 (5)
C9	0.4162 (4)	0.40603 (11)	0.36246 (8)	0.0389 (5)
C10	0.4835 (4)	0.33966 (11)	0.39705 (8)	0.0379 (5)
C11	0.6999 (4)	0.32671 (11)	0.42754 (8)	0.0386 (5)
C12	0.7613 (4)	0.25807 (11)	0.45946 (8)	0.0375 (5)
C13	0.9763 (4)	0.24363 (11)	0.48963 (8)	0.0383 (5)
C14	1.0455 (3)	0.17596 (10)	0.52440 (8)	0.0346 (5)
C15	0.8974 (4)	0.11369 (11)	0.52742 (9)	0.0418 (5)
C16	0.9740 (4)	0.05425 (12)	0.56460 (10)	0.0480 (6)
C17	1.3282 (4)	0.11009 (13)	0.59511 (10)	0.0526 (6)
C18	1.2671 (3)	0.17204 (12)	0.55905 (9)	0.0436 (5)
C19	0.5479 (4)	0.25131 (12)	0.24915 (9)	0.0444 (5)
C20	0.4693 (3)	0.20009 (11)	0.20450 (9)	0.0391 (5)
C21	0.5991 (3)	0.18927 (10)	0.15268 (8)	0.0346 (5)
C22	0.8084 (3)	0.23195 (11)	0.15099 (9)	0.0415 (5)
C23	0.8709 (4)	0.28191 (12)	0.19777 (10)	0.0459 (5)
C24	0.5221 (3)	0.14039 (11)	0.10062 (9)	0.0388 (5)
C25	0.3179 (4)	0.10021 (10)	0.09310 (9)	0.0388 (5)
C26	0.2444 (4)	0.05851 (11)	0.03763 (9)	0.0409 (5)
C27	0.0375 (4)	0.01998 (10)	0.02796 (8)	0.0410 (5)
H1	−0.601 (3)	0.5947 (10)	0.1124 (7)	0.049*
H2	−0.481 (3)	0.5029 (10)	0.1877 (8)	0.049*
H4	0.151 (3)	0.6145 (9)	0.2237 (7)	0.049*
H5	0.016 (3)	0.6982 (10)	0.1492 (7)	0.049*
H6	−0.194 (3)	0.4458 (10)	0.2585 (8)	0.049*
H7	0.258 (3)	0.5183 (10)	0.2906 (7)	0.049*
H8	0.077 (3)	0.3763 (10)	0.3290 (7)	0.049*
H9	0.539 (3)	0.4467 (10)	0.3614 (7)	0.049*
H10	0.361 (3)	0.3004 (10)	0.3966 (7)	0.049*
H11	0.826 (3)	0.3624 (10)	0.4272 (8)	0.049*
H12	0.633 (3)	0.2204 (10)	0.4577 (7)	0.049*
H13	1.103 (3)	0.2809 (10)	0.4894 (7)	0.049*
H15	0.739 (3)	0.1129 (10)	0.5057 (8)	0.049*
H16	0.864 (3)	0.0118 (10)	0.5671 (8)	0.049*
H17	1.483 (3)	0.1070 (10)	0.6207 (8)	0.049*
H18	1.381 (3)	0.2120 (10)	0.5576 (7)	0.049*
H19	0.457 (3)	0.2596 (9)	0.2858 (7)	0.049*
H20	0.319 (3)	0.1734 (10)	0.2092 (7)	0.049*
H22	0.903 (3)	0.2249 (9)	0.1158 (7)	0.049*
H23	1.019 (3)	0.3124 (10)	0.1963 (7)	0.049*
H24	0.628 (3)	0.1390 (9)	0.0662 (8)	0.049*
H25	0.207 (3)	0.1001 (9)	0.1263 (7)	0.049*
H26	0.355 (3)	0.0600 (9)	0.0042 (8)	0.049*
H27	−0.071 (3)	0.0190 (9)	0.0619 (7)	0.049*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
N1	0.0449 (11)	0.0430 (12)	0.0459 (10)	0.0082 (9)	0.0007 (9)	0.0022 (8)
N2	0.0463 (11)	0.0473 (12)	0.0672 (13)	0.0057 (9)	0.0044 (10)	0.0136 (9)
N3	0.0500 (11)	0.0411 (11)	0.0501 (11)	−0.0068 (9)	0.0065 (9)	−0.0035 (8)
C1	0.0402 (13)	0.0470 (15)	0.0424 (13)	0.0078 (11)	−0.0024 (10)	−0.0058 (11)
C2	0.0378 (12)	0.0369 (13)	0.0405 (12)	−0.0004 (9)	0.0029 (10)	−0.0054 (10)
C3	0.0378 (11)	0.0324 (12)	0.0330 (11)	0.0023 (9)	0.0049 (9)	−0.0040 (9)
C4	0.0335 (11)	0.0393 (13)	0.0400 (12)	−0.0003 (10)	0.0028 (9)	0.0024 (10)
C5	0.0424 (13)	0.0398 (14)	0.0480 (13)	0.0016 (10)	0.0059 (11)	0.0071 (11)
C6	0.0437 (13)	0.0315 (13)	0.0401 (12)	−0.0002 (9)	0.0029 (10)	−0.0028 (9)
C7	0.0488 (13)	0.0311 (13)	0.0358 (12)	−0.0022 (9)	0.0034 (10)	0.0012 (9)
C8	0.0476 (13)	0.0310 (12)	0.0357 (11)	0.0008 (9)	0.0040 (10)	0.0001 (9)
C9	0.0520 (13)	0.0308 (13)	0.0336 (11)	−0.0021 (10)	0.0022 (10)	−0.0011 (9)
C10	0.0508 (14)	0.0306 (13)	0.0321 (11)	−0.0005 (9)	0.0025 (10)	−0.0023 (9)
C11	0.0504 (14)	0.0326 (13)	0.0330 (11)	−0.0035 (10)	0.0033 (10)	−0.0007 (9)
C12	0.0480 (13)	0.0311 (13)	0.0335 (11)	0.0002 (9)	0.0033 (10)	−0.0022 (9)
C13	0.0449 (13)	0.0324 (13)	0.0373 (11)	−0.0021 (9)	0.0023 (10)	−0.0011 (9)
C14	0.0358 (11)	0.0353 (12)	0.0333 (11)	0.0026 (9)	0.0061 (9)	−0.0032 (9)
C15	0.0415 (12)	0.0382 (13)	0.0454 (13)	−0.0001 (10)	0.0022 (10)	0.0002 (10)
C16	0.0471 (14)	0.0398 (14)	0.0572 (14)	−0.0024 (11)	0.0062 (11)	0.0082 (11)
C17	0.0419 (14)	0.0562 (17)	0.0590 (15)	0.0076 (12)	0.0009 (11)	0.0135 (12)
C18	0.0401 (13)	0.0400 (14)	0.0505 (13)	−0.0019 (10)	0.0030 (11)	0.0037 (11)
C19	0.0505 (14)	0.0421 (14)	0.0416 (13)	−0.0030 (11)	0.0100 (10)	−0.0022 (10)
C20	0.0375 (12)	0.0356 (13)	0.0444 (12)	−0.0053 (9)	0.0050 (10)	0.0029 (10)
C21	0.0400 (11)	0.0290 (12)	0.0345 (11)	0.0022 (9)	0.0022 (9)	0.0049 (9)
C22	0.0436 (13)	0.0411 (14)	0.0408 (12)	−0.0033 (10)	0.0082 (10)	0.0017 (10)
C23	0.0424 (13)	0.0440 (14)	0.0514 (14)	−0.0091 (10)	0.0039 (11)	0.0035 (11)
C24	0.0457 (13)	0.0344 (12)	0.0372 (12)	0.0035 (10)	0.0090 (10)	0.0019 (9)
C25	0.0463 (13)	0.0298 (12)	0.0407 (13)	0.0033 (10)	0.0053 (10)	0.0005 (10)
C26	0.0510 (14)	0.0332 (13)	0.0386 (13)	0.0036 (10)	0.0045 (10)	0.0014 (10)
C27	0.0510 (14)	0.0309 (12)	0.0409 (13)	0.0030 (10)	0.0031 (10)	0.0015 (9)

Geometric parameters (Å, º) top

N1—C1	1.341 (2)	C12—H12	0.982 (17)
N1—C5	1.341 (2)	C13—C14	1.462 (2)
N2—C17	1.335 (2)	C13—H13	0.972 (17)
N2—C16	1.335 (2)	C14—C18	1.387 (2)
N3—C23	1.334 (2)	C14—C15	1.393 (2)
N3—C19	1.342 (2)	C15—C16	1.380 (3)
C1—C2	1.377 (3)	C15—H15	0.962 (16)
C1—H1	0.996 (16)	C16—H16	0.981 (17)
C2—C3	1.387 (2)	C17—C18	1.382 (3)
C2—H2	0.942 (17)	C17—H17	0.984 (16)
C3—C4	1.394 (2)	C18—H18	0.960 (17)
C3—C6	1.461 (3)	C19—C20	1.375 (3)
C4—C5	1.375 (2)	C19—H19	0.983 (16)
C4—H4	0.968 (16)	C20—C21	1.392 (2)
C5—H5	0.960 (17)	C20—H20	0.974 (17)
C6—C7	1.334 (2)	C21—C22	1.396 (2)
C6—H6	0.964 (17)	C21—C24	1.460 (2)
C7—C8	1.438 (2)	C22—C23	1.372 (3)
C7—H7	0.986 (17)	C22—H22	0.966 (16)
C8—C9	1.343 (2)	C23—H23	0.990 (17)
C8—H8	0.987 (17)	C24—C25	1.343 (2)
C9—C10	1.438 (3)	C24—H24	0.985 (16)
C9—H9	1.000 (17)	C25—C26	1.440 (2)
C10—C11	1.341 (2)	C25—H25	0.983 (16)
C10—H10	0.981 (17)	C26—C27	1.343 (2)
C11—C12	1.438 (2)	C26—H26	0.986 (16)
C11—H11	0.951 (17)	C27—C27ⁱ	1.434 (4)
C12—C13	1.337 (2)	C27—H27	0.985 (16)

C1—N1—C5	115.34 (17)	C18—C14—C15	115.83 (19)
C17—N2—C16	115.36 (19)	C18—C14—C13	120.08 (18)
C23—N3—C19	114.71 (18)	C15—C14—C13	124.05 (17)
N1—C1—C2	123.89 (19)	C16—C15—C14	119.54 (19)
N1—C1—H1	115.4 (10)	C16—C15—H15	119.8 (11)
C2—C1—H1	120.7 (10)	C14—C15—H15	120.6 (11)
C1—C2—C3	120.4 (2)	N2—C16—C15	124.9 (2)
C1—C2—H2	120.7 (11)	N2—C16—H16	117.1 (10)
C3—C2—H2	118.8 (11)	C15—C16—H16	118.0 (10)
C2—C3—C4	116.02 (18)	N2—C17—C18	123.9 (2)
C2—C3—C6	120.39 (18)	N2—C17—H17	114.7 (11)
C4—C3—C6	123.57 (17)	C18—C17—H17	121.5 (11)
C5—C4—C3	119.67 (18)	C17—C18—C14	120.5 (2)
C5—C4—H4	116.6 (10)	C17—C18—H18	119.2 (10)
C3—C4—H4	123.7 (10)	C14—C18—H18	120.3 (10)
N1—C5—C4	124.6 (2)	N3—C19—C20	124.76 (19)
N1—C5—H5	116.0 (10)	N3—C19—H19	114.6 (10)
C4—C5—H5	119.2 (10)	C20—C19—H19	120.6 (10)
C7—C6—C3	127.26 (19)	C19—C20—C21	119.91 (18)
C7—C6—H6	119.5 (10)	C19—C20—H20	118.8 (10)
C3—C6—H6	113.3 (10)	C21—C20—H20	121.3 (10)
C6—C7—C8	123.8 (2)	C20—C21—C22	115.66 (18)
C6—C7—H7	120.6 (10)	C20—C21—C24	124.18 (18)
C8—C7—H7	115.5 (10)	C22—C21—C24	120.07 (17)
C9—C8—C7	125.36 (19)	C23—C22—C21	119.98 (19)
C9—C8—H8	120.8 (10)	C23—C22—H22	122.8 (10)
C7—C8—H8	113.8 (10)	C21—C22—H22	117.2 (10)
C8—C9—C10	123.8 (2)	N3—C23—C22	124.97 (19)
C8—C9—H9	118.2 (10)	N3—C23—H23	115.3 (10)
C10—C9—H9	117.9 (10)	C22—C23—H23	119.8 (10)
C11—C10—C9	125.5 (2)	C25—C24—C21	127.29 (18)
C11—C10—H10	118.3 (10)	C25—C24—H24	116.6 (10)
C9—C10—H10	116.1 (10)	C21—C24—H24	116.0 (10)
C10—C11—C12	123.34 (19)	C24—C25—C26	123.86 (19)
C10—C11—H11	120.8 (11)	C24—C25—H25	119.3 (10)
C12—C11—H11	115.8 (11)	C26—C25—H25	116.8 (10)
C13—C12—C11	124.4 (2)	C27—C26—C25	125.16 (19)
C13—C12—H12	120.2 (10)	C27—C26—H26	118.6 (10)
C11—C12—H12	115.4 (10)	C25—C26—H26	116.3 (10)
C12—C13—C14	126.60 (19)	C26—C27—C27ⁱ	124.9 (3)
C12—C13—H13	118.8 (10)	C26—C27—H27	117.6 (10)
C14—C13—H13	114.6 (10)	C27ⁱ—C27—H27	117.5 (10)

C5—N1—C1—C2	−0.4 (3)	C13—C14—C15—C16	−176.12 (18)
N1—C1—C2—C3	−1.0 (3)	C17—N2—C16—C15	−0.3 (3)
C1—C2—C3—C4	2.1 (3)	C14—C15—C16—N2	−0.6 (3)
C1—C2—C3—C6	−176.14 (17)	C16—N2—C17—C18	0.1 (3)
C2—C3—C4—C5	−1.7 (3)	N2—C17—C18—C14	0.9 (3)
C6—C3—C4—C5	176.43 (18)	C15—C14—C18—C17	−1.7 (3)
C1—N1—C5—C4	0.8 (3)	C13—C14—C18—C17	176.04 (18)
C3—C4—C5—N1	0.3 (3)	C23—N3—C19—C20	−1.0 (3)
C2—C3—C6—C7	178.71 (19)	N3—C19—C20—C21	0.1 (3)
C4—C3—C6—C7	0.7 (3)	C19—C20—C21—C22	1.2 (3)
C3—C6—C7—C8	−174.69 (18)	C19—C20—C21—C24	−175.40 (18)
C6—C7—C8—C9	176.5 (2)	C20—C21—C22—C23	−1.6 (3)
C7—C8—C9—C10	−176.75 (17)	C24—C21—C22—C23	175.19 (17)
C8—C9—C10—C11	176.03 (19)	C19—N3—C23—C22	0.6 (3)
C9—C10—C11—C12	−177.47 (17)	C21—C22—C23—N3	0.7 (3)
C10—C11—C12—C13	179.32 (19)	C20—C21—C24—C25	1.7 (3)
C11—C12—C13—C14	177.90 (17)	C22—C21—C24—C25	−174.80 (18)
C12—C13—C14—C18	−172.99 (19)	C21—C24—C25—C26	174.09 (18)
C12—C13—C14—C15	4.5 (3)	C24—C25—C26—C27	−177.56 (19)
C18—C14—C15—C16	1.5 (3)	C25—C26—C27—C27ⁱ	178.4 (2)

Symmetry code: (i) −x, −y, −z.

Experimental details

Crystal data
Chemical formula	C₁₈H₁₆N₂
M_r	260.33
Crystal system, space group	Monoclinic, P2₁/c
Temperature (K)	173
a, b, c (Å)	5.5565 (12), 17.950 (4), 21.542 (5)
β (°)	94.809 (5)
V (Å³)	2141.0 (8)
Z	6
Radiation type	Mo Kα
µ (mm⁻¹)	0.07
Crystal size (mm)	0.50 × 0.23 × 0.20

Data collection
Diffractometer	Siemens SMART 1K diffractometer
Absorption correction	Multi-scan (SADABS; Bruker 2001)
T_min, T_max	0.979, 0.986
No. of measured, independent and observed [I > 2σ(I)] reflections	13659, 4727, 2195
R_int	0.061
(sin θ/λ)_max (Å⁻¹)	0.642

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.045, 0.102, 0.87
No. of reflections	4727
No. of parameters	343
H-atom treatment	H atoms treated by a mixture of independent and constrained refinement
Δρ_max, Δρ_min (e Å⁻³)	0.15, −0.17

Computer programs: SMART (Bruker, 2001), SAINT (Bruker, 2001), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), ORTEP-3 for Windows (Farrugia, 1997), PLATON (Spek, 2009) and X-SEED (Barbour, 2001)', WinGX (Farrugia, 1999) and PLATON (Spek, 2009).

Footnotes

‡Current address: Department of Chemistry, Georgetown University, 37th and O St. NW, Washington, DC 20057, USA.

Acknowledgements

The authors acknowledge the Higher Education Commission of Pakistan for providing a fellowship to MNA under the International Research Support Initiative Programme (IRSIP).

References

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