(-)-(S)-N,N'-Bis[1-(1-naphth-yl)eth-yl]-oxalamide.

The title mol-ecule, C(26)H(24)N(2)O(2), displays C(2) symmetry, with the mol-ecule located on a twofold axis perpendicular to the plane of the oxalamide unit -NH-CO-CO-NH-. The oxalamide core deviates from planarity, as reflected by the O=C-C=O and N-C-C-N torsion angles of 164.3 (5) and 163.2 (5)°, respectively. The naphthyl groups are oriented toward the same face of the oxalamide mean plane and make a dihedral angle of 43.76 (8)°. This conformation is suitable for the formation of inter-molecular N-H⋯O hydrogen bonds, giving noncentrosymmetric dimers incorporating R(2) (2)(10) ring motifs. These nonbonding inter-actions propagate along the 6(1) screw axis normal to the mol-ecular twofold axis, resulting in a single-stranded right-handed helix parallel to [001]. In the crystal, Δ helices are arranged side-by-side and inter-act through π-π contacts between naphthyl groups. The shortest centroid-centroid separation between inter-acting benzene rings is 3.623 (4) Å.

Related literature

For crystal structures of closely related oxalamides, see: Štefanić et al. (2003 ▶); Zhang et al. (2006 ▶); Lee & Wang (2007 ▶); Lee (2010 ▶). For general references on dicarboxamides and oxalamides, and their synthesis under solvent-free conditions, see: Bernès et al. (2008 ▶); Montero-Vázquez et al. (2008 ▶); Jeon et al. (2005 ▶); Noyori (2005 ▶). For helicity assignment in enanti­omorphic space groups, see: Ha & Allewell (1997 ▶).

Experimental

Crystal data

C26H24N2O2

M = 396.47

Hexagonal,

a = 11.4489 (11) Å

c = 28.350 (4) Å

V = 3218.2 (7) Å3

Z = 6

Mo Kα radiation

μ = 0.08 mm−1

T = 298 K

0.40 × 0.22 × 0.20 mm

Data collection

Siemens P4 diffractometer

5314 measured reflections

1208 independent reflections

730 reflections with I > 2σ(I)

R int = 0.057

3 standard reflections every 97 reflections intensity decay: 1%

Refinement

R[F 2 > 2σ(F 2)] = 0.043

wR(F 2) = 0.138

S = 1.11

1208 reflections

141 parameters

1 restraint

H atoms treated by a mixture of independent and constrained refinement

Δρmax = 0.12 e Å−3

Δρmin = −0.14 e Å−3

Data collection: XSCANS (Siemens, 1996 ▶); cell refinement: XSCANS; data reduction: XSCANS; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: Mercury (Macrae et al., 2006 ▶); software used to prepare material for publication: SHELXL97.

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536810043424/jh2225sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536810043424/jh2225Isup2.hkl

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

C26H24N2O2	Dx = 1.227 Mg m−3
Mr = 396.47	Melting point: 513 K
Hexagonal, P6122	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 61 2 (0 0 -1)	Cell parameters from 67 reflections
a = 11.4489 (11) Å	θ = 4.1–11.9°
c = 28.350 (4) Å	µ = 0.08 mm−1
V = 3218.2 (7) Å3	T = 298 K
Z = 6	Prism, colourless
F(000) = 1260	0.40 × 0.22 × 0.20 mm

Siemens P4 diffractometer	Rint = 0.057
Radiation source: fine-focus sealed tube	θmax = 25.1°, θmin = 2.1°
graphite	h = −13→2
ω scans	k = −1→13
5314 measured reflections	l = −33→1
1208 independent reflections	3 standard reflections every 97 reflections
730 reflections with I > 2σ(I)	intensity decay: 1%

Refinement on F2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.043	H atoms treated by a mixture of independent and constrained refinement
wR(F2) = 0.138	w = 1/[σ2(Fo2) + (0.0649P)2 + 0.2213P] where P = (Fo2 + 2Fc2)/3
S = 1.11	(Δ/σ)max < 0.001
1208 reflections	Δρmax = 0.12 e Å−3
141 parameters	Δρmin = −0.14 e Å−3
1 restraint	Extinction correction: SHELXL97 (Sheldrick, 2008), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
0 constraints	Extinction coefficient: 0.011 (2)
Primary atom site location: structure-invariant direct methods

	x	y	z	Uiso*/Ueq
O1	0.1760 (3)	0.1496 (2)	0.53227 (7)	0.0718 (8)
C1	0.1517 (3)	0.0760 (3)	0.49767 (11)	0.0539 (8)
N2	0.1898 (3)	0.1213 (3)	0.45411 (9)	0.0594 (8)
H2	0.168 (3)	0.058 (3)	0.4311 (9)	0.071*
C3	0.2678 (3)	0.2653 (3)	0.44315 (11)	0.0589 (9)
H3A	0.3249	0.3110	0.4705	0.071*
C4	0.3604 (4)	0.2880 (4)	0.40144 (13)	0.0852 (13)
H4B	0.4194	0.2535	0.4088	0.128*
H4C	0.4131	0.3828	0.3949	0.128*
H4D	0.3072	0.2420	0.3743	0.128*
C5	0.1787 (4)	0.3254 (4)	0.43491 (11)	0.0632 (10)
C6	0.0662 (4)	0.2582 (5)	0.40749 (15)	0.0878 (12)
H6A	0.0436	0.1736	0.3957	0.105*
C7	−0.0158 (6)	0.3123 (7)	0.39661 (18)	0.1117 (17)
H7A	−0.0907	0.2651	0.3773	0.134*
C8	0.0142 (6)	0.4343 (7)	0.4144 (2)	0.1100 (17)
H8B	−0.0420	0.4692	0.4079	0.132*
C9	0.1289 (6)	0.5082 (5)	0.44246 (16)	0.0855 (13)
C10	0.1624 (8)	0.6363 (6)	0.4601 (2)	0.119 (2)
H10B	0.1074	0.6721	0.4529	0.143*
C11	0.2721 (8)	0.7080 (6)	0.4873 (2)	0.126 (2)
H11D	0.2911	0.7913	0.4993	0.151*
C12	0.3575 (6)	0.6564 (5)	0.49739 (19)	0.1110 (17)
H12B	0.4343	0.7068	0.5156	0.133*
C13	0.3293 (5)	0.5332 (4)	0.48084 (13)	0.0781 (12)
H13B	0.3868	0.5003	0.4881	0.094*
C14	0.2145 (4)	0.4552 (4)	0.45291 (12)	0.0660 (10)

	U11	U22	U33	U12	U13	U23
O1	0.0854 (19)	0.0634 (16)	0.0510 (13)	0.0256 (14)	0.0089 (12)	−0.0117 (12)
C1	0.055 (2)	0.0567 (19)	0.0495 (17)	0.0279 (17)	0.0013 (16)	−0.0044 (19)
N2	0.071 (2)	0.0555 (19)	0.0477 (15)	0.0284 (16)	0.0035 (15)	−0.0042 (13)
C3	0.063 (2)	0.056 (2)	0.0540 (18)	0.0272 (19)	0.0031 (17)	−0.0023 (16)
C4	0.088 (3)	0.084 (3)	0.081 (2)	0.041 (3)	0.032 (2)	0.011 (2)
C5	0.068 (3)	0.068 (3)	0.0532 (18)	0.033 (2)	0.0073 (19)	0.0067 (19)
C6	0.087 (3)	0.093 (3)	0.087 (3)	0.048 (3)	−0.015 (3)	−0.001 (3)
C7	0.097 (4)	0.136 (5)	0.113 (4)	0.067 (4)	−0.017 (3)	0.014 (4)
C8	0.108 (4)	0.136 (5)	0.120 (4)	0.087 (4)	0.018 (4)	0.035 (4)
C9	0.104 (4)	0.087 (3)	0.081 (3)	0.060 (3)	0.034 (3)	0.026 (3)
C10	0.175 (7)	0.104 (4)	0.116 (4)	0.098 (5)	0.066 (4)	0.037 (4)
C11	0.178 (7)	0.073 (4)	0.128 (5)	0.065 (4)	0.061 (5)	0.013 (3)
C12	0.129 (5)	0.065 (3)	0.110 (3)	0.027 (3)	0.030 (4)	−0.003 (3)
C13	0.089 (3)	0.058 (3)	0.075 (2)	0.028 (2)	0.015 (2)	−0.002 (2)
C14	0.078 (3)	0.063 (2)	0.0587 (19)	0.036 (2)	0.025 (2)	0.014 (2)

O1—C1	1.231 (4)	C7—C8	1.358 (7)
C1—N2	1.326 (4)	C7—H7A	0.9300
C1—C1i	1.512 (7)	C8—C9	1.400 (7)
N2—C3	1.463 (4)	C8—H8B	0.9300
N2—H2	0.911 (10)	C9—C10	1.409 (7)
C3—C5	1.506 (5)	C9—C14	1.418 (6)
C3—C4	1.522 (5)	C10—C11	1.348 (8)
C3—H3A	0.9800	C10—H10B	0.9300
C4—H4B	0.9600	C11—C12	1.401 (7)
C4—H4C	0.9600	C11—H11D	0.9300
C4—H4D	0.9600	C12—C13	1.363 (6)
C5—C6	1.366 (5)	C12—H12B	0.9300
C5—C14	1.424 (5)	C13—C14	1.406 (6)
C6—C7	1.394 (6)	C13—H13B	0.9300
C6—H6A	0.9300
O1—C1—N2	123.8 (3)	C8—C7—C6	119.6 (5)
O1—C1—C1i	121.4 (4)	C8—C7—H7A	120.2
N2—C1—C1i	114.8 (3)	C6—C7—H7A	120.2
C1—N2—C3	122.3 (3)	C7—C8—C9	120.8 (5)
C1—N2—H2	117 (2)	C7—C8—H8B	119.6
C3—N2—H2	121 (2)	C9—C8—H8B	119.6
N2—C3—C5	112.1 (3)	C8—C9—C10	121.0 (6)
N2—C3—C4	109.8 (3)	C8—C9—C14	120.0 (4)
C5—C3—C4	112.0 (3)	C10—C9—C14	119.0 (5)
N2—C3—H3A	107.6	C11—C10—C9	121.5 (6)
C5—C3—H3A	107.6	C11—C10—H10B	119.2
C4—C3—H3A	107.6	C9—C10—H10B	119.2
C3—C4—H4B	109.5	C10—C11—C12	119.6 (6)
C3—C4—H4C	109.5	C10—C11—H11D	120.2
H4B—C4—H4C	109.5	C12—C11—H11D	120.2
C3—C4—H4D	109.5	C13—C12—C11	120.8 (6)
H4B—C4—H4D	109.5	C13—C12—H12B	119.6
H4C—C4—H4D	109.5	C11—C12—H12B	119.6
C6—C5—C14	119.4 (4)	C12—C13—C14	120.9 (5)
C6—C5—C3	119.6 (3)	C12—C13—H13B	119.6
C14—C5—C3	120.9 (3)	C14—C13—H13B	119.6
C5—C6—C7	122.0 (5)	C13—C14—C9	118.2 (4)
C5—C6—H6A	119.0	C13—C14—C5	123.7 (4)
C7—C6—H6A	119.0	C9—C14—C5	118.1 (4)
O1—C1—N2—C3	1.3 (5)	C8—C9—C10—C11	179.7 (5)
O1—C1—C1i—O1i	164.3 (5)	C14—C9—C10—C11	−1.2 (7)
C1i—C1—N2—C3	−178.1 (2)	C9—C10—C11—C12	1.7 (8)
C1—N2—C3—C5	−86.9 (4)	C10—C11—C12—C13	−1.4 (8)
C1—N2—C3—C4	148.0 (3)	C11—C12—C13—C14	0.5 (7)
N2—C3—C5—C6	−44.7 (4)	C12—C13—C14—C9	0.0 (5)
N2—C1—C1i—N2i	163.2 (5)	C12—C13—C14—C5	−179.4 (4)
C4—C3—C5—C6	79.2 (4)	C8—C9—C14—C13	179.4 (4)
N2—C3—C5—C14	139.2 (3)	C10—C9—C14—C13	0.3 (5)
C4—C3—C5—C14	−96.9 (4)	C8—C9—C14—C5	−1.2 (5)
C14—C5—C6—C7	−0.3 (6)	C10—C9—C14—C5	179.8 (4)
C3—C5—C6—C7	−176.5 (4)	C6—C5—C14—C13	−179.0 (3)
C5—C6—C7—C8	−1.5 (8)	C3—C5—C14—C13	−2.9 (5)
C6—C7—C8—C9	1.9 (8)	C6—C5—C14—C9	1.6 (5)
C7—C8—C9—C10	178.5 (5)	C3—C5—C14—C9	177.7 (3)
C7—C8—C9—C14	−0.6 (7)

D—H···A	D—H	H···A	D···A	D—H···A
N2—H2···O1ii	0.91 (1)	2.06 (2)	2.931 (3)	161 (3)

Table 1

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N2—H2⋯O1i	0.91 (1)	2.06 (2)	2.931 (3)	161 (3)

Symmetry code: (i) .