N,N'-Bis(2-methyl-phen-yl)succinamide.

In the title compound, C(18)H(20)N(2)O(2), the conformations of the N-H and C=O bonds in the C-NH-C(O)-C segments are anti to each other and the amide O atom is anti to the H atoms attached to the adjacent C atoms. Further, the conformations of the N-H bonds in the amide fragments are anti to the ortho-methyl groups in the adjacent benzene rings. The complete molecule is generated by inversion symmetry. The dihedral angle between the benzene ring and the NH-C(O)-CH(2) segment in the two halves of the mol-ecule is 62.1 (2)°. In the crystal, N-H⋯O inter-molecular hydrogen bonds link the mol-ecules into sheet-like infinite chains along the a axis.

Related literature

For our study of the effect of substituents on the structures of this class of compounds, see: Gowda et al. (2010 ▶).

Experimental

Crystal data

C18H20N2O2

M = 296.36

Monoclinic,

a = 11.586 (2) Å

b = 7.955 (1) Å

c = 8.803 (1) Å

β = 101.97 (2)°

V = 793.70 (19) Å3

Z = 2

Mo Kα radiation

μ = 0.08 mm−1

T = 293 K

0.40 × 0.08 × 0.03 mm

Data collection

Oxford Diffraction Xcalibur diffractometer with a Sapphire CCD detector

Absorption correction: multi-scan (CrysAlis RED; Oxford Diffraction, 2009 ▶) T min = 0.968, T max = 0.998

3109 measured reflections

1615 independent reflections

987 reflections with I > 2σ(I)

R int = 0.032

Refinement

R[F 2 > 2σ(F 2)] = 0.066

wR(F 2) = 0.163

S = 0.97

1615 reflections

104 parameters

1 restraint

H atoms treated by a mixture of independent and constrained refinement

Δρmax = 0.19 e Å−3

Δρmin = −0.21 e Å−3

Data collection: CrysAlis CCD (Oxford Diffraction, 2009 ▶); cell refinement: CrysAlis RED (Oxford Diffraction, 2009 ▶); data reduction: CrysAlis RED; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: PLATON (Spek, 2009 ▶); software used to prepare material for publication: SHELXL97.

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536811004442/ds2092sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536811004442/ds2092Isup2.hkl

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

C18H20N2O2	F(000) = 316
Mr = 296.36	Dx = 1.240 Mg m−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 887 reflections
a = 11.586 (2) Å	θ = 2.6–27.6°
b = 7.955 (1) Å	µ = 0.08 mm−1
c = 8.803 (1) Å	T = 293 K
β = 101.97 (2)°	Needle, colourless
V = 793.70 (19) Å3	0.40 × 0.08 × 0.03 mm
Z = 2

Oxford Diffraction Xcalibur diffractometer with a Sapphire CCD detector	1615 independent reflections
Radiation source: fine-focus sealed tube	987 reflections with I > 2σ(I)
graphite	Rint = 0.032
Rotation method data acquisition using ω scans	θmax = 26.4°, θmin = 3.1°
Absorption correction: multi-scan (CrysAlis RED; Oxford Diffraction, 2009)	h = −14→13
Tmin = 0.968, Tmax = 0.998	k = −9→7
3109 measured reflections	l = −5→11

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)] = 0.066	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.163	H atoms treated by a mixture of independent and constrained refinement
S = 0.97	w = 1/[σ2(Fo2) + (0.0688P)2 + 0.5489P] where P = (Fo2 + 2Fc2)/3
1615 reflections	(Δ/σ)max = 0.001
104 parameters	Δρmax = 0.19 e Å−3
1 restraint	Δρmin = −0.21 e Å−3

Experimental. CrysAlis RED (Oxford Diffraction, 2009) Empirical absorption correction using spherical harmonics, implemented in SCALE3 ABSPACK scaling algorithm.

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.

	x	y	z	Uiso*/Ueq
C1	0.2287 (2)	0.4159 (3)	0.4527 (3)	0.0332 (6)
C2	0.3283 (2)	0.3765 (4)	0.3956 (3)	0.0375 (7)
C3	0.3804 (3)	0.5058 (4)	0.3267 (4)	0.0509 (8)
H3	0.4469	0.4828	0.2866	0.061*
C4	0.3357 (3)	0.6671 (4)	0.3168 (4)	0.0572 (9)
H4	0.3712	0.7505	0.2682	0.069*
C5	0.2395 (3)	0.7053 (4)	0.3778 (4)	0.0544 (9)
H5	0.2106	0.8147	0.3732	0.065*
C6	0.1859 (3)	0.5800 (4)	0.4459 (4)	0.0468 (8)
H6	0.1206	0.6051	0.4879	0.056*
C7	0.1138 (2)	0.1563 (3)	0.4500 (3)	0.0299 (6)
C8	0.0525 (2)	0.0450 (4)	0.5479 (3)	0.0356 (7)
H8A	0.1082	−0.0375	0.6013	0.043*
H8B	0.0266	0.1130	0.6259	0.043*
C9	0.3816 (3)	0.2030 (4)	0.4074 (4)	0.0540 (9)
H9A	0.3508	0.1415	0.3140	0.065*
H9B	0.3622	0.1452	0.4946	0.065*
H9C	0.4658	0.2118	0.4212	0.065*
N1	0.1685 (2)	0.2917 (3)	0.5239 (2)	0.0355 (6)
H1N	0.155 (2)	0.310 (3)	0.614 (2)	0.043*
O1	0.11453 (17)	0.1214 (2)	0.31422 (19)	0.0414 (6)

	U11	U22	U33	U12	U13	U23
C1	0.0376 (14)	0.0357 (16)	0.0271 (13)	−0.0083 (12)	0.0085 (11)	−0.0046 (12)
C2	0.0355 (14)	0.0414 (17)	0.0352 (15)	−0.0055 (13)	0.0065 (12)	−0.0030 (13)
C3	0.0444 (17)	0.061 (2)	0.0507 (19)	−0.0170 (17)	0.0179 (15)	0.0004 (17)
C4	0.068 (2)	0.047 (2)	0.057 (2)	−0.0246 (17)	0.0158 (17)	0.0051 (17)
C5	0.070 (2)	0.0332 (18)	0.062 (2)	−0.0114 (16)	0.0176 (18)	−0.0029 (16)
C6	0.0522 (18)	0.0400 (18)	0.0511 (19)	−0.0041 (14)	0.0171 (15)	−0.0092 (15)
C7	0.0344 (14)	0.0312 (14)	0.0249 (13)	−0.0012 (12)	0.0078 (10)	0.0012 (12)
C8	0.0444 (16)	0.0378 (16)	0.0259 (14)	−0.0092 (12)	0.0105 (12)	0.0028 (12)
C9	0.0439 (17)	0.058 (2)	0.062 (2)	0.0057 (16)	0.0154 (15)	0.0040 (17)
N1	0.0465 (13)	0.0373 (13)	0.0262 (11)	−0.0094 (11)	0.0158 (10)	−0.0048 (10)
O1	0.0570 (13)	0.0437 (12)	0.0264 (10)	−0.0154 (10)	0.0157 (9)	−0.0039 (9)

C1—C2	1.387 (4)	C6—H6	0.9300
C1—C6	1.393 (4)	C7—O1	1.229 (3)
C1—N1	1.427 (3)	C7—N1	1.347 (3)
C2—C3	1.393 (4)	C7—C8	1.512 (3)
C2—C9	1.507 (4)	C8—C8i	1.509 (5)
C3—C4	1.380 (5)	C8—H8A	0.9700
C3—H3	0.9300	C8—H8B	0.9700
C4—C5	1.368 (4)	C9—H9A	0.9600
C4—H4	0.9300	C9—H9B	0.9600
C5—C6	1.376 (4)	C9—H9C	0.9600
C5—H5	0.9300	N1—H1N	0.853 (17)
C2—C1—C6	120.8 (3)	O1—C7—N1	123.6 (2)
C2—C1—N1	121.5 (2)	O1—C7—C8	121.4 (2)
C6—C1—N1	117.7 (2)	N1—C7—C8	115.0 (2)
C1—C2—C3	117.3 (3)	C8i—C8—C7	112.3 (3)
C1—C2—C9	122.8 (2)	C8i—C8—H8A	109.2
C3—C2—C9	119.9 (3)	C7—C8—H8A	109.2
C4—C3—C2	121.6 (3)	C8i—C8—H8B	109.2
C4—C3—H3	119.2	C7—C8—H8B	109.2
C2—C3—H3	119.2	H8A—C8—H8B	107.9
C5—C4—C3	120.5 (3)	C2—C9—H9A	109.5
C5—C4—H4	119.8	C2—C9—H9B	109.5
C3—C4—H4	119.8	H9A—C9—H9B	109.5
C4—C5—C6	119.2 (3)	C2—C9—H9C	109.5
C4—C5—H5	120.4	H9A—C9—H9C	109.5
C6—C5—H5	120.4	H9B—C9—H9C	109.5
C5—C6—C1	120.6 (3)	C7—N1—C1	124.5 (2)
C5—C6—H6	119.7	C7—N1—H1N	115.1 (19)
C1—C6—H6	119.7	C1—N1—H1N	119.6 (19)
C6—C1—C2—C3	−2.3 (4)	C2—C1—C6—C5	2.1 (4)
N1—C1—C2—C3	179.4 (2)	N1—C1—C6—C5	−179.5 (3)
C6—C1—C2—C9	176.8 (3)	O1—C7—C8—C8i	−30.5 (4)
N1—C1—C2—C9	−1.5 (4)	N1—C7—C8—C8i	150.9 (3)
C1—C2—C3—C4	0.6 (4)	O1—C7—N1—C1	3.3 (4)
C9—C2—C3—C4	−178.6 (3)	C8—C7—N1—C1	−178.1 (2)
C2—C3—C4—C5	1.4 (5)	C2—C1—N1—C7	−64.0 (4)
C3—C4—C5—C6	−1.6 (5)	C6—C1—N1—C7	117.6 (3)
C4—C5—C6—C1	−0.1 (5)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1N···O1ii	0.85 (2)	1.99 (2)	2.840 (3)	173 (3)

Table 1

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N1—H1N⋯O1i	0.85 (2)	1.99 (2)	2.840 (3)	173 (3)

Symmetry code: (i) .