2,3-Dimethyl-N-[(E)-2,4,5-trimeth-oxy-benzyl-idene]aniline.

In the title compound, C(18)H(21)NO(3), the C=N bond has a trans conformation and the benzene rings are oriented at a dihedral angle of 61.32 (6)°. The C atoms of the three meth-oxy groups are all roughly coplanar with their attached ring [deviations = 0.219 (2), -0.097 (2) and -0.137 (2) Å]. In the crystal, a weak C-H⋯π inter-action may help to establish the packing.

Related literature

For background information on Schiff bases and related crystal structures, see: Tahir et al. (2010a ▶,b ▶); Tariq et al. (2010 ▶).

Experimental

Crystal data

C18H21NO3

M = 299.36

Triclinic,

a = 7.0040 (2) Å

b = 11.0396 (4) Å

c = 11.1585 (4) Å

α = 73.941 (1)°

β = 76.022 (2)°

γ = 82.079 (1)°

V = 802.24 (5) Å3

Z = 2

Mo Kα radiation

μ = 0.08 mm−1

T = 296 K

0.32 × 0.14 × 0.12 mm

Data collection

Bruker Kappa APEXII CCD diffractometer

Absorption correction: multi-scan (SADABS; Bruker, 2005 ▶) T min = 0.980, T max = 0.985

13855 measured reflections

3957 independent reflections

2935 reflections with I > 2σ(I)

R int = 0.024

Refinement

R[F 2 > 2σ(F 2)] = 0.045

wR(F 2) = 0.139

S = 1.07

3957 reflections

204 parameters

H-atom parameters constrained

Δρmax = 0.23 e Å−3

Δρmin = −0.16 e Å−3

Data collection: APEX2 (Bruker, 2009 ▶); cell refinement: SAINT (Bruker, 2009 ▶); 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 (Farrugia, 1997 ▶) and PLATON (Spek, 2009 ▶); software used to prepare material for publication: WinGX (Farrugia, 1999 ▶) and PLATON.

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536810025894/hb5535sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536810025894/hb5535Isup2.hkl

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

C18H21NO3	Z = 2
Mr = 299.36	F(000) = 320
Triclinic, P1	Dx = 1.239 Mg m−3
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 7.0040 (2) Å	Cell parameters from 2938 reflections
b = 11.0396 (4) Å	θ = 1.9–28.4°
c = 11.1585 (4) Å	µ = 0.08 mm−1
α = 73.941 (1)°	T = 296 K
β = 76.022 (2)°	Prism, colorless
γ = 82.079 (1)°	0.32 × 0.14 × 0.12 mm
V = 802.24 (5) Å3

Bruker Kappa APEXII CCD diffractometer	3957 independent reflections
Radiation source: fine-focus sealed tube	2935 reflections with I > 2σ(I)
graphite	Rint = 0.024
Detector resolution: 7.5 pixels mm-1	θmax = 28.4°, θmin = 1.9°
ω scans	h = −7→9
Absorption correction: multi-scan (SADABS; Bruker, 2005)	k = −14→14
Tmin = 0.980, Tmax = 0.985	l = −14→14
13855 measured reflections

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) = 0.139	H-atom parameters constrained
S = 1.07	w = 1/[σ2(Fo2) + (0.0685P)2 + 0.1056P] where P = (Fo2 + 2Fc2)/3
3957 reflections	(Δ/σ)max < 0.001
204 parameters	Δρmax = 0.23 e Å−3
0 restraints	Δρmin = −0.16 e Å−3

Geometry. Bond distances, angles etc. have been calculated using the rounded fractional coordinates. All su's are estimated from the variances of the (full) variance-covariance matrix. The cell e.s.d.'s are taken into account in the estimation of distances, angles and torsion angles

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
O1	1.17927 (17)	0.38228 (10)	0.31146 (12)	0.0704 (4)
O2	1.06960 (13)	0.10870 (9)	0.06502 (9)	0.0499 (3)
O3	0.77474 (16)	0.25536 (10)	0.00283 (11)	0.0649 (4)
N1	0.69274 (15)	0.60252 (10)	0.24254 (10)	0.0448 (3)
C1	0.64619 (17)	0.71547 (11)	0.28410 (11)	0.0393 (3)
C2	0.45691 (17)	0.73509 (12)	0.35802 (12)	0.0408 (4)
C3	0.40689 (18)	0.84878 (12)	0.39403 (12)	0.0447 (4)
C4	0.5412 (2)	0.94029 (13)	0.35392 (14)	0.0528 (4)
C5	0.7257 (2)	0.92062 (13)	0.28035 (15)	0.0567 (5)
C6	0.77862 (19)	0.80817 (13)	0.24555 (13)	0.0491 (4)
C7	0.3148 (2)	0.63405 (16)	0.40020 (17)	0.0641 (6)
C8	0.2084 (2)	0.87330 (18)	0.47689 (19)	0.0722 (6)
C9	0.85705 (18)	0.54088 (11)	0.25246 (12)	0.0410 (4)
C10	0.91943 (17)	0.42826 (11)	0.20390 (11)	0.0390 (3)
C11	1.08153 (17)	0.34815 (11)	0.23517 (12)	0.0417 (4)
C12	1.13627 (17)	0.23966 (11)	0.19044 (12)	0.0414 (3)
C13	1.03063 (17)	0.21157 (11)	0.11341 (11)	0.0387 (3)
C14	0.86709 (17)	0.29209 (12)	0.08024 (12)	0.0425 (4)
C15	0.81463 (17)	0.39796 (12)	0.12541 (12)	0.0423 (4)
C16	1.3221 (3)	0.29635 (15)	0.36533 (17)	0.0657 (6)
C17	1.2405 (2)	0.02807 (15)	0.08431 (18)	0.0666 (6)
C18	0.6215 (2)	0.33758 (15)	−0.04312 (16)	0.0591 (5)
H4	0.50636	1.01641	0.37700	0.0633*
H5	0.81429	0.98309	0.25425	0.0681*
H6	0.90321	0.79454	0.19620	0.0589*
H7A	0.30597	0.59426	0.48932	0.0961*
H7B	0.36042	0.57209	0.35185	0.0961*
H7C	0.18711	0.67105	0.38646	0.0961*
H8A	0.20089	0.95488	0.49338	0.1082*
H8B	0.19176	0.80943	0.55621	0.1082*
H8C	0.10610	0.87119	0.43383	0.1082*
H9	0.94031	0.56796	0.29169	0.0492*
H12	1.24401	0.18624	0.21254	0.0496*
H16	0.70660	0.45111	0.10338	0.0507*
H16A	1.26434	0.21858	0.41271	0.0986*
H16B	1.36937	0.33144	0.42145	0.0986*
H16C	1.43011	0.28035	0.29862	0.0986*
H17A	1.35460	0.07600	0.05100	0.1000*
H17B	1.25245	−0.03752	0.04103	0.1000*
H17C	1.23041	−0.00908	0.17400	0.1000*
H18A	0.51745	0.34926	0.02752	0.0886*
H18B	0.57116	0.30185	−0.09749	0.0886*
H18C	0.67114	0.41771	−0.09075	0.0886*

	U11	U22	U33	U12	U13	U23
O1	0.0813 (7)	0.0513 (6)	0.1068 (9)	0.0226 (5)	−0.0673 (7)	−0.0385 (6)
O2	0.0521 (5)	0.0475 (5)	0.0571 (6)	0.0132 (4)	−0.0173 (4)	−0.0280 (4)
O3	0.0709 (6)	0.0633 (6)	0.0850 (8)	0.0239 (5)	−0.0489 (6)	−0.0447 (6)
N1	0.0471 (5)	0.0455 (6)	0.0486 (6)	0.0100 (4)	−0.0174 (5)	−0.0234 (5)
C1	0.0439 (6)	0.0405 (6)	0.0376 (6)	0.0082 (5)	−0.0159 (5)	−0.0157 (5)
C2	0.0414 (6)	0.0433 (7)	0.0412 (6)	0.0045 (5)	−0.0152 (5)	−0.0145 (5)
C3	0.0444 (6)	0.0457 (7)	0.0455 (7)	0.0107 (5)	−0.0129 (5)	−0.0179 (5)
C4	0.0636 (8)	0.0377 (7)	0.0588 (8)	0.0078 (6)	−0.0145 (7)	−0.0195 (6)
C5	0.0616 (8)	0.0425 (7)	0.0634 (9)	−0.0089 (6)	−0.0045 (7)	−0.0143 (6)
C6	0.0477 (7)	0.0493 (8)	0.0471 (7)	0.0008 (6)	−0.0032 (5)	−0.0151 (6)
C7	0.0542 (8)	0.0645 (10)	0.0787 (11)	−0.0084 (7)	−0.0076 (7)	−0.0305 (8)
C8	0.0537 (8)	0.0756 (11)	0.0892 (12)	0.0108 (8)	−0.0016 (8)	−0.0435 (10)
C9	0.0447 (6)	0.0393 (6)	0.0437 (7)	0.0041 (5)	−0.0166 (5)	−0.0157 (5)
C10	0.0398 (6)	0.0378 (6)	0.0417 (6)	0.0044 (5)	−0.0124 (5)	−0.0141 (5)
C11	0.0427 (6)	0.0398 (6)	0.0483 (7)	0.0020 (5)	−0.0193 (5)	−0.0145 (5)
C12	0.0366 (5)	0.0388 (6)	0.0498 (7)	0.0066 (4)	−0.0140 (5)	−0.0133 (5)
C13	0.0387 (5)	0.0383 (6)	0.0392 (6)	0.0039 (4)	−0.0063 (5)	−0.0150 (5)
C14	0.0420 (6)	0.0463 (7)	0.0449 (7)	0.0059 (5)	−0.0164 (5)	−0.0192 (5)
C15	0.0388 (6)	0.0444 (7)	0.0477 (7)	0.0100 (5)	−0.0164 (5)	−0.0185 (5)
C16	0.0718 (9)	0.0584 (9)	0.0833 (11)	0.0144 (7)	−0.0510 (9)	−0.0240 (8)
C17	0.0627 (9)	0.0577 (9)	0.0902 (12)	0.0253 (7)	−0.0277 (8)	−0.0407 (9)
C18	0.0555 (8)	0.0674 (9)	0.0649 (9)	0.0080 (7)	−0.0316 (7)	−0.0240 (8)

O1—C11	1.3658 (18)	C14—C15	1.3686 (19)
O1—C16	1.406 (2)	C4—H4	0.9300
O2—C13	1.3559 (16)	C5—H5	0.9300
O2—C17	1.4129 (19)	C6—H6	0.9300
O3—C14	1.3656 (17)	C7—H7A	0.9600
O3—C18	1.407 (2)	C7—H7B	0.9600
N1—C1	1.4181 (17)	C7—H7C	0.9600
N1—C9	1.2664 (17)	C8—H8A	0.9600
C1—C2	1.4058 (17)	C8—H8B	0.9600
C1—C6	1.3849 (19)	C8—H8C	0.9600
C2—C3	1.3962 (19)	C9—H9	0.9300
C2—C7	1.499 (2)	C12—H12	0.9300
C3—C4	1.384 (2)	C15—H16	0.9300
C3—C8	1.508 (2)	C16—H16A	0.9600
C4—C5	1.378 (2)	C16—H16B	0.9600
C5—C6	1.378 (2)	C16—H16C	0.9600
C9—C10	1.4625 (18)	C17—H17A	0.9600
C10—C11	1.3917 (18)	C17—H17B	0.9600
C10—C15	1.3993 (18)	C17—H17C	0.9600
C11—C12	1.3937 (18)	C18—H18A	0.9600
C12—C13	1.3785 (17)	C18—H18B	0.9600
C13—C14	1.4076 (18)	C18—H18C	0.9600
C11—O1—C16	119.52 (12)	C2—C7—H7A	109.00
C13—O2—C17	118.84 (11)	C2—C7—H7B	109.00
C14—O3—C18	117.70 (12)	C2—C7—H7C	109.00
C1—N1—C9	119.09 (11)	H7A—C7—H7B	109.00
N1—C1—C2	118.33 (11)	H7A—C7—H7C	109.00
N1—C1—C6	120.89 (11)	H7B—C7—H7C	109.00
C2—C1—C6	120.63 (12)	C3—C8—H8A	109.00
C1—C2—C3	118.61 (12)	C3—C8—H8B	109.00
C1—C2—C7	120.36 (12)	C3—C8—H8C	109.00
C3—C2—C7	121.00 (12)	H8A—C8—H8B	109.00
C2—C3—C4	119.75 (12)	H8A—C8—H8C	109.00
C2—C3—C8	120.94 (13)	H8B—C8—H8C	109.00
C4—C3—C8	119.31 (13)	N1—C9—H9	119.00
C3—C4—C5	121.16 (13)	C10—C9—H9	119.00
C4—C5—C6	119.86 (14)	C11—C12—H12	120.00
C1—C6—C5	119.98 (13)	C13—C12—H12	120.00
N1—C9—C10	121.79 (12)	C10—C15—H16	119.00
C9—C10—C11	121.37 (11)	C14—C15—H16	119.00
C9—C10—C15	120.23 (11)	O1—C16—H16A	109.00
C11—C10—C15	118.40 (11)	O1—C16—H16B	109.00
O1—C11—C10	116.09 (11)	O1—C16—H16C	109.00
O1—C11—C12	123.28 (12)	H16A—C16—H16B	109.00
C10—C11—C12	120.63 (11)	H16A—C16—H16C	109.00
C11—C12—C13	119.97 (12)	H16B—C16—H16C	109.00
O2—C13—C12	125.10 (11)	O2—C17—H17A	109.00
O2—C13—C14	114.82 (11)	O2—C17—H17B	109.00
C12—C13—C14	120.08 (12)	O2—C17—H17C	109.00
O3—C14—C13	114.95 (12)	H17A—C17—H17B	109.00
O3—C14—C15	125.80 (12)	H17A—C17—H17C	110.00
C13—C14—C15	119.25 (12)	H17B—C17—H17C	109.00
C10—C15—C14	121.67 (12)	O3—C18—H18A	109.00
C3—C4—H4	119.00	O3—C18—H18B	109.00
C5—C4—H4	119.00	O3—C18—H18C	110.00
C4—C5—H5	120.00	H18A—C18—H18B	109.00
C6—C5—H5	120.00	H18A—C18—H18C	109.00
C1—C6—H6	120.00	H18B—C18—H18C	109.00
C5—C6—H6	120.00
C16—O1—C11—C10	169.05 (13)	C3—C4—C5—C6	0.1 (2)
C16—O1—C11—C12	−10.5 (2)	C4—C5—C6—C1	0.3 (2)
C17—O2—C13—C12	−5.76 (19)	N1—C9—C10—C11	−168.10 (12)
C17—O2—C13—C14	174.79 (12)	N1—C9—C10—C15	11.16 (19)
C18—O3—C14—C13	−174.38 (12)	C9—C10—C11—O1	−1.04 (18)
C18—O3—C14—C15	5.2 (2)	C9—C10—C11—C12	178.53 (12)
C9—N1—C1—C2	−134.93 (13)	C15—C10—C11—O1	179.69 (12)
C9—N1—C1—C6	49.51 (17)	C15—C10—C11—C12	−0.75 (18)
C1—N1—C9—C10	−175.98 (11)	C9—C10—C15—C14	−178.84 (12)
N1—C1—C2—C3	−176.94 (11)	C11—C10—C15—C14	0.45 (19)
N1—C1—C2—C7	4.86 (18)	O1—C11—C12—C13	−179.82 (12)
C6—C1—C2—C3	−1.38 (18)	C10—C11—C12—C13	0.65 (19)
C6—C1—C2—C7	−179.57 (13)	C11—C12—C13—O2	−179.65 (12)
N1—C1—C6—C5	175.87 (12)	C11—C12—C13—C14	−0.23 (18)
C2—C1—C6—C5	0.4 (2)	O2—C13—C14—O3	−0.99 (16)
C1—C2—C3—C4	1.67 (19)	O2—C13—C14—C15	179.40 (11)
C1—C2—C3—C8	−177.99 (13)	C12—C13—C14—O3	179.53 (11)
C7—C2—C3—C4	179.86 (13)	C12—C13—C14—C15	−0.07 (19)
C7—C2—C3—C8	0.2 (2)	O3—C14—C15—C10	−179.60 (12)
C2—C3—C4—C5	−1.0 (2)	C13—C14—C15—C10	0.0 (2)
C8—C3—C4—C5	178.63 (14)

D—H···A	D—H	H···A	D···A	D—H···A
C16—H16B···Cg1i	0.96	2.99	3.5694 (19)	120

Table 1

Hydrogen-bond geometry (Å, °)

Cg1 is the centroid of the C1–C6 ring.

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C16—H16B⋯Cg1i	0.96	2.99	3.5694 (19)	120

Symmetry code: (i) .