N,N'-Bis[4-(dimethyl­amino)benzyl­idene]ethane-1,2-diamine

The title compound, C₂₀H₂₆N₄, shows a distinctly V-shaped structure. In the crystal structure, parallel rings and short inter­molecular contacts indicate the presence of aromatic stacking inter­actions. A twofold rotation axis passes through the mid-point of the central C-C bond.

Key indicators

• Single-crystal X-ray study
• T = 298 K
• Mean [sigma](C-C) = 0.004 Å
• R factor = 0.079
• wR factor = 0.230
• Data-to-parameter ratio = 15.8

checkCIF/PLATON results

No syntax errors found



Alert level B
PLAT412_ALERT_2_B Short Intra XH3 .. XHn     H1A    ..  H8A     ..       1.78 Ang.
PLAT412_ALERT_2_B Short Intra XH3 .. XHn     H2A    ..  H4A     ..       1.78 Ang.

Alert level C
PLAT066_ALERT_1_C Predicted and Reported Transmissions Identical .          ?
PLAT790_ALERT_4_C Centre of Gravity not Within Unit Cell: Resd.  #          1
              C20 H26 N4

   0 ALERT level A = In general: serious problem
   2 ALERT level B = Potentially serious problem
   2 ALERT level C = Check and explain
   0 ALERT level G = General alerts; check

   1 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   2 ALERT type 2 Indicator that the structure model may be wrong or deficient
   0 ALERT type 3 Indicator that the structure quality may be low
   1 ALERT type 4 Improvement, methodology, query or suggestion

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Computing details

Data collection: SMART (Bruker, 2001); cell refinement: SAINT (Bruker, 2001); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEPII (Johnson, 1976); software used to prepare material for publication: SHELXL97.

N,N'-Bis[4-(dimethylamino)benzylidene]ethane-1,2-diamine

Crystal data

C20H26N4	F(000) = 696
Mr = 322.45	Dx = 1.213 Mg m^−3
Monoclinic, C2/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -C 2yc	Cell parameters from 1200 reflections
a = 24.151 (10) Å	θ = 3.2–25°
b = 6.503 (3) Å	µ = 0.07 mm^−1
c = 12.390 (5) Å	T = 298 K
β = 114.869 (8)°	Plate, red
V = 1765.5 (12) Å^3	0.31 × 0.30 × 0.11 mm
Z = 4

Data collection

Bruker SMART APEX 2000 diffractometer	1721 independent reflections
Radiation source: fine-focus sealed tube	1347 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.028
φ and ω scans	θmax = 26.0°, θmin = 1.9°
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	h = −20→29
Tmin = 0.978, Tmax = 0.992	k = −8→7
4624 measured reflections	l = −15→8

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.079	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.230	H-atom parameters constrained
S = 1.08	w = 1/[σ^2(Fo^2) + (0.1093P)^2 + 2.2949P] where P = (Fo^2 + 2Fc^2)/3
1721 reflections	(Δ/σ)max < 0.001
109 parameters	Δρmax = 0.32 e Å^−3
0 restraints	Δρmin = −0.27 e Å^−3

Special details

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 (Ų)

	x	y	z	Uiso*/Ueq
C6	0.41021 (12)	0.0696 (4)	0.5065 (2)	0.0415 (7)
C3	0.34589 (11)	−0.2914 (4)	0.3996 (2)	0.0422 (7)
C9	0.44526 (12)	0.2529 (4)	0.5597 (2)	0.0455 (7)
H9A	0.4721	0.2994	0.5289	0.055*
C4	0.33896 (12)	−0.1966 (4)	0.4942 (2)	0.0443 (7)
H4A	0.3123	−0.2533	0.5227	0.053*
C5	0.37052 (12)	−0.0218 (4)	0.5460 (2)	0.0437 (7)
H5A	0.3651	0.0368	0.6094	0.052*
C7	0.41614 (13)	−0.0230 (5)	0.4118 (2)	0.0488 (7)
H7A	0.4421	0.0366	0.3826	0.059*
C8	0.38566 (13)	−0.1981 (5)	0.3591 (2)	0.0478 (7)
H8A	0.3914	−0.2556	0.2958	0.057*
C10	0.48226 (13)	0.5303 (4)	0.6834 (3)	0.0508 (8)
H10A	0.4580	0.6548	0.6592	0.061*
H10B	0.5105	0.5298	0.6462	0.061*
C1	0.32328 (16)	−0.5642 (5)	0.2532 (3)	0.0653 (9)
H1A	0.3478	−0.4782	0.2276	0.098*
H1B	0.2844	−0.5873	0.1878	0.098*
H1C	0.3435	−0.6935	0.2805	0.098*
C2	0.27889 (15)	−0.5716 (5)	0.3976 (3)	0.0645 (9)
H2A	0.2763	−0.4902	0.4600	0.097*
H2B	0.2978	−0.7011	0.4294	0.097*
H2C	0.2386	−0.5949	0.3367	0.097*
N2	0.44267 (10)	0.3541 (4)	0.6433 (2)	0.0468 (7)
N1	0.31453 (12)	−0.4652 (4)	0.3481 (2)	0.0578 (7)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C6	0.0385 (14)	0.0449 (15)	0.0406 (14)	0.0038 (12)	0.0162 (11)	0.0059 (11)
C3	0.0383 (14)	0.0467 (15)	0.0355 (13)	0.0046 (12)	0.0095 (11)	0.0014 (11)
C9	0.0438 (15)	0.0468 (16)	0.0474 (15)	0.0014 (12)	0.0206 (12)	0.0083 (13)
C4	0.0426 (15)	0.0522 (16)	0.0425 (14)	−0.0040 (12)	0.0221 (12)	0.0000 (12)
C5	0.0463 (15)	0.0483 (16)	0.0395 (14)	0.0036 (12)	0.0208 (12)	−0.0012 (12)
C7	0.0485 (16)	0.0566 (18)	0.0488 (16)	0.0029 (13)	0.0279 (13)	0.0065 (13)
C8	0.0526 (17)	0.0566 (18)	0.0385 (14)	0.0060 (13)	0.0234 (13)	−0.0025 (12)
C10	0.0485 (16)	0.0401 (15)	0.0578 (18)	−0.0005 (12)	0.0165 (13)	0.0041 (13)
C1	0.074 (2)	0.060 (2)	0.0595 (19)	−0.0016 (17)	0.0266 (17)	−0.0168 (16)
C2	0.062 (2)	0.0549 (19)	0.075 (2)	−0.0112 (16)	0.0280 (18)	−0.0094 (17)
N2	0.0459 (13)	0.0459 (13)	0.0455 (13)	−0.0030 (10)	0.0162 (10)	0.0000 (10)
N1	0.0665 (16)	0.0587 (16)	0.0494 (15)	−0.0130 (13)	0.0258 (12)	−0.0148 (12)

Geometric parameters (Å, º)

C6—C7	1.378 (4)	C8—H8A	0.9300
C6—C5	1.381 (4)	C10—N2	1.440 (3)
C6—C9	1.450 (4)	C10—C10^i	1.506 (6)
C3—N1	1.361 (4)	C10—H10A	0.9700
C3—C4	1.396 (4)	C10—H10B	0.9700
C3—C8	1.396 (4)	C1—N1	1.432 (4)
C9—N2	1.251 (4)	C1—H1A	0.9600
C9—H9A	0.9300	C1—H1B	0.9600
C4—C5	1.369 (4)	C1—H1C	0.9600
C4—H4A	0.9300	C2—N1	1.428 (4)
C5—H5A	0.9300	C2—H2A	0.9600
C7—C8	1.365 (4)	C2—H2B	0.9600
C7—H7A	0.9300	C2—H2C	0.9600
C7—C6—C5	116.8 (3)	N2—C10—H10A	109.3
C7—C6—C9	119.7 (2)	C10^i—C10—H10A	109.3
C5—C6—C9	123.5 (2)	N2—C10—H10B	109.3
N1—C3—C4	121.4 (3)	C10^i—C10—H10B	109.3
N1—C3—C8	121.6 (3)	H10A—C10—H10B	108.0
C4—C3—C8	117.0 (3)	N1—C1—H1A	109.5
N2—C9—C6	125.9 (3)	N1—C1—H1B	109.5
N2—C9—H9A	117.1	H1A—C1—H1B	109.5
C6—C9—H9A	117.1	N1—C1—H1C	109.5
C5—C4—C3	121.4 (2)	H1A—C1—H1C	109.5
C5—C4—H4A	119.3	H1B—C1—H1C	109.5
C3—C4—H4A	119.3	N1—C2—H2A	109.5
C4—C5—C6	121.6 (3)	N1—C2—H2B	109.5
C4—C5—H5A	119.2	H2A—C2—H2B	109.5
C6—C5—H5A	119.2	N1—C2—H2C	109.5
C8—C7—C6	122.9 (3)	H2A—C2—H2C	109.5
C8—C7—H7A	118.5	H2B—C2—H2C	109.5
C6—C7—H7A	118.5	C9—N2—C10	116.6 (2)
C7—C8—C3	120.3 (2)	C3—N1—C2	121.2 (2)
C7—C8—H8A	119.8	C3—N1—C1	120.9 (3)
C3—C8—H8A	119.8	C2—N1—C1	117.3 (3)
N2—C10—C10^i	111.5 (2)
C7—C6—C9—N2	177.8 (3)	C6—C7—C8—C3	0.6 (4)
C5—C6—C9—N2	−2.7 (4)	N1—C3—C8—C7	179.5 (3)
N1—C3—C4—C5	180.0 (3)	C4—C3—C8—C7	0.5 (4)
C8—C3—C4—C5	−1.0 (4)	C6—C9—N2—C10	179.2 (2)
C3—C4—C5—C6	0.6 (4)	C10^i—C10—N2—C9	−130.5 (3)
C7—C6—C5—C4	0.4 (4)	C4—C3—N1—C2	−7.6 (4)
C9—C6—C5—C4	−179.1 (2)	C8—C3—N1—C2	173.4 (3)
C5—C6—C7—C8	−1.0 (4)	C4—C3—N1—C1	−178.3 (3)
C9—C6—C7—C8	178.5 (2)	C8—C3—N1—C1	2.8 (4)

Symmetry code: (i) −x+1, y, −z+3/2.