1,4-Bis(4-dimethyl­amino­benz­yl)-2,3-diaza-1,3-butadiene

The title Schiff base compound, C₁₈H₂₂N₄, is derived from the condensation reaction of hydrazine and 4-(dimethyl­amino)benzaldehyde. There is a crystallographic centre of symmetry at the mid-point of the N-N bond.

Key indicators

• Single-crystal X-ray study
• T = 292 K
• Mean [sigma](C-C) = 0.003 Å
• R factor = 0.065
• wR factor = 0.167
• Data-to-parameter ratio = 16.6

checkCIF/PLATON results

No syntax errors found





Alert level B
PLAT029_ALERT_3_B _diffrn_measured_fraction_theta_full Low .......       0.95

Alert level C
PLAT063_ALERT_3_C Crystal Probably too Large for Beam Size .......       0.62 mm

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

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

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Computing details

Data collection: CrystalClear (Rigaku, 2002); cell refinement: CrystalClear; data reduction: CrystalClear; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: PLATON (Spek, 2003); software used to prepare material for publication: SHELXL97.

1,4-Bis(4-dimethylaminobenzyl)-2,3-diaza-1,3-butadiene

Crystal data

C18H22N4	F(000) = 316
Mr = 294.40	Dx = 1.183 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 1199 reflections
a = 8.232 (4) Å	θ = 2.5–27.5°
b = 6.065 (3) Å	µ = 0.07 mm^−1
c = 16.710 (9) Å	T = 292 K
β = 97.864 (6)°	Block, yellow
V = 826.4 (7) Å^3	0.62 × 0.45 × 0.40 mm
Z = 2

Data collection

Rigaku Mercury CCD area-detector diffractometer	1794 independent reflections
Radiation source: fine-focus sealed tube	1192 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.041
Detector resolution: 14.6306 pixels mm^-1	θmax = 27.5°, θmin = 2.5°
ω scans	h = −10→10
Absorption correction: multi-scan (SPHERE in CrystalClear; Rigaku, 2002)	k = −7→4
Tmin = 0.910, Tmax = 0.980	l = −21→21
4511 measured reflections

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.065	H-atom parameters constrained
wR(F^2) = 0.167	w = 1/[σ^2(Fo^2) + (0.067P)^2 + 0.1316P] where P = (Fo^2 + 2Fc^2)/3
S = 1.10	(Δ/σ)max < 0.001
1794 reflections	Δρmax = 0.14 e Å^−3
108 parameters	Δρmin = −0.14 e Å^−3
0 restraints	Extinction correction: SHELXL97 (Sheldrick, 1997), Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.13 (2)

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
N1	0.3398 (2)	−0.0872 (3)	0.63132 (10)	0.0585 (6)
N2	0.0441 (2)	−0.0437 (3)	0.97031 (10)	0.0536 (5)
C1	0.3090 (4)	0.0617 (4)	0.56302 (14)	0.0765 (8)
H1A	0.1959	0.1059	0.5560	0.115*
H1B	0.3329	−0.0119	0.5151	0.115*
H1C	0.3776	0.1895	0.5728	0.115*
C2	0.4157 (3)	−0.2941 (4)	0.61729 (15)	0.0688 (7)
H2C	0.5003	−0.3253	0.6613	0.103*
H2D	0.4628	−0.2863	0.5679	0.103*
H2E	0.3349	−0.4091	0.6133	0.103*
C3	0.2806 (2)	−0.0412 (3)	0.70215 (12)	0.0441 (5)
C4	0.2039 (3)	0.1609 (3)	0.71400 (13)	0.0494 (6)
H4A	0.1973	0.270	0.6733	0.059*
C5	0.1382 (2)	0.2034 (3)	0.78379 (11)	0.0467 (6)
H5A	0.0873	0.343	0.78996	0.056*
C6	0.1438 (2)	0.0491 (3)	0.84561 (11)	0.0438 (5)
C7	0.2249 (2)	−0.1495 (3)	0.83540 (12)	0.0473 (6)
H7A	0.2334	−0.258	0.8779	0.057*
C8	0.2929 (2)	−0.1941 (3)	0.76631 (12)	0.0482 (6)
H8A	0.3512	−0.336	0.76160	0.058*
C9	0.0604 (2)	0.0973 (4)	0.91475 (11)	0.0474 (5)
H9A	0.0111	0.255	0.91949	0.057*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
N1	0.0746 (13)	0.0519 (11)	0.0529 (12)	0.0129 (10)	0.0226 (10)	0.0046 (9)
N2	0.0593 (12)	0.0610 (11)	0.0419 (10)	−0.0047 (9)	0.0118 (8)	−0.0035 (8)
C1	0.109 (2)	0.0687 (16)	0.0584 (15)	0.0145 (15)	0.0355 (15)	0.0117 (13)
C2	0.0721 (16)	0.0676 (16)	0.0694 (16)	0.0222 (13)	0.0194 (13)	0.0013 (12)
C3	0.0418 (11)	0.0459 (11)	0.0452 (12)	−0.0017 (9)	0.0080 (9)	0.0029 (9)
C4	0.0547 (13)	0.0435 (11)	0.0519 (12)	0.0058 (10)	0.0139 (10)	0.0090 (10)
C5	0.0481 (12)	0.0433 (11)	0.0494 (12)	0.0037 (9)	0.0094 (10)	0.0015 (9)
C6	0.0410 (11)	0.0481 (11)	0.0418 (11)	−0.0053 (9)	0.0038 (9)	−0.0011 (9)
C7	0.0518 (12)	0.0462 (12)	0.0430 (12)	0.0002 (10)	0.0032 (9)	0.0089 (9)
C8	0.0483 (12)	0.0440 (11)	0.0521 (13)	0.0047 (9)	0.0058 (10)	0.0050 (9)
C9	0.0460 (11)	0.0543 (12)	0.0411 (11)	−0.0037 (10)	0.0036 (9)	−0.0021 (9)

Geometric parameters (Å, º)

N1—C3	1.369 (3)	C3—C8	1.411 (3)
N1—C2	1.435 (3)	C4—C5	1.375 (3)
N1—C1	1.450 (3)	C4—H4A	0.9434
N2—C9	1.282 (3)	C5—C6	1.390 (3)
N2—N2^i	1.410 (3)	C5—H5A	0.9559
C1—H1A	0.9600	C6—C7	1.398 (3)
C1—H1B	0.9600	C6—C9	1.452 (3)
C1—H1C	0.9600	C7—C8	1.377 (3)
C2—H2C	0.9600	C7—H7A	0.9649
C2—H2D	0.9600	C8—H8A	0.9916
C2—H2E	0.9600	C9—H9A	1.0461
C3—C4	1.405 (3)
C3—N1—C2	122.27 (18)	C5—C4—C3	121.30 (19)
C3—N1—C1	120.58 (18)	C5—C4—H4A	119.4
C2—N1—C1	116.68 (18)	C3—C4—H4A	119.4
C9—N2—N2^i	112.0 (2)	C4—C5—C6	121.80 (19)
N1—C1—H1A	109.5	C4—C5—H5A	119.1
N1—C1—H1B	109.5	C6—C5—H5A	119.1
H1A—C1—H1B	109.5	C5—C6—C7	117.20 (19)
N1—C1—H1C	109.5	C5—C6—C9	118.99 (19)
H1A—C1—H1C	109.5	C7—C6—C9	123.76 (19)
H1B—C1—H1C	109.5	C8—C7—C6	121.80 (19)
N1—C2—H2C	109.5	C8—C7—H7A	119.1
N1—C2—H2D	109.5	C6—C7—H7A	119.1
H2C—C2—H2D	109.5	C7—C8—C3	120.9 (2)
N1—C2—H2E	109.5	C7—C8—H8A	119.6
H2C—C2—H2E	109.5	C3—C8—H8A	119.6
H2D—C2—H2E	109.5	N2—C9—C6	123.3 (2)
N1—C3—C4	121.31 (18)	N2—C9—H9A	118.3
N1—C3—C8	121.75 (19)	C6—C9—H9A	118.3
C4—C3—C8	116.94 (19)

Symmetry code: (i) −x, −y, −z+2.