2-Methyl­benzaldehyde 2-methyl­benzyl­idenehydrazone

Abstract

The mol­ecule of the title compound, C₁₆H₁₆N₂, is centrosymmetric and the dihedral angle between the benzene ring and the dimethyl­hydrazine mean plane is 16.11 (15)°.

Related literature

For background, see: Shan et al. (2003 ▶). For related structures, see: Fan et al. (2008 ▶); Shan et al. (2004 ▶, 2008 ▶).

Experimental

Crystal data

• C₁₆H₁₆N₂

• M _r = 236.31

• Monoclinic,

• a = 6.1578 (11) Å

• b = 13.248 (2) Å

• c = 8.8161 (16) Å

• β = 105.398 (12)°

• V = 693.4 (2) ų

• Z = 2

• Mo Kα radiation

• μ = 0.07 mm⁻¹

• T = 295 (2) K

• 0.32 × 0.28 × 0.12 mm

Data collection

• Rigaku R-AXIS RAPID IP diffractometer

• Absorption correction: none

• 5451 measured reflections

• 1503 independent reflections

• 1168 reflections with I > 2σ(I)

• R _int = 0.020

Refinement

• R[F ² > 2σ(F ²)] = 0.038

• wR(F ²) = 0.115

• S = 1.10

• 1503 reflections

• 84 parameters

• H-atom parameters constrained

• Δρ_max = 0.12 e Å⁻³

• Δρ_min = −0.10 e Å⁻³

Data collection: PROCESS-AUTO (Rigaku, 1998 ▶); cell refinement: PROCESS-AUTO; data reduction: CrystalStructure (Rigaku/MSC, 2002 ▶); program(s) used to solve structure: SIR92 (Altomare et al., 1993 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997 ▶); software used to prepare material for publication: WinGX (Farrugia, 1999 ▶).

Supplementary Material

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

supplementary crystallographic information

Comment

As part of our ongong studies of hydrazone derivatives (Shan et al., 2003), the title compound, (I), has been prepared and its crystal structure is reported here (Fig. 1).

The molecule of (I) is centrosymmetric, with the mid-point of the N—N bond located on an inversion center. The N=C7 double bond distance of 1.2727 (14) Å is shorter than the C=N bond distances found in related hydrazone structures, i.e. 1.295 (2)Å in (E)-3-methoxyacetophenone 4-nitrophenylhydrazone (Fan et al., 2008), 1.2977 (18) Å in (E)-2-furyl methyl ketone 2,4-dinitrophenylhydrazone (Shan et al., 2008) and 1.293 (2) Å in benzylideneacetone 2,4-dinitrophenylhydrazone (Shan et al. 2004). In (I), the terminal benzene ring is twisted with respect to the central dimethylhydrazine plane by 16.11 (15)°. The crystal packing is controlled by van der Waals forces.

Experimental

Hydrazine hydrate (0.10 g, 2 mmol) was dissolved in ethanol (10 ml), then acetic acid (0.1 ml) was added slowly to the ethanol solution with stirring. The solution was heated at 333 K for several minutes until the solution cleared. 2-Methylbenzaldehyde (0.24 g, 2 mmol) was then dropped slowly into the solution, and the mixture was kept at 333 K with continuous stirring for 2 h. After the solution had cooled to room temperature yellow powder appeared. The crude title compound was separated and washed with water three times. Recrystallization from an absolute ethanol yielded yellow plates of (I).

Refinement

Methyl H atoms were placed in calculated positions with C—H = 0.96 Å and the torsion angle was refined to fit the electron density with U_iso(H) = 1.5U_eq(C). The other H atoms were placed in calculated positions with C—H = 0.93 and refined as riding with U_iso(H) = 1.2U_eq(C).

Figures

Fig. 1.

The molecular structure of (I) with 50% probability displacement ellipsoids for non-H atoms. Symmetry code: (i) -x, 1-y, -z.

Crystal data

C16H16N2	F000 = 252
Mr = 236.31	Dx = 1.132 Mg m−3
Monoclinic, P21/c	Mo Kα radiation λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 2246 reflections
a = 6.1578 (11) Å	θ = 3.0–25.5º
b = 13.248 (2) Å	µ = 0.07 mm−1
c = 8.8161 (16) Å	T = 295 (2) K
β = 105.398 (12)º	Plate, yellow
V = 693.4 (2) Å3	0.32 × 0.28 × 0.12 mm
Z = 2

Data collection

Rigaku R-AXIS RAPID IP diffractometer	1503 independent reflections
Radiation source: fine-focus sealed tube	1168 reflections with I > 2σ(I)
Monochromator: graphite	Rint = 0.020
Detector resolution: 10.00 pixels mm-1	θmax = 27.0º
T = 295(2) K	θmin = 2.9º
ω scans	h = −7→7
Absorption correction: none	k = −15→16
5451 measured reflections	l = −11→11

Refinement

Refinement on F2	Hydrogen site location: inferred from neighbouring sites
Least-squares matrix: full	H-atom parameters constrained
R[F2 > 2σ(F2)] = 0.039	w = 1/[σ2(Fo2) + (0.0537P)2 + 0.0481P] where P = (Fo2 + 2Fc2)/3
wR(F2) = 0.115	(Δ/σ)max < 0.001
S = 1.10	Δρmax = 0.12 e Å−3
1503 reflections	Δρmin = −0.10 e Å−3
84 parameters	Extinction correction: SHELXL97 (Sheldrick, 2008), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.099 (12)
Secondary atom site location: difference Fourier map

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
N	0.03959 (16)	0.45944 (7)	0.05193 (11)	0.0545 (3)
C1	0.33920 (18)	0.40583 (8)	0.26999 (12)	0.0495 (3)
C2	0.56653 (19)	0.41758 (9)	0.35123 (13)	0.0553 (3)
C3	0.6648 (2)	0.34407 (11)	0.46155 (15)	0.0731 (4)
H3	0.8162	0.3499	0.5151	0.088*
C4	0.5435 (3)	0.26319 (11)	0.49318 (18)	0.0813 (5)
H4	0.6129	0.2158	0.5682	0.098*
C5	0.3198 (3)	0.25229 (10)	0.41412 (16)	0.0754 (4)
H5	0.2377	0.1977	0.4356	0.090*
C6	0.2186 (2)	0.32277 (9)	0.30309 (14)	0.0617 (4)
H6	0.0678	0.3151	0.2492	0.074*
C7	0.22666 (19)	0.47938 (8)	0.15044 (13)	0.0514 (3)
H7	0.2935	0.5419	0.1466	0.062*
C8	0.7057 (2)	0.50502 (11)	0.32086 (16)	0.0720 (4)
H8A	0.6477	0.5668	0.3517	0.108*
H8B	0.6986	0.5078	0.2108	0.108*
H8C	0.8593	0.4963	0.3807	0.108*

Atomic displacement parameters (Ų)

	U11	U22	U33	U12	U13	U23
N	0.0577 (6)	0.0502 (6)	0.0522 (6)	0.0060 (4)	0.0086 (4)	0.0054 (4)
C1	0.0564 (6)	0.0494 (6)	0.0427 (6)	0.0049 (5)	0.0129 (5)	−0.0008 (5)
C2	0.0563 (7)	0.0624 (7)	0.0471 (6)	0.0058 (5)	0.0137 (5)	−0.0003 (5)
C3	0.0655 (8)	0.0849 (10)	0.0623 (8)	0.0139 (7)	0.0055 (6)	0.0119 (7)
C4	0.0945 (11)	0.0741 (9)	0.0686 (9)	0.0164 (8)	0.0097 (8)	0.0235 (7)
C5	0.0976 (11)	0.0571 (8)	0.0700 (9)	−0.0035 (7)	0.0198 (8)	0.0121 (6)
C6	0.0682 (8)	0.0567 (7)	0.0570 (7)	−0.0038 (6)	0.0112 (6)	0.0030 (5)
C7	0.0549 (6)	0.0492 (6)	0.0495 (6)	0.0012 (5)	0.0126 (5)	0.0009 (5)
C8	0.0568 (7)	0.0860 (10)	0.0711 (8)	−0.0059 (6)	0.0135 (6)	0.0053 (7)

Geometric parameters (Å, °)

N—C7	1.2727 (14)	C4—C5	1.376 (2)
N—Ni	1.4121 (17)	C4—H4	0.9300
C1—C6	1.4007 (16)	C5—C6	1.3764 (17)
C1—C2	1.4016 (16)	C5—H5	0.9300
C1—C7	1.4672 (15)	C6—H6	0.9300
C2—C3	1.3956 (17)	C7—H7	0.9300
C2—C8	1.5065 (17)	C8—H8A	0.9600
C3—C4	1.3761 (19)	C8—H8B	0.9600
C3—H3	0.9300	C8—H8C	0.9600
C7—N—Ni	112.25 (11)	C4—C5—H5	120.3
C6—C1—C2	119.57 (10)	C6—C5—H5	120.3
C6—C1—C7	119.74 (10)	C5—C6—C1	121.08 (12)
C2—C1—C7	120.70 (10)	C5—C6—H6	119.5
C3—C2—C1	117.90 (12)	C1—C6—H6	119.5
C3—C2—C8	119.92 (11)	N—C7—C1	121.44 (11)
C1—C2—C8	122.18 (10)	N—C7—H7	119.3
C4—C3—C2	121.77 (13)	C1—C7—H7	119.3
C4—C3—H3	119.1	C2—C8—H8A	109.5
C2—C3—H3	119.1	C2—C8—H8B	109.5
C5—C4—C3	120.20 (12)	H8A—C8—H8B	109.5
C5—C4—H4	119.9	C2—C8—H8C	109.5
C3—C4—H4	119.9	H8A—C8—H8C	109.5
C4—C5—C6	119.48 (13)	H8B—C8—H8C	109.5

Symmetry codes: (i) −x, −y+1, −z.