(E,E)-1,2-Bis(2,4,5-trimeth­­oxy­benzyl­­idene)hydrazine

The asymmetric unit of the title compound, C₂₀H₂₄N₂O₆, contains one half-mol­ecule, the complete mol­ecule being generated by a crystallographic inversion centre. The mol­ecule is nearly planar with a dihedral angle between the two benzene rings of 0.03 (4)° and the central C/N/N/C plane making a dihedral angle of 8.59 (7)° with each of its two adjacent benzene rings. The two meth­oxy groups at the ortho and meta positions are slightly twisted [C—O—C—C torsion angles = 7.23 (12) and 5.73 (13)°], whereas the meth­oxy group at the para position is almost coplanar with the attached benzene ring [C—O—C—C torsion angle = −2.02 (13)°]. The crystal structure is stabilized by a weak C—H⋯π inter­action.

Related literature

For bond-length data, see: Allen et al. (1987). For related structures, see: Fun et al. (2010); Jansrisewangwong et al. (2010); Zhao et al. (2006). For background to and the bio­logical activity of hydrazones, see: Avaji et al. (2009); El-Tabl et al. (2008); Kitaev et al. (1970); Qin et al. (2009); Ramamohan et al. (1995); Rollas & Küçükgüzel (2007). For the stability of the temperature controller used in the data collection, see: Cosier & Glazer (1986).

Experimental

Crystal data

• C₂₀H₂₄N₂O₆

• M_r = 388.41

• Monoclinic, P 2₁ /c

• a = 7.5056 (1) Å

• b = 7.2523 (1) Å

• c = 17.4489 (2) Å

• β = 90.600 (1)°

• V = 949.74 (2) ų

• Z = 2

• Mo Kα radiation

• μ = 0.10 mm⁻¹

• T = 100 K

• 0.47 × 0.29 × 0.10 mm

Data collection

• Bruker APEXII CCD area-detector diffractometer

• Absorption correction: multi-scan (SADABS; Bruker, 2005) T_min = 0.954, T_max = 0.990

• 18099 measured reflections

• 2778 independent reflections

• 2384 reflections with I > 2σ(I)

• R_int = 0.028

Refinement

• R[F² > 2σ(F²)] = 0.038

• wR(F²) = 0.113

• S = 1.04

• 2778 reflections

• 175 parameters

• All H-atom parameters refined

• Δρ_max = 0.45 e Å⁻³

• Δρ_min = −0.22 e Å⁻³

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
C8—H8C⋯Cg1^i	0.974 (13)	2.675 (14)	3.4837 (10)	140.7 (10)
Symmetry code: (i) -x+1, -y+1, -z+1.

Data collection: APEX2 (Bruker, 2005); cell refinement: SAINT (Bruker, 2005); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL and PLATON (Spek, 2009).

Supporting information

S1. Comment

Hydrazones, which is a class of compounds containing the >C=N—N=C< (Avaji et al., 2009), have been studied for their fluorescence properties (Qin et al., 2009) and biological activities such as insecticides, antitumor agents, antioxidants (Kitaev et al., 1970), antimicrobial (Ramamohan et al., 1995) and antiviral properties (El-Tabl et al., 2008; Rollas & Küçükgüzel, 2007). We have previously reported the crystal structure of (E,E)-1,2-bis(2,4,6-trimethoxybenzylidene)hydrazine (Fun et al., 2010). In this work, 2,4,5-trimethoxy substituents on the benzene ring was used in order to get information about the effect of trimethoxy substituent positions on the fluorescence property of the compound. Herein we report the synthesis and crystal structure of the title compound (I).

The asymmetric unit of (I) (Fig. 1), C₂₀H₂₄N₂O₆, contains one half-molecule and the complete molecule is generated by a crystallographic inversion centre -x, -y, 1 - z. The molecule of (I) exists in an E,E configuration with respect to the two C═N double bonds [1.2870 (12) Å] and the torsion angle N1A–N1–C7–C1 = -178.99 (9)°. The molecule is nearly planar with the dihedral angle between the two benzene rings being 0.03 (4)°. Atoms C7/N1/N1A/C7A lie on a same plane [r.m.s 0.000 (1) Å]. This C/N/N/C plane makes a dihedral angle of 8.59 (7)° with each of its two adjacent benzene rings. The three methoxy groups of the 2,4,5-trimethoxyphenyl unit have two different orientations: two methoxy groups at the ortho and meta positions (at atom C2 and C5 positions) are slightly twisted with the attached benzene ring with torsion angles C8–O1–C2–C3 = 7.23 (12)° and C10–O3–C5–C6 = 5.73 (13)° whereas the third one at para position (at atom C4) is co-planarly attached with the torsion angle C9–O2–C4–C3 = -2.02 (13)°. The bond distances are of normal values (Allen et al., 1987) and are comparable with related structures (Fun et al., 2010; Jansrisewangwong et al., 2010; Zhao et al., 2006).

In the crystal structure (Fig. 2), the molecules are arranged into screw chains along the c axis and these chains stacked along the a direction. the molecules are consolidated by C—H···π (Table 1) and π–π interactions with the Cg1···Cg1 distances of 4.6314 (5) Å (symmetry code: -x, 1 - y, 1 - z) and 4.9695 (5) Å (symmetry code: 1 - x, 1 - y, 1 - z). C···C [3.3411 (12)–3.3987 (12) Å] short contacts were observed.

Related literature

For bond-length data, see: Allen et al. (1987). For related structures, see: Fun et al. (2010); Jansrisewangwong et al. (2010); Zhao et al. (2006). For background to and the biological activity of hydrazones, see: Avaji et al. (2009); El-Tabl et al. (2008); Kitaev et al. (1970); Qin et al. (2009); Ramamohan et al. (1995); Rollas & Küçükgüzel (2007). For the stability of the temperature controller used in the data collection, see: Cosier & Glazer (1986).

S2. Experimental

The title compound was synthesized by mixing a solution (1:2 molar ratio) of hydrazine hydrate (0.097 ml, 2 mmol) and 2,4,5-trimethoxybenzaldehyde (0.785 mg, 4 mmol) in ethanol (20 ml). The resulting solution was refluxed for 5 h, yielding the yellow solid. The resultant solid was filtered off and washed with methanol. Yellow block-shaped single crystals of the title compound suitable for x-ray structure determination were recrystallized from acetone by slow evaporation of the solvent at room temperature over several days, m.p. 523 K (decompose).

S3. Refinement

All H atoms are located from a difference map and refined isotropically [refined distances: C—H = 0.924 (13)–0.995 (12) Å].

Computing details

Data collection: APEX2 (Bruker, 2005); cell refinement: SAINT (Bruker, 2005); data reduction: SAINT (Bruker, 2005); program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008) and PLATON (Spek, 2009).

Figures

	Fig. 1. The molecular structure of the title compound, showing 50% probability displacement ellipsoids and the atom-numbering scheme. Atoms with suffix A were generated by symmetry code -x, -y, 1 - z.
	Fig. 2. The crystal packing of the title compound viewed along the a axis, showing screw chains running along the c axis and stacked along the a axis.

(E,E)-1,2-Bis(2,4,5-trimethoxybenzylidene)hydrazine

Crystal data

C20H24N2O6	F(000) = 412
Mr = 388.41	Dx = 1.358 Mg m^−3
Monoclinic, P21/c	Melting point = 523 decompose–523 K
Hall symbol: -P 2ybc	Mo Kα radiation, λ = 0.71073 Å
a = 7.5056 (1) Å	Cell parameters from 2778 reflections
b = 7.2523 (1) Å	θ = 2.3–30.0°
c = 17.4489 (2) Å	µ = 0.10 mm^−1
β = 90.600 (1)°	T = 100 K
V = 949.74 (2) Å^3	Needle, colorless
Z = 2	0.47 × 0.29 × 0.10 mm

Data collection

Bruker APEXII CCD area-detector diffractometer	2778 independent reflections
Radiation source: sealed tube	2384 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.028
ϕ and ω scans	θmax = 30.0°, θmin = 2.3°
Absorption correction: multi-scan (SADABS; Bruker, 2005)	h = −10→10
Tmin = 0.954, Tmax = 0.990	k = −10→10
18099 measured reflections	l = −24→24

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)] = 0.038	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.113	All H-atom parameters refined
S = 1.04	w = 1/[σ^2(Fo^2) + (0.0652P)^2 + 0.2144P] where P = (Fo^2 + 2Fc^2)/3
2778 reflections	(Δ/σ)max = 0.001
175 parameters	Δρmax = 0.45 e Å^−3
0 restraints	Δρmin = −0.22 e Å^−3

Special details

Experimental. The crystal was placed in the cold stream of an Oxford Cryosystems Cobra open-flow nitrogen cryostat (Cosier & Glazer, 1986) operating at 100.0 (1) K.

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
O1	0.26607 (9)	0.49751 (9)	0.57223 (4)	0.01763 (16)
O2	0.36459 (9)	0.78767 (10)	0.32476 (4)	0.02050 (17)
O3	0.19145 (9)	0.52720 (10)	0.25671 (4)	0.01952 (17)
N1	0.03148 (10)	0.06200 (11)	0.47211 (4)	0.01607 (17)
C1	0.16786 (11)	0.35906 (12)	0.45749 (5)	0.01377 (18)
C2	0.25348 (11)	0.50724 (13)	0.49415 (5)	0.01428 (18)
C3	0.32155 (11)	0.65346 (13)	0.45116 (5)	0.01573 (18)
H3	0.3849 (17)	0.7563 (18)	0.4767 (7)	0.017 (3)*
C4	0.30093 (11)	0.65370 (13)	0.37186 (5)	0.01537 (18)
C5	0.21005 (12)	0.50854 (13)	0.33441 (5)	0.01493 (18)
C6	0.14716 (11)	0.36283 (12)	0.37708 (5)	0.01463 (18)
H6	0.0847 (18)	0.261 (2)	0.3529 (8)	0.027 (3)*
C7	0.09679 (11)	0.20862 (13)	0.50302 (5)	0.01512 (18)
H7	0.0952 (17)	0.2209 (18)	0.5580 (8)	0.024 (3)*
C8	0.33469 (13)	0.65505 (14)	0.61202 (6)	0.0198 (2)
H8A	0.3252 (17)	0.6258 (19)	0.6634 (8)	0.024 (3)*
H8B	0.2642 (17)	0.767 (2)	0.5997 (8)	0.026 (3)*
H8C	0.4583 (18)	0.6749 (19)	0.5978 (7)	0.024 (3)*
C9	0.45348 (15)	0.94046 (15)	0.35983 (6)	0.0249 (2)
H9A	0.3707 (19)	1.004 (2)	0.3925 (8)	0.034 (4)*
H9B	0.5579 (18)	0.897 (2)	0.3891 (8)	0.031 (3)*
H9C	0.4852 (18)	1.010 (2)	0.3165 (8)	0.028 (3)*
C10	0.08467 (16)	0.39153 (16)	0.21898 (6)	0.0263 (2)
H10A	−0.0319 (16)	0.3831 (18)	0.2454 (7)	0.019 (3)*
H10B	0.1449 (19)	0.274 (2)	0.2202 (8)	0.032 (4)*
H10C	0.0681 (19)	0.439 (2)	0.1671 (9)	0.036 (4)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.0217 (3)	0.0191 (3)	0.0121 (3)	−0.0045 (3)	−0.0015 (2)	−0.0018 (2)
O2	0.0267 (3)	0.0158 (3)	0.0191 (3)	−0.0071 (3)	0.0024 (3)	0.0024 (3)
O3	0.0275 (3)	0.0192 (4)	0.0119 (3)	−0.0045 (3)	−0.0002 (2)	0.0015 (2)
N1	0.0200 (3)	0.0150 (4)	0.0132 (3)	−0.0027 (3)	0.0013 (3)	0.0023 (3)
C1	0.0144 (4)	0.0136 (4)	0.0133 (4)	−0.0009 (3)	0.0004 (3)	0.0001 (3)
C2	0.0145 (3)	0.0155 (4)	0.0128 (4)	−0.0004 (3)	0.0001 (3)	−0.0010 (3)
C3	0.0159 (4)	0.0136 (4)	0.0178 (4)	−0.0020 (3)	0.0005 (3)	−0.0014 (3)
C4	0.0162 (4)	0.0129 (4)	0.0171 (4)	−0.0003 (3)	0.0024 (3)	0.0013 (3)
C5	0.0172 (4)	0.0156 (4)	0.0121 (4)	−0.0005 (3)	0.0010 (3)	0.0004 (3)
C6	0.0166 (4)	0.0135 (4)	0.0138 (4)	−0.0018 (3)	0.0005 (3)	−0.0004 (3)
C7	0.0168 (4)	0.0164 (4)	0.0121 (4)	−0.0013 (3)	0.0001 (3)	0.0011 (3)
C8	0.0215 (4)	0.0204 (5)	0.0173 (4)	−0.0020 (4)	−0.0017 (3)	−0.0057 (3)
C9	0.0301 (5)	0.0182 (5)	0.0266 (5)	−0.0096 (4)	0.0038 (4)	−0.0007 (4)
C10	0.0402 (6)	0.0241 (5)	0.0145 (4)	−0.0086 (5)	−0.0043 (4)	−0.0010 (4)

Geometric parameters (Å, º)

O1—C2	1.3664 (10)	C4—C5	1.4112 (12)
O1—C8	1.4301 (11)	C5—C6	1.3789 (12)
O2—C4	1.3624 (11)	C6—H6	0.970 (14)
O2—C9	1.4279 (12)	C7—H7	0.964 (13)
O3—C5	1.3681 (10)	C8—H8A	0.924 (13)
O3—C10	1.4257 (12)	C8—H8B	0.991 (14)
N1—C7	1.2870 (12)	C8—H8C	0.974 (13)
N1—N1^i	1.4103 (15)	C9—H9A	0.966 (15)
C1—C2	1.4031 (12)	C9—H9B	0.981 (14)
C1—C6	1.4102 (12)	C9—H9C	0.944 (14)
C1—C7	1.4544 (12)	C10—H10A	0.995 (12)
C2—C3	1.3987 (12)	C10—H10B	0.967 (16)
C3—C4	1.3906 (12)	C10—H10C	0.976 (15)
C3—H3	0.988 (13)
C2—O1—C8	117.62 (7)	N1—C7—C1	122.08 (8)
C4—O2—C9	117.39 (7)	N1—C7—H7	119.0 (8)
C5—O3—C10	116.12 (7)	C1—C7—H7	118.9 (8)
C7—N1—N1^i	111.49 (9)	O1—C8—H8A	104.9 (8)
C2—C1—C6	118.95 (8)	O1—C8—H8B	111.1 (8)
C2—C1—C7	119.62 (8)	H8A—C8—H8B	110.6 (11)
C6—C1—C7	121.39 (8)	O1—C8—H8C	109.5 (8)
O1—C2—C3	123.51 (8)	H8A—C8—H8C	111.4 (11)
O1—C2—C1	116.21 (8)	H8B—C8—H8C	109.4 (11)
C3—C2—C1	120.28 (8)	O2—C9—H9A	108.9 (9)
C4—C3—C2	119.81 (8)	O2—C9—H9B	110.1 (9)
C4—C3—H3	119.7 (7)	H9A—C9—H9B	111.1 (12)
C2—C3—H3	120.5 (7)	O2—C9—H9C	101.2 (9)
O2—C4—C3	124.41 (8)	H9A—C9—H9C	112.6 (12)
O2—C4—C5	115.05 (8)	H9B—C9—H9C	112.4 (12)
C3—C4—C5	120.54 (8)	O3—C10—H10A	108.7 (7)
O3—C5—C6	125.38 (8)	O3—C10—H10B	109.8 (9)
O3—C5—C4	115.40 (8)	H10A—C10—H10B	110.4 (12)
C6—C5—C4	119.22 (8)	O3—C10—H10C	104.5 (9)
C5—C6—C1	121.15 (8)	H10A—C10—H10C	110.3 (11)
C5—C6—H6	121.1 (8)	H10B—C10—H10C	112.8 (12)
C1—C6—H6	117.8 (8)
C8—O1—C2—C3	7.23 (12)	C10—O3—C5—C4	−173.90 (8)
C8—O1—C2—C1	−173.26 (8)	O2—C4—C5—O3	−2.95 (12)
C6—C1—C2—O1	178.64 (7)	C3—C4—C5—O3	177.39 (8)
C7—C1—C2—O1	0.86 (12)	O2—C4—C5—C6	177.39 (8)
C6—C1—C2—C3	−1.84 (13)	C3—C4—C5—C6	−2.26 (13)
C7—C1—C2—C3	−179.61 (8)	O3—C5—C6—C1	−177.86 (8)
O1—C2—C3—C4	−179.16 (8)	C4—C5—C6—C1	1.76 (13)
C1—C2—C3—C4	1.34 (13)	C2—C1—C6—C5	0.27 (13)
C9—O2—C4—C3	−2.02 (13)	C7—C1—C6—C5	178.00 (8)
C9—O2—C4—C5	178.34 (8)	N1^i—N1—C7—C1	−178.99 (9)
C2—C3—C4—O2	−178.90 (8)	C2—C1—C7—N1	−173.65 (8)
C2—C3—C4—C5	0.72 (13)	C6—C1—C7—N1	8.63 (13)
C10—O3—C5—C6	5.73 (13)

Symmetry code: (i) −x, −y, −z+1.

Hydrogen-bond geometry (Å, º)

Cg1 is the centroid of the C1–C6 ring.

D—H···A	D—H	H···A	D···A	D—H···A
C8—H8C···Cg1^ii	0.974 (13)	2.675 (14)	3.4837 (10)	140.7 (10)

Symmetry code: (ii) −x+1, −y+1, −z+1.

 

Footnotes

‡Thomson Reuters ResearcherID: A-3561-2009.

§Additional correspondence author, e-mail: [e-mail]. Thomson Reuters ResearcherID: A-5085-2009.