2-[N-(4-{4-[(2-Hy­droxy-5-meth­oxy­benzyl­idene)amino]­benz­yl}phen­yl)carboximido­yl]-4-meth­oxy­phenol

Abstract

In the title Schiff base, C₂₉H₂₆N₂O₄, the complete molecule is generated by a crystallographic twofold axis and is V-shaped. The planes of the benzene rings of the central diphenyl­methane unit make a dihedral angle of 78.11 (4)° while adjacent benzene and 5-meth­oxy­salicyl­idene rings are twisted with respect to each other by a dihedral angle of 11.84 (8)°. The Schiff base is in the enol–imino form and an intra­molecular O—H⋯N hydrogen bond is observed.

Related literature  

For related bis-bidentate Schiff base ligand structures, see: Birkedal & Pattison (2006 ▶); Shahverdizadeh & Tiekink (2011 ▶). For Schiff base ligands, see: Chu & Huang (2007 ▶); Yoshida & Ichikawa, (1997 ▶); Kruger et al. (2001 ▶); Moutet & Ourari (1997 ▶). For applications of bis-bidentate Schiff base ligands, see: Lin et al. (2008 ▶); Sadeghi et al. (2003 ▶).

Experimental  

Crystal data  

• C₂₉H₂₆N₂O₄

• M _r = 466.52

• Monoclinic,

• a = 41.307 (4) Å

• b = 4.5993 (3) Å

• c = 12.2229 (13) Å

• β = 93.653 (12)°

• V = 2317.4 (4) ų

• Z = 4

• Mo Kα radiation

• μ = 0.09 mm⁻¹

• T = 293 K

• 0.69 × 0.38 × 0.06 mm

Data collection  

• Stoe IPDS diffractometer

• Absorption correction: gaussian (ABSGAUSS in PLATON; Spek, 2009 ▶) T _min = 0.953, T _max = 0.993

• 10694 measured reflections

• 2244 independent reflections

• 1662 reflections with I > 2σ(I)

• R _int = 0.037

Refinement  

• R[F ² > 2σ(F ²)] = 0.039

• wR(F ²) = 0.116

• S = 1.06

• 2244 reflections

• 160 parameters

• H-atom parameters constrained

• Δρ_max = 0.17 e Å⁻³

• Δρ_min = −0.15 e Å⁻³

Data collection: EXPOSE (Stoe & Cie, 1995 ▶); cell refinement: X-RED (Stoe & Cie, 1995 ▶); data reduction: X-RED; 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: publCIF (Westrip, 2010 ▶).

Supplementary Material

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

Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O1—H1⋯N1	0.89	1.81	2.6177 (15)	151

supplementary crystallographic information

Comment

Bis-bidentate Schiff base ligands have been extensively studied and used as building blocks in metallo-supramolecular chemistry (Birkedal & Pattison, 2006; Shahverdizadeh & Tiekink, 2011; Chu & Huang, 2007; Yoshida & Ichikawa, 1997; Kruger et al., 2001). These compounds were also used as thermosetting resins (Lin et al., 2008) and in ion selective membranes for detecting traces of copper (Sadeghi et al., 2003). We were interested in such ligands owing to their diverse applications in coordination chemistry, catalysis and electrocatalysis (Moutet & Ourari, 1997).

The molecule of the title compound is arranged around the two fold axis at 1/2, y, 3/4 of the unit cell and methylene carbon C14 coinciding with it. The molecule is V-shaped and has a dihedral angle of 78.11 (4)° between the two inner phenyl rings. The phenyl and the 5-methoxysalicylidene rings are slightly twisted with respect to each other by a dihedral angle of 11.84 (8)°. There are two symmetry equivalent intramolecular O-H···N hydrogen bonds. The bond lengths and bond angles within the molecule agree well with those of the closely related compounds C₂₇H₂₂N₂O₂ (CCDC refcode YEFWUC; Birkedal & Pattison, 2006) and C₂₆H₂₀N₂O₃ (Shahverdizadeh & Tiekink, 2011). In the unit cell, the molecules are tightly stacked one above the other along the short b-axis (b = 4.5993 (3) Å) and are held together in this direction by slipped π-π stacking interactions between the phenyl rings and the iminomethylidene groups. The architecture and space group of the title structure is identical with CCDC YEFWUC.

Experimental

5-Methoxysalicyaldehyde (98%), 4, 4'-diaminodiphenylmethane (97%), anhydrous ethanol were all purchased from Alfa aesar and used as received. 200 mg (1 mmol) of 4, 4'-diaminodiphenylmethane were dissolved in 10 ml of absolute ethanol. To this solution, 304 mg (2 mmol) of 5-methoxysalicyaldehyde in 5 ml of absolute ethanol was dropwisely added under stirring. Then, this mixture was heated for 15 min at 50 °C. The resulting yellow precipitate was recovered by filtration, washed several times with a small portions of EtOH and then with diethyl ether to give 443 mg (95%) of the title compound. Suitable crystals were obtained by slow evaporation of a solution in dichloromethane/ethanol (9/1, v /v).

Refinement

All H atoms attached to C were fixed geometrically and treated as riding with C—H = 0.96 Å (methyl), 0.92 Å (methylene) or 0.93 Å (aromatic) with U_iso(H) = 1.2U_eq(C) or U_iso(H) = 1.5U_eq(methyl). The H atom of the hydroxyl group was initially refined using a soft restraint O—H = 0.89 (1) Å and U_iso(H) = 1.2U_eq(O). Then, in the last cycles of refinement, it was treated as riding on its parent O atom.

Figures

Fig. 1.

A molecule of the title compound with the atom-labelling scheme. Displacement ellipsoids are drawn at the 50% probability level. H atoms are represented as small spheres of arbitrary radii. Hydrogen bonds are shown as dashed lines. [Symmetry code: (i) -x + 1, y, -z + 3/2]

Crystal data

C29H26N2O4	F(000) = 984
Mr = 466.52	Dx = 1.337 Mg m−3
Monoclinic, C2/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -C 2yc	Cell parameters from 8000 reflections
a = 41.307 (4) Å	θ = 2.0–25.9°
b = 4.5993 (3) Å	µ = 0.09 mm−1
c = 12.2229 (13) Å	T = 293 K
β = 93.653 (12)°	Plate, yellow
V = 2317.4 (4) Å3	0.69 × 0.38 × 0.06 mm
Z = 4

Data collection

Stoe IPDS diffractometer	2244 independent reflections
Radiation source: normal-focus sealed tube	1662 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.037
Detector resolution: 6.66 pixels mm-1	θmax = 25.8°, θmin = 2.0°
0.6° φ scans	h = −50→50
Absorption correction: gaussian (PLATON-ABSGAUSS; Spek, 2009)	k = −5→5
Tmin = 0.953, Tmax = 0.993	l = −14→15
10694 measured reflections

Refinement

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)] = 0.039	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.116	H-atom parameters constrained
S = 1.06	w = 1/[σ2(Fo2) + (0.072P)2 + 0.1658P] where P = (Fo2 + 2Fc2)/3
2244 reflections	(Δ/σ)max = 0.001
160 parameters	Δρmax = 0.17 e Å−3
0 restraints	Δρmin = −0.15 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
O1	0.37635 (3)	0.9988 (3)	0.40329 (8)	0.0634 (3)
H1	0.3881	0.8694	0.4423	0.076*
O2	0.28937 (3)	1.4522 (3)	0.68223 (9)	0.0651 (4)
N1	0.40032 (2)	0.7019 (2)	0.57231 (8)	0.0404 (3)
C1	0.35488 (3)	1.1095 (3)	0.47152 (10)	0.0435 (3)
C2	0.33158 (3)	1.3024 (4)	0.43070 (11)	0.0521 (4)
H2	0.3309	1.3538	0.3570	0.063*
C3	0.30928 (3)	1.4206 (3)	0.49763 (12)	0.0502 (4)
H3	0.2936	1.5494	0.4687	0.060*
C4	0.31021 (3)	1.3469 (3)	0.60828 (11)	0.0451 (3)
C5	0.33363 (3)	1.1561 (3)	0.64977 (11)	0.0438 (3)
H5	0.3345	1.1092	0.7239	0.053*
C6	0.35595 (3)	1.0324 (3)	0.58312 (10)	0.0377 (3)
C7	0.26320 (4)	1.6273 (4)	0.64047 (16)	0.0725 (5)
H7A	0.2715	1.8012	0.6091	0.109*
H7B	0.2498	1.6779	0.6989	0.109*
H7C	0.2506	1.5214	0.5851	0.109*
C8	0.37983 (3)	0.8291 (3)	0.63036 (10)	0.0405 (3)
H8	0.3803	0.7902	0.7051	0.049*
C9	0.42351 (3)	0.5050 (3)	0.62024 (10)	0.0381 (3)
C10	0.42235 (3)	0.3824 (3)	0.72409 (11)	0.0460 (3)
H10	0.4053	0.4280	0.7673	0.055*
C11	0.44638 (3)	0.1933 (3)	0.76319 (11)	0.0463 (3)
H11	0.4450	0.1111	0.8323	0.056*
C12	0.47241 (3)	0.1226 (3)	0.70280 (11)	0.0411 (3)
C13	0.47310 (3)	0.2425 (3)	0.59852 (12)	0.0489 (4)
H13	0.4902	0.1979	0.5556	0.059*
C14	0.44889 (3)	0.4265 (3)	0.55754 (11)	0.0467 (4)
H14	0.4496	0.4989	0.4867	0.056*
C15	0.5000	−0.0659 (4)	0.7500	0.0474 (5)
H15A	0.4922	−0.1658	0.8076	0.057*

Atomic displacement parameters (Ų)

	U11	U22	U33	U12	U13	U23
O1	0.0703 (7)	0.0835 (8)	0.0375 (5)	0.0297 (6)	0.0109 (5)	0.0061 (5)
O2	0.0592 (6)	0.0793 (8)	0.0583 (6)	0.0268 (6)	0.0149 (5)	0.0052 (6)
N1	0.0401 (5)	0.0405 (6)	0.0402 (6)	0.0025 (5)	−0.0008 (4)	−0.0006 (5)
C1	0.0460 (7)	0.0490 (8)	0.0353 (6)	0.0034 (6)	0.0015 (5)	−0.0016 (6)
C2	0.0586 (8)	0.0599 (10)	0.0372 (7)	0.0101 (7)	−0.0021 (6)	0.0062 (6)
C3	0.0472 (7)	0.0528 (9)	0.0496 (8)	0.0094 (6)	−0.0055 (6)	0.0050 (6)
C4	0.0417 (6)	0.0468 (8)	0.0471 (7)	0.0038 (6)	0.0050 (6)	−0.0013 (6)
C5	0.0463 (7)	0.0481 (8)	0.0370 (6)	0.0028 (6)	0.0029 (5)	0.0038 (6)
C6	0.0387 (6)	0.0378 (7)	0.0363 (6)	−0.0012 (5)	−0.0011 (5)	−0.0008 (5)
C7	0.0619 (10)	0.0752 (12)	0.0819 (12)	0.0267 (9)	0.0173 (9)	0.0054 (10)
C8	0.0444 (7)	0.0419 (8)	0.0348 (6)	0.0008 (6)	−0.0003 (5)	0.0013 (5)
C9	0.0380 (6)	0.0358 (7)	0.0399 (6)	−0.0009 (5)	−0.0026 (5)	−0.0017 (5)
C10	0.0411 (7)	0.0519 (9)	0.0451 (7)	0.0042 (6)	0.0050 (5)	0.0047 (6)
C11	0.0462 (7)	0.0477 (8)	0.0444 (7)	−0.0017 (6)	−0.0020 (6)	0.0080 (6)
C12	0.0393 (7)	0.0312 (7)	0.0516 (7)	−0.0039 (5)	−0.0059 (5)	−0.0040 (6)
C13	0.0471 (7)	0.0487 (9)	0.0515 (8)	0.0076 (6)	0.0075 (6)	−0.0037 (6)
C14	0.0518 (7)	0.0485 (9)	0.0401 (7)	0.0070 (6)	0.0055 (6)	0.0015 (6)
C15	0.0445 (10)	0.0342 (11)	0.0626 (12)	0.000	−0.0055 (9)	0.000

Geometric parameters (Å, º)

O1—C1	1.3548 (15)	C7—H7B	0.9600
O1—H1	0.8879	C7—H7C	0.9600
O2—C4	1.3754 (16)	C8—H8	0.9300
O2—C7	1.4168 (19)	C9—C14	1.3852 (17)
N1—C8	1.2802 (16)	C9—C10	1.3926 (18)
N1—C9	1.4176 (16)	C10—C11	1.3822 (19)
C1—C2	1.379 (2)	C10—H10	0.9300
C1—C6	1.4074 (18)	C11—C12	1.3814 (18)
C2—C3	1.3819 (19)	C11—H11	0.9300
C2—H2	0.9300	C12—C13	1.3908 (19)
C3—C4	1.392 (2)	C12—C15	1.5161 (17)
C3—H3	0.9300	C13—C14	1.3795 (19)
C4—C5	1.3787 (19)	C13—H13	0.9300
C5—C6	1.3901 (18)	C14—H14	0.9300
C5—H5	0.9300	C15—C12i	1.5161 (17)
C6—C8	1.4520 (18)	C15—H15A	0.9160
C7—H7A	0.9600
C1—O1—H1	106.2	H7B—C7—H7C	109.5
C4—O2—C7	117.30 (12)	N1—C8—C6	122.03 (12)
C8—N1—C9	121.08 (11)	N1—C8—H8	119.0
O1—C1—C2	119.22 (12)	C6—C8—H8	119.0
O1—C1—C6	121.38 (12)	C14—C9—C10	118.04 (12)
C2—C1—C6	119.40 (12)	C14—C9—N1	116.95 (11)
C1—C2—C3	121.01 (13)	C10—C9—N1	125.00 (11)
C1—C2—H2	119.5	C11—C10—C9	120.28 (12)
C3—C2—H2	119.5	C11—C10—H10	119.9
C2—C3—C4	120.06 (13)	C9—C10—H10	119.9
C2—C3—H3	120.0	C12—C11—C10	122.00 (13)
C4—C3—H3	120.0	C12—C11—H11	119.0
O2—C4—C5	115.87 (12)	C10—C11—H11	119.0
O2—C4—C3	124.94 (13)	C11—C12—C13	117.28 (12)
C5—C4—C3	119.19 (12)	C11—C12—C15	121.54 (11)
C4—C5—C6	121.39 (12)	C13—C12—C15	121.11 (11)
C4—C5—H5	119.3	C14—C13—C12	121.29 (12)
C6—C5—H5	119.3	C14—C13—H13	119.4
C5—C6—C1	118.95 (12)	C12—C13—H13	119.4
C5—C6—C8	119.31 (11)	C13—C14—C9	121.04 (13)
C1—C6—C8	121.75 (11)	C13—C14—H14	119.5
O2—C7—H7A	109.5	C9—C14—H14	119.5
O2—C7—H7B	109.5	C12i—C15—C12	110.27 (15)
H7A—C7—H7B	109.5	C12i—C15—H15A	106.7
O2—C7—H7C	109.5	C12—C15—H15A	106.6
H7A—C7—H7C	109.5
C6—C8—N1—C9	179.75 (11)

Symmetry code: (i) −x+1, y, −z+3/2.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1···N1	0.89	1.81	2.6177 (15)	151