Two (E)-2-({[4-(dialkyl­amino)­phenyl]imino}­meth­yl)-4-nitro­phenols

The slow evaporation of analytical NMR samples resulted in the formation of crystals of (E)-2-({[4-(dimethyl­amino)­phenyl]­imino}­methyl)-4-nitro­phenol, C₁₅H₁₅N₃O₃, (I), and (E)-2-({[4-(diethyl­amino)­phenyl]­imino}­methyl)-4-nitrophenol, C₁₇H₁₉N₃O₃, (II). Despite the small structural difference between these two N-salicylidene­aniline derivatives, they show different space groups and diverse mol­ecular packing. The mol­ecules of both compounds are close to being planar due to an intra­molecular O—H...N hydrogen bond. The 4-alkyl­amino-substituted benzene ring is inclined at an angle of 13.44 (19)° in (I) and 2.57 (8)° in (II) with respect to the 4-nitro-substituted phenol ring. Only very weak inter­molecular π–π stacking and C—H...O inter­actions were found in these structures.

S1. Comment

The title compounds, (I) and (II), are products from the condensation reaction of N,N-dimethyl-p-phenylenediamine or N,N-diethyl-p-phenylenediamine, respectively, with 2-hydroxy-5-nitrobenzaldehyde. These two compounds have the potential to occur in two tautomeric forms, and they were prepared in order to check whether increased acidity of OH (due to the presence of an NO₂ group in the para-position) and increased basicity of the –N═CH– N atom would result in the enamine form of these compounds. This study shows that they occur in the solid state in the imine form (Figs. 1 and 2). However, in solution there is a fast H-atom exchange observed from the chemical shifts of atoms C1, C6, C7 and N4, between the imine (–OH) and enaminone [enamine?] (–NH) forms. As previously observed with similar compounds (Gawinecki et al., 2007), the enaminone [enamine?] form predominates in chloroform solution. Recently, (I) was studied to obtain novel Grubbs-type bidentate Schiff base ruthenium catalysts, but its pK_a value was too low for it to be utilized by that method (Drozdzak & Nishioka, 2010). Previously, the electronic properties of (I) were investigated (Avramovici et al., 1973, 1974) and it was also studied for the preparation of organometallic Ga^III complexes (Chesnut et al., 1998). To the best of our knowledge, (II) has not previously been discussed in the literature.

The crystal structure of (I) is ordered (Fig. 1), but in (II) a small static disorder exists in one ethyl group (Fig. 2), with the occupancy of the major component equal to 0.788 (6). The molecules of both compounds are rather planar. However, the dihedral angle between the two aromatic rings in (I) is 13.44 (19)°, significantly larger than that in (II), which is 2.57 (8)°. Furthermore, the dimethylamine group shows dihedral angles of -13.8 (6) (C16—N15—C12—C13) and 5.2 (6)° (C18—N15—C12—C11) with respect to the parent benzene ring in (I). The corresponding angles in (II) are -2.1 (3) [major component; for the minor C16B—N15—C12—C13 component the angle is 37.1 (4)°] and -14.6 (3)°, respectively. Overall, the structure of (II) is more planar than (I) and the only significant deviation from the plane is found for the diethylamine group.

The presence of an intramolecular hydrogen bond in (I) was predicted according to previous studies on salicylideneanilines and proved by spectroscopic methods in solution about 40 years ago (Avramovici et al., 1973). Due to the conjugated system and the intramolecular hydrogen bond with an S(6) graph-set motif (Bernstein et al., 1995) in the solid state, the benzylideneamine group becomes closely planar, as demonstrated by the dihedral angles of 179.7 (4) (C5—C6—C7—N8) and 0.9 (6)° (C1—C6—C7—N8) between the imine bond and the phenolic ring in (I). In (II), these torsion angles are similar, with values of -178.28 (15) and 0.9 (2)°, respectively.

The H atom in both compounds was found from an electron-density map within bonding distance (~1 Å) of the O atom, before being refined at its geometrically idealized position. Although this shows signs of the structures occurring in the imine form, determination of the exact H-atom position using X-ray diffraction is not possible. More evidence of the predominant imine form can be seen from the bond distances. The O1—C1 distance in both compounds [1.338 (5) Å in (I) and 1.334 (2) Å in (II)] is close to normal values reported for single C—O bonds in phenols and salicylideneamines (e.g. Ozeryanskii et al., 2006). Also, the N8—C7 bond is short in both compounds [1.294 (5) Å in (I) and 1.289 (2) Å in (II)], strongly indicating the existence of a conjugated C═N bond, while the long C6—C7 bond [1.446 (5) Å in (I) and 1.457 (2) Å in (II)] implies a single bond. Based on these facts, the presence of an intramolecular O—H···N bond (Tables 1 and 2) and the pure (E)-isomer in both compounds are justified. These features are similar to what has been observed in related N-salicylidene-(4-dimethylamino)anilines (Filipenko et al., 1983; Aldoshin et al., 1984; Wozniak et al., 1995; Pizzala et al., 2000; Gül et al., 2007). Whereas these structures, including the present, ones show phenolic imine forms, the related 4,5-bis(dimethylamino)-1-[(2-hydroxy-5-nitrobenzylidene)amino]naphthalene is reported to have the enaminone [enamine?] form (Ozeryanskii et al., 2006).

The molecule of (I) has intermolecular C—H···O contacts between the methyl groups and the nitro group (Fig. 3), and between atom C2 and the nitro group (Table 1). There are also two different weak π–π stacking interactions with rather long centroid–centroid distances between the phenol (C1–C6) and phenylenediamine (C9–C14) rings at (-x+1, y, -z+3/2) [3.759 (2) Å] and (-x+1, -y+1, -z+1) [3.878 (2) Å] (Fig. 3). These π–π interactions and two C—H···O interactions connect the molecules into antiparallel stacks. The other three C—H···O contacts connect the stacks to neighbouring ones.

There is only one C—H···O contact between the methyl groups and the nitro group in (II) (Table 2). Arylic atoms C5 and C14 donate C—H···O contacts, which are accepted by nitro and hydroxyl groups, respectively. In (II), there are π–π stacking interactions between the phenol (C1–C6) and phenylenediamine (C9–C14) rings at (-x+2, -y, -z+1) [centroid–centroid distance = 3.5826 (10) Å] and between two phenol (C1–C6) rings [3.6267 (9) Å; symmetry code for the second ring (-x+2, -y, -z+2)]. Due to the different intermolecular interactions, the packing in (II) is different, as can be seen from Fig. 4. Furthermore, the only C—H···O contact between a methyl (C17) and a nitro group is not sufficiently strong to hold the C16—C17 ethyl group completely in one conformation. The minor component does not show a similar close contact.

Related literature

For related literature, see: Aldoshin et al. (1984); Avramovici et al. (1973, 1974); Bernstein et al. (1995); Chesnut et al. (1998); Drozdzak & Nishioka (2010); Filipenko et al. (1983); Gül et al. (2007); Gawinecki et al. (2007); Ozeryanskii et al. (2006); Pizzala et al. (2000); Wozniak et al. (1995).

S2. Experimental

A solution of N,N-dimethyl-p-phenylenediamine (0.68 g, 5 mmol) and 2-hydroxy-5-nitrobenzaldehyde (0.83 g, 5 mmol) in ethanol (20 ml) was refluxed for 15 min. The precipitated solid from the cooled reaction mixture was filtered off and recrystallized twice from ethanol to give crystals.

Analysis for compound (I): yield 91%; brown crystals [Red in CIF - please clarify], m.p. 488–491 K. Elemental analysis for C₁₅H₁₅N₃O₃ (M_r = 285.30), calculated: C 63.15, H 5.30, N 14.73%; found: C 63.01, H 5.49, N 14.59%. Spectroscopic analysis: ¹H NMR (CDCl₃, δ, p.p.m.): 15.19 (br. s, 1H, OH/NH), 8.65 (s, 1H, H7), 8.31 (s, 1H, H5), 8.19 (d, J = 9.0 Hz, 1H, H3), 7.32 (d, J = 9.0 Hz, 2H, H10 and H14), 7.02 (d, J = 9.2 Hz, 1H, H2), 6.75 (d, J = 9.0 Hz, 2H, H11 and H13), 3.03 (s, 6H, 2× CH₃); ¹³C NMR (CDCl₃, δ, p.p.m.): 167.4 (C1), 154.5 (C7), 150.6 (C12), 139.6 (C9), 134.4 (C4), 127.5 (C5), 127.4 (C3), 122.4 (C10 and C14), 118.5 (C6), 118.2 (C2), 112.6 (C11 and C13), 40.4 (C16 and C18); ¹⁵N NMR (CDCl₃/ext. CH₃NO₂, δ, p.p.m.): -13.1 (N4), -93.8 (N8), -331.3 (N15).

Analysis for compound (II): yield 89%; red crystals, m.p. 441–443 K. Elemental analysis for C₁₇H₁₉N₃O₃ (M_r = 313.36), calculated: C 65.16, H 6.11, N 13.41%; found: C 65.11, H 6.17, N 13.37%. Spectroscopic analysis: ¹H NMR (CDCl₃, δ, p.p.m.): 15.30 (br. s, 1H, OH/NH), 8.63 (s, 1H, H7), 8.30 (s, 1H, H5), 8.18 (d, J = 9.0 Hz, 1H, H3), 7.30 (d, J = 9.0 Hz, 2H, H10 and H14), 7.01 (d, J = 9.2 Hz, 1H, H2), 6.70 (d, J = 9.0 Hz, 2H, H11 and H13), 3.41 (q, J = 7.1 Hz, 4H, 2× CH₂), 1.21 (t, J = 7.1, 6H, 2 × CH₃); ¹³C NMR (CDCl₃, δ, p.p.m.): 167.5 (C1), 153.7 (C7), 148.1 (C12), 139.5 (C9), 133.3 (C4), 127.5 (C5), 127.2 (C3), 122.7 (C10 and C14), 118.6 (C6), 118.2 (C2), 111.9 (C11 and C13), 44.58 (C16 and C18), 12.56 (C17 and C19); ¹⁵N NMR (CDCl₃/ext. CH₃NO₂, δ, p.p.m.): -13.4 (N4), -95.3 (N8), -302.3 (N15).

Single crystals of both compounds suitable for X-ray diffraction were obtained by very slow evaporation of analytical samples from NMR tubes, where CDCl₃ was used as solvent.

S3. Refinement

All H atoms were located from electron-density maps, but they were calculated at their idealized positions and allowed to ride on their parent atoms, with C—H = 0.95 (aromatic), 0.98 (methyl) or 0.99 Å (methylene) and O—H = 0.84 Å, and with U_iso(H) = 1.2U_eq(C) for aromatic or methylene groups or 1.5U_eq(C,O) for methyl or hydroxyl groups. The treatment of disorder in (II) required the use of restraints to equalize the bonding distances N15—C16 and N15—C16B, and also the C16—C17 and C16B—C17B distances (s.u. = 0.02 Å). Restraints were also applied for the minor component to make the anisotropic displacement parameters of C16B and C17B more similar (s.u. = 0.02).

Computing details

For both compounds, data collection: COLLECT (Bruker, 2008); cell refinement: DENZO-SMN (Otwinowski & Minor, 1997); data reduction: DENZO-SMN (Otwinowski & Minor, 1997); program(s) used to solve structure: SIR2004 (Burla et al., 2005); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 (Farrugia, 1997) and Mercury (Macrae et al., 2008); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).

Figures

	Fig. 1. A view of the asymmetric unit of (I), showing the atom-labelling scheme. Displacement ellipsoids are drawn at the 50% probability level.
	Fig. 2. A view of the asymmetric unit of (II), showing the atom-labelling scheme. Displacement ellipsoids are drawn at the 50% probability level.
	Fig. 3. A packing diagram for (I), viewed along the b axis, showing the stacked molecules and the C—H···O interactions (dashed lines) between methyl and nitro groups.
	Fig. 4. A packing diagram for (II), viewed along the a axis, showing two adjacent chains along the b axis and the C—H···O interactions (dashed lines).

(I) (E)-2-({[4-(dimethylamino)phenyl]imino}methyl)-4-nitrophenol

Crystal data

C15H15N3O3	F(000) = 1200
Mr = 285.30	Dx = 1.402 Mg m^−3
Monoclinic, C2/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -C 2yc	Cell parameters from 3324 reflections
a = 31.688 (2) Å	θ = 0.4–28.3°
b = 6.7674 (5) Å	µ = 0.10 mm^−1
c = 13.146 (1) Å	T = 123 K
β = 106.545 (6)°	Plate, red
V = 2702.4 (3) Å^3	0.15 × 0.13 × 0.03 mm
Z = 8

Data collection

Bruker Kappa APEXII CCD area-detector diffractometer	2467 independent reflections
Radiation source: fine-focus sealed tube	1242 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.108
Detector resolution: 9 pixels mm^-1	θmax = 25.4°, θmin = 3.1°
ϕ and ω scans	h = −38→37
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	k = −7→8
Tmin = 0.985, Tmax = 0.997	l = −15→15
4611 measured reflections

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)] = 0.082	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.167	H-atom parameters constrained
S = 1.02	w = 1/[σ^2(Fo^2) + (0.0415P)^2 + 5.4351P] where P = (Fo^2 + 2Fc^2)/3
2467 reflections	(Δ/σ)max < 0.001
193 parameters	Δρmax = 0.27 e Å^−3
0 restraints	Δρmin = −0.25 e Å^−3

Special details

Geometry. All s.u.'s (except the s.u. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell s.u.'s are taken into account individually in the estimation of s.u.'s in distances, angles and torsion angles; correlations between s.u.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell s.u.'s is used for estimating s.u.'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 > 2σ(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	0.52621 (9)	1.0161 (4)	0.6531 (3)	0.0392 (9)
H1	0.5043	0.9460	0.6235	0.059*
O4A	0.71055 (9)	0.6370 (5)	0.8492 (2)	0.0353 (8)
O4B	0.67200 (9)	0.3711 (4)	0.7984 (2)	0.0297 (7)
N4	0.67536 (11)	0.5524 (5)	0.8074 (3)	0.0271 (9)
N8	0.48098 (11)	0.6959 (5)	0.5994 (3)	0.0226 (8)
N15	0.31176 (10)	0.3775 (5)	0.4226 (3)	0.0288 (9)
C1	0.56150 (13)	0.9003 (6)	0.6902 (3)	0.0258 (10)
C2	0.60210 (14)	0.9886 (6)	0.7378 (4)	0.0324 (12)
H2	0.6039	1.1284	0.7440	0.039*
C3	0.63947 (13)	0.8768 (6)	0.7759 (3)	0.0282 (11)
H3	0.6671	0.9379	0.8075	0.034*
C4	0.63598 (12)	0.6738 (6)	0.7670 (3)	0.0203 (10)
C5	0.59640 (12)	0.5812 (6)	0.7212 (3)	0.0203 (10)
H5	0.5953	0.4411	0.7166	0.024*
C6	0.55827 (13)	0.6899 (6)	0.6818 (3)	0.0207 (10)
C7	0.51652 (12)	0.5931 (6)	0.6357 (3)	0.0227 (10)
H7	0.5152	0.4530	0.6319	0.027*
C9	0.43969 (13)	0.6029 (6)	0.5577 (3)	0.0221 (10)
C10	0.43060 (12)	0.4040 (6)	0.5674 (3)	0.0218 (10)
H10	0.4535	0.3171	0.6036	0.026*
C11	0.38834 (13)	0.3317 (6)	0.5246 (3)	0.0237 (10)
H11	0.3828	0.1954	0.5326	0.028*
C12	0.35325 (13)	0.4541 (6)	0.4695 (3)	0.0231 (10)
C13	0.36290 (13)	0.6552 (6)	0.4624 (3)	0.0250 (10)
H13	0.3401	0.7438	0.4276	0.030*
C14	0.40491 (13)	0.7256 (6)	0.5054 (3)	0.0244 (10)
H14	0.4104	0.8624	0.4992	0.029*
C16	0.27433 (12)	0.5130 (7)	0.3847 (4)	0.0320 (12)
H16A	0.2703	0.5892	0.4447	0.048*
H16B	0.2476	0.4368	0.3522	0.048*
H16C	0.2801	0.6034	0.3321	0.048*
C18	0.30268 (15)	0.1728 (6)	0.4367 (4)	0.0378 (12)
H18A	0.3230	0.0898	0.4114	0.057*
H18B	0.2723	0.1425	0.3962	0.057*
H18C	0.3066	0.1464	0.5121	0.057*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.0297 (18)	0.0243 (18)	0.057 (2)	0.0043 (14)	0.0009 (17)	0.0084 (16)
O4A	0.0213 (16)	0.040 (2)	0.040 (2)	−0.0061 (15)	0.0006 (14)	−0.0023 (17)
O4B	0.0276 (16)	0.0250 (18)	0.0339 (19)	0.0002 (14)	0.0045 (14)	0.0003 (15)
N4	0.027 (2)	0.026 (2)	0.029 (2)	−0.0033 (17)	0.0082 (17)	−0.0010 (18)
N8	0.0207 (19)	0.030 (2)	0.018 (2)	0.0004 (16)	0.0071 (16)	−0.0013 (17)
N15	0.0203 (19)	0.029 (2)	0.034 (2)	0.0024 (17)	0.0030 (16)	0.0029 (18)
C1	0.028 (2)	0.023 (3)	0.026 (3)	0.005 (2)	0.006 (2)	0.006 (2)
C2	0.034 (3)	0.017 (3)	0.043 (3)	−0.003 (2)	0.006 (2)	0.001 (2)
C3	0.028 (2)	0.023 (2)	0.030 (3)	−0.007 (2)	0.003 (2)	−0.003 (2)
C4	0.027 (2)	0.020 (3)	0.017 (2)	−0.0035 (18)	0.0105 (19)	−0.0048 (19)
C5	0.022 (2)	0.022 (2)	0.020 (2)	0.0014 (18)	0.0109 (19)	−0.0009 (19)
C6	0.021 (2)	0.025 (2)	0.017 (2)	0.0020 (19)	0.0062 (18)	0.004 (2)
C7	0.023 (2)	0.020 (2)	0.027 (3)	−0.0018 (18)	0.010 (2)	−0.0031 (19)
C9	0.021 (2)	0.026 (2)	0.020 (2)	−0.0007 (19)	0.0067 (19)	−0.001 (2)
C10	0.022 (2)	0.021 (2)	0.021 (3)	0.0028 (18)	0.005 (2)	0.0034 (19)
C11	0.022 (2)	0.025 (3)	0.027 (3)	0.0057 (19)	0.0113 (19)	0.004 (2)
C12	0.027 (2)	0.028 (3)	0.016 (2)	0.003 (2)	0.009 (2)	0.0037 (19)
C13	0.023 (2)	0.023 (2)	0.029 (3)	0.0067 (19)	0.0083 (19)	0.000 (2)
C14	0.030 (3)	0.018 (2)	0.025 (3)	0.0023 (19)	0.008 (2)	0.0028 (19)
C16	0.016 (2)	0.047 (3)	0.032 (3)	0.007 (2)	0.005 (2)	0.001 (2)
C18	0.033 (3)	0.036 (3)	0.041 (3)	−0.004 (2)	0.005 (2)	0.000 (2)

Geometric parameters (Å, º)

O1—C1	1.338 (5)	C6—C7	1.446 (5)
O1—H1	0.8400	C7—H7	0.9500
O4A—N4	1.235 (4)	C9—C10	1.390 (5)
O4B—N4	1.234 (4)	C9—C14	1.395 (5)
N4—C4	1.462 (5)	C10—C11	1.386 (5)
N8—C7	1.294 (5)	C10—H10	0.9500
N8—C9	1.414 (5)	C11—C12	1.410 (6)
N15—C12	1.384 (5)	C11—H11	0.9500
N15—C18	1.438 (5)	C12—C13	1.404 (6)
N15—C16	1.470 (5)	C13—C14	1.374 (6)
C1—C2	1.395 (6)	C13—H13	0.9500
C1—C6	1.430 (6)	C14—H14	0.9500
C2—C3	1.374 (6)	C16—H16A	0.9800
C2—H2	0.9500	C16—H16B	0.9800
C3—C4	1.380 (6)	C16—H16C	0.9800
C3—H3	0.9500	C18—H18A	0.9800
C4—C5	1.378 (5)	C18—H18B	0.9800
C5—C6	1.383 (5)	C18—H18C	0.9800
C5—H5	0.9500
C1—O1—H1	109.5	C10—C9—N8	126.1 (4)
O4B—N4—O4A	123.1 (4)	C14—C9—N8	116.1 (4)
O4B—N4—C4	118.9 (3)	C11—C10—C9	120.4 (4)
O4A—N4—C4	118.0 (3)	C11—C10—H10	119.8
C7—N8—C9	121.1 (4)	C9—C10—H10	119.8
C12—N15—C18	120.2 (4)	C10—C11—C12	122.0 (4)
C12—N15—C16	119.3 (4)	C10—C11—H11	119.0
C18—N15—C16	118.2 (3)	C12—C11—H11	119.0
O1—C1—C2	118.7 (4)	N15—C12—C13	122.1 (4)
O1—C1—C6	121.4 (4)	N15—C12—C11	121.2 (4)
C2—C1—C6	119.9 (4)	C13—C12—C11	116.7 (4)
C3—C2—C1	121.1 (4)	C14—C13—C12	120.8 (4)
C3—C2—H2	119.4	C14—C13—H13	119.6
C1—C2—H2	119.4	C12—C13—H13	119.6
C2—C3—C4	118.5 (4)	C13—C14—C9	122.2 (4)
C2—C3—H3	120.7	C13—C14—H14	118.9
C4—C3—H3	120.7	C9—C14—H14	118.9
C5—C4—C3	122.0 (4)	N15—C16—H16A	109.5
C5—C4—N4	118.7 (4)	N15—C16—H16B	109.5
C3—C4—N4	119.3 (4)	H16A—C16—H16B	109.5
C4—C5—C6	120.7 (4)	N15—C16—H16C	109.5
C4—C5—H5	119.6	H16A—C16—H16C	109.5
C6—C5—H5	119.6	H16B—C16—H16C	109.5
C5—C6—C1	117.7 (4)	N15—C18—H18A	109.5
C5—C6—C7	120.9 (4)	N15—C18—H18B	109.5
C1—C6—C7	121.4 (4)	H18A—C18—H18B	109.5
N8—C7—C6	120.5 (4)	N15—C18—H18C	109.5
N8—C7—H7	119.7	H18A—C18—H18C	109.5
C6—C7—H7	119.7	H18B—C18—H18C	109.5
C10—C9—C14	117.8 (4)
O1—C1—C2—C3	−179.1 (4)	C5—C6—C7—N8	179.7 (4)
C6—C1—C2—C3	0.9 (7)	C1—C6—C7—N8	0.9 (6)
C1—C2—C3—C4	−0.7 (7)	C7—N8—C9—C10	12.4 (6)
C2—C3—C4—C5	0.2 (6)	C7—N8—C9—C14	−169.9 (4)
C2—C3—C4—N4	−179.8 (4)	C14—C9—C10—C11	1.0 (6)
O4B—N4—C4—C5	0.5 (6)	N8—C9—C10—C11	178.6 (4)
O4A—N4—C4—C5	−179.3 (4)	C9—C10—C11—C12	0.4 (6)
O4B—N4—C4—C3	−179.5 (4)	C18—N15—C12—C13	−176.6 (4)
O4A—N4—C4—C3	0.7 (6)	C16—N15—C12—C13	−13.8 (6)
C3—C4—C5—C6	0.0 (6)	C18—N15—C12—C11	5.2 (6)
N4—C4—C5—C6	−179.9 (3)	C16—N15—C12—C11	168.0 (4)
C4—C5—C6—C1	0.1 (6)	C10—C11—C12—N15	176.7 (4)
C4—C5—C6—C7	−178.7 (4)	C10—C11—C12—C13	−1.7 (6)
O1—C1—C6—C5	179.4 (4)	N15—C12—C13—C14	−176.8 (4)
C2—C1—C6—C5	−0.6 (6)	C11—C12—C13—C14	1.5 (6)
O1—C1—C6—C7	−1.8 (6)	C12—C13—C14—C9	−0.1 (6)
C2—C1—C6—C7	178.3 (4)	C10—C9—C14—C13	−1.1 (6)
C9—N8—C7—C6	−177.6 (4)	N8—C9—C14—C13	−179.0 (4)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1···N8	0.84	1.84	2.583 (4)	147
C16—H16A···O4A^i	0.98	2.62	3.495 (5)	148
C16—H16A···O4A^ii	0.98	2.69	3.062 (5)	103
C16—H16C···O4B^iii	0.98	2.60	3.411 (5)	140
C2—H2···O4B^iv	0.95	2.64	3.352 (5)	132

Symmetry codes: (i) −x+1, y, −z+3/2; (ii) x−1/2, −y+3/2, z−1/2; (iii) −x+1, −y+1, −z+1; (iv) x, y+1, z.

(II) (E)-2-({[4-(diethylamino)phenyl]imino}methyl)-4-nitrophenol

Crystal data

C17H19N3O3	F(000) = 664
Mr = 313.35	Dx = 1.365 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 3812 reflections
a = 6.5848 (1) Å	θ = 0.4–28.3°
b = 22.2544 (4) Å	µ = 0.10 mm^−1
c = 10.8735 (2) Å	T = 123 K
β = 106.811 (1)°	Plate, red
V = 1525.31 (5) Å^3	0.20 × 0.16 × 0.06 mm
Z = 4

Data collection

Bruker Kappa APEXII CCD area-detector diffractometer	3790 independent reflections
Radiation source: fine-focus sealed tube	2653 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.030
Detector resolution: 9 pixels mm^-1	θmax = 28.3°, θmin = 2.7°
ϕ and ω scans	h = −8→8
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	k = −29→25
Tmin = 0.981, Tmax = 0.994	l = −14→14
6646 measured reflections

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)] = 0.056	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.123	H-atom parameters constrained
S = 1.04	w = 1/[σ^2(Fo^2) + (0.0343P)^2 + 0.8927P] where P = (Fo^2 + 2Fc^2)/3
3790 reflections	(Δ/σ)max < 0.001
228 parameters	Δρmax = 0.38 e Å^−3
8 restraints	Δρmin = −0.25 e Å^−3

Special details

Geometry. All s.u.'s (except the s.u. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell s.u.'s are taken into account individually in the estimation of s.u.'s in distances, angles and torsion angles; correlations between s.u.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell s.u.'s is used for estimating s.u.'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 > 2σ(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	Occ. (<1)
O1	0.62487 (19)	−0.00420 (6)	0.65774 (11)	0.0292 (3)
H1	0.6717	0.0187	0.6108	0.044*
O4A	1.2373 (2)	−0.11842 (6)	1.14921 (12)	0.0369 (3)
O4B	1.4676 (2)	−0.07660 (6)	1.06910 (13)	0.0371 (3)
N4	1.2831 (2)	−0.08873 (7)	1.06541 (14)	0.0272 (3)
N8	0.8984 (2)	0.05530 (6)	0.58184 (13)	0.0219 (3)
N15	0.9700 (2)	0.21352 (7)	0.19249 (16)	0.0344 (4)
C1	0.7858 (3)	−0.02429 (8)	0.75424 (15)	0.0224 (4)
C2	0.7423 (3)	−0.06292 (8)	0.84506 (16)	0.0253 (4)
H2	0.6000	−0.0745	0.8365	0.030*
C3	0.9037 (3)	−0.08426 (8)	0.94667 (16)	0.0246 (4)
H3	0.8736	−0.1102	1.0086	0.029*
C4	1.1114 (3)	−0.06732 (7)	0.95727 (15)	0.0221 (4)
C5	1.1597 (3)	−0.02930 (7)	0.86918 (16)	0.0219 (4)
H5	1.3029	−0.0184	0.8788	0.026*
C6	0.9984 (3)	−0.00712 (7)	0.76660 (15)	0.0210 (4)
C7	1.0492 (3)	0.03371 (7)	0.67494 (16)	0.0223 (4)
H7	1.1925	0.0443	0.6838	0.027*
C9	0.9309 (3)	0.09557 (7)	0.48881 (15)	0.0206 (3)
C10	1.1272 (3)	0.11697 (8)	0.48217 (16)	0.0223 (4)
H10	1.2536	0.1042	0.5441	0.027*
C11	1.1391 (3)	0.15641 (7)	0.38660 (16)	0.0230 (4)
H11	1.2742	0.1705	0.3846	0.028*
C12	0.9561 (3)	0.17650 (8)	0.29146 (17)	0.0245 (4)
C13	0.7602 (3)	0.15488 (8)	0.30041 (17)	0.0260 (4)
H13	0.6329	0.1676	0.2393	0.031*
C14	0.7495 (3)	0.11537 (8)	0.39666 (16)	0.0240 (4)
H14	0.6148	0.1014	0.3998	0.029*
C16	0.7773 (4)	0.23028 (11)	0.0887 (3)	0.0257 (7)	0.789 (6)
H16A	0.6813	0.1952	0.0666	0.031*	0.789 (6)
H16B	0.8178	0.2419	0.0111	0.031*	0.789 (6)
C17	0.6615 (5)	0.28215 (12)	0.1294 (2)	0.0313 (7)	0.789 (6)
H17A	0.5351	0.2923	0.0591	0.047*	0.789 (6)
H17B	0.7557	0.3171	0.1500	0.047*	0.789 (6)
H17C	0.6191	0.2705	0.2053	0.047*	0.789 (6)
C16B	0.7851 (15)	0.2594 (4)	0.1507 (9)	0.029 (3)	0.211 (6)
H16C	0.7019	0.2614	0.2133	0.034*	0.211 (6)
H16D	0.8367	0.3001	0.1382	0.034*	0.211 (6)
C17B	0.658 (2)	0.2316 (5)	0.0247 (11)	0.051 (3)	0.211 (6)
H17D	0.5326	0.2562	−0.0137	0.076*	0.211 (6)
H17E	0.6143	0.1909	0.0404	0.076*	0.211 (6)
H17F	0.7465	0.2296	−0.0341	0.076*	0.211 (6)
C18	1.1665 (3)	0.24487 (8)	0.19747 (19)	0.0305 (4)
H18A	1.1560	0.2607	0.1107	0.037*
H18B	1.2844	0.2155	0.2198	0.037*
C19	1.2213 (4)	0.29653 (10)	0.2927 (2)	0.0458 (6)
H19A	1.3548	0.3150	0.2897	0.069*
H19B	1.2368	0.2813	0.3795	0.069*
H19C	1.1077	0.3266	0.2704	0.069*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.0257 (7)	0.0352 (7)	0.0249 (7)	−0.0052 (6)	0.0046 (5)	0.0048 (5)
O4A	0.0429 (8)	0.0383 (8)	0.0310 (7)	0.0053 (6)	0.0132 (6)	0.0119 (6)
O4B	0.0272 (7)	0.0400 (8)	0.0424 (8)	0.0031 (6)	0.0072 (6)	0.0113 (6)
N4	0.0342 (9)	0.0231 (8)	0.0251 (8)	0.0033 (7)	0.0098 (7)	0.0021 (6)
N8	0.0271 (8)	0.0187 (7)	0.0207 (7)	−0.0018 (6)	0.0083 (6)	−0.0021 (6)
N15	0.0257 (8)	0.0366 (9)	0.0404 (9)	−0.0002 (7)	0.0087 (7)	0.0178 (7)
C1	0.0251 (9)	0.0228 (8)	0.0192 (8)	−0.0020 (7)	0.0065 (7)	−0.0044 (6)
C2	0.0268 (9)	0.0270 (9)	0.0238 (9)	−0.0067 (7)	0.0099 (7)	−0.0038 (7)
C3	0.0333 (10)	0.0211 (8)	0.0221 (9)	−0.0025 (7)	0.0125 (7)	−0.0012 (7)
C4	0.0282 (9)	0.0196 (8)	0.0181 (8)	0.0020 (7)	0.0059 (7)	−0.0018 (6)
C5	0.0225 (8)	0.0201 (8)	0.0244 (8)	−0.0012 (7)	0.0091 (7)	−0.0023 (7)
C6	0.0266 (9)	0.0188 (8)	0.0193 (8)	−0.0010 (7)	0.0092 (7)	−0.0032 (6)
C7	0.0241 (9)	0.0198 (8)	0.0242 (8)	−0.0009 (7)	0.0088 (7)	−0.0016 (7)
C9	0.0252 (9)	0.0188 (8)	0.0191 (8)	−0.0011 (7)	0.0084 (7)	−0.0019 (6)
C10	0.0215 (8)	0.0225 (8)	0.0213 (8)	0.0020 (7)	0.0036 (7)	−0.0003 (7)
C11	0.0220 (8)	0.0225 (8)	0.0256 (9)	−0.0020 (7)	0.0089 (7)	−0.0002 (7)
C12	0.0270 (9)	0.0196 (8)	0.0280 (9)	0.0005 (7)	0.0098 (7)	0.0028 (7)
C13	0.0211 (9)	0.0251 (9)	0.0299 (9)	0.0015 (7)	0.0045 (7)	0.0057 (7)
C14	0.0219 (8)	0.0243 (9)	0.0264 (9)	−0.0020 (7)	0.0079 (7)	−0.0010 (7)
C16	0.0341 (16)	0.0242 (13)	0.0203 (14)	−0.0001 (11)	0.0100 (12)	0.0004 (11)
C17	0.0333 (16)	0.0263 (13)	0.0343 (14)	0.0031 (12)	0.0099 (11)	0.0045 (10)
C16B	0.031 (6)	0.021 (5)	0.038 (5)	0.008 (4)	0.016 (4)	−0.003 (4)
C17B	0.049 (7)	0.045 (6)	0.042 (7)	−0.002 (5)	−0.012 (6)	0.011 (5)
C18	0.0297 (10)	0.0283 (9)	0.0362 (10)	−0.0006 (8)	0.0139 (8)	0.0077 (8)
C19	0.0578 (15)	0.0337 (11)	0.0497 (13)	−0.0057 (10)	0.0217 (11)	−0.0002 (10)

Geometric parameters (Å, º)

O1—C1	1.334 (2)	C10—H10	0.9500
O1—H1	0.8400	C11—C12	1.414 (2)
O4A—N4	1.2316 (19)	C11—H11	0.9500
O4B—N4	1.233 (2)	C12—C13	1.406 (2)
N4—C4	1.456 (2)	C13—C14	1.384 (2)
N8—C7	1.289 (2)	C13—H13	0.9500
N8—C9	1.413 (2)	C14—H14	0.9500
N15—C12	1.379 (2)	C16—C17	1.518 (4)
N15—C18	1.457 (2)	C16—H16A	0.9900
N15—C16	1.481 (3)	C16—H16B	0.9900
N15—C16B	1.553 (9)	C17—H17A	0.9800
C1—C2	1.400 (2)	C17—H17B	0.9800
C1—C6	1.420 (2)	C17—H17C	0.9800
C2—C3	1.377 (2)	C16B—C17B	1.515 (13)
C2—H2	0.9500	C16B—H16C	0.9900
C3—C4	1.391 (2)	C16B—H16D	0.9900
C3—H3	0.9500	C17B—H17D	0.9800
C4—C5	1.382 (2)	C17B—H17E	0.9800
C5—C6	1.389 (2)	C17B—H17F	0.9800
C5—H5	0.9500	C18—C19	1.519 (3)
C6—C7	1.457 (2)	C18—H18A	0.9900
C7—H7	0.9500	C18—H18B	0.9900
C9—C14	1.390 (2)	C19—H19A	0.9800
C9—C10	1.399 (2)	C19—H19B	0.9800
C10—C11	1.380 (2)	C19—H19C	0.9800
C1—O1—H1	109.5	C14—C13—C12	121.18 (16)
O4A—N4—O4B	122.88 (15)	C14—C13—H13	119.4
O4A—N4—C4	118.29 (15)	C12—C13—H13	119.4
O4B—N4—C4	118.83 (14)	C13—C14—C9	121.70 (16)
C7—N8—C9	123.82 (15)	C13—C14—H14	119.2
C12—N15—C18	121.03 (15)	C9—C14—H14	119.2
C12—N15—C16	120.63 (16)	N15—C16—C17	111.1 (2)
C18—N15—C16	117.62 (16)	N15—C16—H16A	109.4
C12—N15—C16B	113.4 (4)	C17—C16—H16A	109.4
C18—N15—C16B	108.0 (4)	N15—C16—H16B	109.4
O1—C1—C2	118.84 (15)	C17—C16—H16B	109.4
O1—C1—C6	121.43 (15)	H16A—C16—H16B	108.0
C2—C1—C6	119.73 (15)	C16—C17—H17A	109.5
C3—C2—C1	120.65 (16)	C16—C17—H17B	109.5
C3—C2—H2	119.7	H17A—C17—H17B	109.5
C1—C2—H2	119.7	C16—C17—H17C	109.5
C2—C3—C4	119.03 (16)	H17A—C17—H17C	109.5
C2—C3—H3	120.5	H17B—C17—H17C	109.5
C4—C3—H3	120.5	C17B—C16B—N15	100.1 (8)
C5—C4—C3	121.75 (16)	C17B—C16B—H16C	111.8
C5—C4—N4	118.65 (15)	N15—C16B—H16C	111.8
C3—C4—N4	119.59 (15)	C17B—C16B—H16D	111.8
C4—C5—C6	119.89 (16)	N15—C16B—H16D	111.8
C4—C5—H5	120.1	H16C—C16B—H16D	109.5
C6—C5—H5	120.1	C16B—C17B—H17D	109.5
C5—C6—C1	118.95 (15)	C16B—C17B—H17E	109.5
C5—C6—C7	119.82 (15)	H17D—C17B—H17E	109.5
C1—C6—C7	121.22 (15)	C16B—C17B—H17F	109.5
N8—C7—C6	119.51 (15)	H17D—C17B—H17F	109.5
N8—C7—H7	120.2	H17E—C17B—H17F	109.5
C6—C7—H7	120.2	N15—C18—C19	114.89 (16)
C14—C9—C10	117.97 (15)	N15—C18—H18A	108.5
C14—C9—N8	116.11 (15)	C19—C18—H18A	108.5
C10—C9—N8	125.91 (15)	N15—C18—H18B	108.5
C11—C10—C9	120.65 (16)	C19—C18—H18B	108.5
C11—C10—H10	119.7	H18A—C18—H18B	107.5
C9—C10—H10	119.7	C18—C19—H19A	109.5
C10—C11—C12	122.02 (16)	C18—C19—H19B	109.5
C10—C11—H11	119.0	H19A—C19—H19B	109.5
C12—C11—H11	119.0	C18—C19—H19C	109.5
N15—C12—C13	121.84 (16)	H19A—C19—H19C	109.5
N15—C12—C11	121.65 (16)	H19B—C19—H19C	109.5
C13—C12—C11	116.47 (15)
O1—C1—C2—C3	−179.48 (15)	N8—C9—C10—C11	−179.88 (15)
C6—C1—C2—C3	0.3 (3)	C9—C10—C11—C12	−0.5 (3)
C1—C2—C3—C4	−0.6 (3)	C18—N15—C12—C13	167.89 (17)
C2—C3—C4—C5	0.5 (3)	C16—N15—C12—C13	−2.1 (3)
C2—C3—C4—N4	178.95 (15)	C16B—N15—C12—C13	37.1 (4)
O4A—N4—C4—C5	173.99 (15)	C18—N15—C12—C11	−14.6 (3)
O4B—N4—C4—C5	−6.2 (2)	C16—N15—C12—C11	175.41 (18)
O4A—N4—C4—C3	−4.5 (2)	C16B—N15—C12—C11	−145.4 (4)
O4B—N4—C4—C3	175.30 (15)	C10—C11—C12—N15	−176.66 (16)
C3—C4—C5—C6	−0.1 (2)	C10—C11—C12—C13	1.0 (2)
N4—C4—C5—C6	−178.58 (14)	N15—C12—C13—C14	176.75 (17)
C4—C5—C6—C1	−0.2 (2)	C11—C12—C13—C14	−0.9 (3)
C4—C5—C6—C7	179.04 (15)	C12—C13—C14—C9	0.3 (3)
O1—C1—C6—C5	179.86 (15)	C10—C9—C14—C13	0.2 (2)
C2—C1—C6—C5	0.1 (2)	N8—C9—C14—C13	179.99 (15)
O1—C1—C6—C7	0.6 (2)	C12—N15—C16—C17	82.2 (2)
C2—C1—C6—C7	−179.09 (15)	C18—N15—C16—C17	−88.1 (2)
C9—N8—C7—C6	179.41 (14)	C12—N15—C16B—C17B	−106.0 (6)
C5—C6—C7—N8	−178.28 (15)	C18—N15—C16B—C17B	117.0 (6)
C1—C6—C7—N8	0.9 (2)	C12—N15—C18—C19	−72.0 (2)
C7—N8—C9—C14	−178.65 (15)	C16—N15—C18—C19	98.3 (2)
C7—N8—C9—C10	1.1 (3)	C16B—N15—C18—C19	61.1 (4)
C14—C9—C10—C11	−0.1 (2)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1···N8	0.84	1.81	2.557 (2)	148
C14—H14···O1^i	0.95	2.64	3.421 (2)	139
C17—H17B···O4A^ii	0.98	2.60	3.195 (3)	119
C5—H5···O4B^iii	0.95	2.56	3.328 (2)	138

Symmetry codes: (i) −x+1, −y, −z+1; (ii) −x+2, y+1/2, −z+3/2; (iii) −x+3, −y, −z+2.