(E)-4-[(4-Diethyl-amino-2-hy-droxy-benzyl-idene)amino]-benzoic acid.

In the title compound, C(18)H(20)N(2)O(3), a potential bidentate N,O-donor Schiff base ligand, the benzene rings are inclined at an angle of 12.25 (19)°. The mol-ecule has an E conformation about the C=N bond. One of the ethyl groups is disordered over two positions, with a refined site-occupancy ratio of 0.55 (1):0.45 (1). An intra-molecular O-H⋯N hydrogen bond makes an S(6) ring motif. In the crystal, pairs of O-H⋯O hydrogen bonds link mol-ecules, forming inversion dimers with R(2) (2)(8) ring motifs.

Related literature

For background to Schiff base ligands and their metal complexes, see: Kargar et al. (2011 ▶, 2012 ▶); Kia et al. (2010 ▶). For standard bond lengths, see: Allen et al. (1987 ▶). For hydrogen-bond motifs, see: Bernstein et al. (1995 ▶).

Experimental

Crystal data

C18H20N2O3

M = 312.36

Monoclinic,

a = 12.4216 (8) Å

b = 8.1511 (6) Å

c = 16.0820 (11) Å

β = 93.001 (3)°

V = 1626.06 (19) Å3

Z = 4

Mo Kα radiation

μ = 0.09 mm−1

T = 296 K

0.25 × 0.12 × 0.10 mm

Data collection

Bruker SMART APEXII CCD area-detector diffractometer

Absorption correction: multi-scan (SADABS; Bruker, 2005 ▶) T min = 0.978, T max = 0.991

11192 measured reflections

2872 independent reflections

918 reflections with I > 2σ(I)

R int = 0.097

Refinement

R[F 2 > 2σ(F 2)] = 0.058

wR(F 2) = 0.133

S = 0.94

2872 reflections

219 parameters

H-atom parameters constrained

Δρmax = 0.14 e Å−3

Δρmin = −0.13 e Å−3

Data collection: APEX2 (Bruker, 2005 ▶); cell refinement: SAINT (Bruker, 2005 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: SHELXTL (Sheldrick, 2008 ▶); software used to prepare material for publication: SHELXTL and PLATON (Spek, 2009 ▶).

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S160053681200997X/su2388sup1.cif

Structure factors: contains datablock(s) I. DOI: 10.1107/S160053681200997X/su2388Isup2.hkl

Supplementary material file. DOI: 10.1107/S160053681200997X/su2388Isup3.cml

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

C18H20N2O3	F(000) = 664
Mr = 312.36	Dx = 1.276 Mg m−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 3270 reflections
a = 12.4216 (8) Å	θ = 2.8–28.8°
b = 8.1511 (6) Å	µ = 0.09 mm−1
c = 16.0820 (11) Å	T = 296 K
β = 93.001 (3)°	Block, pale-yellow
V = 1626.06 (19) Å3	0.25 × 0.12 × 0.10 mm
Z = 4

Bruker SMART APEXII CCD area-detector diffractometer	2872 independent reflections
Radiation source: fine-focus sealed tube	918 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.097
φ and ω scans	θmax = 25.0°, θmin = 2.5°
Absorption correction: multi-scan (SADABS; Bruker, 2005)	h = −14→12
Tmin = 0.978, Tmax = 0.991	k = −9→9
11192 measured reflections	l = −19→19

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)] = 0.058	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.133	H-atom parameters constrained
S = 0.94	w = 1/[σ2(Fo2) + (0.0393P)2] where P = (Fo2 + 2Fc2)/3
2872 reflections	(Δ/σ)max < 0.001
219 parameters	Δρmax = 0.14 e Å−3
0 restraints	Δρmin = −0.13 e Å−3

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds 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 > 2sigma(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.

	x	y	z	Uiso*/Ueq	Occ. (<1)
C1	0.9492 (3)	0.4842 (5)	0.8861 (2)	0.0584 (12)
C2	0.9076 (3)	0.4702 (5)	0.7993 (2)	0.0508 (11)
C3	0.8265 (3)	0.3620 (5)	0.7757 (2)	0.0684 (13)
H18	0.7990	0.2917	0.8150	0.082*
C4	0.7858 (3)	0.3574 (5)	0.6946 (2)	0.0703 (13)
H17	0.7299	0.2852	0.6801	0.084*
C5	0.8256 (3)	0.4564 (5)	0.6347 (2)	0.0541 (12)
C6	0.9084 (3)	0.5642 (5)	0.6578 (2)	0.0657 (13)
H10	0.9371	0.6327	0.6184	0.079*
C7	0.9481 (3)	0.5692 (5)	0.7398 (2)	0.0633 (12)
H11	1.0036	0.6416	0.7547	0.076*
C8	0.8135 (3)	0.5152 (5)	0.4913 (2)	0.0627 (13)
H7	0.8806	0.5655	0.4982	0.075*
C9	0.7599 (3)	0.5179 (5)	0.4096 (2)	0.0507 (11)
C10	0.8031 (3)	0.5970 (5)	0.3437 (2)	0.0644 (12)
H5	0.8700	0.6476	0.3520	0.077*
C11	0.7519 (3)	0.6043 (5)	0.2663 (2)	0.0627 (12)
H4	0.7842	0.6589	0.2234	0.075*
C12	0.6503 (4)	0.5293 (5)	0.2515 (2)	0.0655 (13)
C13	0.6062 (3)	0.4454 (5)	0.3171 (2)	0.0696 (14)
H15	0.5408	0.3909	0.3083	0.084*
C14	0.6582 (4)	0.4422 (5)	0.3949 (2)	0.0614 (12)
C15	0.6378 (3)	0.6430 (6)	0.1074 (2)	0.0862 (15)
H2A	0.6707	0.7408	0.1319	0.103*
H2B	0.5769	0.6770	0.0713	0.103*
C16	0.7176 (4)	0.5578 (5)	0.0570 (3)	0.1024 (17)
H1A	0.7796	0.5285	0.0920	0.154*
H1B	0.7391	0.6293	0.0134	0.154*
H1C	0.6856	0.4604	0.0329	0.154*
C17	0.4751 (11)	0.5013 (14)	0.1607 (7)	0.089 (5)	0.549 (11)
H17A	0.4373	0.5097	0.2118	0.107*	0.549 (11)
H17B	0.4407	0.5708	0.1182	0.107*	0.549 (11)
C18	0.4858 (16)	0.3342 (18)	0.1334 (11)	0.111 (6)	0.549 (11)
H18A	0.4156	0.2891	0.1200	0.167*	0.549 (11)
H18B	0.5212	0.2706	0.1771	0.167*	0.549 (11)
H18C	0.5277	0.3313	0.0850	0.167*	0.549 (11)
C17A	0.5142 (16)	0.405 (2)	0.1518 (10)	0.058 (5)	0.451 (11)
H17C	0.5183	0.3745	0.0937	0.070*	0.451 (11)
H17D	0.5286	0.3077	0.1855	0.070*	0.451 (11)
C18A	0.40179 (14)	0.4703 (4)	0.16718 (11)	0.075 (4)	0.451 (11)
H18D	0.3490	0.3878	0.1523	0.112*	0.451 (11)
H18E	0.3880	0.5665	0.1339	0.112*	0.451 (11)
H18F	0.3977	0.4977	0.2250	0.112*	0.451 (11)
N1	0.77425 (12)	0.44793 (19)	0.55449 (9)	0.0639 (11)
N2	0.59881 (15)	0.5375 (3)	0.17449 (16)	0.0925 (14)
O1	1.00875 (12)	0.59948 (19)	0.90912 (8)	0.0827 (10)
O2	0.91877 (12)	0.37246 (19)	0.93606 (10)	0.0889 (10)
H2	0.9476	0.3876	0.9825	0.133*
O3	0.6110 (2)	0.3604 (4)	0.45575 (15)	0.0883 (10)
H3	0.6443	0.3772	0.5003	0.132*

	U11	U22	U33	U12	U13	U23
C1	0.061 (3)	0.068 (3)	0.045 (3)	0.010 (3)	−0.004 (2)	0.005 (2)
C2	0.049 (3)	0.055 (3)	0.047 (3)	0.003 (2)	−0.007 (2)	−0.001 (2)
C3	0.078 (3)	0.078 (4)	0.049 (3)	−0.012 (3)	−0.002 (2)	0.009 (2)
C4	0.078 (3)	0.078 (4)	0.053 (3)	−0.026 (3)	−0.010 (3)	0.005 (3)
C5	0.065 (3)	0.053 (3)	0.044 (2)	0.003 (2)	−0.005 (2)	−0.004 (2)
C6	0.078 (4)	0.072 (3)	0.046 (3)	−0.016 (3)	−0.001 (2)	0.005 (2)
C7	0.068 (3)	0.066 (3)	0.055 (3)	−0.016 (2)	−0.009 (2)	0.000 (2)
C8	0.069 (3)	0.058 (3)	0.060 (3)	0.004 (2)	−0.007 (3)	−0.013 (2)
C9	0.056 (3)	0.051 (3)	0.044 (3)	0.000 (2)	−0.004 (2)	−0.003 (2)
C10	0.064 (3)	0.076 (3)	0.054 (3)	−0.005 (3)	0.004 (2)	0.003 (3)
C11	0.068 (3)	0.076 (3)	0.043 (3)	−0.010 (3)	−0.005 (2)	0.008 (2)
C12	0.064 (3)	0.081 (4)	0.050 (3)	−0.011 (3)	−0.008 (3)	0.006 (3)
C13	0.073 (3)	0.085 (4)	0.050 (3)	−0.024 (3)	−0.011 (3)	0.007 (3)
C14	0.077 (4)	0.058 (3)	0.049 (3)	−0.011 (3)	0.006 (3)	0.009 (2)
C15	0.076 (4)	0.121 (4)	0.060 (3)	0.000 (3)	−0.011 (3)	0.016 (3)
C16	0.111 (5)	0.116 (5)	0.079 (3)	0.000 (3)	−0.002 (3)	−0.005 (3)
C17	0.112 (15)	0.077 (10)	0.078 (7)	0.023 (9)	0.002 (7)	0.012 (7)
C18	0.138 (15)	0.088 (14)	0.109 (13)	−0.014 (10)	0.007 (9)	−0.011 (9)
C17A	0.076 (11)	0.055 (14)	0.040 (7)	0.008 (10)	−0.024 (7)	−0.009 (9)
C18A	0.034 (7)	0.100 (11)	0.090 (8)	0.013 (6)	0.000 (6)	0.013 (7)
N1	0.080 (3)	0.066 (3)	0.045 (2)	−0.0010 (19)	−0.007 (2)	0.0019 (19)
N2	0.071 (3)	0.155 (4)	0.050 (2)	−0.037 (3)	−0.015 (2)	0.022 (3)
O1	0.097 (2)	0.089 (2)	0.0590 (19)	−0.0284 (19)	−0.0243 (16)	0.0038 (17)
O2	0.124 (3)	0.090 (2)	0.0495 (18)	−0.023 (2)	−0.0197 (17)	0.0063 (17)
O3	0.105 (3)	0.105 (2)	0.0537 (18)	−0.042 (2)	−0.0093 (17)	0.0086 (19)

C1—O1	1.240 (4)	C13—H15	0.9300
C1—O2	1.284 (4)	C14—O3	1.344 (4)
C1—C2	1.468 (4)	C15—N2	1.481 (4)
C2—C7	1.368 (4)	C15—C16	1.485 (5)
C2—C3	1.377 (4)	C15—H2A	0.9700
C3—C4	1.374 (4)	C15—H2B	0.9700
C3—H18	0.9300	C16—H1A	0.9600
C4—C5	1.369 (4)	C16—H1B	0.9600
C4—H17	0.9300	C16—H1C	0.9600
C5—C6	1.389 (4)	C17—C18	1.440 (19)
C5—N1	1.410 (4)	C17—N2	1.569 (14)
C6—C7	1.383 (5)	C17—H17A	0.9700
C6—H10	0.9300	C17—H17B	0.9700
C7—H11	0.9300	C18—H18A	0.9600
C8—N1	1.274 (4)	C18—H18B	0.9600
C8—C9	1.441 (4)	C18—H18C	0.9600
C8—H7	0.9300	C17A—C18A	1.53 (2)
C9—C10	1.374 (4)	C17A—N2	1.538 (15)
C9—C14	1.414 (5)	C17A—H17C	0.9700
C10—C11	1.370 (4)	C17A—H17D	0.9700
C10—H5	0.9300	C18A—H18D	0.9600
C11—C12	1.411 (5)	C18A—H18E	0.9600
C11—H4	0.9300	C18A—H18F	0.9600
C12—N2	1.365 (4)	O2—H2	0.8200
C12—C13	1.394 (5)	O3—H3	0.8200
C13—C14	1.379 (5)
O1—C1—O2	122.8 (3)	O3—C14—C9	121.0 (4)
O1—C1—C2	121.2 (3)	C13—C14—C9	121.1 (4)
O2—C1—C2	116.0 (4)	N2—C15—C16	112.3 (4)
C7—C2—C3	118.4 (3)	N2—C15—H2A	109.1
C7—C2—C1	119.7 (4)	C16—C15—H2A	109.1
C3—C2—C1	121.9 (4)	N2—C15—H2B	109.1
C4—C3—C2	120.4 (4)	C16—C15—H2B	109.1
C4—C3—H18	119.8	H2A—C15—H2B	107.9
C2—C3—H18	119.8	C15—C16—H1A	109.5
C5—C4—C3	121.6 (4)	C15—C16—H1B	109.5
C5—C4—H17	119.2	H1A—C16—H1B	109.5
C3—C4—H17	119.2	C15—C16—H1C	109.5
C4—C5—C6	118.3 (3)	H1A—C16—H1C	109.5
C4—C5—N1	116.9 (4)	H1B—C16—H1C	109.5
C6—C5—N1	124.7 (4)	C18—C17—N2	96.6 (12)
C7—C6—C5	119.7 (4)	C18—C17—H17A	112.4
C7—C6—H10	120.1	N2—C17—H17A	112.4
C5—C6—H10	120.1	C18—C17—H17B	112.4
C2—C7—C6	121.6 (4)	N2—C17—H17B	112.4
C2—C7—H11	119.2	H17A—C17—H17B	110.0
C6—C7—H11	119.2	C18A—C17A—N2	109.6 (11)
N1—C8—C9	123.8 (4)	C18A—C17A—H17C	109.8
N1—C8—H7	118.1	N2—C17A—H17C	109.8
C9—C8—H7	118.1	C18A—C17A—H17D	109.8
C10—C9—C14	117.2 (4)	N2—C17A—H17D	109.8
C10—C9—C8	122.0 (4)	H17C—C17A—H17D	108.2
C14—C9—C8	120.8 (4)	C17A—C18A—H18D	109.5
C11—C10—C9	122.7 (4)	C17A—C18A—H18E	109.5
C11—C10—H5	118.7	H18D—C18A—H18E	109.5
C9—C10—H5	118.7	C17A—C18A—H18F	109.5
C10—C11—C12	120.2 (4)	H18D—C18A—H18F	109.5
C10—C11—H4	119.9	H18E—C18A—H18F	109.5
C12—C11—H4	119.9	C8—N1—C5	122.4 (3)
N2—C12—C13	121.8 (4)	C12—N2—C15	122.2 (3)
N2—C12—C11	120.3 (4)	C12—N2—C17A	117.5 (7)
C13—C12—C11	118.0 (4)	C15—N2—C17A	118.8 (7)
C14—C13—C12	120.8 (4)	C12—N2—C17	121.8 (5)
C14—C13—H15	119.6	C15—N2—C17	111.2 (5)
C12—C13—H15	119.6	C1—O2—H2	109.5
O3—C14—C13	117.9 (4)	C14—O3—H3	109.5
O1—C1—C2—C7	10.7 (6)	C12—C13—C14—C9	−2.7 (6)
O2—C1—C2—C7	−170.5 (3)	C10—C9—C14—O3	179.1 (4)
O1—C1—C2—C3	−167.8 (4)	C8—C9—C14—O3	−2.6 (6)
O2—C1—C2—C3	11.1 (6)	C10—C9—C14—C13	1.2 (6)
C7—C2—C3—C4	−1.5 (6)	C8—C9—C14—C13	179.5 (4)
C1—C2—C3—C4	176.9 (4)	C9—C8—N1—C5	−175.9 (3)
C2—C3—C4—C5	1.4 (6)	C4—C5—N1—C8	−169.4 (3)
C3—C4—C5—C6	−0.5 (6)	C6—C5—N1—C8	14.6 (5)
C3—C4—C5—N1	−176.7 (3)	C13—C12—N2—C15	172.2 (4)
C4—C5—C6—C7	−0.1 (6)	C11—C12—N2—C15	−9.0 (5)
N1—C5—C6—C7	175.8 (3)	C13—C12—N2—C17A	−21.8 (10)
C3—C2—C7—C6	0.9 (6)	C11—C12—N2—C17A	157.0 (9)
C1—C2—C7—C6	−177.6 (4)	C13—C12—N2—C17	18.6 (7)
C5—C6—C7—C2	−0.1 (6)	C11—C12—N2—C17	−162.5 (6)
N1—C8—C9—C10	177.6 (4)	C16—C15—N2—C12	88.2 (4)
N1—C8—C9—C14	−0.6 (6)	C16—C15—N2—C17A	−77.6 (10)
C14—C9—C10—C11	0.0 (6)	C16—C15—N2—C17	−115.7 (5)
C8—C9—C10—C11	−178.2 (4)	C18A—C17A—N2—C12	97.2 (10)
C9—C10—C11—C12	0.2 (6)	C18A—C17A—N2—C15	−96.3 (11)
C10—C11—C12—N2	179.6 (4)	C18A—C17A—N2—C17	−9.9 (8)
C10—C11—C12—C13	−1.5 (6)	C18—C17—N2—C12	−98.4 (11)
N2—C12—C13—C14	−178.3 (4)	C18—C17—N2—C15	105.4 (10)
C11—C12—C13—C14	2.8 (6)	C18—C17—N2—C17A	−4.7 (18)
C12—C13—C14—O3	179.4 (4)

D—H···A	D—H	H···A	D···A	D—H···A
O3—H3···N1	0.82	1.88	2.609 (3)	147
O2—H2···O1i	0.82	1.80	2.613 (2)	170

Table 1

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O3—H3⋯N1	0.82	1.88	2.609 (3)	147
O2—H2⋯O1i	0.82	1.80	2.613 (2)	170

Symmetry code: (i) .