(E)-1-[4-(2,4-Dihydroxy­benzyl­idene­amino)phen­yl]ethanone sesquihydrate

The asymmetric unit of the title compound, C₁₅H₁₃NO₃·1.5H₂O, consists of one ethanone mol­ecule, one water mol­ecule and one half-mol­ecule of water. The organic mol­ecule is a phenol–imine tautomer, as evidenced from C—O, C—N and C—C bond lengths and it is stabilized by an intra­molecular O—H...N hydrogen bond which generates an S(6) ring motif. It is nearly planar, with a dihedral angle of 1.40 (10)° between the two aromatic rings. Mol­ecules are linked by three inter­molecular O—H...O hydrogen bonds, forming dimers, and are further linked by C—H...π inter­actions, forming a three-dimensional network.

Key indicators

• Single-crystal X-ray study
• T = 296 K
• Mean [sigma](C-C) = 0.003 Å
• Disorder in solvent or counterion
• R factor = 0.043
• wR factor = 0.108
• Data-to-parameter ratio = 13.3

checkCIF/PLATON results

No syntax errors found



Alert level B
PLAT245_ALERT_2_B U(iso) H5O     Smaller than U(eq) O5      by ...       0.09 AngSq
PLAT417_ALERT_2_B Short Inter D-H..H-D       H4A    ..  H4A     ..       1.39 Ang.

Alert level C
PLAT041_ALERT_1_C Calc. and Rep. SumFormula Strings    Differ ....          ?
PLAT042_ALERT_1_C Calc. and Rep. MoietyFormula Strings Differ ....          ?
PLAT045_ALERT_1_C Calculated and Reported Z Differ by ............       0.50 Ratio
PLAT154_ALERT_1_C The su's on the Cell Angles are Equal  (x 10000)       1000 Deg.
PLAT302_ALERT_4_C Anion/Solvent Disorder .........................      33.00 Perc.

Alert level G
PLAT860_ALERT_3_G Note: Number of Least-Squares Restraints .......          4

   0 ALERT level A = In general: serious problem
   2 ALERT level B = Potentially serious problem
   5 ALERT level C = Check and explain
   1 ALERT level G = General alerts; check

   4 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   2 ALERT type 2 Indicator that the structure model may be wrong or deficient
   1 ALERT type 3 Indicator that the structure quality may be low
   1 ALERT type 4 Improvement, methodology, query or suggestion
   0 ALERT type 5 Informative message, check

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S1. Comment

The present work is part of a structural study of Schiff bases Özek et al., 2007; Odabaşoǧlu et al., 2007a,b) and we report here the structure of (E)-1-(4-(2,4-dihydroxybenzylideneamino)phenyl)ethanone. 3/2 hydrate, (I).

In general, O-hydroxy Schiff bases exhibit two possible tautomeric forms, the phenol-imine (or benzenoid) and keto-amine (or quinoid) forms. Depending on the tautomers, two types of intra-molecular hydrogen bonds are possible: O—H···N in benzenoid and N—H···O in quinoid tautomers. The H atom in title compound (I) is located on atom O1, thus the phenol-imine tautomer is favored over the keto-amine form, as indicated by the C6—O1, C7—N1, C1—C7 and C1—C6 bond lengths (Fig. 1 and Table 1). The O1—C6 bond length of 1.346 (2) Å indicates single-bond character, whereas the N1—C7 bond length of 1.287 (2) Å indicates a high degree of double-bond character. A similar work was observed for 2-(3-Methoxysalicylideneamino)-1H-benzimidazolemonohydrate [C—O=1.357 (2) Å, C—N= 1.285 (2) Å, Albayrak et al., 2005]. It is known that Schiff bases may exhibit thermochromism or photochromism, depending on the planarity or non-planarity of the molecule, respectively. Therefore, one can expect thermochromic properties in (I) caused by planarity of the molecules; the dihedral angle between rings A(C1—C6) and B ring (C8—C13) is 1.4 °. Fig.1 shows an intramolecular O1—H1···N1 hydrogen bond that generates an S(6) ring motif. The O1···N1 distance of 2.608 (2) Å is comparable to those observed for analogous hydrogen bonds in N-(2-hydroxyphenyl)salicylaldimine [2.675 (7) Å; Elerman et al., 1995] and Three (E)-2-[(bromophenyl)iminomethyl]-4-methoxyphenols [2.603 (2) Å, 2.638 (7) Å, 2.577 (4) Å;Özek et al., 2007]. In the crystal structure of (I), the molecules are linked by three O—H···O intermolecular hydrogen bonds (Fig.2) and further linked by C—H···π interactions (Table 2), forming a three-dimensional network.

Related literature

For related literature, see: Elerman et al., 1995; Özek et al., 2007; Albayrak et al., 2005; Odabaşoğlu et al. (2005); Odabaşoǧlu et al. (2007a, 2007b).

S2. Experimental

The title compounds were prepared as described by (Odabaşoğlu et al., 2005), 4-acetylaniline and 4-hydroxysalicylaldehyde as starting materials. Well shaped crystals of (I) were obtained by slow evaporation of an ethyl alcohol solution [(I): yield 76%; m.p. 447–449 K].

S3. Refinement

The coordinates of the H atoms of the water molecules were located in the difference Fourier map and were then allowed to refine subject to a restraint of the distance O—H = 0.82 Å. All other H atoms were refined using a riding model, with C—H distance of 0.93Å for aromatic H atoms and 0.96Å for methyl H atoms, O—H distances of 0.82 Å, and U_iso(H) = 1.5U_eq(C) for methyl H atoms and 1.2U_eq(C,O) for the remaining H atoms.

Computing details

Data collection: X-AREA (Stoe & Cie, 2002); cell refinement: X-AREA (Stoe & Cie, 2002); data reduction: X-RED32 (Stoe & Cie, 2002); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997); software used to prepare material for publication: WinGX (Farrugia, 1999).

Figures

	Fig. 1. An ORTEP view of (I), with the atom-numbering scheme and 50% probability displacement ellipsoids. Dashed line indicates intramolecular hydrogen bond.
	Fig. 2. A partial packing view of (I), showing the formation of the intermolecular hydrogen bonds and C—H···π interactions. Hydrogen bonds are shown as dashed lines. H atoms not involved in hydrogen bonding have been omitted for clarity. [Symmetry code; (i): 1 - x, y - 1/2, 1 - z; (ii): -x, -y, -z]
	Fig. 3. Tautomers

(E)-1-[4-(2,4-Dihydroxybenzylideneamino)phenyl]ethanone sesquihydrate

Crystal data

C15H13NO3·1.5H2O	Z = 2
Mr = 282.29	F(000) = 298
Triclinic, P1	Dx = 1.366 Mg m^−3
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 5.9812 (7) Å	Cell parameters from 10420 reflections
b = 7.3117 (10) Å	θ = 2.5–29.4°
c = 16.450 (2) Å	µ = 0.10 mm^−1
α = 101.031 (10)°	T = 296 K
β = 90.948 (10)°	Plate, yellow
γ = 103.984 (10)°	0.47 × 0.28 × 0.05 mm
V = 683.68 (15) Å^3

Data collection

Stoe IPDS-2 diffractometer	2675 independent reflections
Radiation source: fine-focus sealed tube	1351 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.084
Detector resolution: 6.67 pixels mm^-1	θmax = 26.0°, θmin = 2.5°
ω scans	h = −7→7
Absorption correction: integration (X-RED32; Stoe & Cie, 2002)	k = −8→9
Tmin = 0.972, Tmax = 0.996	l = −20→20
10420 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)] = 0.043	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.108	H atoms treated by a mixture of independent and constrained refinement
S = 0.87	w = 1/[σ^2(Fo^2) + (0.0726P)^2] where P = (Fo^2 + 2Fc^2)/3
2675 reflections	(Δ/σ)max < 0.001
201 parameters	Δρmax = 0.14 e Å^−3
4 restraints	Δρmin = −0.15 e Å^−3

Special details

Experimental. 390 frames, detector distance = 100 mm

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	Occ. (<1)
C1	0.4432 (3)	0.5425 (3)	0.30698 (11)	0.0430 (5)
C2	0.2610 (3)	0.4313 (3)	0.25090 (11)	0.0509 (5)
H2	0.1124	0.4050	0.2692	0.061*
C3	0.2932 (3)	0.3603 (3)	0.17049 (12)	0.0551 (6)
H3	0.1686	0.2871	0.1344	0.066*
C4	0.5149 (3)	0.3986 (3)	0.14294 (12)	0.0503 (5)
C5	0.6998 (3)	0.5072 (3)	0.19635 (12)	0.0545 (5)
H5	0.8473	0.5332	0.1772	0.065*
C6	0.6665 (3)	0.5773 (3)	0.27794 (11)	0.0459 (5)
C7	0.4009 (3)	0.6152 (3)	0.39078 (11)	0.0481 (5)
H7	0.2496	0.5897	0.4065	0.058*
C8	0.5185 (3)	0.7859 (3)	0.52783 (11)	0.0426 (5)
C9	0.7081 (3)	0.8923 (3)	0.58016 (11)	0.0510 (5)
H9	0.8541	0.9144	0.5597	0.061*
C10	0.6836 (3)	0.9658 (3)	0.66222 (12)	0.0510 (5)
H10	0.8135	1.0352	0.6965	0.061*
C11	0.4683 (3)	0.9379 (3)	0.69432 (10)	0.0427 (5)
C12	0.2788 (3)	0.8344 (3)	0.64127 (12)	0.0528 (5)
H12	0.1324	0.8154	0.6614	0.063*
C13	0.3019 (3)	0.7593 (3)	0.55983 (12)	0.0554 (6)
H13	0.1717	0.6899	0.5257	0.067*
C14	0.6365 (4)	1.1200 (3)	0.84147 (13)	0.0641 (6)
H14A	0.6803	1.2521	0.8360	0.096*
H14B	0.7634	1.0625	0.8290	0.096*
H14C	0.5961	1.1135	0.8973	0.096*
C15	0.4330 (3)	1.0136 (3)	0.78228 (12)	0.0482 (5)
N1	0.5631 (3)	0.7144 (2)	0.44546 (9)	0.0456 (4)
O2	0.5554 (2)	0.3308 (2)	0.06343 (8)	0.0715 (5)
H2A	0.4333	0.2690	0.0378	0.107*
O1	0.8501 (2)	0.6808 (2)	0.32915 (8)	0.0659 (5)
H1	0.8074	0.7135	0.3756	0.099*
O3	0.2375 (3)	0.9894 (2)	0.80607 (8)	0.0663 (4)
O4	0.1563 (3)	0.1450 (3)	−0.03210 (10)	0.0806 (6)
H4A	0.090 (5)	0.056 (4)	−0.0173 (19)	0.121*
H4B	0.192 (5)	0.103 (4)	−0.0814 (12)	0.121*
O5	−0.026 (7)	0.505 (5)	0.0116 (19)	0.139 (5)	0.50
H5O	0.005 (6)	0.405 (4)	−0.009 (2)	0.050 (9)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.0447 (10)	0.0441 (12)	0.0389 (10)	0.0115 (9)	0.0035 (8)	0.0049 (9)
C2	0.0413 (10)	0.0607 (14)	0.0453 (11)	0.0075 (10)	0.0019 (8)	0.0041 (10)
C3	0.0500 (12)	0.0623 (15)	0.0448 (11)	0.0081 (11)	−0.0046 (9)	−0.0015 (10)
C4	0.0562 (12)	0.0531 (13)	0.0391 (10)	0.0146 (10)	0.0039 (9)	0.0017 (9)
C5	0.0459 (11)	0.0654 (15)	0.0479 (11)	0.0123 (11)	0.0080 (9)	0.0025 (10)
C6	0.0387 (10)	0.0489 (13)	0.0456 (11)	0.0077 (9)	−0.0001 (8)	0.0028 (9)
C7	0.0430 (10)	0.0551 (14)	0.0451 (11)	0.0121 (10)	0.0047 (9)	0.0074 (10)
C8	0.0452 (10)	0.0431 (12)	0.0391 (10)	0.0119 (9)	0.0022 (8)	0.0064 (9)
C9	0.0398 (10)	0.0640 (15)	0.0452 (11)	0.0089 (10)	0.0037 (8)	0.0064 (10)
C10	0.0434 (11)	0.0597 (14)	0.0429 (11)	0.0057 (10)	−0.0021 (8)	0.0028 (10)
C11	0.0482 (11)	0.0425 (12)	0.0368 (10)	0.0108 (9)	0.0010 (8)	0.0069 (9)
C12	0.0406 (10)	0.0662 (15)	0.0451 (11)	0.0070 (10)	0.0071 (8)	0.0030 (10)
C13	0.0428 (11)	0.0685 (16)	0.0444 (11)	0.0037 (11)	0.0010 (9)	−0.0012 (10)
C14	0.0689 (14)	0.0687 (16)	0.0443 (11)	0.0107 (12)	−0.0055 (10)	−0.0051 (10)
C15	0.0557 (12)	0.0458 (13)	0.0420 (10)	0.0119 (10)	0.0027 (9)	0.0070 (9)
N1	0.0464 (9)	0.0490 (11)	0.0395 (8)	0.0128 (8)	0.0026 (7)	0.0031 (7)
O2	0.0660 (9)	0.0953 (12)	0.0411 (8)	0.0151 (9)	0.0065 (7)	−0.0096 (8)
O1	0.0431 (7)	0.0862 (12)	0.0504 (8)	0.0025 (7)	0.0012 (6)	−0.0122 (7)
O3	0.0608 (9)	0.0832 (12)	0.0456 (8)	0.0106 (8)	0.0116 (7)	−0.0013 (7)
O4	0.0796 (12)	0.1020 (15)	0.0457 (9)	0.0092 (11)	0.0095 (8)	−0.0041 (9)
O5	0.165 (15)	0.169 (7)	0.103 (14)	0.101 (8)	0.010 (9)	0.001 (9)

Geometric parameters (Å, º)

C1—C2	1.397 (3)	C10—C11	1.384 (3)
C1—C6	1.407 (2)	C10—H10	0.9300
C1—C7	1.429 (3)	C11—C12	1.385 (3)
C2—C3	1.360 (3)	C11—C15	1.485 (3)
C2—H2	0.9300	C12—C13	1.370 (3)
C3—C4	1.389 (3)	C12—H12	0.9300
C3—H3	0.9300	C13—H13	0.9300
C4—O2	1.355 (2)	C14—C15	1.499 (3)
C4—C5	1.379 (3)	C14—H14A	0.9600
C5—C6	1.378 (3)	C14—H14B	0.9600
C5—H5	0.9300	C14—H14C	0.9600
C6—O1	1.346 (2)	C15—O3	1.222 (2)
C7—N1	1.287 (2)	O2—H2A	0.8200
C7—H7	0.9300	O1—H1	0.8200
C8—C9	1.385 (2)	O4—H4A	0.760 (16)
C8—C13	1.390 (3)	O4—H4B	0.860 (16)
C8—N1	1.410 (2)	O5—O5^i	0.50 (4)
C9—C10	1.378 (3)	O5—H5O	0.81 (2)
C9—H9	0.9300
C2—C1—C6	117.59 (16)	C9—C10—C11	120.94 (17)
C2—C1—C7	120.31 (17)	C9—C10—H10	119.5
C6—C1—C7	122.10 (17)	C11—C10—H10	119.5
C3—C2—C1	122.27 (18)	C10—C11—C12	117.84 (17)
C3—C2—H2	118.9	C10—C11—C15	122.98 (17)
C1—C2—H2	118.9	C12—C11—C15	119.18 (17)
C2—C3—C4	119.11 (18)	C13—C12—C11	121.60 (18)
C2—C3—H3	120.4	C13—C12—H12	119.2
C4—C3—H3	120.4	C11—C12—H12	119.2
O2—C4—C5	118.32 (19)	C12—C13—C8	120.51 (18)
O2—C4—C3	121.20 (18)	C12—C13—H13	119.7
C5—C4—C3	120.48 (18)	C8—C13—H13	119.7
C6—C5—C4	120.21 (18)	C15—C14—H14A	109.5
C6—C5—H5	119.9	C15—C14—H14B	109.5
C4—C5—H5	119.9	H14A—C14—H14B	109.5
O1—C6—C5	119.11 (16)	C15—C14—H14C	109.5
O1—C6—C1	120.56 (16)	H14A—C14—H14C	109.5
C5—C6—C1	120.33 (16)	H14B—C14—H14C	109.5
N1—C7—C1	122.84 (18)	O3—C15—C11	119.72 (17)
N1—C7—H7	118.6	O3—C15—C14	120.24 (19)
C1—C7—H7	118.6	C11—C15—C14	120.04 (18)
C9—C8—C13	118.16 (17)	C7—N1—C8	122.20 (16)
C9—C8—N1	116.39 (17)	C4—O2—H2A	109.5
C13—C8—N1	125.45 (17)	C6—O1—H1	109.5
C10—C9—C8	120.93 (18)	H4A—O4—H4B	105 (2)
C10—C9—H9	119.5	O5^i—O5—H5O	53 (7)
C8—C9—H9	119.5
C6—C1—C2—C3	−1.1 (3)	N1—C8—C9—C10	−178.88 (19)
C7—C1—C2—C3	179.6 (2)	C8—C9—C10—C11	−1.0 (3)
C1—C2—C3—C4	0.2 (3)	C9—C10—C11—C12	−0.2 (3)
C2—C3—C4—O2	180.0 (2)	C9—C10—C11—C15	179.8 (2)
C2—C3—C4—C5	0.0 (3)	C10—C11—C12—C13	0.8 (3)
O2—C4—C5—C6	−179.3 (2)	C15—C11—C12—C13	−179.2 (2)
C3—C4—C5—C6	0.6 (3)	C11—C12—C13—C8	−0.3 (3)
C4—C5—C6—O1	179.2 (2)	C9—C8—C13—C12	−0.9 (3)
C4—C5—C6—C1	−1.5 (3)	N1—C8—C13—C12	179.5 (2)
C2—C1—C6—O1	−178.99 (19)	C10—C11—C15—O3	177.6 (2)
C7—C1—C6—O1	0.4 (3)	C12—C11—C15—O3	−2.4 (3)
C2—C1—C6—C5	1.7 (3)	C10—C11—C15—C14	−2.2 (3)
C7—C1—C6—C5	−179.00 (19)	C12—C11—C15—C14	177.8 (2)
C2—C1—C7—N1	178.31 (19)	C1—C7—N1—C8	179.68 (19)
C6—C1—C7—N1	−1.0 (3)	C9—C8—N1—C7	−179.31 (18)
C13—C8—C9—C10	1.5 (3)	C13—C8—N1—C7	0.3 (3)

Symmetry code: (i) −x, −y+1, −z.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O2—H2A···O4	0.82	1.92	2.740 (2)	173
O1—H1···N1	0.82	1.87	2.608 (2)	148
O4—H4B···O3^ii	0.86 (2)	1.93 (2)	2.787 (2)	173 (3)
O4—H4A···O4^iii	0.76 (2)	2.11 (2)	2.848 (4)	165 (4)
C14—H14a···Cg1^iv	0.96	2.78	3.590 (2)	143

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