Methyl 2-[(E)-(3-formyl-4-hydroxyphen­yl)diazen­yl]benzoate

The title compound, C₁₅H₁₂N₂O₄, displays a twisted conformation as reflected in the dihedral angle between the aromatic rings of 59.77 (7)°. Intra- and inter­molecular O—H...O inter­actions are found, with the latter leading to a double chain arranged about a zigzag chain of {O—H...O}_n inter­actions.

Key indicators

• Single-crystal X-ray study
• T = 153 K
• Mean [sigma](C-C) = 0.002 Å
• R factor = 0.046
• wR factor = 0.129
• Data-to-parameter ratio = 13.6

checkCIF/PLATON results

No syntax errors found



Alert level C
ABSTM02_ALERT_3_C  The ratio of expected to reported Tmax/Tmin(RR') is < 0.90
            Tmin and Tmax reported:      0.878     1.000
            Tmin(prime) and Tmax expected:      0.968     0.987
            RR(prime) =      0.895
            Please check that your absorption correction is appropriate.
PLAT029_ALERT_3_C _diffrn_measured_fraction_theta_full Low .......       0.97
PLAT061_ALERT_3_C Tmax/Tmin Range Test RR' too Large .............       0.89
PLAT062_ALERT_4_C Rescale T(min) & T(max) by .....................       0.99
PLAT152_ALERT_1_C Supplied and Calc Volume s.u. Inconsistent .....          ?
PLAT432_ALERT_2_C Short Inter X...Y Contact  C8     ..  C12'    ..       3.19 Ang.
PLAT480_ALERT_4_C Long H...A H-Bond Reported H9     ..  N2      ..       2.66 Ang.
PLAT480_ALERT_4_C Long H...A H-Bond Reported H4     ..  O2      ..       2.84 Ang.

Alert level G
PLAT860_ALERT_3_G Note: Number of Least-Squares Restraints .......          1

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

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

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S1. Comment

The synthesis of the title compound (I) and their interactions with triorganotin(IV) moieties, have attracted much interest owing to their novel structural possibilities (Basu Baul et al., 1996, 2006), and their significant biological activity towards mosquito larvae (Basu Baul et al., 2004) and sea urchin early development stages (Basu Baul et al., 2006).

Compound (I), Fig. 1, assumes an E-conformation. There is a twist in the molecule as seen in the N1—N2—C8—C9 and, in particular, the N2—N1—C7—C2 torsion angles of -163.77 (13) and -141.01 (14)°, respectively. This is also reflected in the dihedral angle of 59.77 (7)° formed between the C2—C7 and C8—C13 aromatic rings.

The hydroxyl group participates in an intramolecular O3—H···O4 hydrogen-bond and at the same time forms an intermolecular O3—H···O3 interaction with a centrosymmetric mate, Table 1, to form a double chain, Fig. 2. Additional stabilization to the chain are afforded by C—H···O1 contacts. Further, this arrangement allows for the close approach of the C=O4 carbonyl to the π-system of a translationally related C8—C13 ring; C12'=O4···Cg(C18—C13) = 3.2061 (13)ⁱⁱ Å for ii: x, -1 + y, z. The double-chains stack in columns parallel to the b axis. Connections between columns are afforded by weak C—H···O contacts, involving an aromatic C4—H and O2 atoms, and weak C—H···N contacts involving aromatic C9—H and azo-N2 atoms, the latter leading to a eight-membered [···HCCN]₂ synthon.

Related literature

For related literature, see: Basu Baul et al. (1996, 2006, 2004).

S2. Experimental

2-[(E)-2-(3-Formyl-4-hydroxyphenyl)-1-diazenyl]benzoic acid (2.0 g, 7.40 mmol), prepared as in the literature (Basu Baul et al., 1996), was dissolved in anhydrous methanol (150 ml) and transferred to a three-necked round bottom flask equipped with a dropping funnel, water-cooled condenser and a guard tube, all placed in an ice/salt bath. The clear solution was allowed to cool as the stirring was continued. After sufficient cooling, SOCl₂ (1.62 ml, 22.19 mmol) was added drop-wise over 30 min. The whole reaction mixture was allowed to warm to room temperature, stirred for 20 h, and then the volatiles were removed using a rotary evaporator. Water was added to the residue and neutralized with aqueous NaHCO₃ solution. The product was extracted in ethyl acetate and the resulting two-phase system was mixed well and filtered, and the layers were separated. The ethyl acetate portion was washed with water, dried over Na₂SO₄, and the solvent was evaporated to one-fourth of its initial solvent volume and kept at room temperature to yield (I). The solid was washed with hexane, dried in vacuo and recrystallized from an ethyl acetate-methanol mixture (v/v, 1:1) which afforded the orange crystals (m.p. 333–335 K) in 85% (1.78 g) yield. Elemental analysis, found: C 63.41, H 4.27, N 9.87%; C₁₅H₁₂N₂O₄ requires C 63.37, H 4.25, N 9.85%. IR (KBr, cm^-1): 1725 ν(OCO)_asym. ¹H NMR (CDCl₃, 400.13 MHz): δ H: 11.37 [s, 1H, H4], 10.02 [s, 1H, H7], 8.41 [d, 2.6 Hz, 1H, H2], 8.19 [dd, 2.6, 8.8 Hz, 1H, H6], 7.83 [dd, 1.5, 7.7 Hz, 1H, H3'], 7.60 [dt, 1.5, 7.7 Hz, 2H, H4' & H6'], 7.51 [dt, 1.5, 7.7 Hz, 1H, H5'], 7.11 [d, 8.8 Hz, 1H, H5], 4.00 [s, 3H, H8'] p.p.m. ¹³C NMR (CDCl₃, 100.62 MHz): δ C: 196.9, 168.2, 164.6, 152.1, 146.4, 132.5, 131.1, 130.4, 130.3, 130.2, 129.0, 120.7, 119.2, 119.0, 52.8 p.p.m.

S3. Refinement

All C-bound H atoms were included in the riding-model approximation, with C—H = 0.95 to 0.98 Å, and with U_iso(H) = 1.2U_eq(C). The hydroxyl-H atom was located from a difference map and included so that O—H = 0.84 Å and U_iso(H) = 1.5U_eq(O).

Computing details

Data collection: CrystalClear (Rigaku/MSC, 2005); cell refinement: CrystalClear; data reduction: CrystalClear; program(s) used to solve structure: SIR92 (Altomare et al., 1994); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEPII (Johnson, 1976) and DIAMOND (Brandenburg, 2006); software used to prepare material for publication: SHELXL97.

Figures

	Fig. 1. Molecular structure of (I) showing atom-labelling scheme and displacement ellipsoids at the 50% probability level.
	Fig. 2. View of the supramolecular chain in (I) mediated by hydrogen bonds, shown as orange-dashed lines. Colour code: red (oxygen), blue (nitrogen), grey (carbon) and green (hydrogen).

Methyl 2-[(E)-(3-formyl-4-hydroxyphenyl)diazenyl]benzoate

Crystal data

C15H12N2O4	F(000) = 592
Mr = 284.27	Dx = 1.444 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71070 Å
Hall symbol: -P 2ybc	Cell parameters from 2012 reflections
a = 14.164 (2) Å	θ = 2.9–30.2°
b = 4.6113 (8) Å	µ = 0.11 mm^−1
c = 21.067 (3) Å	T = 153 K
β = 108.140 (4)°	Block, orange
V = 1307.6 (4) Å^3	0.30 × 0.15 × 0.12 mm
Z = 4

Data collection

Rigaku AFC12K/SATURN724 diffractometer	2638 independent reflections
Radiation source: fine-focus sealed tube	2510 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.021
ω scans	θmax = 26.5°, θmin = 2.9°
Absorption correction: multi-scan (ABSCOR; Higashi, 1995)	h = −17→14
Tmin = 0.878, Tmax = 1	k = −5→4
11141 measured reflections	l = −21→26

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)] = 0.046	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.129	H-atom parameters constrained
S = 1.08	w = 1/[σ^2(Fo^2) + (0.0717P)^2 + 0.3817P] where P = (Fo^2 + 2Fc^2)/3
2638 reflections	(Δ/σ)max = 0.001
194 parameters	Δρmax = 0.21 e Å^−3
1 restraint	Δρmin = −0.22 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	0.60419 (8)	0.6564 (3)	0.46402 (5)	0.0425 (3)
O2	0.48259 (8)	0.7820 (3)	0.37164 (5)	0.0439 (3)
O3	0.99285 (8)	−0.2764 (2)	0.70389 (5)	0.0360 (3)
H3O	0.9518	−0.4018	0.7075	0.054*
O4	0.82006 (8)	−0.5682 (2)	0.67043 (5)	0.0387 (3)
N1	0.74996 (9)	0.3207 (3)	0.43726 (6)	0.0328 (3)
N2	0.84243 (9)	0.3272 (3)	0.46527 (6)	0.0304 (3)
C1	0.57480 (10)	0.6905 (3)	0.40427 (7)	0.0331 (3)
C2	0.63371 (10)	0.6449 (3)	0.35758 (7)	0.0313 (3)
C3	0.60542 (11)	0.7840 (3)	0.29581 (8)	0.0365 (4)
H3	0.5472	0.9006	0.2834	0.044*
C4	0.66068 (12)	0.7554 (4)	0.25217 (8)	0.0397 (4)
H4	0.6408	0.8533	0.2104	0.048*
C5	0.74493 (12)	0.5833 (4)	0.26977 (8)	0.0389 (4)
H5	0.7823	0.5599	0.2397	0.047*
C6	0.77477 (11)	0.4460 (3)	0.33085 (7)	0.0348 (3)
H6	0.8328	0.3286	0.3426	0.042*
C7	0.72068 (10)	0.4773 (3)	0.37562 (7)	0.0309 (3)
C8	0.87549 (10)	0.1598 (3)	0.52484 (7)	0.0286 (3)
C9	0.97161 (10)	0.2172 (3)	0.56704 (7)	0.0312 (3)
H9	1.0116	0.3564	0.5541	0.037*
C10	1.00897 (10)	0.0743 (3)	0.62710 (7)	0.0322 (3)
H10	1.0734	0.1202	0.6560	0.039*
C11	0.95250 (10)	−0.1370 (3)	0.64554 (7)	0.0295 (3)
C12	0.85650 (10)	−0.2015 (3)	0.60252 (7)	0.0286 (3)
C12'	0.79609 (11)	−0.4270 (3)	0.61856 (7)	0.0333 (3)
H12'	0.7336	−0.4681	0.5866	0.040*
C13	0.81883 (10)	−0.0505 (3)	0.54276 (7)	0.0291 (3)
H13	0.7538	−0.0919	0.5141	0.035*
C14	0.42299 (11)	0.8673 (5)	0.41328 (9)	0.0473 (4)
H14A	0.4272	0.7175	0.4470	0.071*
H14B	0.3537	0.8907	0.3855	0.071*
H14C	0.4478	1.0514	0.4354	0.071*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.0320 (5)	0.0608 (8)	0.0328 (6)	0.0020 (5)	0.0070 (4)	0.0048 (5)
O2	0.0301 (5)	0.0631 (8)	0.0353 (6)	0.0097 (5)	0.0054 (5)	0.0033 (5)
O3	0.0390 (6)	0.0332 (6)	0.0303 (6)	−0.0002 (4)	0.0027 (5)	0.0029 (4)
O4	0.0432 (6)	0.0379 (6)	0.0359 (6)	−0.0005 (5)	0.0135 (5)	0.0037 (5)
N1	0.0312 (6)	0.0318 (7)	0.0333 (7)	0.0014 (5)	0.0068 (5)	0.0025 (5)
N2	0.0303 (6)	0.0298 (6)	0.0293 (6)	0.0018 (5)	0.0067 (5)	−0.0002 (5)
C1	0.0272 (7)	0.0355 (8)	0.0318 (8)	−0.0023 (6)	0.0021 (6)	0.0010 (6)
C2	0.0284 (7)	0.0314 (7)	0.0304 (8)	−0.0028 (5)	0.0038 (6)	−0.0005 (6)
C3	0.0334 (7)	0.0377 (8)	0.0327 (8)	0.0015 (6)	0.0022 (6)	0.0010 (6)
C4	0.0430 (8)	0.0440 (9)	0.0281 (8)	−0.0021 (7)	0.0053 (6)	0.0038 (6)
C5	0.0410 (8)	0.0434 (9)	0.0328 (8)	−0.0030 (7)	0.0120 (6)	−0.0028 (7)
C6	0.0323 (7)	0.0360 (8)	0.0342 (8)	0.0009 (6)	0.0076 (6)	−0.0016 (6)
C7	0.0301 (7)	0.0295 (7)	0.0300 (7)	−0.0032 (5)	0.0051 (5)	0.0002 (5)
C8	0.0301 (7)	0.0271 (7)	0.0279 (7)	0.0036 (5)	0.0081 (5)	−0.0009 (5)
C9	0.0303 (7)	0.0285 (7)	0.0348 (8)	0.0002 (5)	0.0099 (6)	−0.0008 (6)
C10	0.0281 (7)	0.0306 (7)	0.0336 (8)	0.0009 (6)	0.0035 (6)	−0.0025 (6)
C11	0.0322 (7)	0.0266 (7)	0.0274 (7)	0.0047 (5)	0.0062 (5)	−0.0026 (5)
C12	0.0299 (7)	0.0263 (7)	0.0294 (7)	0.0010 (5)	0.0088 (5)	−0.0034 (5)
C12'	0.0333 (7)	0.0331 (8)	0.0331 (8)	0.0007 (6)	0.0096 (6)	−0.0001 (6)
C13	0.0277 (6)	0.0289 (7)	0.0289 (7)	0.0025 (5)	0.0063 (5)	−0.0032 (5)
C14	0.0317 (8)	0.0643 (11)	0.0468 (10)	0.0069 (8)	0.0136 (7)	0.0050 (8)

Geometric parameters (Å, º)

C1—O1	1.2066 (19)	C5—H5	0.9500
C1—O2	1.3407 (17)	C6—C7	1.396 (2)
C14—O2	1.448 (2)	C6—H6	0.9500
O3—C11	1.3467 (17)	C8—C13	1.384 (2)
O3—H3O	0.8401	C8—C9	1.400 (2)
O4—C12'	1.2257 (18)	C9—C10	1.378 (2)
N1—N2	1.2582 (17)	C9—H9	0.9500
N1—C7	1.4298 (18)	C10—C11	1.390 (2)
N2—C8	1.4230 (18)	C10—H10	0.9500
C1—C2	1.490 (2)	C11—C12	1.4112 (19)
C2—C3	1.393 (2)	C12—C13	1.392 (2)
C2—C7	1.402 (2)	C12—C12'	1.452 (2)
C3—C4	1.387 (2)	C12'—H12'	0.9500
C3—H3	0.9500	C13—H13	0.9500
C4—C5	1.384 (2)	C14—H14A	0.9800
C4—H4	0.9500	C14—H14B	0.9800
C5—C6	1.377 (2)	C14—H14C	0.9800
C1—O2—C14	115.68 (12)	C13—C8—N2	124.14 (12)
C11—O3—H3O	107.5	C9—C8—N2	116.44 (12)
N2—N1—C7	112.28 (12)	C10—C9—C8	120.81 (13)
N1—N2—C8	114.16 (12)	C10—C9—H9	119.6
O1—C1—O2	122.71 (14)	C8—C9—H9	119.6
O1—C1—C2	126.03 (13)	C9—C10—C11	120.12 (13)
O2—C1—C2	111.25 (12)	C9—C10—H10	119.9
C3—C2—C7	118.68 (14)	C11—C10—H10	119.9
C3—C2—C1	119.63 (13)	O3—C11—C10	118.16 (12)
C7—C2—C1	121.60 (13)	O3—C11—C12	122.41 (13)
C2—C3—C4	121.18 (14)	C10—C11—C12	119.43 (13)
C2—C3—H3	119.4	C13—C12—C11	119.79 (13)
C4—C3—H3	119.4	C13—C12—C12'	118.77 (13)
C5—C4—C3	119.64 (14)	C11—C12—C12'	121.42 (13)
C5—C4—H4	120.2	O4—C12'—C12	124.63 (13)
C3—C4—H4	120.2	O4—C12'—H12'	117.7
C4—C5—C6	120.14 (15)	C12—C12'—H12'	117.7
C4—C5—H5	119.9	C8—C13—C12	120.39 (12)
C6—C5—H5	119.9	C8—C13—H13	119.8
C7—C6—C5	120.69 (14)	C12—C13—H13	119.8
C7—C6—H6	119.7	O2—C14—H14A	109.5
C5—C6—H6	119.7	O2—C14—H14B	109.5
C6—C7—C2	119.64 (13)	H14A—C14—H14B	109.5
C6—C7—N1	119.76 (13)	O2—C14—H14C	109.5
C2—C7—N1	120.42 (13)	H14A—C14—H14C	109.5
C13—C8—C9	119.41 (13)	H14B—C14—H14C	109.5
C7—N1—N2—C8	−176.49 (11)	N2—N1—C7—C2	−141.01 (14)
C14—O2—C1—O1	6.2 (2)	N1—N2—C8—C13	16.02 (19)
C14—O2—C1—C2	−172.67 (14)	N1—N2—C8—C9	−163.77 (13)
O1—C1—C2—C3	−157.39 (16)	C13—C8—C9—C10	−2.3 (2)
O2—C1—C2—C3	21.44 (19)	N2—C8—C9—C10	177.52 (12)
O1—C1—C2—C7	19.0 (2)	C8—C9—C10—C11	2.2 (2)
O2—C1—C2—C7	−162.17 (13)	C9—C10—C11—O3	178.37 (12)
C7—C2—C3—C4	1.0 (2)	C9—C10—C11—C12	−0.6 (2)
C1—C2—C3—C4	177.50 (14)	O3—C11—C12—C13	−179.87 (12)
C2—C3—C4—C5	0.7 (2)	C10—C11—C12—C13	−1.0 (2)
C3—C4—C5—C6	−1.3 (2)	O3—C11—C12—C12'	−1.0 (2)
C4—C5—C6—C7	0.2 (2)	C10—C11—C12—C12'	177.91 (13)
C5—C6—C7—C2	1.5 (2)	C13—C12—C12'—O4	−177.73 (13)
C5—C6—C7—N1	176.71 (13)	C11—C12—C12'—O4	3.4 (2)
C3—C2—C7—C6	−2.1 (2)	C9—C8—C13—C12	0.7 (2)
C1—C2—C7—C6	−178.52 (13)	N2—C8—C13—C12	−179.08 (12)
C3—C2—C7—N1	−177.23 (13)	C11—C12—C13—C8	0.9 (2)
C1—C2—C7—N1	6.3 (2)	C12'—C12—C13—C8	−178.02 (13)
N2—N1—C7—C6	43.86 (18)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O3—H3O···O4	0.84	1.94	2.6876 (16)	147
O3—H3O···O3^i	0.84	2.48	2.9810 (15)	119
C13—H13···O1^ii	0.95	2.36	3.268 (2)	160
C9—H9···N2^iii	0.95	2.66	3.596 (2)	167
C4—H4···O2^iv	0.95	2.84	3.677 (2)	147

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