5-Bromo-2-hy­droxy­benzaldehyde 4-ethyl­thio­semicarbazone

In the title Schiff base compound, C₁₀H₁₂BrN₃OS, the C-N-N-C torsion angle is 172.07 (11)°. An intra­molecular hydrogen bond exists between the hy­droxy H atom and the azomethine N atom. In the crystal, pairs of hydrogen bonds involving the imino H atom and the S atom give rise to supra­molecular dimers.

Key indicators

• Single-crystal X-ray study
• T = 123 K
• Mean [sigma](C-C) = 0.005 Å
• R factor = 0.042
• wR factor = 0.114
• Data-to-parameter ratio = 15.0

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT029_ALERT_3_C _diffrn_measured_fraction_theta_full Low .......      0.974
PLAT906_ALERT_3_C Large K value in the Analysis of Variance ......      2.247
PLAT910_ALERT_3_C Missing # of FCF Reflections Below Th(Min) .....          3
PLAT911_ALERT_3_C Missing # FCF Refl Between THmin & STh/L=  0.600         54
PLAT913_ALERT_3_C Missing # of Very Strong Reflections in FCF ....         19

Alert level G
PLAT002_ALERT_2_G Number of Distance or Angle Restraints on AtSite          6
PLAT005_ALERT_5_G No _iucr_refine_instructions_details  in the CIF          ?
PLAT860_ALERT_3_G Note: Number of Least-Squares Restraints .......          3
PLAT912_ALERT_4_G Missing # of FCF Reflections Above STh/L=  0.600          4

   0 ALERT level A = Most likely a serious problem - resolve or explain
   0 ALERT level B = A potentially serious problem, consider carefully
   5 ALERT level C = Check. Ensure it is not caused by an omission or oversight
   4 ALERT level G = General information/check it is not something unexpected

   0 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
   6 ALERT type 3 Indicator that the structure quality may be low
   1 ALERT type 4 Improvement, methodology, query or suggestion
   1 ALERT type 5 Informative message, check

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S1. Comment

A Schiff ligand was synthesized through one-pot reaction with high yield using 5-bromo-2-hydroxybenzaldehyde and 4-ethyl-3-thiosemicarbazide (Fig. 1). The title compound can be used as tridentate chelating ligand to construct spin-crossover complexes. Isostructural 5-chloro-2-hydroxybenzaldehyde-4-ethylthiosemicarbazone was reported previously (Lo et al., 2011).

In the title compound, a strong intramolecular hydrogen bond O—H···N is observed. An intermolecular N—H···S hydrogen bond connects two molecules into a supramolecular dimer as shown in Figure 2.

Related literature

For the isostructural compound 5-chloro-2-hydroxybenzaldehyde 4-ethylthiosemicarbazone, see: Lo et al. (2011)

S2. Experimental

5-Bromo-2-hydroxybenzaldehyde (4.02 g, 20 mmol) in 50 ml ethanol and 4-ethyl-3-thiosemicarbazide (2.38 g, 20 mmol) were reacted for 6 h at 350 K. Slow evaporation of the yellow solution gave large colorless crystals.

S3. Refinement

Carbon-bound H-atoms were placed in calculated positions (C—H 0.95, 0.98 and 0.99 Å) and were included in the refinement in the riding model approximation, with U_iso(H) =1.5U_eq(C) for methyl H atoms and 1.2U_eq(C) for the others. The hydroxy and amino H atoms were located in a difference Fourier map, and were refined with distance restraints of O—H 0.85±0.01 and N—H 0.88±0.01 Å; with U_iso(H) =1.2U_eq(N and O).

Computing details

Data collection: CrystalClear (Rigaku, 2008); cell refinement: CrystalClear (Rigaku, 2008); data reduction: CrystalClear (Rigaku, 2008); 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: publCIF (Westrip, 2010).

Figures

	Fig. 1. Displacement ellipsoid plot (50% probability level) of the title compound, with atom numbering of structurally unique non-H atoms and the H atoms.
	Fig. 2. The packing diagram of the title compound, with H atoms omitted for clarity. Hydrogen bonds are shown as dashed lines.

5-Bromo-2-hydroxybenzaldehyde 4-ethylthiosemicarbazone

Crystal data

C10H12BrN3OS	F(000) = 1216
Mr = 302.20	Dx = 1.651 Mg m^−3
Monoclinic, C2/c	Mo Kα radiation, λ = 0.710747 Å
Hall symbol: -C 2yc	Cell parameters from 3650 reflections
a = 22.040 (4) Å	θ = 3.1–27.5°
b = 11.844 (2) Å	µ = 3.54 mm^−1
c = 9.5102 (19) Å	T = 123 K
β = 101.69 (3)°	Block, colourless
V = 2431.1 (8) Å^3	0.20 × 0.10 × 0.05 mm
Z = 8

Data collection

Rigaku Saturn70 diffractometer	2331 independent reflections
Radiation source: Rotating Anode	1760 reflections with I > 2σ(I)
Confocal monochromator	Rint = 0.032
Detector resolution: 28.5714 pixels mm^-1	θmax = 26.0°, θmin = 3.1°
dtprofit.ref scans	h = −27→20
Absorption correction: multi-scan (CrystalClear; Rigaku, 2008)	k = −9→14
Tmin = 0.661, Tmax = 0.838	l = −11→10
4201 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)] = 0.042	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.114	H atoms treated by a mixture of independent and constrained refinement
S = 0.95	w = 1/[σ^2(Fo^2) + (0.0752P)^2] where P = (Fo^2 + 2Fc^2)/3
2331 reflections	(Δ/σ)max = 0.001
155 parameters	Δρmax = 0.70 e Å^−3
3 restraints	Δρmin = −1.01 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
Br1	0.484097 (17)	0.67444 (4)	1.01744 (4)	0.04059 (19)
C1	0.69767 (15)	0.6276 (2)	1.0597 (3)	0.0180 (7)
C2	0.67216 (16)	0.6364 (3)	1.1818 (3)	0.0197 (7)
H2	0.6985	0.6352	1.2742	0.024*
C3	0.60893 (17)	0.6470 (3)	1.1699 (4)	0.0227 (7)
H3	0.5919	0.6537	1.2536	0.027*
C4	0.57021 (16)	0.6476 (3)	1.0343 (4)	0.0222 (7)
C5	0.59471 (16)	0.6361 (3)	0.9125 (3)	0.0198 (7)
H5	0.5678	0.6343	0.8208	0.024*
C6	0.65841 (15)	0.6271 (3)	0.9228 (3)	0.0164 (7)
C7	0.68243 (15)	0.6269 (3)	0.7906 (3)	0.0179 (7)
H7	0.6542	0.6340	0.7012	0.021*
C8	0.81461 (14)	0.6124 (2)	0.6421 (3)	0.0150 (6)
C9	0.91521 (15)	0.5238 (3)	0.7381 (3)	0.0216 (7)
H9A	0.9408	0.5182	0.8363	0.026*
H9B	0.9339	0.5821	0.6855	0.026*
C10	0.91576 (17)	0.4111 (3)	0.6625 (4)	0.0270 (8)
H10A	0.9008	0.3519	0.7190	0.040*
H10B	0.9581	0.3935	0.6524	0.040*
H10C	0.8887	0.4152	0.5672	0.040*
H1A	0.7730 (17)	0.634 (3)	1.002 (2)	0.032*
H2A	0.7325 (16)	0.680 (2)	0.600 (3)	0.032*
H3A	0.8346 (17)	0.525 (3)	0.810 (3)	0.032*
N1	0.74029 (12)	0.6174 (2)	0.7914 (3)	0.0169 (6)
N2	0.75628 (13)	0.6333 (2)	0.6594 (3)	0.0177 (6)
N3	0.85244 (13)	0.5580 (2)	0.7468 (3)	0.0172 (6)
O1	0.75977 (11)	0.62315 (19)	1.0781 (2)	0.0207 (5)
S1	0.83506 (4)	0.65794 (7)	0.48834 (9)	0.0201 (2)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Br1	0.0165 (2)	0.0815 (4)	0.0261 (2)	0.00156 (19)	0.00976 (16)	0.00158 (19)
C1	0.0186 (18)	0.0130 (14)	0.0228 (17)	0.0006 (13)	0.0052 (14)	−0.0009 (13)
C2	0.0227 (19)	0.0187 (15)	0.0172 (16)	0.0008 (13)	0.0031 (14)	0.0002 (13)
C3	0.026 (2)	0.0234 (16)	0.0223 (16)	−0.0019 (14)	0.0134 (15)	0.0023 (14)
C4	0.0145 (18)	0.0314 (18)	0.0221 (17)	−0.0023 (14)	0.0066 (14)	−0.0001 (14)
C5	0.0163 (17)	0.0239 (16)	0.0180 (16)	−0.0019 (13)	0.0010 (13)	0.0013 (13)
C6	0.0173 (17)	0.0151 (14)	0.0180 (16)	0.0018 (13)	0.0065 (13)	0.0018 (13)
C7	0.0176 (17)	0.0187 (15)	0.0172 (15)	0.0003 (13)	0.0032 (13)	0.0011 (13)
C8	0.0166 (17)	0.0131 (14)	0.0162 (15)	0.0007 (12)	0.0056 (13)	−0.0023 (13)
C9	0.0152 (17)	0.0291 (17)	0.0198 (16)	0.0029 (14)	0.0017 (13)	0.0026 (14)
C10	0.021 (2)	0.033 (2)	0.0274 (18)	0.0060 (15)	0.0064 (15)	−0.0024 (15)
N1	0.0195 (15)	0.0169 (12)	0.0158 (13)	−0.0005 (11)	0.0073 (11)	0.0006 (11)
N2	0.0166 (15)	0.0213 (13)	0.0164 (13)	0.0046 (11)	0.0060 (11)	0.0034 (11)
N3	0.0145 (14)	0.0227 (14)	0.0145 (13)	0.0024 (11)	0.0036 (11)	0.0030 (11)
O1	0.0153 (13)	0.0259 (12)	0.0205 (12)	0.0017 (10)	0.0031 (10)	0.0040 (10)
S1	0.0192 (5)	0.0253 (4)	0.0175 (4)	0.0038 (3)	0.0079 (3)	0.0032 (3)

Geometric parameters (Å, º)

Br1—C4	1.899 (4)	C8—N3	1.329 (4)
C1—O1	1.345 (4)	C8—N2	1.351 (4)
C1—C2	1.393 (5)	C8—S1	1.703 (3)
C1—C6	1.410 (5)	C9—N3	1.460 (4)
C2—C3	1.381 (5)	C9—C10	1.517 (5)
C2—H2	0.9500	C9—H9A	0.9900
C3—C4	1.395 (5)	C9—H9B	0.9900
C3—H3	0.9500	C10—H10A	0.9800
C4—C5	1.380 (5)	C10—H10B	0.9800
C5—C6	1.391 (4)	C10—H10C	0.9800
C5—H5	0.9500	N1—N2	1.384 (3)
C6—C7	1.460 (4)	N2—H2A	0.879 (10)
C7—N1	1.278 (4)	N3—H3A	0.876 (10)
C7—H7	0.9500	O1—H1A	0.846 (10)
O1—C1—C2	117.8 (3)	N3—C8—S1	124.2 (2)
O1—C1—C6	122.5 (3)	N2—C8—S1	118.0 (2)
C2—C1—C6	119.6 (3)	N3—C9—C10	111.7 (3)
C3—C2—C1	120.6 (3)	N3—C9—H9A	109.3
C3—C2—H2	119.7	C10—C9—H9A	109.3
C1—C2—H2	119.7	N3—C9—H9B	109.3
C2—C3—C4	119.7 (3)	C10—C9—H9B	109.3
C2—C3—H3	120.2	H9A—C9—H9B	107.9
C4—C3—H3	120.2	C9—C10—H10A	109.5
C5—C4—C3	120.4 (3)	C9—C10—H10B	109.5
C5—C4—Br1	120.0 (3)	H10A—C10—H10B	109.5
C3—C4—Br1	119.5 (3)	C9—C10—H10C	109.5
C4—C5—C6	120.6 (3)	H10A—C10—H10C	109.5
C4—C5—H5	119.7	H10B—C10—H10C	109.5
C6—C5—H5	119.7	C7—N1—N2	114.8 (3)
C5—C6—C1	119.1 (3)	C8—N2—N1	120.6 (3)
C5—C6—C7	118.4 (3)	C8—N2—H2A	120 (3)
C1—C6—C7	122.2 (3)	N1—N2—H2A	116 (3)
N1—C7—C6	122.0 (3)	C8—N3—C9	123.4 (3)
N1—C7—H7	119.0	C8—N3—H3A	115 (3)
C6—C7—H7	119.0	C9—N3—H3A	119 (3)
N3—C8—N2	117.8 (3)	C1—O1—H1A	114 (3)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1A···N1	0.84 (3)	2.00 (2)	2.674 (3)	137 (3)
N2—H2A···S1^i	0.88 (3)	2.47 (3)	3.316 (3)	161 (2)
N3—H3A···S1^ii	0.87 (3)	2.75 (3)	3.510 (3)	146 (3)

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