5-Bromo-1H-indole-3-carbaldehyde thio­semicarbazone

In the essentially planar title mol­ecule, C₁₀H₉BrN₄S, the C=N double bond is in a trans configuration. In the crystal structure, the S atom acts as a hydrogen-bond acceptor for the aromatic NH, aliphatic NH and terminal NH₂ groups of three symmetry-related mol­ecules, forming a weak hydrogen-bonded layer structure.

Key indicators

• Single-crystal X-ray study
• T = 100 K
• Mean [sigma](C-C) = 0.003 Å
• R factor = 0.025
• wR factor = 0.066
• Data-to-parameter ratio = 15.9

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT062_ALERT_4_C Rescale T(min) & T(max) by .....................       0.90
PLAT153_ALERT_1_C The su's on the Cell Axes   are Equal (x 100000)         20 Ang.
PLAT154_ALERT_1_C The su's on the Cell Angles are Equal  (x 10000)        100 Deg.
PLAT180_ALERT_3_C Check Cell Rounding: # of Values Ending with 0 =          3
PLAT716_ALERT_1_C H...A   Unknown or Inconsistent Label ..........    H1<I>N<
PLAT716_ALERT_1_C H...A   Unknown or Inconsistent Label ..........    H3<I>N<
PLAT716_ALERT_1_C H...A   Unknown or Inconsistent Label ..........    H4<I>N<
PLAT720_ALERT_4_C Number of Unusual/Non-Standard Label(s) ........          2

Alert level G
ABSTM02_ALERT_3_G  When printed, the submitted absorption T values will be
            replaced by the scaled T values. Since the ratio of scaled T's
            is identical to the ratio of reported T values, the scaling
            does not imply a change to the absorption corrections used in
            the study.
            Ratio of Tmax expected/reported      0.904
            Tmax scaled      0.467 Tmin scaled      0.344
PLAT860_ALERT_3_G Note: Number of Least-Squares Restraints .......          4

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

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

---

S1. Comment

Indole-3-carboxaldehyde thiosemicarbazone and its substituted analogs possess useful medicinal properties; such activity has been known for a long time (Doyle et al., 1956; French & Blanz, 1966; Fukukawa et al., 1966; Libermann et al., 1953; Usi, 1968; Weller et al., 1954). The compounds, in the form of their metal derivatives, have been assesses for similar activity.

In the title compound (I) (Fig. 1), the double-bonded sulfur atom is a hydrogen-bond acceptor for the aromatic -N-H, aliphatic -N-H and terminal -NH₂ groups of three adjacent molecules, forming a weak hydrogen-bonded layer structure.

Related literature

For a previous synthesis of the title compound, see: Dubey & Babu (2006). For related literature, see: Doyle et al. (1956); French & Blanz (1966); Fukukawa et al. (1966); Libermann et al. (1953); Usi (1968); Weller et al. (1954).

S2. Experimental

5-Bromoindole-3-carboxaldehyde (0.3 g, 1.3 mmol) and thiosemicarbazide (0.12 g, 1.3 mmol) were heated in ethanol (50 ml) for an hour. The solvent was removed and the product and recrystallized from ethanol.

S3. Refinement

Carbon-bound H atoms were placed in calculated positions, and were included in the refinement in the riding model approximation. The nitrogen-bound H atoms were located in a difference Fourier map, and were refined with a distance restraint of N–H 0.88±0.01 Å; their temperature factors were freely refined.

Computing details

Data collection: APEX2 (Bruker, 2007); cell refinement: SAINT (Bruker, 2007); data reduction: SAINT (Bruker, 2007); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: X-SEED (Barbour, 2001); software used to prepare material for publication: publCIF (Westrip, 2008).

Figures

Fig. 1. The title molecule drawn using 70% probabilty ellipsoids. Hydrogen atoms are drawn as spheres of arbitrary radius.

5-Bromo-1H-indole-3-carboxaldehyde thiosemicarbazone

Crystal data

C10H9BrN4S	Z = 2
Mr = 297.18	F(000) = 296
Triclinic, P1	Dx = 1.753 Mg m^−3
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 6.7731 (2) Å	Cell parameters from 6604 reflections
b = 8.7551 (2) Å	θ = 4.0–28.3°
c = 10.6539 (2) Å	µ = 3.81 mm^−1
α = 69.280 (1)°	T = 100 K
β = 79.969 (1)°	Block, yellow
γ = 72.886 (1)°	0.30 × 0.20 × 0.20 mm
V = 563.00 (2) Å^3

Data collection

Bruker SMART APEX diffractometer	2563 independent reflections
Radiation source: fine-focus sealed tube	2281 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.025
ω scans	θmax = 27.5°, θmin = 2.1°
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	h = −6→8
Tmin = 0.381, Tmax = 0.516	k = −11→11
6176 measured reflections	l = −13→13

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)] = 0.024	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.066	H atoms treated by a mixture of independent and constrained refinement
S = 1.06	w = 1/[σ^2(Fo^2) + (0.0383P)^2 + 0.1P] where P = (Fo^2 + 2Fc^2)/3
2563 reflections	(Δ/σ)max = 0.001
161 parameters	Δρmax = 0.36 e Å^−3
4 restraints	Δρmin = −0.40 e Å^−3

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
Br1	0.51693 (4)	0.13022 (2)	0.31237 (2)	0.02102 (9)
S1	0.01187 (9)	0.22591 (6)	1.06142 (5)	0.01534 (12)
N1	0.2717 (3)	0.8577 (2)	0.27383 (17)	0.0153 (4)
N2	0.1383 (3)	0.4698 (2)	0.68281 (16)	0.0116 (3)
N3	0.0718 (3)	0.4342 (2)	0.81750 (16)	0.0118 (3)
N4	0.1492 (3)	0.1567 (2)	0.83268 (18)	0.0169 (4)
C1	0.1846 (3)	0.8475 (3)	0.4006 (2)	0.0151 (4)
H1	0.1266	0.9415	0.4320	0.018*
C2	0.3383 (3)	0.6981 (2)	0.2626 (2)	0.0122 (4)
C3	0.4355 (3)	0.6471 (3)	0.1529 (2)	0.0142 (4)
H3	0.4641	0.7265	0.0687	0.017*
C4	0.4889 (3)	0.4765 (3)	0.1711 (2)	0.0131 (4)
H4	0.5573	0.4359	0.0990	0.016*
C5	0.4422 (3)	0.3633 (2)	0.2960 (2)	0.0127 (4)
C6	0.3464 (3)	0.4108 (2)	0.40581 (19)	0.0118 (4)
H6	0.3184	0.3300	0.4893	0.014*
C7	0.2917 (3)	0.5832 (2)	0.38933 (19)	0.0109 (4)
C8	0.1921 (3)	0.6825 (2)	0.4770 (2)	0.0120 (4)
C9	0.1249 (3)	0.6266 (2)	0.6176 (2)	0.0127 (4)
H9	0.0693	0.7074	0.6633	0.015*
C10	0.0822 (3)	0.2737 (2)	0.8937 (2)	0.0123 (4)
H1N	0.254 (5)	0.953 (2)	0.207 (2)	0.028 (7)*
H3N	0.037 (4)	0.510 (2)	0.858 (2)	0.013 (6)*
H4N1	0.137 (4)	0.0533 (17)	0.876 (2)	0.023 (7)*
H4N2	0.173 (5)	0.190 (4)	0.7452 (11)	0.035 (8)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Br1	0.02971 (15)	0.01243 (12)	0.02039 (12)	−0.00512 (9)	0.00410 (9)	−0.00765 (8)
S1	0.0217 (3)	0.0111 (2)	0.0101 (2)	−0.0029 (2)	0.00152 (19)	−0.00200 (18)
N1	0.0190 (10)	0.0104 (8)	0.0119 (8)	−0.0022 (7)	0.0015 (7)	−0.0005 (6)
N2	0.0105 (8)	0.0144 (8)	0.0100 (8)	−0.0056 (6)	0.0021 (6)	−0.0034 (6)
N3	0.0154 (9)	0.0112 (8)	0.0091 (7)	−0.0032 (7)	0.0020 (6)	−0.0051 (6)
N4	0.0239 (10)	0.0117 (8)	0.0144 (8)	−0.0050 (7)	0.0044 (7)	−0.0056 (7)
C1	0.0176 (11)	0.0133 (9)	0.0127 (9)	−0.0021 (8)	0.0005 (8)	−0.0045 (8)
C2	0.0120 (10)	0.0108 (9)	0.0134 (9)	−0.0032 (7)	−0.0023 (8)	−0.0025 (7)
C3	0.0121 (10)	0.0167 (10)	0.0119 (9)	−0.0036 (8)	−0.0015 (8)	−0.0022 (7)
C4	0.0109 (10)	0.0174 (10)	0.0111 (9)	−0.0028 (8)	−0.0020 (7)	−0.0049 (7)
C5	0.0113 (10)	0.0106 (9)	0.0165 (9)	−0.0031 (7)	−0.0014 (8)	−0.0042 (7)
C6	0.0102 (10)	0.0124 (9)	0.0117 (9)	−0.0030 (7)	−0.0017 (7)	−0.0021 (7)
C7	0.0090 (10)	0.0132 (9)	0.0103 (9)	−0.0028 (7)	−0.0012 (7)	−0.0032 (7)
C8	0.0114 (10)	0.0116 (9)	0.0131 (9)	−0.0035 (8)	−0.0011 (7)	−0.0037 (7)
C9	0.0107 (10)	0.0137 (9)	0.0133 (9)	−0.0024 (8)	−0.0003 (8)	−0.0049 (7)
C10	0.0103 (10)	0.0129 (9)	0.0130 (9)	−0.0029 (7)	0.0001 (7)	−0.0038 (7)

Geometric parameters (Å, º)

Br1—C5	1.9032 (19)	C1—H1	0.9500
S1—C10	1.699 (2)	C2—C3	1.388 (3)
N1—C1	1.359 (3)	C2—C7	1.418 (3)
N1—C2	1.378 (3)	C3—C4	1.379 (3)
N1—H1N	0.878 (10)	C3—H3	0.9500
N2—C9	1.284 (3)	C4—C5	1.399 (3)
N2—N3	1.378 (2)	C4—H4	0.9500
N3—C10	1.339 (3)	C5—C6	1.372 (3)
N3—H3N	0.876 (10)	C6—C7	1.398 (3)
N4—C10	1.331 (3)	C6—H6	0.9500
N4—H4N1	0.880 (10)	C7—C8	1.447 (3)
N4—H4N2	0.873 (10)	C8—C9	1.437 (3)
C1—C8	1.376 (3)	C9—H9	0.9500
C1—N1—C2	109.25 (17)	C3—C4—H4	120.1
C1—N1—H1N	122.5 (19)	C5—C4—H4	120.1
C2—N1—H1N	126.2 (18)	C6—C5—C4	123.94 (18)
C9—N2—N3	115.12 (17)	C6—C5—Br1	118.76 (15)
C10—N3—N2	119.25 (16)	C4—C5—Br1	117.30 (15)
C10—N3—H3N	117.5 (16)	C5—C6—C7	117.04 (18)
N2—N3—H3N	122.8 (16)	C5—C6—H6	121.5
C10—N4—H4N1	119.9 (17)	C7—C6—H6	121.5
C10—N4—H4N2	118.1 (19)	C6—C7—C2	119.09 (17)
H4N1—N4—H4N2	120 (3)	C6—C7—C8	134.17 (18)
N1—C1—C8	110.69 (18)	C2—C7—C8	106.75 (17)
N1—C1—H1	124.7	C1—C8—C9	124.92 (18)
C8—C1—H1	124.7	C1—C8—C7	105.86 (17)
N1—C2—C3	129.70 (18)	C9—C8—C7	129.10 (18)
N1—C2—C7	107.45 (17)	N2—C9—C8	121.41 (18)
C3—C2—C7	122.85 (18)	N2—C9—H9	119.3
C4—C3—C2	117.27 (18)	C8—C9—H9	119.3
C4—C3—H3	121.4	N4—C10—N3	117.36 (18)
C2—C3—H3	121.4	N4—C10—S1	122.58 (16)
C3—C4—C5	119.81 (18)	N3—C10—S1	120.06 (15)
C9—N2—N3—C10	−179.30 (19)	C3—C2—C7—C6	0.3 (3)
C2—N1—C1—C8	0.5 (3)	N1—C2—C7—C8	0.4 (2)
C1—N1—C2—C3	180.0 (2)	C3—C2—C7—C8	179.9 (2)
C1—N1—C2—C7	−0.6 (2)	N1—C1—C8—C9	176.0 (2)
N1—C2—C3—C4	178.9 (2)	N1—C1—C8—C7	−0.2 (3)
C7—C2—C3—C4	−0.6 (3)	C6—C7—C8—C1	179.4 (2)
C2—C3—C4—C5	0.8 (3)	C2—C7—C8—C1	−0.2 (2)
C3—C4—C5—C6	−0.8 (3)	C6—C7—C8—C9	3.4 (4)
C3—C4—C5—Br1	179.01 (16)	C2—C7—C8—C9	−176.2 (2)
C4—C5—C6—C7	0.6 (3)	N3—N2—C9—C8	178.80 (19)
Br1—C5—C6—C7	−179.25 (15)	C1—C8—C9—N2	−179.4 (2)
C5—C6—C7—C2	−0.3 (3)	C7—C8—C9—N2	−4.0 (4)
C5—C6—C7—C8	−179.8 (2)	N2—N3—C10—N4	−2.8 (3)
N1—C2—C7—C6	−179.18 (18)	N2—N3—C10—S1	177.10 (15)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1n···S1^i	0.88 (1)	2.60 (2)	3.390 (2)	150 (3)
N3—H3n···S1^ii	0.88 (1)	2.65 (1)	3.508 (2)	167 (2)
N4—H4n1···S1^iii	0.88 (1)	2.74 (1)	3.569 (2)	158 (2)

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