N′-(5-Bromo-1H-indol-3-ylmethyl­idene)-3,4,5-trihydroxy­benzohydrazide

The two aromatic parts of the title mol­ecule, C₁₆H₁₂BrN₃O₄, are connected through a conjugated –CH=N—NH—C(O)– fragment to furnish an almost planar mol­ecule. Adjacent mol­ecules are linked by N—H...O and O—H...O hydrogen bonds into a three-dimensional network. An intramolecular O—H...O link also occurs.

Key indicators

• Single-crystal X-ray study
• T = 100 K
• Mean [sigma](C-C) = 0.003 Å
• R factor = 0.029
• wR factor = 0.078
• Data-to-parameter ratio = 15.5

checkCIF/PLATON results

No syntax errors found



Alert level C
            Value of measurement temperature given =   100.000
            Value of melting point given =     0.000
PLAT414_ALERT_2_C Short Intra D-H..H-X       H1N    ..  H6      ..       1.94 Ang.
PLAT062_ALERT_4_C Rescale T(min) & T(max) by .....................       0.99

Alert level G
CELLZ01_ALERT_1_G Difference between formula and atom_site contents detected.
CELLZ01_ALERT_1_G ALERT: Large difference may be due to a
            symmetry error - see SYMMG tests
           From the CIF: _cell_formula_units_Z    4
           From the CIF: _chemical_formula_sum  C16 H12 Br N3 O4
           TEST: Compare cell contents of formula and atom_site data

           atom    Z*formula  cif sites diff
           C         64.00     64.00    0.00
           H         48.00     48.00    0.00
           Br         0.00      4.00   -4.00
           N         12.00     12.00    0.00
           O         16.00     16.00    0.00

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

   2 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
   0 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

---

S1. Comment

The molecule of (I), Fig. 1, is almost planar with the aromatic groups connected via a conjugated –CH═N–NH–C(O)– fragment. Molecules are connected into a 3-D network via N—H···O and O—H···O hydrogen bonds, Table 1.

Related literature

For other Schiff bases derived by condensing 5-bromo-1H-indole-3-carbaldehyde with aroylhydrazines, see: Ali et al. (2005a,b,c).

S2. Experimental

5-Bromoindole-3-carbaldehyde (0.34 g, 1.5 mmol) and 3,4,5-trihydroxybenzoylhydrazine (0.27 g, 1.5 mmol) were heated in ethanol (20 ml) for 3 h. About 1 ml of acetic acid also added. The solution was set aside for the growth of crystals.

S3. Refinement

Hydrogen atoms were placed at calculated positions (C—H 0.95, N—H 0.88 and O—H 0.84 Å) and were treated as riding on their parent atoms, with U(H) set to 1.2–1.5 times U_eq(C,N,O). For the hydroxy groups, an sp² type of hybridization was assumed.

Computing details

Data collection: APEX2 (Bruker, 2007); cell refinement: APEX2 (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. Thermal ellipsoid plot (Barbour, 2001) of (I) at the 70% probability level. Hydrogen atoms are drawn as spheres of arbitrary radius.

N'-(5-Bromo-1H-indol-3-ylmethylidene)-3,4,5- trihydroxybenzohydrazide

Crystal data

C16H12BrN3O4	F(000) = 784
Mr = 390.20	Dx = 1.743 Mg m^−3
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2yn	Cell parameters from 3960 reflections
a = 9.6454 (2) Å	θ = 2.4–28.2°
b = 14.9694 (4) Å	µ = 2.79 mm^−1
c = 10.3845 (2) Å	T = 100 K
β = 97.390 (1)°	Block, orange
V = 1486.92 (6) Å^3	0.40 × 0.25 × 0.10 mm
Z = 4

Data collection

Bruker SMART APEX diffractometer	3403 independent reflections
Radiation source: fine-focus sealed tube	2786 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.024
ω scans	θmax = 27.5°, θmin = 2.4°
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	h = −12→11
Tmin = 0.401, Tmax = 0.768	k = −19→19
10182 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)] = 0.029	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.078	H-atom parameters constrained
S = 1.02	w = 1/[σ^2(Fo^2) + (0.0419P)^2 + 0.9663P] where P = (Fo^2 + 2Fc^2)/3
3403 reflections	(Δ/σ)max = 0.003
220 parameters	Δρmax = 0.62 e Å^−3
0 restraints	Δρmin = −0.36 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.

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

	x	y	z	Uiso*/Ueq
Br1	1.00401 (2)	1.090710 (16)	0.25205 (2)	0.02243 (8)
O1	0.69032 (15)	0.83598 (10)	0.56939 (13)	0.0157 (3)
O2	0.64359 (15)	0.62930 (10)	0.94165 (13)	0.0163 (3)
H2O	0.5987	0.5999	0.9914	0.024*
O3	0.37031 (15)	0.59355 (9)	0.93388 (13)	0.0133 (3)
H3O	0.3085	0.6178	0.9721	0.020*
O4	0.17544 (15)	0.67374 (10)	0.73325 (13)	0.0141 (3)
H4O	0.1569	0.6421	0.7956	0.021*
N1	0.46882 (18)	0.86863 (11)	0.48158 (15)	0.0134 (3)
H1N	0.3788	0.8619	0.4852	0.016*
N2	0.51457 (18)	0.92346 (11)	0.38712 (16)	0.0129 (3)
N3	0.40143 (19)	1.10565 (11)	0.03097 (16)	0.0151 (4)
H3N	0.3557	1.1326	−0.0369	0.018*
C1	0.5056 (2)	0.76400 (13)	0.66032 (18)	0.0123 (4)
C2	0.6012 (2)	0.72451 (13)	0.75620 (18)	0.0129 (4)
H2	0.6984	0.7361	0.7598	0.016*
C3	0.5519 (2)	0.66829 (13)	0.84567 (18)	0.0128 (4)
C4	0.4097 (2)	0.65084 (13)	0.84261 (18)	0.0116 (4)
C5	0.3160 (2)	0.68919 (13)	0.74520 (18)	0.0122 (4)
C6	0.3639 (2)	0.74523 (13)	0.65414 (18)	0.0124 (4)
H6	0.2996	0.7709	0.5873	0.015*
C7	0.5628 (2)	0.82603 (13)	0.56719 (18)	0.0128 (4)
C8	0.4168 (2)	0.96589 (13)	0.31563 (19)	0.0133 (4)
H8	0.3229	0.9587	0.3324	0.016*
C9	0.4446 (2)	1.02350 (13)	0.21187 (19)	0.0125 (4)
C10	0.3424 (2)	1.05580 (14)	0.11812 (19)	0.0150 (4)
H10	0.2451	1.0447	0.1152	0.018*
C11	0.5760 (2)	1.05663 (13)	0.17868 (18)	0.0121 (4)
C12	0.7151 (2)	1.05011 (13)	0.23622 (18)	0.0135 (4)
H12	0.7399	1.0177	0.3144	0.016*
C13	0.8147 (2)	1.09278 (13)	0.1744 (2)	0.0152 (4)
C14	0.7829 (2)	1.14153 (14)	0.0594 (2)	0.0172 (4)
H14	0.8558	1.1685	0.0195	0.021*
C15	0.6456 (2)	1.15045 (14)	0.00394 (19)	0.0158 (4)
H15	0.6215	1.1845	−0.0728	0.019*
C16	0.5443 (2)	1.10761 (13)	0.06493 (19)	0.0138 (4)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Br1	0.01187 (12)	0.03131 (14)	0.02403 (13)	−0.00169 (9)	0.00198 (8)	0.00285 (9)
O1	0.0119 (7)	0.0181 (7)	0.0178 (7)	−0.0008 (6)	0.0047 (6)	0.0012 (6)
O2	0.0100 (7)	0.0235 (8)	0.0151 (7)	−0.0005 (6)	0.0010 (6)	0.0048 (6)
O3	0.0120 (7)	0.0162 (7)	0.0122 (6)	0.0003 (6)	0.0039 (5)	0.0011 (5)
O4	0.0101 (7)	0.0174 (7)	0.0145 (7)	−0.0035 (6)	0.0005 (5)	0.0038 (5)
N1	0.0114 (9)	0.0144 (8)	0.0152 (8)	−0.0019 (7)	0.0050 (7)	0.0021 (7)
N2	0.0149 (9)	0.0123 (8)	0.0125 (7)	−0.0020 (7)	0.0051 (7)	−0.0006 (6)
N3	0.0158 (9)	0.0156 (9)	0.0133 (8)	0.0028 (7)	−0.0004 (7)	−0.0001 (6)
C1	0.0123 (10)	0.0122 (9)	0.0133 (9)	−0.0012 (8)	0.0044 (7)	−0.0035 (7)
C2	0.0093 (9)	0.0150 (9)	0.0150 (9)	0.0001 (8)	0.0031 (7)	−0.0024 (8)
C3	0.0116 (10)	0.0149 (10)	0.0116 (8)	0.0016 (8)	−0.0002 (7)	−0.0027 (7)
C4	0.0133 (10)	0.0111 (9)	0.0109 (8)	−0.0017 (7)	0.0035 (7)	−0.0017 (7)
C5	0.0101 (9)	0.0126 (9)	0.0143 (9)	−0.0010 (8)	0.0025 (7)	−0.0042 (7)
C6	0.0119 (10)	0.0124 (9)	0.0127 (9)	0.0006 (8)	0.0009 (7)	0.0003 (7)
C7	0.0148 (10)	0.0114 (9)	0.0131 (9)	−0.0005 (8)	0.0046 (8)	−0.0044 (7)
C8	0.0117 (10)	0.0133 (9)	0.0155 (9)	−0.0012 (8)	0.0042 (7)	−0.0031 (8)
C9	0.0131 (10)	0.0104 (9)	0.0141 (9)	0.0005 (8)	0.0018 (8)	−0.0029 (7)
C10	0.0144 (10)	0.0146 (9)	0.0162 (9)	0.0008 (8)	0.0027 (8)	−0.0021 (8)
C11	0.0148 (10)	0.0099 (9)	0.0119 (8)	0.0009 (8)	0.0032 (7)	−0.0025 (7)
C12	0.0165 (10)	0.0125 (9)	0.0116 (9)	0.0023 (8)	0.0028 (7)	−0.0013 (7)
C13	0.0132 (10)	0.0146 (10)	0.0176 (9)	0.0000 (8)	0.0017 (8)	−0.0028 (8)
C14	0.0194 (11)	0.0149 (10)	0.0185 (10)	−0.0026 (9)	0.0072 (8)	−0.0002 (8)
C15	0.0233 (11)	0.0116 (9)	0.0128 (9)	0.0002 (8)	0.0035 (8)	0.0004 (7)
C16	0.0166 (10)	0.0117 (9)	0.0126 (9)	0.0021 (8)	0.0005 (8)	−0.0024 (7)

Geometric parameters (Å, º)

Br1—C13	1.899 (2)	C2—H2	0.9500
O1—C7	1.236 (3)	C3—C4	1.392 (3)
O2—C3	1.375 (2)	C4—C5	1.391 (3)
O2—H2O	0.8400	C5—C6	1.387 (3)
O3—C4	1.368 (2)	C6—H6	0.9500
O3—H3O	0.8400	C8—C9	1.432 (3)
O4—C5	1.365 (2)	C8—H8	0.9500
O4—H4O	0.8400	C9—C10	1.381 (3)
N1—C7	1.346 (3)	C9—C11	1.443 (3)
N1—N2	1.394 (2)	C10—H10	0.9500
N1—H1N	0.8800	C11—C12	1.401 (3)
N2—C8	1.290 (3)	C11—C16	1.406 (3)
N3—C10	1.354 (3)	C12—C13	1.379 (3)
N3—C16	1.378 (3)	C12—H12	0.9500
N3—H3N	0.8800	C13—C14	1.400 (3)
C1—C6	1.388 (3)	C14—C15	1.381 (3)
C1—C2	1.398 (3)	C14—H14	0.9500
C1—C7	1.497 (3)	C15—C16	1.388 (3)
C2—C3	1.382 (3)	C15—H15	0.9500
C3—O2—H2O	109.5	O1—C7—C1	120.77 (18)
C4—O3—H3O	109.5	N1—C7—C1	116.61 (18)
C5—O4—H4O	109.5	N2—C8—C9	122.40 (19)
C7—N1—N2	119.79 (17)	N2—C8—H8	118.8
C7—N1—H1N	120.1	C9—C8—H8	118.8
N2—N1—H1N	120.1	C10—C9—C8	123.76 (19)
C8—N2—N1	114.89 (17)	C10—C9—C11	106.28 (17)
C10—N3—C16	109.48 (17)	C8—C9—C11	129.92 (19)
C10—N3—H3N	125.3	N3—C10—C9	109.93 (19)
C16—N3—H3N	125.3	N3—C10—H10	125.0
C6—C1—C2	120.15 (18)	C9—C10—H10	125.0
C6—C1—C7	122.57 (18)	C12—C11—C16	119.25 (18)
C2—C1—C7	117.28 (18)	C12—C11—C9	134.17 (18)
C3—C2—C1	118.93 (18)	C16—C11—C9	106.54 (18)
C3—C2—H2	120.5	C13—C12—C11	117.12 (18)
C1—C2—H2	120.5	C13—C12—H12	121.4
O2—C3—C2	120.06 (18)	C11—C12—H12	121.4
O2—C3—C4	118.49 (17)	C12—C13—C14	123.3 (2)
C2—C3—C4	121.44 (18)	C12—C13—Br1	118.96 (15)
O3—C4—C3	117.54 (18)	C14—C13—Br1	117.63 (16)
O3—C4—C5	123.37 (18)	C15—C14—C13	119.95 (19)
C3—C4—C5	119.04 (18)	C15—C14—H14	120.0
O4—C5—C6	117.06 (17)	C13—C14—H14	120.0
O4—C5—C4	122.77 (17)	C14—C15—C16	117.31 (19)
C6—C5—C4	120.17 (19)	C14—C15—H15	121.3
C1—C6—C5	120.23 (18)	C16—C15—H15	121.3
C1—C6—H6	119.9	N3—C16—C15	129.25 (19)
C5—C6—H6	119.9	N3—C16—C11	107.77 (18)
O1—C7—N1	122.61 (18)	C15—C16—C11	122.99 (19)
C7—N1—N2—C8	−175.49 (18)	N2—C8—C9—C10	166.76 (19)
C6—C1—C2—C3	−1.3 (3)	N2—C8—C9—C11	−10.6 (3)
C7—C1—C2—C3	178.65 (17)	C16—N3—C10—C9	0.0 (2)
C1—C2—C3—O2	−179.39 (17)	C8—C9—C10—N3	−177.81 (18)
C1—C2—C3—C4	−0.4 (3)	C11—C9—C10—N3	0.1 (2)
O2—C3—C4—O3	−1.8 (3)	C10—C9—C11—C12	177.6 (2)
C2—C3—C4—O3	179.23 (17)	C8—C9—C11—C12	−4.7 (4)
O2—C3—C4—C5	−179.37 (17)	C10—C9—C11—C16	−0.1 (2)
C2—C3—C4—C5	1.7 (3)	C8—C9—C11—C16	177.60 (19)
O3—C4—C5—O4	0.9 (3)	C16—C11—C12—C13	−1.9 (3)
C3—C4—C5—O4	178.29 (17)	C9—C11—C12—C13	−179.3 (2)
O3—C4—C5—C6	−178.58 (18)	C11—C12—C13—C14	0.2 (3)
C3—C4—C5—C6	−1.2 (3)	C11—C12—C13—Br1	177.22 (14)
C2—C1—C6—C5	1.8 (3)	C12—C13—C14—C15	1.6 (3)
C7—C1—C6—C5	−178.16 (18)	Br1—C13—C14—C15	−175.44 (15)
O4—C5—C6—C1	179.97 (17)	C13—C14—C15—C16	−1.7 (3)
C4—C5—C6—C1	−0.6 (3)	C10—N3—C16—C15	−179.9 (2)
N2—N1—C7—O1	2.9 (3)	C10—N3—C16—C11	0.0 (2)
N2—N1—C7—C1	−176.32 (16)	C14—C15—C16—N3	179.8 (2)
C6—C1—C7—O1	−174.49 (18)	C14—C15—C16—C11	0.0 (3)
C2—C1—C7—O1	5.5 (3)	C12—C11—C16—N3	−178.04 (17)
C6—C1—C7—N1	4.7 (3)	C9—C11—C16—N3	0.1 (2)
C2—C1—C7—N1	−175.23 (17)	C12—C11—C16—C15	1.8 (3)
N1—N2—C8—C9	−178.50 (17)	C9—C11—C16—C15	179.91 (18)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O2—H2O···O3	0.84	2.21	2.681 (2)	116
O3—H3O···O1^i	0.84	1.76	2.595 (2)	173
O4—H4O···N2^i	0.84	2.02	2.778 (2)	150
N1—H1N···O2^ii	0.88	2.26	3.111 (2)	163
N3—H3N···O4^iii	0.88	2.11	2.932 (2)	154

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