Sodium 2-oxo-3-semicarbazono-2,3-dihydro-1H-indole-5-sulfonate dihydrate

The title compound, Na⁺·C₉H₇N₄O₅S^-·2H₂O, presents a Z configuration around the imine C=N bond and an E configuration around the C(O)NH₂ group, stabilized by two intra­molecular hydrogen bonds. The packing is governed by ionic inter­actions between the Na⁺ cation and the surrounding O atoms. The ionic unit, Na⁺ and 2-oxo-3-semicarbazono-2,3-dihydro-1H-indole-5-sulfonate, forms layers extending in the bc plane. The layers are connected by hydrogen bonds involving the water mol­ecules.

S1. Comment

The biological properties of isatin derivatives are well known (Pandeya et al., 1999). We have been working on these systems (Rodríguez-Argüelles et al., 1999, 2004; Casas et al., 2000; Belicchi Ferrari et al., 2002; Bacchi et al., 2005) and the main problem that these compounds present for their use in biological experiments is their poor solubility in water. To overcome this problem, we have decided to turn our attention to sulfonated isatin. Against this background, we report here the synthesis and solid-state characterization of the sodium salt of isatin-3-semicarbazone-5-sulfonate, (I).

In compound (I) (Fig. 1), the isatin-3-semicarbazone moiety presents the same configuration as the corresponding nonsulfonated ligand reported previously (Pelosi et al., 2005) and is stabilized by intramolecular hydrogen bonds, with N2—H···O2 = 2.903 (4) Å and N1—H···N3 = 2.586 (5) Å. Bond distances and angles of the organic moiety are comparable with those found in isatin-3-semicarbazone. The six- and five-membered rings of the isatin moiety are less planar than those found in isatin 3-semicarbazone (Pelosi et al., 2005).

The dihedral angle between the mean planes of the two rings is 3.9 (1)°, and that between the mean planes of the entire isatin and semicarbazide groups is 6.1 (1)°, similar to the value found in isatin 3-semicarbazone (Pelosi et al., 2005). The O—S distance range [1.450(s.u.?)–1.454(s.u.?) Å] agrees with the values reported in the literature for similar anions.

The Na⁺ ion is surrounded in a slightly distorted octahedral fashion by six O atoms: O5 of the sulfonate group, O3 of a sulfonate at symmetry position (x, −y + 1/2, +z + 1/2), O1 of the semicarbazide group at symmetry position (−x + 1, −y, −z), O2 of the isatin moiety at symmetry position (−x + 1, +y + 1/2, −z + 1/2) and two water atoms, O6 and O7. The Na—O distance range [2.365 (3)–2.484 (3) Å] is slightly lower than the mean value of 2.600 (2) Å reported in the Cambridge Structural Database (Version? How many hits?; Allen, 2002).

The packing (Fig. 2) is formed by sheets stacked up along the a direction. Within the layers, the molecules are connected by an extended system of hydrogen bonds involving atoms N1 and N4, two O atoms of the sulfonate group (O3 and O5) and the O atom of the semicarbazide group (O1). These layers are connected by hydrogen bonds between atom O4 of a sulfonate moiety and water atom O7 at symmetry position (+x − 1, −y + 1/2, +z − 1/2).

S2. Experimental

The ligand was prepared by a standard procedure (Battaglia et al., 1994), using ethanol intead of methanol. Sodium isatin-3-semicarbazone-5-sulfonate dihydrate was prepared by what means? and was obtained as a yellow solid (m.p. >300 K or °C?; yield 37%). Analysis, found: C 31.4, H 3.2, N 16.5, S 8.9%; calculated for C₉H₇N₄NaO₅S 2H₂O: C 31.6, H 3.2, N 16.4, S 9.4%. Mass FAB (m-nitrobenzyl alcohol, m/z) 285 (21%, M ± 2H₂O - Na), 199 (100%, C₇H₅NO₄S). The solid was dissolved in dimethyl sulfoxide and, after several days at room temperature, the solution afforded crystals of (I) suitable for X-ray diffraction studies.

S3. Refinement

All H atoms were located in a difference map and refined freely, except for those of the water molecules. [Please give range of refined C—H distances]

Computing details

Data collection: Software title? (Belletti et al., 1988); cell refinement: Please give missing details; data reduction: Please give missing details; program(s) used to solve structure: SIR97 (Altomare et al., 1999); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEPIII (Burnett & Johnson, 1996) and PLATON( Spek, 2003); software used to prepare material for publication: Please give missing details.

Figures

	Fig. 1. A view of the anionic moiety of (I), with the atom-numbering scheme. Displacement ellipsoids are drawn at the 50% probability level and H atoms are shown as small spheres of arbitrary radii. Water molecules and Na atoms have been omitted for clarity.
	Fig. 2. A packing diagram, viewed along the b direction. Hydrogen bonds are indicated by dotted lines.

Sodium 2-oxo-3-semicarbazono-2,3-dihydro-1H-indole-5-sulfonate dihydrate

Crystal data

Na^+·C9H7N4O5S^−·2H2O	F(000) = 704
Mr = 342.27	Dx = 1.730 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71069 Å
Hall symbol: -P 2ybc	Cell parameters from 24 reflections
a = 7.379 (3) Å	θ = 8–18°
b = 17.139 (4) Å	µ = 0.32 mm^−1
c = 10.788 (3) Å	T = 291 K
β = 105.60 (2)°	Prism, yellow
V = 1314.1 (7) Å^3	0.5 × 0.4 × 0.3 mm
Z = 4

Data collection

Philips PW1100 diffractometer	Rint = 0.035
Radiation source: fine-focus sealed tube	θmax = 30.0°, θmin = 3.1°
Graphite monochromator	h = −10→9
θ/2θ scans	k = 0→24
4008 measured reflections	l = 0→15
3838 independent reflections	1 standard reflections every 0 reflections
1535 reflections with I > 2σ(I)	intensity decay: none

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)] = 0.057	Hydrogen site location: difference Fourier map
wR(F^2) = 0.112	All H-atom parameters refined
S = 0.90	w = 1/[σ^2(Fo^2) + (0.0239P)^2] where P = (Fo^2 + 2Fc^2)/3
3838 reflections	(Δ/σ)max = 0.010
227 parameters	Δρmax = 0.37 e Å^−3
0 restraints	Δρmin = −0.34 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
C1	0.3174 (5)	−0.0271 (2)	−0.3843 (3)	0.0287 (9)
C2	0.2553 (5)	−0.01329 (18)	−0.0731 (3)	0.0228 (8)
C3	0.2682 (5)	0.04115 (19)	0.0324 (3)	0.0212 (8)
C4	0.3201 (5)	0.1190 (2)	0.0492 (3)	0.0232 (8)
C5	0.3280 (5)	0.15314 (19)	0.1662 (3)	0.0233 (8)
C6	0.2769 (5)	0.1124 (2)	0.2629 (4)	0.0300 (9)
C7	0.2229 (5)	0.0341 (2)	0.2451 (4)	0.0299 (9)
C8	0.2260 (5)	−0.0010 (2)	0.1315 (3)	0.0234 (8)
C9	0.2094 (5)	−0.0918 (2)	−0.0259 (3)	0.0266 (8)
N1	0.3499 (5)	0.04902 (19)	−0.3949 (3)	0.0381 (9)
N2	0.2684 (4)	−0.04875 (18)	−0.2740 (3)	0.0286 (8)
N3	0.2803 (4)	0.00578 (15)	−0.1827 (3)	0.0249 (7)
N4	0.1907 (4)	−0.07940 (17)	0.0947 (3)	0.0283 (7)
O1	0.3270 (4)	−0.07654 (14)	−0.4645 (2)	0.0411 (7)
O2	0.1950 (3)	−0.15414 (14)	−0.0824 (2)	0.0357 (7)
O3	0.4455 (3)	0.28021 (13)	0.0823 (2)	0.0343 (7)
O4	0.3006 (4)	0.29330 (14)	0.2565 (3)	0.0449 (8)
O5	0.6084 (3)	0.23504 (14)	0.2952 (2)	0.0365 (7)
O6	0.9193 (3)	0.18891 (14)	0.7393 (2)	0.0396 (7)
O7	1.0228 (4)	0.18680 (19)	0.4601 (3)	0.0657 (9)
S1	0.42735 (13)	0.24791 (5)	0.20264 (9)	0.0261 (2)
Na1	0.7285 (2)	0.20999 (8)	0.51664 (13)	0.0348 (4)
H1	0.344 (5)	0.076 (2)	−0.329 (3)	0.038 (12)*
H2	0.408 (5)	0.060 (2)	−0.446 (3)	0.039 (13)*
H3	0.257 (5)	−0.0967 (19)	−0.262 (3)	0.030 (11)*
H4	0.162 (5)	−0.117 (2)	0.155 (4)	0.063 (13)*
H5	0.207 (4)	0.0055 (16)	0.310 (3)	0.020 (9)*
H6	0.280 (4)	0.1393 (18)	0.345 (3)	0.037 (11)*
H7	0.347 (4)	0.1464 (16)	−0.014 (3)	0.034 (8)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.040 (2)	0.022 (2)	0.024 (2)	−0.0012 (17)	0.0091 (18)	0.0006 (17)
C2	0.024 (2)	0.0187 (18)	0.027 (2)	0.0028 (15)	0.0095 (16)	0.0037 (15)
C3	0.023 (2)	0.0226 (18)	0.0194 (19)	0.0021 (15)	0.0091 (16)	0.0021 (16)
C4	0.025 (2)	0.027 (2)	0.019 (2)	0.0009 (16)	0.0077 (17)	0.0044 (17)
C5	0.022 (2)	0.0254 (19)	0.023 (2)	0.0033 (15)	0.0076 (17)	−0.0022 (16)
C6	0.031 (2)	0.036 (2)	0.024 (2)	0.0027 (18)	0.0102 (18)	−0.0011 (19)
C7	0.033 (2)	0.036 (2)	0.024 (2)	−0.0019 (18)	0.0129 (18)	0.0096 (19)
C8	0.0201 (19)	0.027 (2)	0.023 (2)	0.0005 (16)	0.0069 (15)	0.0041 (17)
C9	0.024 (2)	0.024 (2)	0.032 (2)	0.0009 (17)	0.0077 (18)	0.0043 (17)
N1	0.068 (3)	0.0217 (19)	0.034 (2)	−0.0042 (18)	0.030 (2)	−0.0003 (17)
N2	0.045 (2)	0.0163 (16)	0.0289 (19)	−0.0038 (15)	0.0173 (16)	−0.0013 (15)
N3	0.0269 (17)	0.0236 (16)	0.0256 (17)	−0.0018 (13)	0.0095 (14)	−0.0068 (14)
N4	0.0355 (19)	0.0221 (16)	0.0296 (18)	−0.0043 (14)	0.0127 (15)	0.0047 (15)
O1	0.074 (2)	0.0246 (14)	0.0294 (15)	0.0007 (14)	0.0226 (15)	−0.0038 (12)
O2	0.0461 (18)	0.0225 (14)	0.0401 (17)	−0.0025 (13)	0.0146 (14)	−0.0024 (12)
O3	0.0553 (18)	0.0249 (14)	0.0246 (14)	−0.0010 (12)	0.0143 (13)	0.0025 (11)
O4	0.0493 (19)	0.0366 (16)	0.0555 (19)	0.0094 (13)	0.0256 (16)	−0.0115 (14)
O5	0.0291 (15)	0.0415 (17)	0.0334 (15)	−0.0041 (12)	−0.0013 (13)	0.0064 (13)
O6	0.0463 (18)	0.0386 (16)	0.0363 (16)	0.0048 (13)	0.0152 (14)	0.0117 (13)
O7	0.050 (2)	0.092 (3)	0.059 (2)	0.0063 (18)	0.0199 (17)	−0.0060 (19)
S1	0.0322 (5)	0.0218 (4)	0.0253 (5)	0.0014 (5)	0.0095 (4)	−0.0022 (4)
Na1	0.0413 (9)	0.0294 (8)	0.0347 (9)	−0.0021 (7)	0.0120 (8)	−0.0008 (7)

Geometric parameters (Å, º)

C1—O1	1.227 (4)	C9—N4	1.361 (4)
C1—N1	1.337 (4)	N1—H1	0.86 (3)
C1—N2	1.384 (4)	N1—H2	0.81 (3)
C2—N3	1.287 (4)	N2—N3	1.344 (4)
C2—C3	1.455 (4)	N2—H3	0.84 (3)
C2—C9	1.510 (4)	N4—H4	0.98 (4)
C3—C4	1.386 (4)	O1—Na1^i	2.365 (3)
C3—C8	1.393 (4)	O2—Na1^ii	2.455 (3)
C4—C5	1.378 (4)	O3—S1	1.450 (2)
C4—H7	0.89 (3)	O3—Na1^iii	2.384 (3)
C5—C6	1.389 (4)	O4—S1	1.453 (2)
C5—S1	1.782 (3)	O5—S1	1.454 (2)
C6—C7	1.398 (5)	O5—Na1	2.353 (3)
C6—H6	0.99 (3)	O6—Na1	2.462 (3)
C7—C8	1.371 (5)	O7—Na1	2.441 (3)
C7—H5	0.89 (3)	Na1—O1^i	2.365 (3)
C8—N4	1.406 (4)	Na1—O3^iv	2.384 (3)
C9—O2	1.221 (4)	Na1—O2^v	2.455 (3)
O1—C1—N1	124.6 (4)	N3—N2—H3	124 (2)
O1—C1—N2	120.0 (3)	C1—N2—H3	117 (2)
N1—C1—N2	115.4 (3)	C2—N3—N2	120.0 (3)
N3—C2—C3	124.1 (3)	C9—N4—C8	111.2 (3)
N3—C2—C9	129.6 (3)	C9—N4—H4	129 (2)
C3—C2—C9	106.3 (3)	C8—N4—H4	120 (2)
C4—C3—C8	120.6 (3)	C1—O1—Na1^i	142.8 (2)
C4—C3—C2	132.6 (3)	C9—O2—Na1^ii	134.7 (2)
C8—C3—C2	106.7 (3)	S1—O3—Na1^iii	126.30 (15)
C5—C4—C3	118.1 (3)	S1—O5—Na1	138.67 (15)
C5—C4—H7	120.6 (19)	O4—S1—O3	112.22 (15)
C3—C4—H7	121.3 (19)	O4—S1—O5	112.20 (16)
C4—C5—C6	121.4 (3)	O3—S1—O5	112.57 (15)
C4—C5—S1	120.2 (3)	O4—S1—C5	107.79 (16)
C6—C5—S1	118.1 (3)	O3—S1—C5	106.38 (15)
C5—C6—C7	120.3 (4)	O5—S1—C5	105.12 (15)
C5—C6—H6	119.3 (19)	O5—Na1—O1^i	86.64 (10)
C7—C6—H6	120.4 (19)	O5—Na1—O3^iv	99.66 (10)
C8—C7—C6	118.1 (3)	O1^i—Na1—O3^iv	91.67 (10)
C8—C7—H5	120.2 (19)	O5—Na1—O7	83.90 (10)
C6—C7—H5	121 (2)	O1^i—Na1—O7	83.80 (11)
C7—C8—C3	121.3 (3)	O3^iv—Na1—O7	174.09 (11)
C7—C8—N4	128.7 (3)	O5—Na1—O2^v	96.60 (9)
C3—C8—N4	110.0 (3)	O1^i—Na1—O2^v	176.10 (11)
O2—C9—N4	126.7 (3)	O3^iv—Na1—O2^v	89.94 (9)
O2—C9—C2	127.5 (3)	O7—Na1—O2^v	94.35 (10)
N4—C9—C2	105.8 (3)	O5—Na1—O6	167.82 (11)
C1—N1—H1	114 (2)	O1^i—Na1—O6	96.14 (10)
C1—N1—H2	115 (3)	O3^iv—Na1—O6	92.13 (10)
H1—N1—H2	127 (4)	O7—Na1—O6	84.61 (10)
N3—N2—C1	117.6 (3)	O2^v—Na1—O6	80.25 (9)

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