Hydro­gen-bonded dimers in N-(2-nitro­phenyl­thio)­saccharin

In the title compound, 2-(2-nitro­phenyl­thio)-1,2-benzo­thia­zol-3(2H)-one 1,1-dioxide, 2-O₂NC₆H₄S(C₇H₄NO₃S) or C₁₃H₈N₂­O₅S₂, the planes of the saccharin and nitro­phenyl­thiol­ate portions are almost orthogonal. The mol­ecules are linked by C-H...O=S hydrogen bonds [C...O 3.308 (3) Å, H...O 2.44 Å and C-H...O 155°] into cyclic centrosymmetric R²₂(16) dimers, reinforced by aromatic [pi]...[pi] stacking interactions between the nitrated aryl rings.

S1. Comment

We have recently discussed the interplay between molecular conformation and intermolecular forces, particularly soft hydrogen bonds of the C—H···O ype, in a range of 2-nitrophenylthiolates 2-O₂NC₆H₄SX (Low, Storey et al., 2000; Low, Glidewell & Wardell, 2000; Glidewell et al., 2000). We report here an investigation of N-(2-nitrophenylthio)saccharin, (I), selected for study because of its incorporation of three different groups, CO, NO₂ and SO₂, known to be good acceptors of C—H···O hydrogen bonds. In a previous paper (Low, Storey et al., 2000), we reported the structure of the pyrrolidinedione derivative (II), clearly related to (I), in which both carbonyl O atoms and one of the two nitro O atoms act as acceptors of C—H···O hydrogen bonds; similarly, in the phthalimido analogue (III) (Iwasaki & Masuko, 1986), the same three O atoms act as acceptors. In both (II) and (III), the C—H···O hydrogen bonds link the molecules into continuous sheets, albeit in entirely different ways (Low, Storey et al., 2000).

The overall molecular conformation of (I) (Fig. 1) closely resembles those observed previously for (II) and (III). Both the nitro group and the α atom of the X substituent are nearly coplanar with the nitrated aryl ring, while the plane of the heterocyclic component is almost orthogonal (Table 1). The near orthogonality of these planes must be ascribed to the mutually repulsive effect of the lone pairs on S and N normal to these two planes, which themselves seek to be become orthogonal in order to minimize their mutual overlap and resonance integrals. The sum of the bond angles at N2 in the heterocyclic ring is almost 360°; within this ring, the internal angle at S2 is extremely small for four-coordinate S^VI and it is very much smaller than the mean internal angles, 108°, in a planar five-membered ring. Neither (II) nor (III) show any peculiarities in the internal ring angles, but in saccharin itself (IV) (Okaya, 1969), the internal angle at S is 92.2° (no s.u. given). The idealized internal angles in this ring, which contains three trigonal C, one planar trigonal N and a four-coordinate S atom, sum to ca 590°, some 50° greater than the maximum possible for such a ring. It is evident that the S atom makes the greatest contribution to the relief of bond-angle strain in this ring, followed by carbonyl C27 atom (Table 1).

The N—C and N—S bond lengths within the heterocyclic ring are both very much shorter than the mean values for their types, 1.414 and 1.688 Å, respectively (Allen et al., 1987); similarly, the C27—O7 distance is closer to the mean values observed in four-membered rings (1.198 Å in cyclobutanones and 1.198 Å in β-lactams) than to those in five-membered rings (1.208 Å in cyclopentanones and 1.225 Å in γ-lactams). The corresponding values observed in (IV) were 1.369 (5), 1.663 (4) and 1.214 (5) Å, respectively (Okaya, 1969).

The surprising feature of the crystal structure of (I) is the comparative paucity of hydrogen bonds (Table 2). A single C—H···O hydrogen bond links the molecules into cyclic centrosymmetric dimers based on an R²₂(16) motif (Bernstein et al., 1995) (Fig. 2). Neither the carbonyl nor the nitro O atoms in (I) act as hydrogen-bond acceptors, in sharp contrast to the behaviour of the corresponding atoms in (II) and (III). The hydrogen bonds forming the dimers are reinforced by aromatic π···π-stacking interactions between the two nitrated aryl rings within the dimer; the planes of the parallel aryl rings at (x, y, z) and (2 − x, 1 − y, −z) are ca 3.47 Å apart and the ring centroids are offset by ca 1.41 Å, ideal for the development of these interactions. Doubtless the near planarity of the 2-O₂NC₆H₄SN< fragment is conducive to the occurrence of these interactions. There are, however, no such interactions involving the saccharin portion of the molecule.

The formation of finite dimers in (I) may be contrasted with the extensive intermolecular hydrogen bonding in saccharin itself, (IV), where there are hard hydrogen bonds of the N—H···O═C type linking pairs of molecules into cyclic R²₂(8) dimers (Okaya, 1969). In addition, although not mentioned in the original report, there are rather strong C—H···O═S hydrogen bonds [C···O 3.383, H···O 2.46 Å and C—H···O 164° (s.u.'s uncertain)] linking the molecules into continuous sheets built from R⁶₆(30) rings (Fig. 3). Each individual molecule is hydrogen bonded to three others, while each R²₂(8) dimer is hydrogen bonded to four others; thus, the description of the net topology (Batten & Robson, 1998) differs depending upon whether monomers or dimers are taken to be the nodes of the net. For monomer nodes, the net is of (6,3) type, while for dimer nodes the net is of (4,4) type.

S2. Experimental

A sample of compound (I) was obtained from Aldrich. Crystals suitable for single-crystal X-ray diffraction analysis were grown from an ethanol solution.

S3. Refinement

Compound (I) crystallized in the monoclinic system; space group C2/c or Cc from the systematic absences. C2/c was assumed and confirmed by the analysis. H atoms were treated as riding atoms with C—H = 0.93 Å and O—H = 0.82 Å. Examination of the structure with PLATON (Spek, 2000) showed that there were no solvent-accessible voids in the crystal lattice.

Computing details

Data collection: XPREP (Bruker, 1997); cell refinement: XPREP; data reduction: XPREP; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEPII (Johnson, 1976) and PLATON (Spek, 2000); software used to prepare material for publication: SHELXL97 and WORDPERFECT macro PRPKAPPA (Ferguson, 1999).

Figures

	Fig. 1. The asymmetric unit of compound (I), showing the atom-labelling scheme. Displacement ellipsoids are drawn at the 30% probability level.
	Fig. 2. Part of the crystal structure of (I) showing formation of a cyclic centrosymmetric dimer. For the sake of clarity, H atoms not involved in dimer formation have been omitted. The atom marked with an asterisk (*) is at the symmetry position (1 − x, −y, 1 − z).
	Fig. 3. Part of the crystal structure of (IV) showing formation of one of the R^66(30) rings making up the (6,3) net. Atom labelling is as in Okaya (1969). For the sake of clarity, H atoms not involved in hydrogen bonding have been omitted. Atoms marked with an asterisk (*) or hash (#) are at the symmetry positions (-x, 0.5 + y, 0.5 − z) and (1 − x, −y, 1 − z), repectively.

N-(2-Nitrophenylthio)saccharin

Crystal data

C13H8N2O5S2	F(000) = 1376
Mr = 336.33	Dx = 1.626 Mg m^−3
Monoclinic, C2/c	Mo Kα radiation, λ = 0.71073 Å
a = 23.6968 (15) Å	Cell parameters from 2420 reflections
b = 7.6510 (5) Å	θ = 2.7–25.0°
c = 15.1664 (10) Å	µ = 0.41 mm^−1
β = 92.360 (1)°	T = 298 K
V = 2747.4 (3) Å^3	Plate, yellow
Z = 8	0.35 × 0.25 × 0.10 mm

Data collection

KappaCCD diffractometer	2420 independent reflections
Radiation source: fine-focus sealed X-ray tube	1740 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.026
ϕ and ω scans with κ offsets	θmax = 25.0°, θmin = 2.7°
Absorption correction: multi-scan (SADABS; Bruker, 1997)	h = −28→28
Tmin = 0.869, Tmax = 0.960	k = −9→8
8477 measured reflections	l = −18→17

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)] = 0.033	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.081	H-atom parameters constrained
S = 0.92	w = 1/[σ^2(Fo^2) + (0.0445P)^2] where P = (Fo^2 + 2Fc^2)/3
2420 reflections	(Δ/σ)max = 0.001
199 parameters	Δρmax = 0.24 e Å^−3
0 restraints	Δρmin = −0.24 e Å^−3

Special details

Geometry. Mean-plane data from the final SHELXL97 refinement run:-

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

	x	y	z	Uiso*/Ueq
S1	0.85203 (3)	0.40865 (8)	0.02879 (4)	0.05091 (19)
C11	0.91310 (9)	0.3797 (3)	−0.03385 (13)	0.0380 (5)
C12	0.93616 (9)	0.5201 (3)	−0.07903 (13)	0.0392 (5)
N1	0.91033 (10)	0.6916 (2)	−0.07343 (13)	0.0503 (5)
O11	0.86521 (9)	0.7009 (2)	−0.03682 (13)	0.0757 (6)
O12	0.93362 (8)	0.8179 (2)	−0.10435 (13)	0.0692 (6)
C13	0.98344 (10)	0.5039 (3)	−0.12831 (14)	0.0489 (6)
C14	1.00923 (11)	0.3438 (3)	−0.13454 (16)	0.0537 (6)
C15	0.98689 (10)	0.2026 (3)	−0.09110 (15)	0.0487 (6)
C16	0.94000 (10)	0.2193 (3)	−0.04172 (15)	0.0434 (5)
N2	0.84796 (8)	0.2100 (2)	0.07937 (12)	0.0461 (5)
S2	0.87621 (3)	0.18599 (7)	0.18263 (4)	0.04568 (18)
O21	0.85659 (9)	0.3214 (2)	0.23753 (11)	0.0643 (5)
O22	0.93548 (7)	0.1616 (2)	0.17862 (12)	0.0644 (5)
C21	0.84104 (9)	−0.0115 (3)	0.19775 (14)	0.0396 (5)
C22	0.80770 (9)	−0.0542 (3)	0.12378 (14)	0.0416 (5)
C23	0.77640 (10)	−0.2066 (3)	0.12412 (16)	0.0522 (6)
C24	0.78064 (11)	−0.3122 (3)	0.19736 (17)	0.0590 (7)
C25	0.81389 (12)	−0.2679 (3)	0.26993 (17)	0.0583 (7)
C26	0.84473 (10)	−0.1158 (3)	0.27165 (16)	0.0503 (6)
C27	0.81064 (9)	0.0754 (3)	0.05071 (15)	0.0430 (5)
H13	0.9978	0.6006	−0.1571	0.059*
H14	1.0412	0.3306	−0.1675	0.064*
H15	1.0040	0.0938	−0.0955	0.058*
H16	0.9260	0.1219	−0.0131	0.052*
H23	0.7530	−0.2370	0.0758	0.063*
H24	0.7604	−0.4163	0.1977	0.071*
H25	0.8156	−0.3418	0.3187	0.070*
H26	0.8672	−0.0845	0.3208	0.060*
O7	0.78763 (7)	0.0703 (2)	−0.02118 (10)	0.0598 (5)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
S1	0.0516 (4)	0.0466 (4)	0.0553 (4)	0.0061 (3)	0.0116 (3)	0.0112 (3)
C11	0.0405 (13)	0.0370 (12)	0.0361 (12)	−0.0023 (10)	−0.0035 (10)	0.0008 (9)
C12	0.0462 (14)	0.0340 (12)	0.0367 (12)	−0.0024 (10)	−0.0060 (10)	−0.0008 (9)
N1	0.0658 (15)	0.0383 (12)	0.0462 (12)	0.0000 (11)	−0.0049 (11)	0.0055 (9)
O11	0.0859 (15)	0.0548 (12)	0.0884 (15)	0.0234 (11)	0.0293 (12)	0.0192 (10)
O12	0.0864 (15)	0.0371 (10)	0.0834 (14)	−0.0118 (9)	−0.0035 (11)	0.0144 (9)
C13	0.0529 (15)	0.0498 (15)	0.0440 (14)	−0.0125 (12)	0.0002 (11)	0.0033 (11)
C14	0.0484 (16)	0.0641 (17)	0.0489 (15)	−0.0018 (13)	0.0062 (12)	−0.0052 (12)
C15	0.0494 (15)	0.0433 (14)	0.0532 (15)	0.0061 (11)	−0.0016 (12)	−0.0062 (11)
C16	0.0497 (14)	0.0345 (12)	0.0456 (13)	−0.0023 (11)	−0.0020 (11)	0.0012 (10)
N2	0.0493 (12)	0.0474 (12)	0.0415 (11)	−0.0099 (9)	−0.0005 (9)	0.0074 (9)
S2	0.0483 (4)	0.0431 (3)	0.0453 (4)	−0.0078 (3)	−0.0023 (3)	0.0021 (3)
O21	0.0934 (15)	0.0437 (10)	0.0553 (11)	0.0012 (9)	−0.0047 (10)	−0.0076 (8)
O22	0.0424 (11)	0.0794 (13)	0.0709 (13)	−0.0172 (9)	−0.0039 (9)	0.0097 (9)
C21	0.0376 (12)	0.0391 (12)	0.0423 (13)	−0.0024 (10)	0.0054 (10)	−0.0005 (10)
C22	0.0365 (12)	0.0476 (13)	0.0412 (13)	−0.0025 (10)	0.0071 (10)	−0.0042 (10)
C23	0.0519 (15)	0.0556 (16)	0.0494 (15)	−0.0154 (12)	0.0056 (12)	−0.0117 (12)
C24	0.0675 (18)	0.0450 (15)	0.0656 (18)	−0.0164 (13)	0.0152 (15)	−0.0008 (13)
C25	0.0699 (18)	0.0483 (15)	0.0572 (17)	−0.0016 (13)	0.0076 (14)	0.0098 (12)
C26	0.0536 (15)	0.0509 (15)	0.0461 (14)	−0.0008 (12)	−0.0021 (11)	0.0043 (11)
C27	0.0383 (13)	0.0510 (14)	0.0402 (13)	−0.0025 (11)	0.0050 (10)	−0.0037 (11)
O7	0.0632 (11)	0.0728 (12)	0.0428 (10)	−0.0073 (9)	−0.0063 (8)	0.0005 (8)

Geometric parameters (Å, º)

C11—C16	1.391 (3)	C27—N2	1.414 (3)
C11—C12	1.398 (3)	S2—O21	1.4195 (17)
C12—C13	1.378 (3)	S2—O22	1.4206 (18)
N1—O11	1.227 (3)	S2—C21	1.745 (2)
N1—O12	1.216 (2)	C21—C26	1.375 (3)
N1—C12	1.452 (3)	C21—C22	1.384 (3)
S1—C11	1.777 (2)	C22—C23	1.382 (3)
S1—N2	1.7072 (18)	C22—C27	1.491 (3)
C13—C14	1.375 (3)	C23—C24	1.374 (3)
C13—H13	0.9300	C23—H23	0.9300
C14—C15	1.382 (3)	C24—C25	1.369 (3)
C14—H14	0.9300	C24—H24	0.9300
C15—C16	1.371 (3)	C25—C26	1.374 (3)
C15—H15	0.9300	C25—H25	0.9300
C16—H16	0.9300	C26—H26	0.9300
S2—N2	1.6876 (19)	C27—O7	1.199 (2)
N2—S1—C11	101.04 (10)	C14—C15—H15	119.2
C16—C11—C12	116.5 (2)	C15—C16—C11	120.9 (2)
C16—C11—S1	122.83 (17)	C15—C16—H16	119.5
C12—C11—S1	120.64 (17)	C11—C16—H16	119.5
C13—C12—C11	122.7 (2)	O21—S2—N2	109.75 (10)
C13—C12—N1	117.9 (2)	O22—S2—N2	109.25 (10)
C11—C12—N1	119.5 (2)	O21—S2—C21	112.65 (11)
O11—N1—O12	123.1 (2)	O22—S2—C21	111.75 (11)
O12—N1—C12	119.8 (2)	C26—C21—C22	122.6 (2)
O11—N1—C12	117.1 (2)	C26—C21—S2	126.47 (17)
O21—S2—O22	117.98 (11)	C23—C22—C21	119.0 (2)
S1—N2—S2	119.09 (11)	C23—C22—C27	127.3 (2)
S1—N2—C27	123.81 (15)	C24—C23—C22	118.5 (2)
S2—N2—C27	115.17 (14)	C24—C23—H23	120.7
N2—S2—C21	92.45 (9)	C22—C23—H23	120.7
S2—C21—C22	110.95 (16)	C25—C24—C23	121.7 (2)
C21—C22—C27	113.75 (19)	C25—C24—H24	119.2
C22—C27—N2	107.67 (18)	C23—C24—H24	119.2
C14—C13—C12	119.4 (2)	C24—C25—C26	120.8 (2)
C14—C13—H13	120.3	C24—C25—H25	119.6
C12—C13—H13	120.3	C26—C25—H25	119.6
C13—C14—C15	118.9 (2)	C25—C26—C21	117.4 (2)
C13—C14—H14	120.5	C25—C26—H26	121.3
C15—C14—H14	120.5	C21—C26—H26	121.3
C16—C15—C14	121.5 (2)	O7—C27—N2	123.9 (2)
C16—C15—H15	119.2	O7—C27—C22	128.4 (2)
N2—S1—C11—C16	8.04 (19)	O21—S2—C21—C26	−68.5 (2)
C12—C11—S1—N2	−172.72 (16)	O22—S2—C21—C26	67.0 (2)
C16—C11—C12—C13	−0.8 (3)	N2—S2—C21—C26	178.9 (2)
S1—C11—C12—C13	179.94 (16)	O21—S2—C21—C22	111.81 (17)
C16—C11—C12—N1	−179.75 (18)	O22—S2—C21—C22	−112.66 (17)
S1—C11—C12—N1	1.0 (3)	N2—S2—C21—C22	−0.80 (17)
C13—C12—N1—O12	−7.1 (3)	C26—C21—C22—C23	0.6 (3)
C11—C12—N1—O12	171.91 (19)	S2—C21—C22—C23	−179.67 (18)
C13—C12—N1—O11	172.9 (2)	C26—C21—C22—C27	−179.0 (2)
C11—C12—N1—O11	−8.0 (3)	S2—C21—C22—C27	0.7 (2)
C11—C12—C13—C14	0.5 (3)	C21—C22—C23—C24	−1.5 (4)
N1—C12—C13—C14	179.53 (19)	C27—C22—C23—C24	178.1 (2)
C12—C13—C14—C15	0.1 (3)	C22—C23—C24—C25	1.5 (4)
C13—C14—C15—C16	−0.4 (4)	C23—C24—C25—C26	−0.5 (4)
C14—C15—C16—C11	0.2 (3)	C24—C25—C26—C21	−0.4 (4)
C12—C11—C16—C15	0.4 (3)	C22—C21—C26—C25	0.3 (4)
S1—C11—C16—C15	179.68 (17)	S2—C21—C26—C25	−179.3 (2)
C11—S1—N2—S2	95.94 (14)	S2—N2—C27—O7	−178.71 (19)
C11—S1—N2—C27	−100.68 (19)	S1—N2—C27—O7	17.3 (3)
C27—N2—S2—O21	−114.43 (17)	S2—N2—C27—C22	−0.4 (2)
S1—N2—S2—O21	50.35 (16)	S1—N2—C27—C22	−164.40 (15)
C27—N2—S2—O22	114.78 (17)	C23—C22—C27—O7	−1.6 (4)
S1—N2—S2—O22	−80.45 (15)	C21—C22—C27—O7	178.0 (2)
C27—N2—S2—C21	0.71 (18)	C23—C22—C27—N2	−179.8 (2)
S1—N2—S2—C21	165.49 (13)	C21—C22—C27—N2	−0.2 (3)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C13—H13···O22^i	0.93	2.44	3.308 (3)	155

Symmetry code: (i) −x+2, −y+1, −z.