A 1:1 molecular complex of bis(4-aminophenyl) disulfide and 4-aminothiophenol

The centrosymmetric crystal structure of the title complex, C₁₂H₁₂N₂S₂·C₆H₇NS, is built up of dimers of the constituent mol­ecules and stabilized by a herring-bone geometry between the phenyl rings. The structure reveals an N—H...N—H...N—H...S co-operative hydrogen-bonded chain, and C—H...S and N—H...π hydrogen bonds. The S—H group forms an uncommon S—H...π interaction.

S1. Comment

Crystals of the title complex, (I), were obtained during an investigation of 4-aminothiophenol. Aerial oxidation of this compound leads to the disulfide, which co-crystallizes with the original thiophenol to give the 1:1 molecular complex. \sch

Complex (I) illustrates a situation wherein a crystal structure is stabilized by the interplay of strong as well as weak intermolecular interactions. The molecular geometry and numbering are given in Fig. 1. The S—S distance of 2.0645 (7) Å is normal and is comparable with the length of 2.074 (1) Å reported for bis(4-aminophenyl) disulfide (Vittal & Anjali, 1998). The C—S—S—C torsion angle in (I) is 94.8 (1)° [80.2 (1)° in bis(4-aminophenyl) disulfide]. Fig. 2 shows the packing diagram of (I) viewed down the [010] axis. The intermolecular interactions and geometrical parameters are listed in Table 1.

The structure of (I) is stabilized by a finite cooperative chain of N3—H3A···N2—H2B···N1—H1A···S2 hydrogen bonds in the ac plane. The weak C2—H2···S2 interaction is anticooperative with respect to the above set of interactions. Other anticooperative interactions, namely N3—H3B···π and C3—H3···π, are also seen. A weak C15—H15···π interaction exists between screw-related molecules.

Although the S—H group is considered to be one of the classical hydrogen-bonding groups, it does not form S—H···X interactions very often (Desiraju & Steiner, 1999; Allen et al., 1997; Steiner, 2000). In (I), there is a well characterized S—H···π interaction, which is uncommon. In the Cambridge Structural Database (CSD, Version 5.23; Allen & Kennard, 1993), there are only eight crystal structures [refcodes HIPMUO (Zhu-Ohlbach et al., 1998), SIZBAE (Bernardinelli et al., 1991), TASPOS (Slusarchyk et al., 1995), TAXMUA (Nishio et al., 1996), VOPBEH (Garbarczyk & Krolikowska, 1992), YOMWAY01 (Gibbs et al.,1995), and YULZOU and YULZUA (Sellmann et al., 1995)], containing 12 thiol groups, wherein such S—H···π interactions are seen. Not many crystal structures of aminothiols have been reported to date. The present structure is in contrast with that of 6-aminopyridine-1-thiol (Sabino et al., 2002), where N—H···N hydrogen bonds are preferentially formed. References were missing for all eight refcodes - please check carefully the citations added above and the references added to the list below.

S2. Experimental

Aerial oxidation of 4-aminothiophenol leads to the disulfide which co-crystallizes with the original thiophenol leading to yellow crystals of the 1:1 molecular complex.

S3. Refinement

H atoms on C atoms were refined using a riding model starting from idealized geometries, with U_iso(H) = 1.5U_eq(C). The positions of H atoms on N and S atoms were taken from a difference Fourier map and these H atoms were also refined as riding, with U_iso(H) = 1.2U_eq(N) or 1.5U_eq(S). We note that the geometry around the amino group N1 is pyramidal and this is in accord with previous observations in crystal structures of aromatic amines where the N-atom is a hydrogen bond acceptor (Allen et al., 1997). The maximum/minimum residual electron densities are located close to the S-atoms, obviously also influencing the position of the attached H1-atom.

Computing details

Data collection: SMART (Bruker, 1997); cell refinement: SMART (Bruker, 1997); data reduction: SAINT (Bruker, 2000); program(s) used to solve structure: SHELXTL (Bruker, 2001); program(s) used to refine structure: SHELXTL (Bruker, 2001); molecular graphics: SHELXTL (Bruker, 2001); software used to prepare material for publication: SHELXTL (Bruker, 2001).

Figures

	Fig. 1. A view of the molecular structure 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.
	Fig. 2. The packing of (I) viewed down [010]. N and S atoms are shaded differently for clarity and hydrogen bonds are shown as dotted lines. Note the N—H···N—H···N—H···S chain and the S—H···π interaction.

Bis(4-aminophenyl)disulfide-4-aminothiophenol (1/1)

Crystal data

C12H12N2S2·C6H7NS	F(000) = 784
Mr = 373.54	Dx = 1.389 Mg m^−3
Monoclinic, P21/n	Melting point: 200 K
Hall symbol: -P 2yn	Mo Kα radiation, λ = 0.71073 Å
a = 15.210 (3) Å	Cell parameters from 5202 reflections
b = 6.0099 (11) Å	θ = 2.7–28.3°
c = 19.683 (4) Å	µ = 0.42 mm^−1
β = 96.814 (3)°	T = 203 K
V = 1786.6 (6) Å^3	Rod, yellow
Z = 4	0.28 × 0.08 × 0.05 mm

Data collection

Bruker SMART CCD area-detector diffractometer	4410 independent reflections
Radiation source: fine-focus sealed tube	3497 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.081
Detector resolution: 512 pixels mm^-1	θmax = 28.3°, θmin = 1.8°
Hemi sphere data collection scans	h = −20→20
Absorption correction: empirical (using intensity measurements) (SADABS; Blessing, 1995)	k = 0→8
Tmin = 0.89, Tmax = 0.99	l = −26→26
8776 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)] = 0.050	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.128	H-atom parameters constrained
S = 1.04	w = 1/[σ^2(Fo^2) + (0.07P)^2 + 0.063P] where P = (Fo^2 + 2Fc^2)/3
4410 reflections	(Δ/σ)max = 0.001
217 parameters	Δρmax = 0.79 e Å^−3
0 restraints	Δρmin = −0.25 e Å^−3

Special details

Experimental. Hemi sphere data collection with omega at 0.3 ° scan width, two runs with 740 frames, phi = 0, 270(°) and two runs with 436 frames, phi = 88, 180(°)

Bruker SADABS program multi-scan V2.03 R·H. Blessing, Acta Cryst. (1995) A51 33–38

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	0.15155 (11)	0.5469 (2)	0.15570 (8)	0.0318 (3)
C2	0.14980 (12)	0.3331 (3)	0.18260 (8)	0.0352 (3)
H2	0.0982	0.2805	0.1992	0.042*
C3	0.22339 (12)	0.1968 (3)	0.18514 (8)	0.0353 (3)
H3	0.2213	0.0533	0.2039	0.042*
C4	0.30057 (11)	0.2684 (2)	0.16057 (7)	0.0325 (3)
C5	0.30172 (11)	0.4846 (2)	0.13336 (8)	0.0333 (3)
H5	0.3532	0.5372	0.1165	0.040*
C6	0.22851 (11)	0.6204 (2)	0.13103 (8)	0.0329 (3)
H6	0.2306	0.7643	0.1126	0.039*
N1	0.37355 (11)	0.1251 (2)	0.15862 (7)	0.0410 (3)
H1A	0.4251	0.1947	0.1624	0.049*
H1B	0.3794	0.0377	0.1900	0.049*
S1	0.06154 (3)	0.73431 (7)	0.15535 (2)	0.04440 (15)
H1	0.0128	0.6495	0.1577	0.053*
C7	0.56318 (11)	0.7629 (3)	0.14613 (8)	0.0330 (3)
C8	0.59837 (12)	0.9756 (3)	0.15723 (9)	0.0382 (4)
H8	0.5989	1.0430	0.2004	0.046*
C9	0.63242 (13)	1.0880 (3)	0.10530 (9)	0.0416 (4)
H9	0.6570	1.2303	0.1137	0.050*
C10	0.63100 (12)	0.9935 (3)	0.04024 (9)	0.0395 (4)
C11	0.59223 (12)	0.7840 (3)	0.02866 (8)	0.0397 (4)
H11	0.5883	0.7203	−0.0152	0.048*
C12	0.55975 (12)	0.6698 (3)	0.08127 (8)	0.0357 (3)
H12	0.5349	0.5277	0.0730	0.043*
C13	0.63360 (12)	0.7444 (3)	0.34511 (9)	0.0373 (4)
C14	0.68407 (12)	0.9354 (3)	0.33891 (9)	0.0422 (4)
H14	0.7122	0.9569	0.2994	0.051*
C15	0.69319 (13)	1.0939 (3)	0.38987 (9)	0.0456 (4)
H15	0.7278	1.2212	0.3849	0.055*
C16	0.65152 (13)	1.0673 (3)	0.44909 (9)	0.0437 (4)
C17	0.60226 (13)	0.8734 (3)	0.45598 (9)	0.0421 (4)
H17	0.5750	0.8504	0.4958	0.050*
C18	0.59399 (12)	0.7134 (3)	0.40442 (9)	0.0391 (4)
H18	0.5608	0.5839	0.4097	0.047*
N2	0.67105 (13)	1.0968 (3)	−0.01082 (9)	0.0563 (5)
H2A	0.6769	1.2344	−0.0034	0.068*
H2B	0.6549	1.0549	−0.0527	0.068*
N3	0.65603 (15)	1.2320 (3)	0.49806 (9)	0.0587 (5)
H3A	0.6964	1.3430	0.4973	0.070*
H3B	0.6404	1.1878	0.5363	0.070*
S2	0.51935 (3)	0.61204 (7)	0.21176 (2)	0.03839 (14)
S3	0.62695 (3)	0.53320 (7)	0.28168 (2)	0.04368 (15)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.0293 (8)	0.0331 (7)	0.0327 (7)	0.0009 (6)	0.0024 (6)	−0.0046 (5)
C2	0.0336 (8)	0.0372 (8)	0.0359 (7)	−0.0072 (7)	0.0079 (6)	−0.0040 (6)
C3	0.0420 (9)	0.0284 (7)	0.0352 (7)	−0.0028 (6)	0.0037 (6)	0.0001 (6)
C4	0.0340 (8)	0.0337 (7)	0.0290 (7)	0.0018 (6)	−0.0001 (6)	−0.0010 (5)
C5	0.0306 (8)	0.0360 (7)	0.0336 (7)	−0.0041 (6)	0.0051 (6)	0.0011 (6)
C6	0.0358 (9)	0.0285 (7)	0.0341 (7)	−0.0034 (6)	0.0027 (6)	0.0008 (5)
N1	0.0405 (9)	0.0397 (7)	0.0420 (7)	0.0103 (6)	0.0012 (6)	0.0049 (6)
S1	0.0337 (3)	0.0427 (2)	0.0563 (3)	0.00621 (17)	0.0033 (2)	−0.00657 (17)
C7	0.0285 (8)	0.0338 (7)	0.0365 (8)	0.0021 (6)	0.0024 (6)	0.0016 (6)
C8	0.0400 (9)	0.0335 (7)	0.0397 (8)	0.0038 (7)	−0.0013 (7)	−0.0045 (6)
C9	0.0407 (10)	0.0315 (8)	0.0502 (9)	−0.0027 (7)	−0.0050 (7)	0.0035 (6)
C10	0.0329 (8)	0.0412 (8)	0.0431 (9)	−0.0011 (7)	−0.0008 (7)	0.0092 (6)
C11	0.0403 (10)	0.0445 (9)	0.0336 (8)	−0.0032 (7)	0.0024 (7)	−0.0008 (6)
C12	0.0334 (8)	0.0341 (7)	0.0393 (8)	−0.0038 (6)	0.0028 (6)	−0.0022 (6)
C13	0.0306 (8)	0.0403 (8)	0.0399 (8)	0.0038 (7)	−0.0003 (6)	0.0097 (6)
C14	0.0297 (9)	0.0520 (10)	0.0437 (9)	−0.0028 (7)	−0.0008 (7)	0.0169 (7)
C15	0.0356 (9)	0.0455 (9)	0.0517 (10)	−0.0089 (8)	−0.0115 (8)	0.0167 (7)
C16	0.0447 (10)	0.0405 (8)	0.0412 (9)	−0.0016 (8)	−0.0136 (7)	0.0089 (7)
C17	0.0453 (10)	0.0440 (9)	0.0359 (8)	−0.0035 (8)	0.0009 (7)	0.0086 (6)
C18	0.0384 (9)	0.0365 (8)	0.0413 (8)	−0.0032 (7)	−0.0002 (7)	0.0098 (6)
N2	0.0610 (12)	0.0582 (10)	0.0492 (9)	−0.0189 (9)	0.0050 (8)	0.0137 (7)
N3	0.0787 (14)	0.0454 (8)	0.0468 (9)	−0.0104 (9)	−0.0136 (9)	0.0052 (7)
S2	0.0341 (2)	0.0431 (2)	0.0387 (2)	−0.00334 (16)	0.00754 (16)	−0.00024 (15)
S3	0.0456 (3)	0.0420 (2)	0.0437 (2)	0.01216 (18)	0.00654 (19)	0.00776 (16)

Geometric parameters (Å, º)

C1—C2	1.391 (2)	C10—N2	1.383 (2)
C1—C6	1.391 (2)	C10—C11	1.397 (2)
C1—S1	1.7721 (16)	C11—C12	1.382 (2)
C2—C3	1.383 (2)	C11—H11	0.9400
C2—H2	0.9400	C12—H12	0.9400
C3—C4	1.390 (3)	C13—C18	1.388 (3)
C3—H3	0.9400	C13—C14	1.394 (2)
C4—C5	1.407 (2)	C13—S3	1.7749 (18)
C4—N1	1.409 (2)	C14—C15	1.379 (3)
C5—C6	1.377 (2)	C14—H14	0.9400
C5—H5	0.9400	C15—C16	1.400 (3)
C6—H6	0.9400	C15—H15	0.9400
N1—H1A	0.8841	C16—N3	1.378 (2)
N1—H1B	0.8078	C16—C17	1.401 (2)
S1—H1	0.9051	C17—C18	1.393 (3)
C7—C12	1.389 (2)	C17—H17	0.9400
C7—C8	1.393 (2)	C18—H18	0.9400
C7—S2	1.7719 (17)	N2—H2A	0.8427
C8—C9	1.377 (3)	N2—H2B	0.8697
C8—H8	0.9400	N3—H3A	0.9074
C9—C10	1.399 (3)	N3—H3B	0.8580
C9—H9	0.9400	S2—S3	2.0645 (7)
C2—C1—C6	118.73 (15)	C11—C10—C9	118.40 (16)
C2—C1—S1	122.60 (13)	C12—C11—C10	120.45 (15)
C6—C1—S1	118.60 (12)	C12—C11—H11	119.8
C3—C2—C1	120.59 (16)	C10—C11—H11	119.8
C3—C2—H2	119.6	C11—C12—C7	120.73 (15)
C1—C2—H2	119.8	C11—C12—H12	119.6
C2—C3—C4	121.15 (14)	C7—C12—H12	119.6
C2—C3—H3	119.5	C18—C13—C14	118.84 (16)
C4—C3—H3	119.4	C18—C13—S3	120.10 (13)
C3—C4—C5	117.87 (15)	C14—C13—S3	120.88 (15)
C3—C4—N1	121.40 (14)	C15—C14—C13	120.96 (18)
C5—C4—N1	120.60 (16)	C15—C14—H14	119.4
C6—C5—C4	120.91 (16)	C13—C14—H14	119.7
C6—C5—H5	119.5	C14—C15—C16	120.67 (16)
C4—C5—H5	119.5	C14—C15—H15	119.7
C5—C6—C1	120.74 (14)	C16—C15—H15	119.6
C5—C6—H6	119.6	N3—C16—C15	120.69 (18)
C1—C6—H6	119.6	N3—C16—C17	120.86 (19)
C4—N1—H1A	113.7	C15—C16—C17	118.41 (16)
C4—N1—H1B	113.1	C18—C17—C16	120.45 (18)
H1A—N1—H1B	103.1	C18—C17—H17	119.7
C1—S1—H1	106.2	C16—C17—H17	119.8
C12—C7—C8	119.04 (15)	C13—C18—C17	120.64 (16)
C12—C7—S2	119.19 (12)	C13—C18—H18	119.7
C8—C7—S2	121.73 (12)	C17—C18—H18	119.6
C9—C8—C7	120.35 (15)	C10—N2—H2A	111.1
C9—C8—H8	119.7	C10—N2—H2B	117.4
C7—C8—H8	119.9	H2A—N2—H2B	117.5
C8—C9—C10	120.94 (15)	C16—N3—H3A	119.6
C8—C9—H9	119.6	C16—N3—H3B	113.3
C10—C9—H9	119.5	H3A—N3—H3B	120.0
N2—C10—C11	119.99 (17)	C7—S2—S3	105.44 (6)
N2—C10—C9	121.52 (16)	C13—S3—S2	106.22 (6)
C6—C1—C2—C3	0.4 (2)	C8—C7—C12—C11	1.2 (3)
S1—C1—C2—C3	−176.48 (11)	S2—C7—C12—C11	179.14 (13)
C1—C2—C3—C4	−0.5 (2)	C18—C13—C14—C15	−1.5 (2)
C2—C3—C4—C5	0.4 (2)	S3—C13—C14—C15	−176.47 (13)
C2—C3—C4—N1	−175.51 (14)	C13—C14—C15—C16	−0.3 (3)
C3—C4—C5—C6	−0.2 (2)	C14—C15—C16—N3	−175.91 (17)
N1—C4—C5—C6	175.72 (14)	C14—C15—C16—C17	1.5 (3)
C4—C5—C6—C1	0.1 (2)	N3—C16—C17—C18	176.38 (17)
C2—C1—C6—C5	−0.2 (2)	C15—C16—C17—C18	−1.1 (3)
S1—C1—C6—C5	176.78 (11)	C14—C13—C18—C17	1.9 (3)
C12—C7—C8—C9	−2.6 (2)	S3—C13—C18—C17	176.97 (13)
S2—C7—C8—C9	179.61 (14)	C16—C17—C18—C13	−0.7 (3)
C7—C8—C9—C10	1.2 (3)	C12—C7—S2—S3	113.14 (13)
C8—C9—C10—N2	−174.90 (17)	C8—C7—S2—S3	−69.02 (14)
C8—C9—C10—C11	1.5 (3)	C18—C13—S3—S2	94.31 (14)
N2—C10—C11—C12	173.65 (17)	C14—C13—S3—S2	−90.74 (14)
C9—C10—C11—C12	−2.8 (3)	C7—S2—S3—C13	94.81 (8)
C10—C11—C12—C7	1.5 (3)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N2—H2B···N1^i	0.87	2.34	3.199 (2)	168
N1—H1A···S2	0.88	2.99	3.7452 (16)	144
N3—H3A···N2^ii	0.91	2.52	3.410 (3)	168
C2—H2···S2^iii	0.94	2.84	3.7387 (18)	162
S1—H1···Cg3^iii	0.90	2.89	3.7310 (12)	155
N3—H3B···Cg1^iv	0.86	2.65	3.312 (2)	135
C3—H3···Cg1^iii	0.94	2.88	3.544 (2)	129
C15—H15···Cg2^ii	0.94	2.83	3.614 (2)	142

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