2,3-Bis(3-fluoro­phen­yl)tetra­zolium-5-thiol­ate

The zwitterionic title compound, C₁₃H₈F₂N₄S, is situated on a twofold rotation axis running along the C—S [1.691 (2) Å] single bond. The phenyl­ene ring is twisted out of the tetra­zolium plane by 42.18 (7)°. Relatively short distances [3.7572 (9) and 4.0625 (6) Å] between the centroids of the phenyl­ene and tetra­zolium rings of neighbouring mol­ecules suggest π–π inter­actions. The crystal under investigation was a non-merohedral twin, with a 33% twin component.

Related literature

For details of the synthesis, see: Mirkhalaf et al. (1998); Irving et al. (1971). For comparison bond distances, see: Allen et al. (1987). For the indexing of twinned crystals by the CELL_NOW program, see: Bruker (2008).

Experimental

Crystal data

• C₁₃H₈F₂N₄S

• M_r = 290.29

• Monoclinic, C 2/c

• a = 14.500 (3) Å

• b = 12.656 (3) Å

• c = 6.9066 (14) Å

• β = 92.93 (3)°

• V = 1265.8 (5) ų

• Z = 4

• Mo Kα radiation

• μ = 0.27 mm⁻¹

• T = 100 K

• 0.33 × 0.11 × 0.11 mm

Data collection

• Bruker APEXII CCD diffractometer

• Absorption correction: multi-scan (TWINABS; Bruker, 2008) T_min = 0.915, T_max = 0.971

• 1562 measured reflections

• 1562 independent reflections

• 1360 reflections with I > 2σ(I)

Refinement

• R[F² > 2σ(F²)] = 0.038

• wR(F²) = 0.101

• S = 1.07

• 1562 reflections

• 93 parameters

• H-atom parameters constrained

• Δρ_max = 0.32 e Å⁻³

• Δρ_min = −0.23 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C6—H6⋯S^i	0.95	2.79	3.6828 (19)	157
Symmetry code: (i) .

Data collection: APEX2 (Bruker, 2005); cell refinement: SAINT-Plus (Bruker, 2004); data reduction: SAINT-Plus; program(s) used to solve structure: SIR97 (Altomare et al., 1999); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: DIAMOND (Brandenburg & Putz, 2005); software used to prepare material for publication: WinGX (Farrugia, 1999).

Supporting information

S1. Comment

During the process of synthesizing a series of electronically altered dithizones for the purpose of investigating its effect on the photochromic isomerization reaction of metal dithizonates, several phenyl substituted species were fully oxidized to its dehydrodithizone derivatives. Dehydrodithizones, most probably due to their zwitter-ionic nature, crystallizes much more readily than the parent compound. The yellow meta-fluoro dehydrodithizone crystals, suitable for X-ray crystallography, were isolated from a mixture of polar solvents, i.e. acetone and water.

The title compound crystallizes in the monoclininc space group C2/c (Z = 4) resulting in molecules lying on special positions in the crystal lattice. All bond lengths and angles (see Table 1, Fig. 1) are within range of their expected values (Allen et al., 1987). The phenyl rings adopt a non-parallel arrangement with the dehydrodithizone backbone with dihedral angles of 42.18 (7)° for ring C2—C7, mainly due to their close proximities on the tetrazole moiety. The preferred orientation is supported by the π-π stacking of the phenyl rings of neighbouring molecules (distance between planes = 3.4069 Å, centroid to centroid distance = 3.7572 (9) Å). Similar π-π stacking is also observed between neighbouring tetrazole moieties in a head-to-head fashion (distance between planes = 3.4235 Å, centroid to centroid distance = 4.0625 (6) Å) Additionally, several other close contacts/interactions are noted, among these a rather close contact for C6—H6···S between neighbouring dithizone molecules.

Related literature

For details of the synthesis, see: Mirkhalaf et al. (1998); Irving et al. (1971). For comparison bond distances, see: Allen et al. (1987). For the indexing of twinned crystals by the CELL_NOW program, see: Bruker (2008).

S2. Experimental

Solvents (AR) purchased from Merck and reagents from Sigma-Aldrich were used without further purification. The meta-fluoro derivative of dithizone, (m-FPhNHN)₂CS, was prepared from ammonium sulfide and 3-fluoroaniline according to the procedure reported by Mirkhalaf et al., 1998. The synthesis and crystallization of the title compound, meta-fluoro dehydrodithizone, was done according to a procedure reported by Irving et al., 1971. Hereby a solution of (m-FPhNHN)₂CS (0.3 g, 0.75 mmol) in dichloromethane (100 ml) was stirred (2 hrs) with a solution of potassium hexacyanoiron (III) (0.72 g) and potassium carbonate (0.70 g) in water (30 ml). After the organic layer was washed with water, the solvent was removed under reduced pressure. From hot acetone and water orange crystals, in 52% yield, were crystallized.

M.p 155 °C (explode). λ_max(acetone) 434.9 nm (ε = 1650 dm³ mol^-1 cm^-1). δ_H (300 MHz, (CD₃)₂SO, 7.748 - 7.533 (8 H, m, 2x-C₆H₄).

S3. Refinement

The aromatic H atoms were placed in geometrically idealized positions (C—H = 0.95 Å) and constrained to ride on their parent atoms with U_iso(H) = 1.2U_eq(C). Initial CheckCIF evaluation indicated possible non-merohedral twinning, and the data was subsequantly treated using CELL_NOW to obtain orientation matrix of the two components. The raw data was then integrated as two components resulting in a HKLF5 format file, which greatly improved refinement parameters and yielded the refined composition of the twinned domains in a 33.1:66.9 ratio.

Computing details

Data collection: APEX2 (Bruker, 2005); cell refinement: SAINT-Plus (Bruker, 2004); data reduction: SAINT-Plus (Bruker, 2004); program(s) used to solve structure: SIR97 (Altomare et al., 1999); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: DIAMOND (Brandenburg & Putz, 2005); software used to prepare material for publication: WinGX (Farrugia, 1999).

Figures

	Fig. 1. View of (I) (30% probability displacement ellipsoids). Accented lettering indicate atoms generated by symmetry (-x, y, 1/2 - z).
	Fig. 2. Packing diagram of (I) indicating the π-π interactions

2,3-Bis(3-fluorophenyl)tetrazolium-5-thiolate

Crystal data

C13H8F2N4S	F(000) = 592
Mr = 290.29	Dx = 1.523 Mg m^−3
Monoclinic, C2/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -C 2yc	Cell parameters from 1712 reflections
a = 14.500 (3) Å	θ = 2.8–28.2°
b = 12.656 (3) Å	µ = 0.27 mm^−1
c = 6.9066 (14) Å	T = 100 K
β = 92.93 (3)°	Needle, red
V = 1265.8 (5) Å^3	0.33 × 0.11 × 0.11 mm
Z = 4

Data collection

Bruker X8 APEXII 4K Kappa CCD diffractometer	1562 measured reflections
Radiation source: fine-focus sealed tube	1562 independent reflections
Graphite monochromator	1360 reflections with I > 2σ(I)
Detector resolution: 8.4 pixels mm^-1	θmax = 28.4°, θmin = 2.1°
ϕ and ω scans	h = −19→19
Absorption correction: multi-scan (TWINABS; Bruker, 2008)	k = 0→16
Tmin = 0.915, Tmax = 0.971	l = 0→9

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)] = 0.038	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.101	H-atom parameters constrained
S = 1.07	w = 1/[σ^2(Fo^2) + (0.0484P)^2 + 0.809P] where P = (Fo^2 + 2Fc^2)/3
1562 reflections	(Δ/σ)max < 0.001
93 parameters	Δρmax = 0.32 e Å^−3
0 restraints	Δρmin = −0.23 e Å^−3

Special details

Experimental. The intensity data was collected on a Bruker X8 Apex II 4 K Kappa CCD diffractometer using an exposure time of 180 s/frame. A total of 791 frames were collected with a frame width of 0.5° covering up to θ = 28.36° with 98.9% completeness accomplished.

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
S	0	0.63767 (5)	0.25	0.01916 (16)
N1	0.07681 (9)	0.44217 (11)	0.27936 (18)	0.0170 (3)
N2	0.04565 (8)	0.34445 (11)	0.26789 (18)	0.0156 (3)
F	0.10346 (9)	0.01182 (11)	0.57483 (18)	0.0443 (4)
C1	0	0.50409 (18)	0.25	0.0158 (4)
C2	0.10317 (10)	0.25414 (13)	0.3084 (2)	0.0179 (3)
C3	0.07274 (12)	0.17451 (14)	0.4266 (2)	0.0212 (4)
H3	0.0134	0.1766	0.4786	0.025*
C4	0.13285 (14)	0.09224 (16)	0.4647 (3)	0.0284 (4)
C5	0.22040 (14)	0.08883 (16)	0.3976 (3)	0.0321 (5)
H5	0.2606	0.0316	0.4304	0.039*
C6	0.24883 (12)	0.17000 (16)	0.2820 (3)	0.0310 (4)
H6	0.3092	0.1687	0.2346	0.037*
C7	0.18989 (11)	0.25393 (15)	0.2339 (2)	0.0243 (4)
H7	0.2087	0.3094	0.1522	0.029*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
S	0.0192 (3)	0.0169 (3)	0.0216 (3)	0	0.00337 (19)	0
N1	0.0156 (6)	0.0179 (7)	0.0174 (6)	−0.0005 (5)	0.0011 (4)	−0.0009 (5)
N2	0.0111 (6)	0.0197 (7)	0.0158 (6)	−0.0011 (5)	0.0000 (4)	−0.0007 (5)
F	0.0556 (8)	0.0311 (8)	0.0447 (7)	0.0079 (6)	−0.0118 (6)	0.0152 (5)
C1	0.0159 (10)	0.0193 (11)	0.0123 (9)	0	0.0025 (7)	0
C2	0.0142 (7)	0.0195 (8)	0.0193 (7)	0.0017 (6)	−0.0046 (5)	−0.0042 (6)
C3	0.0209 (8)	0.0219 (9)	0.0199 (8)	0.0016 (7)	−0.0062 (6)	−0.0019 (6)
C4	0.0329 (11)	0.0239 (10)	0.0268 (9)	0.0044 (8)	−0.0121 (7)	−0.0001 (7)
C5	0.0283 (10)	0.0281 (11)	0.0379 (10)	0.0139 (8)	−0.0175 (7)	−0.0120 (8)
C6	0.0165 (8)	0.0369 (11)	0.0388 (10)	0.0066 (7)	−0.0067 (7)	−0.0182 (8)
C7	0.0165 (8)	0.0281 (10)	0.0281 (9)	0.0001 (6)	−0.0006 (6)	−0.0085 (7)

Geometric parameters (Å, º)

S—C1	1.691 (2)	C3—C4	1.375 (3)
N1—N2	1.3177 (18)	C3—H3	0.95
N1—C1	1.3685 (18)	C4—C5	1.374 (3)
N2—N2^i	1.334 (2)	C5—C6	1.377 (3)
N2—C2	1.434 (2)	C5—H5	0.95
F—C4	1.352 (2)	C6—C7	1.393 (3)
C1—N1^i	1.3685 (18)	C6—H6	0.95
C2—C7	1.383 (2)	C7—H7	0.95
C2—C3	1.383 (2)
N2—N1—C1	104.75 (13)	F—C4—C5	119.28 (18)
N1—N2—N2^i	110.19 (8)	F—C4—C3	117.58 (18)
N1—N2—C2	122.82 (12)	C5—C4—C3	123.14 (19)
N2^i—N2—C2	126.72 (8)	C4—C5—C6	118.76 (18)
N1^i—C1—N1	110.1 (2)	C4—C5—H5	120.6
N1^i—C1—S	124.94 (10)	C6—C5—H5	120.6
N1—C1—S	124.94 (10)	C5—C6—C7	120.60 (17)
C7—C2—C3	122.81 (16)	C5—C6—H6	119.7
C7—C2—N2	117.37 (15)	C7—C6—H6	119.7
C3—C2—N2	119.74 (14)	C2—C7—C6	118.11 (18)
C4—C3—C2	116.54 (17)	C2—C7—H7	120.9
C4—C3—H3	121.7	C6—C7—H7	120.9
C2—C3—H3	121.7
C1—N1—N2—N2^i	0.36 (17)	N2—C2—C3—C4	−177.74 (14)
C1—N1—N2—C2	−173.99 (11)	C2—C3—C4—F	−177.94 (14)
N2—N1—C1—N1^i	−0.14 (7)	C2—C3—C4—C5	2.5 (3)
N2—N1—C1—S	179.86 (7)	F—C4—C5—C6	178.54 (16)
N1—N2—C2—C7	−43.6 (2)	C3—C4—C5—C6	−1.9 (3)
N2^i—N2—C2—C7	143.01 (18)	C4—C5—C6—C7	0.0 (3)
N1—N2—C2—C3	133.08 (15)	C3—C2—C7—C6	−0.5 (2)
N2^i—N2—C2—C3	−40.3 (2)	N2—C2—C7—C6	176.04 (14)
C7—C2—C3—C4	−1.2 (2)	C5—C6—C7—C2	1.2 (2)

Symmetry code: (i) −x, y, −z+1/2.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C6—H6···S^ii	0.95	2.79	3.6828 (19)	157

Symmetry code: (ii) x+1/2, y−1/2, z.