2,5-Bis[(3,3,4,4,5,5,6,6,7,7,8,8,8-trideca­fluoro­oct­yl)sulfan­yl]-1,3,4-thia­diazole

The title compound, C₁₈H₈F₂₆N₂S₃, was obtained by double S-perfluoro­hexyl­ethyl­ation of dipotassium 1,3,4-thia­diazole-2,5-di­thiol­ate in methanol. The mol­ecule exhibits twofold rotational symmetry, with the S atom lying on the rotation axis. The fluoro­carbon chains adopt helical conformations and the F atoms of the two terminal C atoms are disordered over two sets of sites. No directional inter­molecular inter­actions occur in the crystal.

Key indicators

• Single-crystal X-ray study
• T = 176 K
• Mean [sigma](C-C) = 0.003 Å
• Disorder in main residue
• R factor = 0.037
• wR factor = 0.099
• Data-to-parameter ratio = 9.1

checkCIF/PLATON results

No syntax errors found



Alert level B
PLAT213_ALERT_2_B Atom F13A            has ADP max/min Ratio .....        4.4 oblate

Alert level C
PLAT088_ALERT_3_C Poor Data / Parameter Ratio ....................       9.13 Note
PLAT213_ALERT_2_C Atom F13             has ADP max/min Ratio .....        3.1 oblate
PLAT213_ALERT_2_C Atom F12A            has ADP max/min Ratio .....        3.2 prolat
PLAT234_ALERT_4_C Large Hirshfeld Difference F11A   --  C9      ..       0.20 Ang.
PLAT242_ALERT_2_C Low    'MainMol' Ueq as Compared to Neighbors of         C7 Check
PLAT250_ALERT_2_C Large U3/U1 Ratio for Average U(i,j) Tensor ....        2.5 Note

Alert level G
PLAT083_ALERT_2_G SHELXL Second Parameter in WGHT  Unusually Large       5.73 Why ?
PLAT230_ALERT_2_G Hirshfeld Test Diff for    F9     --  C8      ..        5.4 s.u.
PLAT242_ALERT_2_G Low    'MainMol' Ueq as Compared to Neighbors of         C8 Check
PLAT242_ALERT_2_G Low    'MainMol' Ueq as Compared to Neighbors of         C9 Check
PLAT300_ALERT_4_G Atom Site Occupancy of >F9     is Constrained at       0.55 Check
PLAT300_ALERT_4_G Atom Site Occupancy of >F10    is Constrained at       0.55 Check
PLAT300_ALERT_4_G Atom Site Occupancy of >F11    is Constrained at       0.55 Check
PLAT300_ALERT_4_G Atom Site Occupancy of >F12    is Constrained at       0.55 Check
PLAT300_ALERT_4_G Atom Site Occupancy of >F13    is Constrained at       0.55 Check
PLAT300_ALERT_4_G Atom Site Occupancy of <F9A    is Constrained at       0.45 Check
PLAT300_ALERT_4_G Atom Site Occupancy of <F10A   is Constrained at       0.45 Check
PLAT300_ALERT_4_G Atom Site Occupancy of <F11A   is Constrained at       0.45 Check
PLAT300_ALERT_4_G Atom Site Occupancy of <F12A   is Constrained at       0.45 Check
PLAT300_ALERT_4_G Atom Site Occupancy of <F13A   is Constrained at       0.45 Check
PLAT301_ALERT_3_G Main Residue  Disorder ..............(Resd  1)..         20 % Note
PLAT367_ALERT_2_G Long?   C(sp?)-C(sp?) Bond  C7     -   C8     ..       1.54 Ang.
PLAT367_ALERT_2_G Long?   C(sp?)-C(sp?) Bond  C8     -   C9     ..       1.53 Ang.
PLAT434_ALERT_2_G Short Inter HL..HL Contact F1     ..  F10     ..       2.84 Ang.
PLAT434_ALERT_2_G Short Inter HL..HL Contact F5     ..  F10A    ..       2.72 Ang.
PLAT909_ALERT_3_G Percentage of Observed Data at Theta(Max) Still          76 % Note
PLAT910_ALERT_3_G Missing # of FCF Reflection(s) Below Theta(Min)           2 Note
PLAT978_ALERT_2_G Number C-C Bonds with Positive Residual Density.          5 Note

   0 ALERT level A = Most likely a serious problem - resolve or explain
   1 ALERT level B = A potentially serious problem, consider carefully
   6 ALERT level C = Check. Ensure it is not caused by an omission or oversight
  22 ALERT level G = General information/check it is not something unexpected

   0 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
  14 ALERT type 2 Indicator that the structure model may be wrong or deficient
   4 ALERT type 3 Indicator that the structure quality may be low
  11 ALERT type 4 Improvement, methodology, query or suggestion
   0 ALERT type 5 Informative message, check


checkCIF publication errors

Alert level A
PUBL024_ALERT_1_A The number of authors is greater than 5.
              Please specify the role of each of the co-authors
              for your paper.

   1 ALERT level A = Data missing that is essential or data in wrong format
   0 ALERT level G = General alerts. Data that may be required is missing

---

Computing details

Data collection: APEX2 (Bruker, 2012); cell refinement: SAINT (Bruker, 2012); data reduction: SAINT (Bruker, 2012); program(s) used to solve structure: XT in SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXL2014 (Sheldrick, 2015); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012); software used to prepare material for publication: Mercury (Macrae et al., 2008).

2,5-Bis[(3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluorooctyl)sulfanyl]-1,3,4-thiadiazole

Crystal data

C18H8F26N2S3	F(000) = 1648
Mr = 842.44	Dx = 2.009 Mg m^−3
Monoclinic, C2/c	Mo Kα radiation, λ = 0.71073 Å
a = 41.014 (11) Å	Cell parameters from 9946 reflections
b = 5.7338 (15) Å	θ = 3.0–25.3°
c = 11.880 (3) Å	µ = 0.46 mm^−1
β = 94.442 (8)°	T = 176 K
V = 2785.4 (13) Å^3	Prism, colourless
Z = 4	0.16 × 0.12 × 0.05 mm

Data collection

Bruker D8 QUEST PHOTON 100 diffractometer	2448 independent reflections
Radiation source: Incoatec Microfocus	2213 reflections with I > 2σ(I)
Multi layered optics monochromator	Rint = 0.045
Detector resolution: 10.4 pixels mm^-1	θmax = 25.0°, θmin = 3.0°
φ and ω scans	h = −48→48
Absorption correction: multi-scan (SADABS; Bruker, 2012)	k = −6→6
Tmin = 0.844, Tmax = 0.914	l = −14→13
26073 measured reflections

Refinement

Refinement on F^2	Hydrogen site location: inferred from neighbouring sites
Least-squares matrix: full	H-atom parameters constrained
R[F^2 > 2σ(F^2)] = 0.037	w = 1/[σ^2(Fo^2) + (0.0443P)^2 + 5.7325P] where P = (Fo^2 + 2Fc^2)/3
wR(F^2) = 0.099	(Δ/σ)max = 0.002
S = 1.10	Δρmax = 0.45 e Å^−3
2448 reflections	Δρmin = −0.25 e Å^−3
268 parameters	Extinction correction: SHELXL2014 (Sheldrick, 2015), Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
0 restraints	Extinction coefficient: 0.0025 (3)

Special details

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

Refinement. Positional disorder around ratio 1:1 of fluorine atoms at the end of the C8F13-unit (F9-F13:F9A-F13A).

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

	x	y	z	Uiso*/Ueq	Occ. (<1)
S1	0.5000	1.00393 (13)	0.7500	0.0257 (2)
S2	0.53603 (2)	0.85182 (11)	0.55112 (5)	0.0335 (2)
N1	0.50855 (5)	0.5709 (3)	0.70144 (15)	0.0275 (4)
C1	0.51458 (5)	0.7812 (4)	0.66790 (17)	0.0230 (5)
C2	0.55301 (5)	0.5683 (4)	0.52066 (19)	0.0283 (5)
H2A	0.5636	0.4978	0.5903	0.034*
H2B	0.5356	0.4619	0.4894	0.034*
C3	0.57815 (6)	0.6099 (4)	0.4343 (2)	0.0321 (5)
H3A	0.5670	0.6765	0.3646	0.039*
H3B	0.5945	0.7248	0.4650	0.039*
C4	0.59534 (5)	0.3881 (4)	0.40543 (18)	0.0253 (5)
C5	0.62393 (5)	0.4299 (4)	0.33031 (19)	0.0269 (5)
C6	0.63965 (5)	0.2116 (4)	0.28023 (19)	0.0285 (5)
C7	0.67203 (6)	0.2533 (4)	0.2252 (2)	0.0324 (5)
C8	0.68717 (6)	0.0386 (5)	0.1714 (2)	0.0426 (7)
C9	0.71765 (7)	0.0801 (7)	0.1079 (3)	0.0549 (8)
F1	0.60748 (4)	0.2780 (3)	0.50030 (12)	0.0435 (4)
F2	0.57418 (3)	0.2354 (3)	0.35119 (14)	0.0485 (4)
F3	0.64731 (3)	0.5471 (3)	0.39435 (14)	0.0452 (4)
F4	0.61347 (4)	0.5721 (3)	0.24509 (13)	0.0509 (5)
F5	0.64402 (4)	0.0478 (3)	0.35936 (13)	0.0468 (4)
F6	0.61772 (3)	0.1280 (3)	0.19835 (14)	0.0530 (5)
F7	0.69446 (4)	0.3290 (3)	0.30676 (16)	0.0614 (5)
F8	0.66726 (4)	0.4198 (3)	0.14744 (16)	0.0605 (5)
F9	0.6973 (3)	−0.1100 (18)	0.2579 (8)	0.065 (3)	0.55
F10	0.6653 (2)	−0.0771 (12)	0.1052 (10)	0.0508 (16)	0.55
F11	0.7399 (4)	0.197 (3)	0.1638 (13)	0.100 (5)	0.55
F12	0.70735 (19)	0.1862 (16)	0.0105 (6)	0.0701 (19)	0.55
F13	0.7295 (3)	−0.140 (2)	0.0725 (10)	0.064 (2)	0.55
F9A	0.6907 (3)	−0.1311 (19)	0.2408 (11)	0.073 (4)	0.45
F10A	0.6647 (4)	−0.011 (2)	0.0816 (14)	0.118 (6)	0.45
F11A	0.7417 (5)	0.128 (4)	0.1932 (19)	0.103 (7)	0.45
F12A	0.7178 (3)	0.267 (2)	0.0470 (10)	0.123 (5)	0.45
F13A	0.7288 (4)	−0.072 (3)	0.0679 (16)	0.099 (5)	0.45

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
S1	0.0308 (4)	0.0205 (4)	0.0274 (4)	0.000	0.0116 (3)	0.000
S2	0.0405 (4)	0.0308 (3)	0.0316 (3)	0.0128 (3)	0.0189 (3)	0.0087 (2)
N1	0.0332 (10)	0.0249 (10)	0.0254 (9)	0.0026 (8)	0.0083 (8)	−0.0001 (8)
C1	0.0228 (10)	0.0251 (11)	0.0215 (11)	0.0042 (9)	0.0036 (8)	0.0003 (9)
C2	0.0244 (11)	0.0299 (12)	0.0313 (12)	0.0049 (9)	0.0065 (9)	−0.0025 (10)
C3	0.0338 (12)	0.0332 (13)	0.0308 (12)	0.0104 (10)	0.0112 (10)	0.0036 (10)
C4	0.0232 (11)	0.0289 (12)	0.0235 (11)	0.0013 (9)	0.0008 (9)	0.0005 (9)
C5	0.0263 (11)	0.0274 (12)	0.0273 (11)	0.0041 (9)	0.0037 (9)	0.0026 (10)
C6	0.0284 (12)	0.0280 (12)	0.0298 (12)	0.0004 (10)	0.0060 (9)	−0.0009 (10)
C7	0.0269 (12)	0.0351 (13)	0.0361 (13)	0.0011 (10)	0.0084 (10)	−0.0009 (11)
C8	0.0363 (14)	0.0461 (17)	0.0465 (16)	0.0037 (12)	0.0115 (12)	−0.0092 (14)
C9	0.0382 (17)	0.065 (2)	0.064 (2)	0.0098 (16)	0.0215 (15)	−0.0073 (19)
F1	0.0452 (8)	0.0535 (9)	0.0337 (8)	0.0231 (7)	0.0148 (6)	0.0159 (7)
F2	0.0269 (7)	0.0560 (10)	0.0642 (10)	−0.0092 (7)	0.0126 (7)	−0.0264 (8)
F3	0.0337 (8)	0.0439 (9)	0.0597 (10)	−0.0106 (7)	0.0146 (7)	−0.0245 (8)
F4	0.0621 (10)	0.0533 (10)	0.0404 (9)	0.0282 (8)	0.0241 (7)	0.0215 (8)
F5	0.0585 (10)	0.0325 (8)	0.0531 (9)	0.0164 (7)	0.0279 (8)	0.0139 (7)
F6	0.0294 (8)	0.0730 (12)	0.0569 (10)	−0.0064 (7)	0.0040 (7)	−0.0358 (9)
F7	0.0266 (8)	0.0831 (13)	0.0747 (12)	−0.0072 (8)	0.0049 (8)	−0.0444 (10)
F8	0.0641 (11)	0.0496 (10)	0.0729 (12)	0.0147 (9)	0.0373 (9)	0.0276 (9)
F9	0.067 (4)	0.079 (7)	0.051 (3)	0.046 (4)	0.016 (3)	0.027 (3)
F10	0.034 (3)	0.047 (2)	0.072 (5)	−0.0019 (16)	0.008 (3)	−0.036 (2)
F11	0.041 (5)	0.152 (13)	0.111 (6)	−0.041 (7)	0.037 (4)	−0.076 (9)
F12	0.062 (4)	0.106 (5)	0.047 (2)	0.013 (3)	0.031 (2)	0.016 (3)
F13	0.053 (3)	0.058 (6)	0.083 (4)	0.021 (3)	0.028 (3)	−0.031 (3)
F9A	0.081 (7)	0.023 (3)	0.123 (9)	0.004 (4)	0.064 (6)	−0.009 (4)
F10A	0.062 (5)	0.202 (14)	0.086 (8)	0.017 (8)	−0.012 (4)	−0.092 (10)
F11A	0.033 (4)	0.102 (8)	0.177 (16)	0.005 (5)	0.025 (7)	−0.046 (8)
F12A	0.092 (8)	0.124 (9)	0.166 (13)	0.042 (6)	0.098 (8)	0.070 (8)
F13A	0.102 (6)	0.068 (9)	0.138 (8)	0.033 (5)	0.078 (6)	−0.027 (6)

Geometric parameters (Å, º)

S1—C1^i	1.741 (2)	C6—F5	1.331 (3)
S1—C1	1.741 (2)	C6—F6	1.360 (3)
S2—C1	1.747 (2)	C6—C7	1.544 (3)
S2—C2	1.816 (2)	C7—F8	1.332 (3)
N1—C1	1.300 (3)	C7—F7	1.355 (3)
N1—N1^i	1.396 (4)	C7—C8	1.540 (4)
C2—C3	1.529 (3)	C8—F9A	1.277 (12)
C2—H2A	0.9900	C8—F10	1.325 (11)
C2—H2B	0.9900	C8—F9	1.374 (9)
C3—C4	1.506 (3)	C8—F10A	1.383 (16)
C3—H3A	0.9900	C8—C9	1.528 (4)
C3—H3B	0.9900	C9—F13A	1.108 (15)
C4—F1	1.353 (3)	C9—F11	1.275 (15)
C4—F2	1.360 (3)	C9—F12A	1.293 (12)
C4—C5	1.546 (3)	C9—F12	1.347 (10)
C5—F4	1.344 (3)	C9—F11A	1.38 (2)
C5—F3	1.355 (3)	C9—F13	1.429 (11)
C5—C6	1.548 (3)
C1^i—S1—C1	85.62 (15)	F5—C6—C5	109.65 (18)
C1—S2—C2	100.09 (10)	F6—C6—C5	106.74 (18)
C1—N1—N1^i	111.92 (12)	C7—C6—C5	115.8 (2)
N1—C1—S1	115.27 (16)	F8—C7—F7	108.8 (2)
N1—C1—S2	125.32 (16)	F8—C7—C8	109.1 (2)
S1—C1—S2	119.41 (13)	F7—C7—C8	106.24 (19)
C3—C2—S2	106.43 (16)	F8—C7—C6	108.65 (19)
C3—C2—H2A	110.4	F7—C7—C6	107.77 (19)
S2—C2—H2A	110.4	C8—C7—C6	116.1 (2)
C3—C2—H2B	110.4	F10—C8—F9	106.6 (7)
S2—C2—H2B	110.4	F9A—C8—F10A	112.2 (9)
H2A—C2—H2B	108.6	F9A—C8—C9	112.5 (7)
C4—C3—C2	111.9 (2)	F10—C8—C9	109.2 (5)
C4—C3—H3A	109.2	F9—C8—C9	104.7 (6)
C2—C3—H3A	109.2	F10A—C8—C9	99.9 (7)
C4—C3—H3B	109.2	F9A—C8—C7	111.7 (6)
C2—C3—H3B	109.2	F10—C8—C7	111.7 (4)
H3A—C3—H3B	107.9	F9—C8—C7	107.1 (5)
F1—C4—F2	105.92 (19)	F10A—C8—C7	102.6 (6)
F1—C4—C3	110.69 (18)	C9—C8—C7	116.9 (3)
F2—C4—C3	111.02 (18)	F13A—C9—F12A	113.0 (12)
F1—C4—C5	107.84 (17)	F11—C9—F12	112.0 (10)
F2—C4—C5	108.12 (18)	F13A—C9—F11A	100.2 (12)
C3—C4—C5	112.95 (19)	F12A—C9—F11A	102.2 (11)
F4—C5—F3	107.01 (19)	F11—C9—F13	111.9 (8)
F4—C5—C4	108.44 (17)	F12—C9—F13	103.7 (6)
F3—C5—C4	106.73 (17)	F13A—C9—C8	118.0 (10)
F4—C5—C6	108.62 (18)	F11—C9—C8	113.8 (7)
F3—C5—C6	108.63 (17)	F12A—C9—C8	116.4 (5)
C4—C5—C6	116.98 (19)	F12—C9—C8	106.3 (4)
F5—C6—F6	107.6 (2)	F11A—C9—C8	103.5 (10)
F5—C6—C7	109.59 (19)	F13—C9—C8	108.5 (6)
F6—C6—C7	107.13 (19)

Symmetry code: (i) −x+1, y, −z+3/2.