2,3,4,5-Tetrakis­[(2-hydroxy­ethyl)­thio]­tetra­thia­fulvalene tetra­fluoro­borate

The title complex, C₁₄H₂₀O₄S₈^+.BF₄^-, is a charge-transfer complex with typical charges for the donor and anion of +1 and -1, respectively. Two centrosymmetrically related donors form a face-to-face [pi]-dimer with a strong intermolecular S...S interaction. These [pi]-dimers stack along the a axis to form a donor column. The structure is extensively hydrogen bonded.

S1. Comment

The structures of many charge-transfer complexes with the donor containing a tetrathiafulvalene (TTF) unit have been reported (Endres, 1981; Bechgarrd et al., 1997; Katayama et al., 1985; Endres, 1987). Studies of the relationship between physical properties and structure have shown the co-existence of high electric conductivity and non-covalent interactions in complexes, such as hydrogen bonds and enhanced van der Waals forces. We have prepared a new charge-transfer complex, (I), with the possibility of hydrogen bonding between donor and acceptor components. The title complex is a charge-transfer complex with one donor and one BF₄^- anion in the asymmetric unit. In the donor, bond distances and angles at S are dependent on the hybridization state of the C atoms to which S is bonded, so S—Csp³ is longer that S—Csp² and angles are wider in the case of an sp²-hydridized C atom. The S—Csp³ bond distance is longer than reported values on derivatives of TTF and S—Csp² bond distances are similar (Saitoh et al., 1995; Katayama et al., 1985; Brunn et al., 1987; Endres, 1981). C═C bond distances in the TTF core are in the same range as in TTF⁺ cores. C—C bond distances in the 2-hydroxyethyl groups are similar to C—C bond distances in the ethyl group in BEDT–TTF (Saitoh et al., 1995). C—O bond distances range from 1.385 (6) to 1.433 (7) Å. With the exception of the four 2-hydroxyethyl groups, all the atoms in the donor are close to coplanar with a deviation of 0.20 Å, owing to a charge-transfer interaction between donor and anion. All four 2-hydroxyethyl groups depart from this plane in the same direction and form a U-type structure not reported previously (Batsanov et al., 1995).

Parallel pairs of donors related by a centre of symmetry lie face-to-face and form an X-type donor dimer with a strong π–π interaction. Donor dimers stack along the a axis to form a donor column. The intermolecular S···S contacts in the π-dimer are significantly shorter than the sum of van der Waals radii, 3.7 Å, but no strong intermolecular contacts exist between dimers in a column. The anion is tetrahedral with bond distances and angles similar to reported values (Hursthouse et al., 1995; Saitoh et al., 1995). Owing to the –OH group in the donor and strongly electronegative element in the anion, a lot of hydrogen bonds of types O—H···F and O—H···O exist in the title complex. This phase is an insulator at room temperature, corresponding to the theory of Pierles distortion in low-dimensional conductors. Experiments on physical properties are in progress.

S2. Experimental

Crystals were obtained by electrocrystallization of 10 mg 2,3,4,5-tetrakis[(2-hydroxyethyl)thio]tetrathiafulvalene dissolved in 50 ml 1,1,2-trichloromethane with 4.96 mg KBF₄ and 7.1 mg dibenzo-18-crown-6 in an H-shaped tube. A constant current of 1.0 µA was applied to the supernatant using platinum electrodes for two weeks.

Computing details

Data collection: DENZO and SCALEPACK (Otwinowski & Minor, 1997); cell refinement: DENZO and SCALEPACK; data reduction: DENZO and SCALEPACK; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); software used to prepare material for publication: SHELXL97.

4,5-bis[(2-hydroxyethyl)thio]-2-{4,5-bis[(2-hydroxyethyl)thio]-1,3-dithiol-2- ylidene}-1,3-dithiole

Crystal data

C14H20O4S8^+·BF4^−	Z = 2
Mr = 595.59	F(000) = 610
Triclinic, P1	Dx = 1.671 Mg m^−3
a = 9.7070 (5) Å	Mo Kα radiation, λ = 0.71073 Å
b = 11.5750 (6) Å	Cell parameters from 3980 reflections
c = 11.5920 (7) Å	θ = 0.9–25.4°
α = 71.333 (3)°	µ = 0.81 mm^−1
β = 85.678 (4)°	T = 293 K
γ = 73.601 (3)°	Block, dark green
V = 1183.58 (11) Å^3	0.25 × 0.15 × 0.10 mm

Data collection

MacScience DIP 2030K image-plate system diffractometer	3623 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.000
Graphite monochromator	θmax = 25.4°, θmin = 2.5°
Detector resolution: 0.84 pixels mm^-1	h = −11→0
ω scans	k = −13→13
3980 measured reflections	l = −13→13
3980 independent 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)] = 0.055	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.149	H-atom parameters constrained
S = 1.08	w = 1/[σ^2(Fo^2) + (0.0676P)^2 + 1.9465P] where P = (Fo^2 + 2Fc^2)/3
3980 reflections	(Δ/σ)max = 0.001
284 parameters	Δρmax = 0.80 e Å^−3
21 restraints	Δρmin = −0.47 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
S1	0.31412 (11)	0.71973 (9)	0.86598 (8)	0.0440 (2)
S2	0.51616 (10)	0.53811 (9)	0.76734 (8)	0.0433 (2)
S3	0.19900 (11)	0.49342 (9)	1.05265 (9)	0.0463 (3)
S4	0.40813 (11)	0.30952 (9)	0.96116 (8)	0.0450 (2)
S5	0.37452 (13)	0.94793 (9)	0.68362 (9)	0.0529 (3)
S6	0.61704 (13)	0.73837 (11)	0.57268 (9)	0.0550 (3)
S7	0.06311 (12)	0.29691 (10)	1.21829 (9)	0.0531 (3)
S8	0.31853 (13)	0.08637 (10)	1.13017 (9)	0.0551 (3)
F1	0.8136 (7)	0.3574 (4)	0.6852 (5)	0.171 (2)
F2	0.8134 (5)	0.2442 (4)	0.8731 (3)	0.1185 (14)
F3	0.8909 (4)	0.1478 (4)	0.7339 (4)	0.1159 (14)
F4	0.6640 (4)	0.2395 (5)	0.7453 (6)	0.172 (2)
O1	0.2341 (7)	0.8653 (4)	0.4824 (4)	0.1145 (18)
H1	0.2185	0.8634	0.4145	0.172*
O2	0.7894 (4)	0.7111 (4)	0.3641 (3)	0.0765 (10)
H2	0.8166	0.7417	0.2952	0.115*
O3	−0.1941 (4)	0.3611 (4)	1.3698 (3)	0.0819 (11)
H3	−0.2005	0.2928	1.4168	0.123*
O4	0.1144 (4)	0.2241 (4)	0.8847 (3)	0.0767 (10)
H4	0.0274	0.2520	0.8723	0.115*
B1	0.7951 (5)	0.2473 (4)	0.7570 (4)	0.0591 (12)
C1	0.3818 (4)	0.5646 (3)	0.8699 (3)	0.0404 (8)
C2	0.3337 (4)	0.4655 (3)	0.9513 (3)	0.0400 (8)
C3	0.4056 (4)	0.7827 (3)	0.7373 (3)	0.0414 (8)
C4	0.5021 (4)	0.6984 (3)	0.6914 (3)	0.0399 (8)
C5	0.1955 (4)	0.3362 (3)	1.1154 (3)	0.0411 (8)
C6	0.2942 (4)	0.2501 (3)	1.0732 (3)	0.0427 (8)
C7	0.2022 (5)	0.9987 (4)	0.6063 (4)	0.0640 (12)
H7A	0.1565	1.0845	0.6042	0.080*
H7B	0.1425	0.9471	0.6536	0.080*
C8	0.2087 (7)	0.9902 (5)	0.4798 (5)	0.0791 (16)
H8A	0.1200	1.0398	0.4379	0.080*
H8B	0.2846	1.0241	0.4365	0.080*
C9	0.6041 (5)	0.6376 (4)	0.4832 (4)	0.0547 (10)
H9A	0.5070	0.6327	0.4829	0.080*
H9B	0.6651	0.5536	0.5173	0.080*
C10	0.6517 (6)	0.6946 (5)	0.3574 (4)	0.0664 (12)
H10A	0.6548	0.6410	0.3083	0.080*
H10B	0.5852	0.7753	0.3208	0.080*
C11	0.0099 (5)	0.4286 (4)	1.2806 (4)	0.0551 (10)
H11A	−0.0526	0.5009	1.2249	0.080*
H11B	0.0930	0.4515	1.2949	0.080*
C12	−0.0675 (5)	0.3859 (5)	1.3979 (4)	0.0608 (11)
H12A	−0.0065	0.3109	1.4518	0.080*
H12B	−0.0927	0.4506	1.4371	0.080*
C13	0.2945 (7)	0.0442 (5)	0.9961 (5)	0.0771 (14)
H13A	0.3250	−0.0464	1.0165	0.080*
H13B	0.3572	0.0774	0.9336	0.080*
C14	0.1493 (7)	0.0900 (5)	0.9450 (6)	0.0829 (16)
H14A	0.1430	0.0474	0.8877	0.080*
H14B	0.0821	0.0708	1.0094	0.080*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
S1	0.0496 (5)	0.0433 (5)	0.0387 (5)	−0.0155 (4)	0.0064 (4)	−0.0111 (4)
S2	0.0482 (5)	0.0418 (5)	0.0394 (5)	−0.0159 (4)	0.0062 (4)	−0.0101 (4)
S3	0.0515 (6)	0.0409 (5)	0.0445 (5)	−0.0176 (5)	0.0094 (4)	−0.0083 (4)
S4	0.0551 (6)	0.0443 (5)	0.0377 (5)	−0.0184 (5)	0.0044 (4)	−0.0123 (4)
S5	0.0678 (7)	0.0407 (5)	0.0525 (6)	−0.0224 (5)	−0.0057 (5)	−0.0096 (4)
S6	0.0688 (7)	0.0634 (7)	0.0463 (5)	−0.0399 (6)	0.0189 (5)	−0.0204 (5)
S7	0.0606 (6)	0.0530 (6)	0.0503 (6)	−0.0298 (5)	0.0140 (5)	−0.0129 (4)
S8	0.0755 (8)	0.0412 (5)	0.0462 (5)	−0.0202 (5)	−0.0053 (5)	−0.0051 (4)
F1	0.223 (6)	0.096 (3)	0.163 (5)	−0.045 (4)	0.093 (4)	−0.016 (3)
F2	0.139 (4)	0.140 (3)	0.088 (2)	−0.025 (3)	0.007 (2)	−0.065 (2)
F3	0.117 (3)	0.109 (3)	0.123 (3)	0.019 (2)	−0.019 (2)	−0.076 (2)
F4	0.085 (3)	0.187 (5)	0.280 (7)	−0.024 (3)	−0.042 (4)	−0.124 (5)
O1	0.208 (6)	0.084 (3)	0.071 (3)	−0.068 (3)	−0.030 (3)	−0.018 (2)
O2	0.080 (2)	0.099 (3)	0.064 (2)	−0.046 (2)	0.0266 (18)	−0.0294 (19)
O3	0.063 (2)	0.111 (3)	0.071 (2)	−0.044 (2)	0.0024 (17)	−0.011 (2)
O4	0.070 (2)	0.088 (3)	0.074 (2)	−0.032 (2)	−0.0093 (18)	−0.0163 (19)
B1	0.064 (3)	0.054 (3)	0.063 (3)	−0.013 (3)	0.006 (2)	−0.027 (2)
C1	0.046 (2)	0.0441 (19)	0.0321 (17)	−0.0187 (17)	0.0020 (14)	−0.0083 (14)
C2	0.047 (2)	0.0424 (19)	0.0308 (16)	−0.0186 (17)	0.0018 (14)	−0.0071 (14)
C3	0.049 (2)	0.0419 (19)	0.0350 (17)	−0.0205 (17)	0.0006 (15)	−0.0066 (14)
C4	0.046 (2)	0.0424 (19)	0.0343 (17)	−0.0211 (17)	0.0026 (14)	−0.0084 (14)
C5	0.050 (2)	0.0427 (19)	0.0323 (17)	−0.0225 (17)	−0.0003 (14)	−0.0047 (14)
C6	0.052 (2)	0.0411 (19)	0.0368 (18)	−0.0202 (18)	−0.0002 (15)	−0.0080 (15)
C7	0.065 (3)	0.048 (2)	0.069 (3)	−0.008 (2)	−0.013 (2)	−0.008 (2)
C8	0.110 (5)	0.064 (3)	0.061 (3)	−0.037 (3)	−0.025 (3)	0.002 (2)
C9	0.062 (3)	0.063 (3)	0.049 (2)	−0.028 (2)	0.0101 (19)	−0.0232 (19)
C10	0.077 (3)	0.088 (3)	0.047 (2)	−0.036 (3)	0.009 (2)	−0.027 (2)
C11	0.054 (2)	0.051 (2)	0.060 (2)	−0.020 (2)	0.0089 (19)	−0.0139 (19)
C12	0.055 (3)	0.071 (3)	0.058 (3)	−0.022 (2)	0.009 (2)	−0.020 (2)
C13	0.097 (4)	0.060 (3)	0.081 (3)	−0.025 (3)	0.008 (3)	−0.028 (3)
C14	0.093 (4)	0.075 (3)	0.091 (4)	−0.039 (3)	−0.017 (3)	−0.022 (3)

Geometric parameters (Å, º)

S1—C1	1.715 (4)	O4—H4	0.8200
S1—C3	1.736 (4)	C1—C2	1.403 (5)
S2—C1	1.727 (4)	C3—C4	1.361 (5)
S2—C4	1.751 (4)	C5—C6	1.361 (6)
S3—C2	1.722 (4)	C7—C8	1.497 (7)
S3—C5	1.740 (4)	C7—H7A	0.9599
S4—C2	1.715 (4)	C7—H7B	0.9639
S4—C6	1.738 (4)	C8—H8A	0.9549
S5—C3	1.754 (4)	C8—H8B	0.9645
S5—C7	1.811 (5)	C9—C10	1.494 (6)
S6—C4	1.734 (3)	C9—H9A	0.9600
S6—C9	1.825 (4)	C9—H9B	0.9572
S7—C5	1.742 (4)	C10—H10A	0.9602
S7—C11	1.821 (4)	C10—H10B	0.9567
S8—C6	1.748 (4)	C11—C12	1.511 (6)
S8—C13	1.820 (5)	C11—H11A	0.9552
F1—B1	1.333 (5)	C11—H11B	0.9584
F2—B1	1.358 (5)	C12—H12A	0.9555
F3—B1	1.349 (5)	C12—H12B	0.9613
F4—B1	1.321 (5)	C13—C14	1.456 (8)
O1—C8	1.387 (6)	C13—H13A	0.9592
O1—H1	0.8200	C13—H13B	0.9654
O2—C10	1.414 (6)	C14—H14A	0.9595
O2—H2	0.8200	C14—H14B	0.9659
O3—C12	1.421 (5)	S4—S1^i	3.356 (1)
O3—H3	0.8200	S3—S2^i	3.456 (1)
O4—C14	1.434 (6)
C1—S1—C3	95.98 (17)	O1—C8—C7	110.7 (4)
C1—S2—C4	95.67 (17)	O1—C8—H8A	109.7
C2—S3—C5	95.67 (18)	C7—C8—H8A	109.4
C2—S4—C6	95.78 (17)	O1—C8—H8B	109.5
C3—S5—C7	102.11 (19)	C7—C8—H8B	109.3
C4—S6—C9	101.87 (18)	H8A—C8—H8B	108.3
C5—S7—C11	102.88 (18)	C10—C9—S6	107.3 (3)
C6—S8—C13	103.4 (2)	C10—C9—H9A	111.3
C8—O1—H1	109.5	S6—C9—H9A	109.8
C10—O2—H2	109.5	C10—C9—H9B	109.4
C12—O3—H3	109.5	S6—C9—H9B	110.6
C14—O4—H4	109.5	H9A—C9—H9B	108.4
F4—B1—F1	111.5 (5)	O2—C10—C9	109.0 (4)
F4—B1—F3	109.0 (4)	O2—C10—H10A	109.9
F1—B1—F3	111.7 (4)	C9—C10—H10A	110.6
F4—B1—F2	108.4 (4)	O2—C10—H10B	109.4
F1—B1—F2	106.2 (4)	C9—C10—H10B	109.1
F3—B1—F2	109.9 (4)	H10A—C10—H10B	108.8
C2—C1—S1	122.8 (3)	C12—C11—S7	107.4 (3)
C2—C1—S2	122.0 (3)	C12—C11—H11A	109.8
S1—C1—S2	115.18 (19)	S7—C11—H11A	110.5
C1—C2—S4	122.9 (3)	C12—C11—H11B	111.0
C1—C2—S3	121.5 (3)	S7—C11—H11B	109.9
S4—C2—S3	115.59 (19)	H11A—C11—H11B	108.3
C4—C3—S1	116.7 (3)	O3—C12—C11	108.3 (4)
C4—C3—S5	125.7 (3)	O3—C12—H12A	110.2
S1—C3—S5	117.5 (2)	C11—C12—H12A	109.6
C3—C4—S6	124.9 (3)	O3—C12—H12B	109.7
C3—C4—S2	115.9 (3)	C11—C12—H12B	110.5
S6—C4—S2	119.1 (2)	H12A—C12—H12B	108.6
C6—C5—S3	116.3 (3)	C14—C13—S8	115.8 (4)
C6—C5—S7	123.2 (3)	C14—C13—H13A	108.9
S3—C5—S7	120.3 (2)	S8—C13—H13A	108.3
C5—C6—S4	116.5 (3)	C14—C13—H13B	108.0
C5—C6—S8	124.2 (3)	S8—C13—H13B	108.3
S4—C6—S8	119.2 (2)	H13A—C13—H13B	107.3
C8—C7—S5	114.9 (4)	O4—C14—C13	110.3 (4)
C8—C7—H7A	109.4	O4—C14—H14A	109.5
S5—C7—H7A	108.4	C13—C14—H14A	109.2
C8—C7—H7B	108.0	O4—C14—H14B	110.1
S5—C7—H7B	108.6	C13—C14—H14B	109.5
H7A—C7—H7B	107.3	H14A—C14—H14B	108.4

Symmetry code: (i) −x+1, −y+1, −z+2.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O2—H2···O4^ii	0.82	2.09	2.891 (5)	166
O1—H1···F3^ii	0.82	2.15	2.930 (5)	143
O1—H1···F4^ii	0.82	2.55	3.224 (7)	153
O3—H3···O1^iii	0.82	1.93	2.748 (6)	174
O4—H4···F2^iv	0.82	2.10	2.875 (6)	157

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