2-Sulfanylidene-1,3-dithiolo[4,5-b]naphtho­[2,3-e][1,4]dithiine-5,10-dione

Méndez-Rojas, M.A.; Bernès, S.; Pérez-Benítez, A.; Romero Zarazúa, M.F.; Castellanos-Uribe, A.

doi:10.1107/S1600536811039079

organic compounds

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ISSN: 2056-9890

Volume 67| Part 11| November 2011| Page o2837

doi:10.1107/S1600536811039079

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2-Sulfanylidene-1,3-dithiolo[4,5-b]naphtho[2,3-e][1,4]dithiine-5,10-dione

Miguel Angel Méndez-Rojas,^a Sylvain Bernès,^b ^* Aarón Pérez-Benítez,^c María Fernanda Romero Zarazúa ^a and Adrián Castellanos-Uribe ^a

^aDepartamento de Ciencias Químico-Biológicas, Universidad de las Américas Puebla, ExHda. de Sta. Catarina Mártir, 72820 San Andrés Cholula, Pue., Mexico, ^bDEP Facultad de Ciencias Químicas, UANL, Guerrero y Progreso S/N, Col. Treviño, 64570 Monterrey, N.L., Mexico, and ^cFacultad de Ciencias Químicas, Benemérita Universidad Autónoma de Puebla, 14 Sur y av. San Claudio, Col. San Manuel, 72570 Puebla, Pue., Mexico
^*Correspondence e-mail: sylvain_bernes@hotmail.com

(Received 6 September 2011; accepted 23 September 2011; online 5 October 2011)

The title molecule, C₁₃H₄O₂S₅, is folded by 47.83 (6)° along the S⋯S vector of the [1,4]dithiine six-membered ring, with the naphthoquinone and [1,3]dithiole-2-thione moieties being nearly planar [largest deviations from least-squares planes = 0.028 (2) and 0.016 (1) Å, respectively]. This boat conformation is close to that observed in the analogous compound [Mendez-Rojas et al. (2001). J. Chem. Crystallogr. 31, 17–28] including a 2-oxo group [folding angle: 42.3 (1)° at 213 (2) K]. Both compounds are indeed isomorphous, and the small difference in the folding angle probably results from the involvement of the thioxo group of the title compound in intermolecular S⋯S contacts [3.5761 (13) Å]. In the crystal structure, molecules are stacked in the [100] direction, with dithiole rings making π–π interactions. In a stack, alternating short and long separations are observed between the centroids of dithiole rings, 3.5254 (17) and 4.7010 (18) Å.

Related literature

For general background to sulfur-containing heterocycles in organic conductors, see: Wudl (1984 ); Jérome (2007 ). For dithiine derivatives and their redox behavior, see: Hayakawa et al. (1982 ); Kao et al. (1985 ); Kniess & Mayer (1996 ); Brisse et al. (2000 ); Mendez-Rojas et al. (2001 ). For the synthesis of the precursor of the title dithiine, see: Wang et al. (1998 ).

Experimental

Crystal data

C₁₃H₄O₂S₅
M_r = 352.46
Triclinic, $[P \overline 1]$
a = 7.8527 (8) Å
b = 8.0281 (9) Å
c = 12.0022 (13) Å
α = 97.934 (9)°
β = 89.227 (9)°
γ = 117.867 (8)°
V = 661.37 (12) Å³
Z = 2
Mo Kα radiation
μ = 0.87 mm⁻¹
T = 296 K
0.48 × 0.12 × 0.08 mm

Data collection

Siemens P4 diffractometer
Absorption correction: ψ scan (XSCANS; Siemens, 1996 ) T_min = 0.679, T_max = 0.733
3881 measured reflections
2323 independent reflections
1748 reflections with I > 2σ(I)
R_int = 0.026
2 standard reflections every 48 reflections intensity decay: 2%

Refinement

R[F² > 2σ(F²)] = 0.035
wR(F²) = 0.090
S = 1.02
2323 reflections
181 parameters
H-atom parameters constrained
Δρ_max = 0.27 e Å⁻³
Δρ_min = −0.28 e Å⁻³

Data collection: XSCANS (Siemens, 1996); cell refinement: XSCANS; data reduction: XSCANS; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: Mercury (Macrae et al., 2006 ); software used to prepare material for publication: SHELXL97.

Supporting information

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536811039079/yk2021sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536811039079/yk2021Isup2.hkl

Supporting information file. DOI: 10.1107/S1600536811039079/yk2021Isup3.mol

Supporting information file. DOI: 10.1107/S1600536811039079/yk2021Isup4.cml

checkCIF report

Comment top

The development of new types of π-electron donors and acceptors with high polarizability continues to be an attractive topic in material sciences. Such compounds are not only interesting as candidates for single-component conductors, but also because they have low excitation energies and promising applications as NLO materials and near-IR absorbing dyes. Sulfur-based heterocycles are good candidates for building such materials, and donors like TTF and BEDT-TTF became emblematic systems in the 70's, after they allowed to synthesize molecular metals and superconductor materials (Wudl, 1984; Jérome, 2007).

The title compound belongs to the 1,4-dithiine derivatives, which have a particular conformational flexibility, because the energy barrier between the planar and boat conformations is very low (Hayakawa et al., 1982). Ab initio computations showed for example that for 1,4-dithiine, the C₂_v(boat) → D₂_h(planar) conformational interconversion requires less than 3 kcal/mol (see Table II and Fig. 4 in Kao et al., 1985). A fine tuning of the geometry and electron distribution may thus be expected by varying the substituents of this heterocycle. For example, electron withdrawing groups seem to stabilize the unfolded conformer (Brisse et al., 2000).

In contrast, the title molecule (Kniess & Mayer, 1996; Mendez-Rojas et al., 2001) adopts a folded conformation (Fig. 1). The dihedral angle between the essentially planar naphthoquinone ring (C4a/C5/C5a/C6···C9/C9a/C10/C10a; max. deviation: 0.028 Å for C4a) and the five membered 1,3-dithiole ring (S1/C2/S3/C3a/C11a; max. deviation: 0.016 Å for C2) is 47.83 (6)°. This boat conformation is favored by intramolecular S···O repulsion effects, characterized by non-bonding distances S11···O10 = 2.874 (2) and S4···O5 = 2.868 (2) Å. Heteroatoms are also involved in intermolecular contacts. Molecules form centrosymmetric dimers through S1···S2ⁱ contacts [3.5761 (13) Å; symmetry code (i): 1 - x, 3 - y, 1 - z] between the thioxo group and one S atom of the dithiole heterocycle. The contacts pattern is completed by bifurcated S1/S11···O5ⁱⁱ interactions [3.158 (2) and 3.159 (2) Å; symmetry code (ii): 1 + x, 1 + y, z], forming a two-dimensional network of contacts in the crystal (Fig. 2). This arrangement is compatible with a stacking structure for molecules, in the [100] direction: two dithiole rings related by inversion give a π···π interaction characterized by a centroid to centroid separation of 3.5254 (17) Å. However, as a consequence of the triclinic symmetry, the following stacked ring generated by inversion is found at a different distance, 4.7010 (18) Å. Short and long separations thus alternate along the stack (Fig. 2, inset), a common situation for one-dimensional materials affected by a Peierls distortion.

The title molecule is isomorphous with the 2-oxo analogue (Mendez-Rojas et al., 2001). However, it is interesting to note that both the molecular and the crystal structures present significantly different metrics for the 2-thioxo and the 2-oxo compounds. In the latter, the folding angle is 42.3 (1)°, and the separations in the dithiole stacks parallel to [100] are 3.566 and 4.345 Å. Despite of the clear dimerization along the stacks for both compounds, the title molecule seems to be more prone to Peierls instability, compared to its 2-oxo analogue.

Related literature top

For general background to sulfur-containing heterocycles in organic conductors, see: Wudl (1984); Jérome (2007). For dithiine derivatives and their redox behavior, see: Hayakawa et al. (1982); Kao et al. (1985); Kniess & Mayer (1996); Brisse et al. (2000); Mendez-Rojas et al. (2001). For the synthesis of the precursor of the title dithiine, see: Wang et al. (1998).

Experimental top

The precursor (NBu₄)₂[Zn(dmit)₂], where H₂dmit is 4,5-dimercapto-1,3-dithiole-2-thione, was prepared as previously reported (Wang et al., 1998). This complex (1.68 g, 2.20 mmol in 20 ml acetone) was reacted with 2,3-dichloro-1,4-naphthoquinone (1 g, 4.40 mmol) at room temperature, forming immediately a dark precipitate. The mixture was stirred overnight and the precipitate was then recovered by vacuum filtration (1.50 g, 99%) and recrystallized from CH₂Cl₂. Small black shiny needles suitable for X-ray diffraction were obtained after several days. M.p. 354–355 °C. IR (KBr, cm^-1) 1663 (vs), 1586 (m), 1553 (m), 1493 (m), 1385 (sm), 1275 (vs), 1134 (m), 1073 (vs), 794 (m), 706 (s), 635 (sm), 505 (sm); ¹H-NMR (CDCl₃, p.p.m.) δ, 7.80 (dd, 2H), 8.16 (dd, 2H). Anal. calcd. for C₁₃H₄O₂S₅: C 44.3%; found: C 42.9%.

Computing details top

Data collection: XSCANS (Siemens, 1996); cell refinement: XSCANS (Siemens, 1996); data reduction: XSCANS (Siemens, 1996); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: Mercury (Macrae et al., 2006); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).

Figures top

	Fig. 1. The structure of the title compound, with displacement ellipsoids for non-H atoms at the 30% probability level.
	Fig. 2. A partial view of the crystal structure for the title compound, with intermolecular S···S and S···O contacts showed as dashed lines. The inset is a view of the crystal normal to the b^* axis. Quoted distances are separations between the centroids of neighboring dithiole rings, stacked along the a axis.

2-Sulfanylidene-1,3-dithiolo[4,5-b]naphtho[2,3-e][1,4]dithiine- 5,10-dione top

Crystal data top

C₁₃H₄O₂S₅	Z = 2
M_r = 352.46	F(000) = 356
Triclinic, P1	D_x = 1.770 Mg m⁻³
Hall symbol: -P 1	Melting point: 627 K
a = 7.8527 (8) Å	Mo Kα radiation, λ = 0.71073 Å
b = 8.0281 (9) Å	Cell parameters from 68 reflections
c = 12.0022 (13) Å	θ = 4.8–12.3°
α = 97.934 (9)°	µ = 0.87 mm⁻¹
β = 89.227 (9)°	T = 296 K
γ = 117.867 (8)°	Needle, brown
V = 661.37 (12) Å³	0.48 × 0.12 × 0.08 mm

Data collection top

Siemens P4 diffractometer	1748 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	R_int = 0.026
Graphite monochromator	θ_max = 25.1°, θ_min = 2.9°
ω scans	h = −5→8
Absorption correction: ψ scan (XSCANS; Siemens, 1996)	k = −9→8
T_min = 0.679, T_max = 0.733	l = −14→14
3881 measured reflections	2 standard reflections every 48 reflections
2323 independent reflections	intensity decay: 2%

Refinement top

Refinement on F²	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F² > 2σ(F²)] = 0.035	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.090	H-atom parameters constrained
S = 1.02	w = 1/[σ²(F_o²) + (0.0433P)² + 0.1487P] where P = (F_o² + 2F_c²)/3
2323 reflections	(Δ/σ)_max < 0.001
181 parameters	Δρ_max = 0.27 e Å⁻³
0 restraints	Δρ_min = −0.28 e Å⁻³
0 constraints

Crystal data top

C₁₃H₄O₂S₅	γ = 117.867 (8)°
M_r = 352.46	V = 661.37 (12) Å³
Triclinic, P1	Z = 2
a = 7.8527 (8) Å	Mo Kα radiation
b = 8.0281 (9) Å	µ = 0.87 mm⁻¹
c = 12.0022 (13) Å	T = 296 K
α = 97.934 (9)°	0.48 × 0.12 × 0.08 mm
β = 89.227 (9)°

Data collection top

Siemens P4 diffractometer	1748 reflections with I > 2σ(I)
Absorption correction: ψ scan (XSCANS; Siemens, 1996)	R_int = 0.026
T_min = 0.679, T_max = 0.733	2 standard reflections every 48 reflections
3881 measured reflections	intensity decay: 2%
2323 independent reflections

Refinement top

R[F² > 2σ(F²)] = 0.035	0 restraints
wR(F²) = 0.090	H-atom parameters constrained
S = 1.02	Δρ_max = 0.27 e Å⁻³
2323 reflections	Δρ_min = −0.28 e Å⁻³
181 parameters

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å²) top

	x	y	z	U_iso*/U_eq
S1	0.44687 (11)	1.23625 (11)	0.59078 (6)	0.0435 (2)
C2	0.3040 (4)	1.1337 (4)	0.4656 (2)	0.0430 (7)
S2	0.30632 (14)	1.25421 (13)	0.36621 (8)	0.0631 (3)
S3	0.15541 (11)	0.88891 (11)	0.45820 (6)	0.0439 (2)
C3A	0.2361 (4)	0.8652 (4)	0.5872 (2)	0.0375 (7)
S4	0.12380 (12)	0.64220 (10)	0.63387 (6)	0.0463 (2)
C4A	0.1022 (4)	0.7202 (4)	0.7760 (2)	0.0369 (7)
C5	−0.0767 (4)	0.5886 (4)	0.8258 (2)	0.0383 (7)
O5	−0.1952 (3)	0.4454 (3)	0.76730 (18)	0.0604 (7)
C5A	−0.0991 (4)	0.6353 (4)	0.9471 (2)	0.0372 (7)
C6	−0.2599 (4)	0.5131 (4)	0.9978 (3)	0.0459 (8)
H6A	−0.3551	0.4037	0.9552	0.055*
C7	−0.2798 (4)	0.5531 (5)	1.1123 (3)	0.0525 (9)
H7A	−0.3879	0.4708	1.1464	0.063*
C8	−0.1369 (4)	0.7168 (5)	1.1754 (3)	0.0521 (9)
H8A	−0.1500	0.7437	1.2519	0.063*
C9	0.0245 (4)	0.8404 (5)	1.1260 (2)	0.0443 (7)
H9A	0.1192	0.9495	1.1692	0.053*
C9A	0.0449 (4)	0.8014 (4)	1.0116 (2)	0.0363 (7)
C10	0.2197 (4)	0.9333 (4)	0.9599 (2)	0.0364 (7)
O10	0.3465 (3)	1.0782 (3)	1.01299 (16)	0.0490 (6)
C10A	0.2389 (4)	0.8801 (4)	0.8376 (2)	0.0353 (6)
S11	0.45668 (10)	1.03981 (11)	0.78538 (6)	0.0444 (2)
C11A	0.3701 (4)	1.0256 (4)	0.6482 (2)	0.0376 (7)

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
S1	0.0400 (4)	0.0385 (4)	0.0406 (4)	0.0090 (3)	0.0052 (3)	0.0064 (3)
C2	0.0377 (16)	0.0456 (17)	0.0435 (16)	0.0176 (14)	0.0072 (13)	0.0073 (14)
S2	0.0727 (6)	0.0530 (5)	0.0559 (5)	0.0202 (5)	−0.0066 (4)	0.0183 (4)
S3	0.0421 (4)	0.0420 (4)	0.0388 (4)	0.0127 (3)	−0.0030 (3)	0.0046 (3)
C3A	0.0347 (15)	0.0379 (15)	0.0363 (15)	0.0146 (13)	0.0046 (12)	0.0039 (12)
S4	0.0571 (5)	0.0334 (4)	0.0363 (4)	0.0125 (4)	0.0006 (3)	0.0004 (3)
C4A	0.0337 (15)	0.0350 (15)	0.0354 (15)	0.0105 (13)	−0.0030 (12)	0.0054 (12)
C5	0.0325 (15)	0.0316 (15)	0.0408 (15)	0.0062 (13)	−0.0062 (12)	0.0061 (12)
O5	0.0494 (13)	0.0469 (13)	0.0490 (13)	−0.0065 (11)	−0.0059 (11)	0.0038 (11)
C5A	0.0288 (15)	0.0384 (15)	0.0416 (15)	0.0124 (12)	−0.0029 (12)	0.0092 (12)
C6	0.0318 (16)	0.0468 (18)	0.0549 (19)	0.0128 (14)	0.0009 (14)	0.0160 (14)
C7	0.0346 (17)	0.066 (2)	0.059 (2)	0.0211 (17)	0.0104 (15)	0.0259 (17)
C8	0.0460 (19)	0.075 (2)	0.0421 (17)	0.0331 (18)	0.0108 (15)	0.0153 (16)
C9	0.0414 (17)	0.0533 (19)	0.0381 (16)	0.0228 (15)	−0.0007 (13)	0.0037 (14)
C9A	0.0323 (15)	0.0418 (16)	0.0362 (15)	0.0179 (13)	−0.0013 (12)	0.0080 (12)
C10	0.0333 (15)	0.0379 (16)	0.0350 (15)	0.0144 (13)	−0.0056 (12)	0.0047 (12)
O10	0.0412 (12)	0.0455 (12)	0.0388 (11)	0.0047 (10)	−0.0066 (9)	−0.0021 (9)
C10A	0.0302 (15)	0.0337 (15)	0.0349 (14)	0.0089 (12)	−0.0003 (12)	0.0057 (12)
S11	0.0287 (4)	0.0493 (5)	0.0367 (4)	0.0032 (3)	−0.0019 (3)	0.0060 (3)
C11A	0.0327 (15)	0.0392 (16)	0.0349 (14)	0.0122 (13)	0.0048 (12)	0.0053 (12)

Geometric parameters (Å, º) top

S1—C2	1.742 (3)	C6—C7	1.392 (4)
S1—C11A	1.748 (3)	C6—H6A	0.9300
C2—S2	1.631 (3)	C7—C8	1.389 (5)
C2—S3	1.744 (3)	C7—H7A	0.9300
S3—C3A	1.747 (3)	C8—C9	1.381 (4)
C3A—C11A	1.340 (4)	C8—H8A	0.9300
C3A—S4	1.756 (3)	C9—C9A	1.389 (4)
S4—C4A	1.768 (3)	C9—H9A	0.9300
C4A—C10A	1.349 (4)	C9A—C10	1.480 (4)
C4A—C5	1.487 (4)	C10—O10	1.216 (3)
C5—O5	1.215 (3)	C10—C10A	1.497 (4)
C5—C5A	1.482 (4)	C10A—S11	1.762 (3)
C5A—C6	1.383 (4)	S11—C11A	1.758 (3)
C5A—C9A	1.409 (4)

C2—S1—C11A	96.73 (14)	C8—C7—H7A	120.3
S2—C2—S1	123.61 (18)	C6—C7—H7A	120.3
S2—C2—S3	123.38 (18)	C9—C8—C7	120.9 (3)
S1—C2—S3	113.00 (17)	C9—C8—H8A	119.5
C2—S3—C3A	96.94 (14)	C7—C8—H8A	119.5
C11A—C3A—S3	116.4 (2)	C8—C9—C9A	119.8 (3)
C11A—C3A—S4	124.4 (2)	C8—C9—H9A	120.1
S3—C3A—S4	118.94 (16)	C9A—C9—H9A	120.1
C3A—S4—C4A	98.37 (13)	C9—C9A—C5A	119.6 (3)
C10A—C4A—C5	121.6 (3)	C9—C9A—C10	119.4 (3)
C10A—C4A—S4	123.9 (2)	C5A—C9A—C10	121.0 (2)
C5—C4A—S4	114.4 (2)	O10—C10—C9A	122.8 (2)
O5—C5—C5A	122.6 (3)	O10—C10—C10A	120.0 (2)
O5—C5—C4A	119.4 (3)	C9A—C10—C10A	117.3 (2)
C5A—C5—C4A	118.0 (2)	C4A—C10A—C10	121.8 (2)
C6—C5A—C9A	119.9 (3)	C4A—C10A—S11	124.2 (2)
C6—C5A—C5	119.9 (3)	C10—C10A—S11	113.92 (19)
C9A—C5A—C5	120.3 (2)	C11A—S11—C10A	98.74 (13)
C5A—C6—C7	120.3 (3)	C3A—C11A—S1	116.9 (2)
C5A—C6—H6A	119.8	C3A—C11A—S11	124.3 (2)
C7—C6—H6A	119.8	S1—C11A—S11	118.53 (16)
C8—C7—C6	119.5 (3)

C11A—S1—C2—S2	−178.7 (2)	C5—C5A—C9A—C9	−178.1 (3)
C11A—S1—C2—S3	2.07 (19)	C6—C5A—C9A—C10	179.2 (3)
S2—C2—S3—C3A	178.6 (2)	C5—C5A—C9A—C10	0.8 (4)
S1—C2—S3—C3A	−2.19 (19)	C9—C9A—C10—O10	−1.4 (4)
C2—S3—C3A—C11A	1.5 (3)	C5A—C9A—C10—O10	179.7 (3)
C2—S3—C3A—S4	175.85 (18)	C9—C9A—C10—C10A	177.3 (3)
C11A—C3A—S4—C4A	38.1 (3)	C5A—C9A—C10—C10A	−1.6 (4)
S3—C3A—S4—C4A	−135.80 (18)	C5—C4A—C10A—C10	0.7 (4)
C3A—S4—C4A—C10A	−39.0 (3)	S4—C4A—C10A—C10	−175.8 (2)
C3A—S4—C4A—C5	144.2 (2)	C5—C4A—C10A—S11	178.5 (2)
C10A—C4A—C5—O5	−179.5 (3)	S4—C4A—C10A—S11	1.9 (4)
S4—C4A—C5—O5	−2.6 (4)	O10—C10—C10A—C4A	179.6 (3)
C10A—C4A—C5—C5A	−1.6 (4)	C9A—C10—C10A—C4A	0.9 (4)
S4—C4A—C5—C5A	175.3 (2)	O10—C10—C10A—S11	1.6 (4)
O5—C5—C5A—C6	0.2 (5)	C9A—C10—C10A—S11	−177.1 (2)
C4A—C5—C5A—C6	−177.6 (3)	C4A—C10A—S11—C11A	36.5 (3)
O5—C5—C5A—C9A	178.6 (3)	C10—C10A—S11—C11A	−145.6 (2)
C4A—C5—C5A—C9A	0.8 (4)	S3—C3A—C11A—S1	−0.3 (3)
C9A—C5A—C6—C7	−0.1 (5)	S4—C3A—C11A—S1	−174.26 (16)
C5—C5A—C6—C7	178.3 (3)	S3—C3A—C11A—S11	174.17 (16)
C5A—C6—C7—C8	0.0 (5)	S4—C3A—C11A—S11	0.2 (4)
C6—C7—C8—C9	0.0 (5)	C2—S1—C11A—C3A	−1.1 (3)
C7—C8—C9—C9A	0.1 (5)	C2—S1—C11A—S11	−175.89 (18)
C8—C9—C9A—C5A	−0.2 (5)	C10A—S11—C11A—C3A	−37.8 (3)
C8—C9—C9A—C10	−179.1 (3)	C10A—S11—C11A—S1	136.56 (18)
C6—C5A—C9A—C9	0.3 (4)

Experimental details

Crystal data
Chemical formula	C₁₃H₄O₂S₅
M_r	352.46
Crystal system, space group	Triclinic, P1
Temperature (K)	296
a, b, c (Å)	7.8527 (8), 8.0281 (9), 12.0022 (13)
α, β, γ (°)	97.934 (9), 89.227 (9), 117.867 (8)
V (Å³)	661.37 (12)
Z	2
Radiation type	Mo Kα
µ (mm⁻¹)	0.87
Crystal size (mm)	0.48 × 0.12 × 0.08

Data collection
Diffractometer	Siemens P4 diffractometer
Absorption correction	ψ scan (XSCANS; Siemens, 1996)
T_min, T_max	0.679, 0.733
No. of measured, independent and observed [I > 2σ(I)] reflections	3881, 2323, 1748
R_int	0.026
(sin θ/λ)_max (Å⁻¹)	0.596

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.035, 0.090, 1.02
No. of reflections	2323
No. of parameters	181
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.27, −0.28

Computer programs: XSCANS (Siemens, 1996), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), Mercury (Macrae et al., 2006).

Acknowledgements

Financial support from CONACyT-48038-R and VIPE-UDLA are gratefully acknowledged.

References

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