Benzyl­triethyl­ammonium 2,2,2,4-tetra­chloro-2,5-di­hydro-1,2λ⁵-oxatellurole

The geometry around the Te atom in the anion in C₁₃H₂₂N⁺·C₃H₃Cl₄OTe⁻ is distorted pseudo-octahedral with three Cl atoms and the O atom forming the equatorial plane, and the C atom lying opposite the tellurium lone pair. Distances and angles are: Te—O 2.0120 (18), Te—C 2.072 (2), Te—Cl 2.5239 (7), 2.5283 (7) and 2.5577 (7) Å; O—Te—C 81.61 (9), O—Te—Cl 90.69 (6), 90.99 (6) and 168.13 (5), C—Te—Cl 87.13 (8), 86.64 (8) and 86.59 (8), and Cl—Te—Cl 87.02 (2), 90.00 (3) and 173.24 (3)°. The anions are arranged in an infinite zigzag chain parallel to the a axis through a secondary Te...Cl bond [3.8391 (8) Å].

S1. Comment

The addition reaction of tellurium tetrachloride to alkynes was described for the first time almost 40 years ago by Campos & Petragnani (1962). After this, only in 1979, did another report about this reaction appear in the literature (Uemura et al., 1979). However, up to now no definitive data concerning the stereochemical outcome of this reaction was provided. The addition of TeCl₄ to a propargylic alcohol followed by treatment with triethylbenzylammonium chloride gives rise to a compound that could be similar to that, (I), obtained by the addition reaction of trichloro(p-methoxyphenyl)tellurium(IV) (Zukerman-Schpector et al., 1999) to the corresponding propargylic alcohol, so that an X-ray crystal structure analysis of (I) was undetaken.

The structure consists of ammonium cations and tellurate(IV) anions. The coordination around the Te atom in the [C₃H₃Cl₄OTe]⁻ anion is distorted square pyramidal or pseudo-octahedral with the non-bonding electron-pair occupying the sixth position. The equatorial square plane composed of three Cl and the O atom is slightly distorted (r.m.s. deviation of 0.046 Å), with the Te atom displaced from the plane by 0.1848 (6) Å away from the apical C1 atom. The bond lengths from the Te^IV to the three surrounding Cl atoms are close to the mean value of 2.52 (3) Å calculated for 22 compounds (Allen et al., 1987). The asymmetry parameter [defined as (b2-b1)/b1; b's are the Te—Cl distances] of 1.74 × 10⁻³ and θ (Cl1—-Te–Cl2 angle) of 173.24 (3)° are in good agreement with the fact that for small asymmetry, θ should be close to 180° (Landrum & Hoffmann, 1998). The Te—Cl3 distance is marginally longer than the other two Te—Cl distances; this can be explained by the fact that the Cl3 is involved in a short intermolecular contact, Cl3···H6ⁱ = 2.83, Cl3···C6ⁱ = 3.551 (3) Å and Cl3···H6ⁱ—Cⁱ = 135° [symmetry code: (i) −x, 1 − y, 1 − z]. Whether or not this is an hydrogen bond it is difficult to assertain because as pointed out by Cotton et al. (1997), `the field is getting muddier and muddier as the definition of an hydrogen bond is relaxed'. In any case, the Cl···H distance is shorter than the sum of the van der Waals radii of H and Cl (3.0 Å; Pauling, 1960). There is a secondary intermolecular bonding between Te and Cl4ⁱⁱ of 3.8391 (8) Å [symmetry code: (ii) 1 + x, y, z], this distance being less than the sum of the van der Waals radii of Te and Cl (4.00 Å; Pauling, 1960). This secondary bond links the anions into zigzag chains parallel to a. The angle C1—Te···Cl4ⁱⁱ is 144.05° rather than 180° as might be expected if the tellurium lone pair was stereochemically inactive. The Te—C1 distance of 2.072 (2) Å is in good agreement with the sum of the Pauling (1960) single-bond covalent radii of Te (1.37 Å) and Csp² (0.667 Å) atoms, and with the value of 2.073 (7) Å reported in Zukerman-Schpector et al. (1995, and references therein). The five-membered chelate ring is planar, the r.m.s. deviation of the fitted atoms being 0.024 Å.

S2. Experimental

The title compound is the addition product of the reaction between tellurium tetrachloride (0.54 g, 2.01 mmol) and propargyl alcohol (0.11 g, 2.01 mmol) in dry benzene (8 ml) at room temperature for 1 h. The crude mixture was reacted with triethylbenzylammonium chloride (0.39 g, 2.02 mmol) in dry ethanol (Petragnani et al., 1976) at room temperature for 2 h. The main product of the reaction was crystallized slowly from CH₂Cl₂ as colourless crystals in 61% yield.

S3. Refinement

H atoms were placed in calculated positions with fixed C–H distances (0.93 Å for Csp² and 0.96 Å for Csp³), each riding on a carrier atom, with an isotropic displacement parameter amounting to 1.5 (for methyl H atoms) or 1.2 (for the other H atoms) times the value of the equivalent isotropic displacement parameter of the carrier atom.

Computing details

Data collection: CAD-4 Software (Enraf-Nonius,1989); cell refinement: CAD-4 Software; data reduction: XCAD4 (Harms & Wocadlo, 1995); program(s) used to solve structure: SIR92 (Altomare et al., 1993); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ZORTEP (Zsolnai, 1995); software used to prepare material for publication: SHELXL97 (Sheldrick, 1997), PARST95 (Nardelli, 1995) and WinGX (Farrugia, 1998).

Figures

Fig. 1. View of the title molecule showing the labeling of the non-H atoms. Displacement ellipsoids are shown at the 50% probability level and H atoms are drawn as small circles of an arbitrary radii.

(I)

Crystal data

C13H22N^+·C3H3Cl4OTe^−	Z = 2
Mr = 516.77	F(000) = 512
Triclinic, P1	Dx = 1.633 Mg m^−3
a = 7.5837 (4) Å	Mo Kα radiation, λ = 0.71073 Å
b = 11.2598 (5) Å	Cell parameters from 25 reflections
c = 12.8491 (7) Å	θ = 9.7–18.1°
α = 94.403 (4)°	µ = 1.93 mm^−1
β = 103.025 (4)°	T = 293 K
γ = 98.284 (4)°	Irregular, colourless
V = 1051.00 (9) Å^3	0.30 × 0.30 × 0.20 mm

Data collection

Enraf-Nonius CAD-4 diffractometer	3633 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.012
Graphite monochromator	θmax = 25.5°, θmin = 2.3°
ω/–2θ scans	h = −9→9
Absorption correction: ψ scan (North et al., 1968)	k = 0→13
Tmin = 0.539, Tmax = 0.678	l = −15→15
4119 measured reflections	3 standard reflections every 60 min
3906 independent reflections	intensity decay: −1.3%

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.022	H-atom parameters constrained
wR(F^2) = 0.059	w = 1/[σ^2(Fo^2) + (0.0329P)^2 + 0.4285P] where P = (Fo^2 + 2Fc^2)/3
S = 1.07	(Δ/σ)max = 0.001
3906 reflections	Δρmax = 0.57 e Å^−3
212 parameters	Δρmin = −0.54 e Å^−3
0 restraints	Extinction correction: SHELXL97, Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.0339 (10)

Special details

Experimental. The ammonium cation has the N—C distances ranging from 1.517 (3) to 1.532 (3) Å. It is worth noting that this cation presents in the [N(CH₂C₆H₅)(C₂H₅)₃⁺][PPh₂(m-C₆H₄SO₃)⁻]·H₂O structure (Roman et al., 1997), two extreme N—C distances of 1.479 (13) and 1.699 (11) Å, and in Hauptman et al. (1999) the N—C distances occur in the range 1.49 (1)–1.52 (1) Å.

Hauptmann, R., Schneider, J., Chen, C. & Henkel, G. (1999). Acta Cryst. C55, 192–194.

Roman, P. J., Paterniti, D. P., See, R. F., Churchill, M. R. & Atwood, J. D. (1997). Organometallics, 16, 1484–1490.

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
Te	0.169452 (19)	0.180958 (13)	0.247386 (11)	0.03806 (8)
Cl1	0.19849 (11)	0.29493 (9)	0.08880 (6)	0.0707 (2)
Cl2	0.10949 (11)	0.07990 (6)	0.40796 (6)	0.05706 (17)
Cl3	0.25405 (12)	0.38006 (6)	0.37106 (6)	0.0646 (2)
Cl4	−0.44295 (10)	0.12574 (10)	0.11170 (7)	0.0801 (3)
N	0.2760 (3)	0.75107 (19)	0.30141 (17)	0.0460 (5)
O	0.0492 (3)	0.02981 (16)	0.14819 (14)	0.0502 (4)
C1	−0.0994 (3)	0.2113 (2)	0.2193 (2)	0.0471 (6)
H1	−0.1364	0.2777	0.2506	0.057*
C2	−0.2099 (3)	0.1253 (3)	0.1521 (2)	0.0486 (6)
C3	−0.1394 (4)	0.0215 (3)	0.1043 (2)	0.0555 (7)
H3A	−0.2039	−0.0539	0.1187	0.067*
H3B	−0.1621	0.0221	0.0270	0.067*
C4	−0.0653 (4)	0.6608 (2)	0.2736 (2)	0.0457 (5)
C5	−0.1156 (4)	0.6257 (3)	0.3653 (2)	0.0519 (6)
H5	−0.0569	0.6683	0.4319	0.062*
C6	−0.2528 (4)	0.5275 (3)	0.3586 (2)	0.0588 (7)
H6	−0.2846	0.5044	0.4208	0.071*
C7	−0.3417 (4)	0.4644 (3)	0.2611 (3)	0.0609 (7)
H7	−0.4330	0.3983	0.2570	0.073*
C8	−0.2956 (5)	0.4989 (3)	0.1702 (3)	0.0703 (9)
H8	−0.3567	0.4568	0.1038	0.084*
C9	−0.1584 (4)	0.5964 (3)	0.1761 (2)	0.0645 (8)
H9	−0.1283	0.6189	0.1133	0.077*
C10	0.0760 (4)	0.7712 (2)	0.2787 (2)	0.0528 (6)
H10A	0.0646	0.8310	0.3342	0.063*
H10B	0.0477	0.8048	0.2108	0.063*
C11	0.3012 (4)	0.6521 (3)	0.2217 (2)	0.0594 (7)
H11A	0.4242	0.6339	0.2452	0.071*
H11B	0.2158	0.5798	0.2237	0.071*
C12	0.2734 (6)	0.6801 (4)	0.1066 (3)	0.0864 (11)
H12A	0.1576	0.7070	0.0845	0.130*
H12B	0.2746	0.6087	0.0610	0.130*
H12C	0.3704	0.7424	0.1010	0.130*
C21	0.3348 (4)	0.7096 (2)	0.4117 (2)	0.0521 (6)
H21A	0.4571	0.6898	0.4199	0.063*
H21B	0.2529	0.6361	0.4148	0.063*
C22	0.3364 (5)	0.8001 (3)	0.5062 (2)	0.0689 (8)
H22A	0.4317	0.8679	0.5114	0.103*
H22B	0.3586	0.7623	0.5713	0.103*
H22C	0.2199	0.8272	0.4955	0.103*
C31	0.3892 (4)	0.8715 (3)	0.2937 (3)	0.0601 (7)
H31A	0.3449	0.8958	0.2230	0.072*
H31B	0.3693	0.9317	0.3461	0.072*
C32	0.5936 (4)	0.8711 (3)	0.3122 (3)	0.0739 (9)
H32A	0.6396	0.8482	0.3823	0.111*
H32B	0.6550	0.9505	0.3071	0.111*
H32C	0.6158	0.8145	0.2587	0.111*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Te	0.03822 (11)	0.04155 (11)	0.03652 (10)	0.01256 (6)	0.00943 (6)	0.00487 (6)
Cl1	0.0652 (4)	0.0975 (6)	0.0555 (4)	0.0163 (4)	0.0168 (3)	0.0353 (4)
Cl2	0.0766 (5)	0.0502 (4)	0.0500 (4)	0.0144 (3)	0.0213 (3)	0.0150 (3)
Cl3	0.0839 (5)	0.0431 (3)	0.0623 (4)	−0.0012 (3)	0.0189 (4)	−0.0040 (3)
Cl4	0.0382 (4)	0.1175 (7)	0.0806 (5)	0.0173 (4)	0.0081 (3)	−0.0023 (5)
N	0.0503 (11)	0.0423 (11)	0.0501 (11)	0.0177 (9)	0.0133 (9)	0.0119 (9)
O	0.0520 (10)	0.0506 (10)	0.0488 (10)	0.0192 (8)	0.0104 (8)	−0.0057 (8)
C1	0.0441 (13)	0.0468 (13)	0.0546 (14)	0.0182 (11)	0.0143 (11)	0.0039 (11)
C2	0.0381 (13)	0.0623 (16)	0.0475 (13)	0.0126 (11)	0.0119 (10)	0.0074 (12)
C3	0.0523 (15)	0.0589 (16)	0.0521 (15)	0.0068 (12)	0.0124 (12)	−0.0099 (12)
C4	0.0477 (13)	0.0453 (13)	0.0471 (13)	0.0156 (11)	0.0110 (11)	0.0104 (10)
C5	0.0561 (15)	0.0557 (15)	0.0440 (13)	0.0113 (12)	0.0124 (11)	0.0013 (11)
C6	0.0628 (17)	0.0610 (17)	0.0587 (17)	0.0104 (14)	0.0256 (14)	0.0115 (13)
C7	0.0571 (16)	0.0547 (16)	0.0732 (19)	0.0087 (13)	0.0232 (14)	−0.0002 (14)
C8	0.0628 (19)	0.083 (2)	0.0563 (17)	0.0039 (16)	0.0087 (14)	−0.0133 (16)
C9	0.0672 (19)	0.085 (2)	0.0418 (14)	0.0093 (16)	0.0143 (13)	0.0084 (14)
C10	0.0531 (15)	0.0472 (14)	0.0636 (16)	0.0209 (12)	0.0133 (13)	0.0193 (12)
C11	0.0657 (18)	0.0621 (17)	0.0562 (16)	0.0262 (14)	0.0180 (14)	0.0041 (13)
C12	0.093 (3)	0.119 (3)	0.0542 (19)	0.027 (2)	0.0248 (18)	0.0100 (19)
C21	0.0590 (16)	0.0507 (14)	0.0498 (14)	0.0201 (12)	0.0099 (12)	0.0131 (11)
C22	0.077 (2)	0.073 (2)	0.0534 (17)	0.0129 (16)	0.0109 (15)	0.0008 (14)
C31	0.0585 (17)	0.0509 (15)	0.076 (2)	0.0119 (13)	0.0207 (15)	0.0209 (14)
C32	0.0549 (18)	0.083 (2)	0.085 (2)	0.0090 (16)	0.0189 (16)	0.0189 (19)

Geometric parameters (Å, º)

Te—O	2.0120 (18)	C2—C3	1.499 (4)
Te—C1	2.072 (2)	C4—C9	1.382 (4)
Te—Cl1	2.5239 (7)	C4—C5	1.385 (4)
Te—Cl2	2.5283 (7)	C4—C10	1.507 (4)
Te—Cl3	2.5577 (7)	C5—C6	1.388 (4)
N—C21	1.517 (3)	C6—C7	1.369 (4)
N—C11	1.518 (3)	C7—C8	1.361 (5)
N—C31	1.519 (3)	C8—C9	1.384 (5)
N—C10	1.532 (3)	C11—C12	1.511 (4)
Cl4—C2	1.727 (3)	C21—C22	1.521 (4)
O—C3	1.401 (3)	C31—C32	1.515 (4)
C1—C2	1.303 (4)
O—Te—C1	81.61 (9)	C2—C1—Te	111.21 (19)
O—Te—Cl1	90.69 (6)	C1—C2—C3	121.2 (2)
C1—Te—Cl1	87.13 (8)	C1—C2—Cl4	122.2 (2)
O—Te—Cl2	90.99 (6)	C3—C2—Cl4	116.6 (2)
C1—Te—Cl2	86.64 (8)	O—C3—C2	110.3 (2)
Cl1—Te—Cl2	173.24 (3)	C9—C4—C5	117.9 (3)
O—Te—Cl3	168.13 (5)	C9—C4—C10	120.7 (3)
C1—Te—Cl3	86.59 (8)	C5—C4—C10	121.3 (2)
Cl1—Te—Cl3	90.00 (3)	C4—C5—C6	120.6 (3)
Cl2—Te—Cl3	87.02 (2)	C7—C6—C5	120.5 (3)
C21—N—C11	106.0 (2)	C8—C7—C6	119.6 (3)
C21—N—C31	111.3 (2)	C7—C8—C9	120.4 (3)
C11—N—C31	111.5 (2)	C4—C9—C8	121.1 (3)
C21—N—C10	111.0 (2)	C4—C10—N	115.8 (2)
C11—N—C10	111.1 (2)	C12—C11—N	115.7 (3)
C31—N—C10	106.02 (19)	N—C21—C22	115.5 (2)
C3—O—Te	115.40 (15)	C32—C31—N	114.7 (2)