Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536807050507/bt2532sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S1600536807050507/bt2532Isup2.hkl |
CCDC reference: 667185
The title compound was synthesized according to a published procedure (Dallaire et al., 1993). Treatment of tin tetrachloride with 4 equivalents of phenyllithium in toluene led to a corresponding tetrakis(alkynyl)tin(IV). Crystals suitable for solid state structure determination were obtained by recrystallization from toluene.
Crystal selected for the X-ray measurement at 120 K was mounted on a glass fibre using the oil drop method (Kottke & Stalke, 1993). All H atoms were introduced in their calculated positions (C—H = 0.95 Å, Uiso=1.2 times the Ueq of the carrier atom) and refined with fixed geometry with respect to their carrier atoms.
There has been much recent interest in tetrakis(alkynyl)tin(IV) as new precursor for preparation of tin-alkoxide and sol-gel chemistry for the preparation of tin-oxide (Jousseaume et al., 1998). Recently, we demonstrated that tetrakis(phenylethynyl)tin(IV) is an efficient initiator for ring-opening polymerization of lactide and ε-caprolactone providing high activity and high molar mass polymers (Lahcini et al., 2004). Here, we describe the crystal structure of tetrakis(phenylethynyl)tin. It crystallized in a tetragonal space group I4, which reflects high symmetry of the molecule. The asymmetric unit cell consists of one fourth of a discrete tin complex (labeled as a Sn1 in Fig. 1) and one half of another one (Sn2) which both posses nearly ideal tetrahedral symmetry. The Sn(1)—C(1)—C(2) (176.5 (5)°) and C(1)—C(2)—C(3) (176.0 (7)°) angles in Sn1 and the Sn(2)—C(11)—C(12) (171.1 (5)°) and C(11)—C(12)—C(13) (178.0 (8)°) as well as the Sn(2)—C(21)—C(22) (177.4 (6)°) and C(21)—C(22)—C(23) (176.2 (8)°) angles in Sn2 illustrate a rather linear coordination of the acetylides on the Sn centers. The Sn—C distances (2.076 Å in Sn1 and 2.065–2.069 Å in Sn2) are short when compared to the sum of the covalent radii of C and Sn (2.177 Å), but coherent with another tetrakis(alkynyl)Sn complex, Me3Si—C≡C—Sn (2.067 Å) (Dallaire et al., 1993). The acetylenic bond distances (1.196 (7) Å in Sn1 and 1.183 (7)–1.207 (7) Å in Sn2) are consistent with a triple C≡C bond and comparable to previously reported phenylethynyl complexes, e.g. trans-[(NH3)Ru(C≡ CPh)(Ph2PCH2CH2PPH2)2] (1.187 (7) Å) (Touchard et al., 1997) and amidotin porphyrin (TTP)Sn(C≡CPh)2 (1.197 (3) Å) (Chen & Woo, 1998). Therefore, despite of the short Sn—C distances, the ligands are mainly σ-bonded to the metal. In the solid state these complexes form a three-dimensional network via agostic C—H interactions as illustrated in Fig. 1; a phenyl proton in ortho position interacts with the acetylenic carbon in α position to the tin center (see table of hydrogen bonds).
For related literature, see: Chen & Woo 1998; Dallaire et al. 1993; Jousseaume et al. 1998; Lahcini et al. 2004; Touchard et al. 1997.
For related literature, see: Kottke & Stalke (1993).
Data collection: COLLECT (Nonius, 2002); cell refinement: COLLECT (Nonius, 2002); data reduction: COLLECT (Nonius, 2002); program(s) used to solve structure: SIR2002 (Burla et al., 2003); program(s) used to refine structure: SHELX97 (Sheldrick, 1997); molecular graphics: SHELXTL (Bruker, 1998); software used to prepare material for publication: SHELX97 (Sheldrick, 1997).
[Sn(C8H5)4] | Dx = 1.384 Mg m−3 |
Mr = 523.17 | Mo Kα radiation, λ = 0.71073 Å |
Tetragonal, I4 | Cell parameters from 9860 reflections |
Hall symbol: I -4 | θ = 3.4–27.6° |
a = 13.689 (1) Å | µ = 1.03 mm−1 |
c = 20.098 (1) Å | T = 173 K |
V = 3766.1 (4) Å3 | Needle, colourless |
Z = 6 | 0.30 × 0.10 × 0.10 mm |
F(000) = 1572 |
Nonius KappaCCD diffractometer | 4311 independent reflections |
Radiation source: fine-focus sealed tube | 2474 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.070 |
φ and ω scans | θmax = 27.6°, θmin = 3.4° |
Absorption correction: multi-scan (SADABS; Sheldrick, 1996) | h = −15→17 |
Tmin = 0.747, Tmax = 0.904 | k = −17→10 |
9860 measured reflections | l = −25→17 |
Refinement on F2 | Secondary atom site location: difference Fourier map |
Least-squares matrix: full | Hydrogen site location: inferred from neighbouring sites |
R[F2 > 2σ(F2)] = 0.049 | H-atom parameters constrained |
wR(F2) = 0.078 | w = 1/[σ2(Fo2) + (0.01P)2] where P = (Fo2 + 2Fc2)/3 |
S = 0.93 | (Δ/σ)max < 0.001 |
4311 reflections | Δρmax = 0.75 e Å−3 |
224 parameters | Δρmin = −0.78 e Å−3 |
0 restraints | Absolute structure: Flack (1983), 2075 Friedel pairs |
Primary atom site location: structure-invariant direct methods | Absolute structure parameter: 0.00 (3) |
[Sn(C8H5)4] | Z = 6 |
Mr = 523.17 | Mo Kα radiation |
Tetragonal, I4 | µ = 1.03 mm−1 |
a = 13.689 (1) Å | T = 173 K |
c = 20.098 (1) Å | 0.30 × 0.10 × 0.10 mm |
V = 3766.1 (4) Å3 |
Nonius KappaCCD diffractometer | 4311 independent reflections |
Absorption correction: multi-scan (SADABS; Sheldrick, 1996) | 2474 reflections with I > 2σ(I) |
Tmin = 0.747, Tmax = 0.904 | Rint = 0.070 |
9860 measured reflections |
R[F2 > 2σ(F2)] = 0.049 | H-atom parameters constrained |
wR(F2) = 0.078 | Δρmax = 0.75 e Å−3 |
S = 0.93 | Δρmin = −0.78 e Å−3 |
4311 reflections | Absolute structure: Flack (1983), 2075 Friedel pairs |
224 parameters | Absolute structure parameter: 0.00 (3) |
0 restraints |
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. |
x | y | z | Uiso*/Ueq | ||
Sn1 | 0.0000 | 0.0000 | 0.0000 | 0.02556 (18) | |
C1 | 0.1148 (4) | 0.0423 (4) | 0.0610 (2) | 0.0315 (16) | |
C2 | 0.1773 (5) | 0.0677 (4) | 0.0988 (3) | 0.0268 (15) | |
C3 | 0.2494 (6) | 0.1040 (7) | 0.1469 (5) | 0.028 (2) | |
C4 | 0.3493 (5) | 0.0952 (5) | 0.1299 (3) | 0.0392 (16) | |
H4A | 0.3687 | 0.0664 | 0.0890 | 0.047* | |
C5 | 0.4185 (7) | 0.1299 (7) | 0.1749 (4) | 0.049 (2) | |
H5A | 0.4860 | 0.1278 | 0.1640 | 0.058* | |
C6 | 0.3886 (6) | 0.1674 (5) | 0.2356 (3) | 0.0466 (19) | |
H6A | 0.4361 | 0.1904 | 0.2664 | 0.056* | |
C7 | 0.2913 (6) | 0.1719 (5) | 0.2520 (3) | 0.0474 (18) | |
H7A | 0.2712 | 0.1975 | 0.2938 | 0.057* | |
C8 | 0.2228 (5) | 0.1384 (5) | 0.2065 (3) | 0.0328 (17) | |
H8A | 0.1555 | 0.1400 | 0.2180 | 0.039* | |
Sn2 | 0.0000 | 0.0000 | 0.312944 (19) | 0.03048 (15) | |
C11 | 0.1112 (4) | 0.0463 (4) | 0.3751 (3) | 0.0328 (15) | |
C12 | 0.1652 (5) | 0.0739 (4) | 0.4170 (3) | 0.0345 (16) | |
C13 | 0.2279 (7) | 0.1074 (7) | 0.4695 (5) | 0.033 (3) | |
C14 | 0.3267 (6) | 0.1345 (5) | 0.4593 (3) | 0.0381 (19) | |
H14A | 0.3544 | 0.1289 | 0.4161 | 0.046* | |
C15 | 0.3827 (5) | 0.1684 (5) | 0.5105 (5) | 0.048 (2) | |
H15A | 0.4491 | 0.1853 | 0.5027 | 0.058* | |
C16 | 0.3428 (5) | 0.1786 (5) | 0.5744 (3) | 0.0395 (17) | |
H16A | 0.3823 | 0.2022 | 0.6098 | 0.047* | |
C17 | 0.2456 (5) | 0.1544 (5) | 0.5862 (3) | 0.0458 (19) | |
H17A | 0.2175 | 0.1623 | 0.6291 | 0.055* | |
C18 | 0.1915 (7) | 0.1186 (7) | 0.5338 (4) | 0.039 (2) | |
H18A | 0.1256 | 0.1005 | 0.5419 | 0.047* | |
C21 | 0.0450 (4) | −0.1128 (5) | 0.2520 (3) | 0.0374 (17) | |
C22 | 0.0675 (5) | −0.1793 (5) | 0.2157 (3) | 0.0389 (17) | |
C23 | 0.0911 (7) | −0.2566 (7) | 0.1682 (4) | 0.034 (2) | |
C24 | 0.0938 (6) | −0.3541 (6) | 0.1889 (4) | 0.072 (3) | |
H24A | 0.0782 | −0.3718 | 0.2333 | 0.086* | |
C25 | 0.1202 (9) | −0.4245 (7) | 0.1420 (4) | 0.082 (4) | |
H25A | 0.1194 | −0.4915 | 0.1543 | 0.098* | |
C26 | 0.1471 (5) | −0.3998 (5) | 0.0790 (3) | 0.050 (2) | |
H26A | 0.1649 | −0.4495 | 0.0483 | 0.060* | |
C27 | 0.1488 (4) | −0.3049 (5) | 0.0597 (3) | 0.0363 (16) | |
H27A | 0.1680 | −0.2878 | 0.0158 | 0.044* | |
C28 | 0.1220 (5) | −0.2327 (5) | 0.1051 (3) | 0.0315 (17) | |
H28A | 0.1252 | −0.1660 | 0.0923 | 0.038* |
U11 | U22 | U33 | U12 | U13 | U23 | |
Sn1 | 0.0240 (3) | 0.0240 (3) | 0.0287 (4) | 0.000 | 0.000 | 0.000 |
C1 | 0.032 (4) | 0.039 (4) | 0.024 (4) | −0.007 (3) | −0.001 (3) | 0.000 (3) |
C2 | 0.030 (4) | 0.025 (4) | 0.025 (4) | 0.000 (3) | 0.001 (3) | −0.001 (3) |
C3 | 0.020 (5) | 0.028 (5) | 0.037 (6) | 0.002 (4) | −0.001 (4) | 0.017 (4) |
C4 | 0.027 (4) | 0.051 (5) | 0.040 (4) | 0.003 (4) | 0.004 (4) | −0.001 (4) |
C5 | 0.040 (5) | 0.060 (6) | 0.046 (6) | 0.000 (4) | −0.001 (4) | 0.014 (4) |
C6 | 0.050 (5) | 0.030 (4) | 0.060 (5) | −0.012 (4) | −0.025 (4) | 0.008 (3) |
C7 | 0.059 (6) | 0.036 (4) | 0.046 (4) | −0.004 (4) | −0.009 (4) | 0.003 (3) |
C8 | 0.027 (4) | 0.039 (5) | 0.033 (4) | −0.003 (4) | −0.004 (3) | 0.005 (3) |
Sn2 | 0.0280 (8) | 0.0333 (8) | 0.0302 (3) | 0.0035 (9) | 0.000 | 0.000 |
C11 | 0.033 (4) | 0.045 (4) | 0.020 (3) | −0.004 (3) | 0.003 (3) | 0.009 (3) |
C12 | 0.034 (5) | 0.037 (4) | 0.032 (4) | 0.007 (3) | 0.003 (3) | 0.007 (3) |
C13 | 0.037 (6) | 0.021 (5) | 0.043 (5) | 0.005 (4) | 0.001 (4) | −0.002 (3) |
C14 | 0.040 (6) | 0.036 (5) | 0.039 (4) | 0.007 (4) | 0.005 (4) | 0.000 (3) |
C15 | 0.038 (4) | 0.042 (4) | 0.065 (7) | −0.009 (3) | −0.005 (5) | 0.000 (5) |
C16 | 0.043 (5) | 0.031 (4) | 0.045 (4) | 0.007 (4) | −0.011 (4) | −0.006 (3) |
C17 | 0.062 (6) | 0.038 (5) | 0.037 (4) | −0.004 (4) | 0.004 (4) | −0.002 (3) |
C18 | 0.034 (6) | 0.028 (5) | 0.055 (6) | 0.000 (5) | −0.005 (4) | −0.004 (3) |
C21 | 0.035 (5) | 0.043 (5) | 0.034 (4) | 0.004 (4) | −0.003 (3) | −0.001 (3) |
C22 | 0.032 (5) | 0.049 (5) | 0.036 (4) | 0.009 (4) | 0.003 (3) | 0.009 (3) |
C23 | 0.016 (4) | 0.043 (6) | 0.044 (7) | 0.002 (4) | 0.009 (3) | −0.002 (4) |
C24 | 0.114 (8) | 0.043 (6) | 0.058 (6) | 0.010 (5) | 0.029 (6) | 0.005 (5) |
C25 | 0.153 (10) | 0.032 (6) | 0.061 (7) | 0.008 (6) | 0.031 (6) | 0.002 (5) |
C26 | 0.070 (6) | 0.031 (5) | 0.050 (5) | 0.008 (4) | 0.011 (4) | −0.003 (3) |
C27 | 0.025 (4) | 0.054 (5) | 0.030 (4) | 0.005 (3) | 0.001 (3) | 0.005 (3) |
C28 | 0.030 (4) | 0.029 (5) | 0.035 (4) | 0.010 (3) | −0.006 (3) | 0.000 (3) |
Sn1—C1 | 2.076 (6) | C13—C14 | 1.417 (11) |
Sn1—C1i | 2.076 (6) | C14—C15 | 1.364 (10) |
Sn1—C1ii | 2.076 (6) | C14—H14A | 0.9500 |
Sn1—C1iii | 2.076 (6) | C15—C16 | 1.404 (12) |
C1—C2 | 1.196 (7) | C15—H15A | 0.9500 |
C2—C3 | 1.467 (10) | C16—C17 | 1.391 (9) |
C3—C8 | 1.339 (10) | C16—H16A | 0.9500 |
C3—C4 | 1.415 (10) | C17—C18 | 1.379 (10) |
C4—C5 | 1.393 (10) | C17—H17A | 0.9500 |
C4—H4A | 0.9500 | C18—H18A | 0.9500 |
C5—C6 | 1.387 (9) | C21—C22 | 1.207 (7) |
C5—H5A | 0.9500 | C22—C23 | 1.461 (11) |
C6—C7 | 1.374 (8) | C23—C28 | 1.377 (10) |
C6—H6A | 0.9500 | C23—C24 | 1.398 (12) |
C7—C8 | 1.387 (8) | C24—C25 | 1.396 (10) |
C7—H7A | 0.9500 | C24—H24A | 0.9500 |
C8—H8A | 0.9500 | C25—C26 | 1.360 (9) |
Sn2—C21 | 2.065 (6) | C25—H25A | 0.9500 |
Sn2—C21ii | 2.065 (6) | C26—C27 | 1.356 (8) |
Sn2—C11 | 2.069 (6) | C26—H26A | 0.9500 |
Sn2—C11ii | 2.069 (6) | C27—C28 | 1.394 (8) |
C11—C12 | 1.183 (7) | C27—H27A | 0.9500 |
C12—C13 | 1.435 (10) | C28—H28A | 0.9500 |
C13—C18 | 1.393 (8) | ||
C1—Sn1—C1i | 110.43 (15) | C14—C13—C12 | 123.3 (8) |
C1—Sn1—C1ii | 107.6 (3) | C15—C14—C13 | 121.1 (7) |
C1i—Sn1—C1ii | 110.43 (15) | C15—C14—H14A | 119.4 |
C1—Sn1—C1iii | 110.43 (15) | C13—C14—H14A | 119.4 |
C1i—Sn1—C1iii | 107.6 (3) | C14—C15—C16 | 120.4 (7) |
C1ii—Sn1—C1iii | 110.43 (15) | C14—C15—H15A | 119.8 |
C2—C1—Sn1 | 176.5 (5) | C16—C15—H15A | 119.8 |
C1—C2—C3 | 176.0 (7) | C17—C16—C15 | 120.3 (6) |
C8—C3—C4 | 120.5 (8) | C17—C16—H16A | 119.9 |
C8—C3—C2 | 121.8 (8) | C15—C16—H16A | 119.9 |
C4—C3—C2 | 117.5 (8) | C18—C17—C16 | 118.0 (7) |
C5—C4—C3 | 118.2 (8) | C18—C17—H17A | 121.0 |
C5—C4—H4A | 120.9 | C16—C17—H17A | 121.0 |
C3—C4—H4A | 120.9 | C17—C18—C13 | 123.7 (9) |
C6—C5—C4 | 119.8 (8) | C17—C18—H18A | 118.1 |
C6—C5—H5A | 120.1 | C13—C18—H18A | 118.1 |
C4—C5—H5A | 120.1 | C22—C21—Sn2 | 177.4 (6) |
C7—C6—C5 | 121.0 (7) | C21—C22—C23 | 176.2 (8) |
C7—C6—H6A | 119.5 | C28—C23—C24 | 119.5 (9) |
C5—C6—H6A | 119.5 | C28—C23—C22 | 119.8 (8) |
C6—C7—C8 | 118.8 (6) | C24—C23—C22 | 120.2 (8) |
C6—C7—H7A | 120.6 | C25—C24—C23 | 117.7 (9) |
C8—C7—H7A | 120.6 | C25—C24—H24A | 121.1 |
C3—C8—C7 | 121.6 (7) | C23—C24—H24A | 121.1 |
C3—C8—H8A | 119.2 | C26—C25—C24 | 121.8 (9) |
C7—C8—H8A | 119.2 | C26—C25—H25A | 119.1 |
C21—Sn2—C21ii | 107.2 (3) | C24—C25—H25A | 119.1 |
C21—Sn2—C11 | 111.6 (2) | C27—C26—C25 | 120.6 (7) |
C21ii—Sn2—C11 | 110.4 (2) | C27—C26—H26A | 119.7 |
C21—Sn2—C11ii | 110.4 (2) | C25—C26—H26A | 119.7 |
C21ii—Sn2—C11ii | 111.6 (2) | C26—C27—C28 | 119.1 (6) |
C11—Sn2—C11ii | 105.7 (3) | C26—C27—H27A | 120.4 |
C12—C11—Sn2 | 171.1 (5) | C28—C27—H27A | 120.4 |
C11—C12—C13 | 178.0 (8) | C23—C28—C27 | 121.0 (7) |
C18—C13—C14 | 116.6 (8) | C23—C28—H28A | 119.5 |
C18—C13—C12 | 120.1 (9) | C27—C28—H28A | 119.5 |
C1i—Sn1—C1—C2 | −145 (9) | C12—C13—C14—C15 | 178.2 (8) |
C1ii—Sn1—C1—C2 | −24 (9) | C13—C14—C15—C16 | −1.0 (11) |
C1iii—Sn1—C1—C2 | 97 (9) | C14—C15—C16—C17 | −0.2 (10) |
Sn1—C1—C2—C3 | −37 (17) | C15—C16—C17—C18 | 1.4 (10) |
C1—C2—C3—C8 | 34 (11) | C16—C17—C18—C13 | −1.5 (13) |
C1—C2—C3—C4 | −150 (10) | C14—C13—C18—C17 | 0.4 (16) |
C8—C3—C4—C5 | −4.6 (12) | C12—C13—C18—C17 | −177.0 (7) |
C2—C3—C4—C5 | 179.6 (7) | C21ii—Sn2—C21—C22 | −71 (13) |
C3—C4—C5—C6 | 3.0 (11) | C11—Sn2—C21—C22 | 168 (13) |
C4—C5—C6—C7 | −0.7 (11) | C11ii—Sn2—C21—C22 | 51 (13) |
C5—C6—C7—C8 | −0.2 (10) | Sn2—C21—C22—C23 | 53 (21) |
C4—C3—C8—C7 | 3.8 (12) | C21—C22—C23—C28 | 45 (12) |
C2—C3—C8—C7 | 179.5 (7) | C21—C22—C23—C24 | −142 (11) |
C6—C7—C8—C3 | −1.4 (10) | C28—C23—C24—C25 | −5.4 (14) |
C21—Sn2—C11—C12 | −141 (3) | C22—C23—C24—C25 | −177.7 (9) |
C21ii—Sn2—C11—C12 | 100 (3) | C23—C24—C25—C26 | 3.1 (16) |
C11ii—Sn2—C11—C12 | −21 (3) | C24—C25—C26—C27 | −0.2 (15) |
Sn2—C11—C12—C13 | 2 (23) | C25—C26—C27—C28 | −0.4 (11) |
C11—C12—C13—C18 | 4 (21) | C24—C23—C28—C27 | 5.1 (13) |
C11—C12—C13—C14 | −173 (100) | C22—C23—C28—C27 | 177.4 (6) |
C18—C13—C14—C15 | 0.9 (14) | C26—C27—C28—C23 | −2.1 (10) |
Symmetry codes: (i) y, −x, −z; (ii) −x, −y, z; (iii) −y, x, −z. |
D—H···A | D—H | H···A | D···A | D—H···A |
C28—H28A···C1 | 0.95 | 2.92 | 3.869 (9) | 174 |
C18—H18A···C11iv | 0.95 | 2.89 | 3.736 (11) | 149 |
C8—H8A···C21ii | 0.95 | 2.85 | 3.795 (9) | 171 |
Symmetry codes: (ii) −x, −y, z; (iv) −y, x, −z+1. |
Experimental details
Crystal data | |
Chemical formula | [Sn(C8H5)4] |
Mr | 523.17 |
Crystal system, space group | Tetragonal, I4 |
Temperature (K) | 173 |
a, c (Å) | 13.689 (1), 20.098 (1) |
V (Å3) | 3766.1 (4) |
Z | 6 |
Radiation type | Mo Kα |
µ (mm−1) | 1.03 |
Crystal size (mm) | 0.30 × 0.10 × 0.10 |
Data collection | |
Diffractometer | Nonius KappaCCD |
Absorption correction | Multi-scan (SADABS; Sheldrick, 1996) |
Tmin, Tmax | 0.747, 0.904 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 9860, 4311, 2474 |
Rint | 0.070 |
(sin θ/λ)max (Å−1) | 0.652 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.049, 0.078, 0.93 |
No. of reflections | 4311 |
No. of parameters | 224 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.75, −0.78 |
Absolute structure | Flack (1983), 2075 Friedel pairs |
Absolute structure parameter | 0.00 (3) |
Computer programs: COLLECT (Nonius, 2002), SIR2002 (Burla et al., 2003), SHELX97 (Sheldrick, 1997), SHELXTL (Bruker, 1998).
D—H···A | D—H | H···A | D···A | D—H···A |
C28—H28A···C1 | 0.95 | 2.92 | 3.869 (9) | 173.7 |
C18—H18A···C11i | 0.95 | 2.89 | 3.736 (11) | 149.4 |
C8—H8A···C21ii | 0.95 | 2.85 | 3.795 (9) | 171.2 |
Symmetry codes: (i) −y, x, −z+1; (ii) −x, −y, z. |
There has been much recent interest in tetrakis(alkynyl)tin(IV) as new precursor for preparation of tin-alkoxide and sol-gel chemistry for the preparation of tin-oxide (Jousseaume et al., 1998). Recently, we demonstrated that tetrakis(phenylethynyl)tin(IV) is an efficient initiator for ring-opening polymerization of lactide and ε-caprolactone providing high activity and high molar mass polymers (Lahcini et al., 2004). Here, we describe the crystal structure of tetrakis(phenylethynyl)tin. It crystallized in a tetragonal space group I4, which reflects high symmetry of the molecule. The asymmetric unit cell consists of one fourth of a discrete tin complex (labeled as a Sn1 in Fig. 1) and one half of another one (Sn2) which both posses nearly ideal tetrahedral symmetry. The Sn(1)—C(1)—C(2) (176.5 (5)°) and C(1)—C(2)—C(3) (176.0 (7)°) angles in Sn1 and the Sn(2)—C(11)—C(12) (171.1 (5)°) and C(11)—C(12)—C(13) (178.0 (8)°) as well as the Sn(2)—C(21)—C(22) (177.4 (6)°) and C(21)—C(22)—C(23) (176.2 (8)°) angles in Sn2 illustrate a rather linear coordination of the acetylides on the Sn centers. The Sn—C distances (2.076 Å in Sn1 and 2.065–2.069 Å in Sn2) are short when compared to the sum of the covalent radii of C and Sn (2.177 Å), but coherent with another tetrakis(alkynyl)Sn complex, Me3Si—C≡C—Sn (2.067 Å) (Dallaire et al., 1993). The acetylenic bond distances (1.196 (7) Å in Sn1 and 1.183 (7)–1.207 (7) Å in Sn2) are consistent with a triple C≡C bond and comparable to previously reported phenylethynyl complexes, e.g. trans-[(NH3)Ru(C≡ CPh)(Ph2PCH2CH2PPH2)2] (1.187 (7) Å) (Touchard et al., 1997) and amidotin porphyrin (TTP)Sn(C≡CPh)2 (1.197 (3) Å) (Chen & Woo, 1998). Therefore, despite of the short Sn—C distances, the ligands are mainly σ-bonded to the metal. In the solid state these complexes form a three-dimensional network via agostic C—H interactions as illustrated in Fig. 1; a phenyl proton in ortho position interacts with the acetylenic carbon in α position to the tin center (see table of hydrogen bonds).