Tetra­kis­­(iodo­methyl)­stannane

Acta Cryst.(2002). E58, m105±m106 DOI: 10.1107/S160053680200274X R. Alan Howieet al. [Sn(CH₂I)₄]

m105

metal-organic papers

Acta Crystallographica Section E Structure Reports Online

ISSN 1600-5368

Tetrakis(iodomethyl)stannane

R. Alan Howie,a_{* Janet M. S.} Skaklea_{and James L. Wardell}b

a_{Department of Chemistry, University of} Aberdeen, Meston Walk, Aberdeen AB24 3UE, Scotland, andb_{Departamento de QuõÂmica} InorgaÃnica, Instituto de QuõÂmica, Universidade Federal do Rio de Janeiro, CP 68563, 21945-970 Rio de Janeiro, RJ, Brazil

Correspondence e-mail: [email protected]

Key indicators

Single-crystal X-ray study

T= 298 K

Mean(Sn±C) = 0.008 AÊ

Rfactor = 0.038

wRfactor = 0.105

Data-to-parameter ratio = 56.7

For details of how these key indicators were automatically derived from the article, see http://journals.iucr.org/e.

#2002 International Union of Crystallography Printed in Great Britain ± all rights reserved

The structure of the title compound, [Sn(CH2I)4], consists of

Sn situated on a crystallographic fourfold rotatory inversion axis, with pendant iodomethyl groups whose atoms are in general positions. In the molecule, with overall crystal-lographically imposedS4molecular symmetry, there is little,

if any, distortion of the tetrahedral environment of Sn, but the bulk of I leads to opening up of the SnÐCÐI angle to 112.4 (3)_.

Comment

The asymmetric unit of the title compound, (I), consists of Sn in the 2bspecial positions of the space groupP421calong with,

in the 8egeneral positions, C, I and two H atoms of a single representative iodomethyl group. As a consequence, relatively high S4 symmetry is imposed upon the molecule as a whole,

which is shown in Fig. 1, and results in the very compact presentation of symmetry-unique bond lengths and angles in Table 1. The bond distances are much as would be expected for a molecule of this type. The bond-angle data show that there is no real distortion of the tetrahedral coordination of Sn. However, the Sn1ÐC1ÐI1 angle of 112.4 (3) _{is clearly} attributable to the physical bulk of the I atom.

Experimental

Compound (I), prepared as described by Burnettet al.(1998) (m.p. 348±349 K) and recrystallized from CHCl3, provided crystals suitable

for analysis.

Crystal data

[Sn(CH2I)4] Mr= 682.40

Tetragonal,P421c a= 9.4019 (5) AÊ

c= 7.4051 (4) AÊ

V= 654.58 (6) AÊ3 Z= 2

Dx= 3.462 Mg mÿ3

MoKradiation Cell parameters from 3436

re¯ections

= 3.1±30.5 = 11.33 mmÿ1 T= 298 (2) K Block, colourless 0.400.200.20 mm

Data collection

Bruker SMART 1000 CCD area-detector diffractometer

'and!scans

Absorption correction: multi-scan (SADABS; Bruker, 1999)

Tmin= 0.416,Tmax= 0.928

6440 measured re¯ections

1191 independent re¯ections 1044 re¯ections withI> 2(I)

Rint= 0.030

max= 32.6 h=ÿ12!14

k=ÿ14!13

l=ÿ11!10

Re®nement

Re®nement onF2 R[F2_{> 2(F}2_{)] = 0.038} wR(F2_{) = 0.105} S= 1.08 1191 re¯ections 21 parameters

H-atom parameters constrained

w= 1/[2_(F

o2) + (0.0512P)2

+ 1.6332P]

whereP= (Fo2+ 2Fc2)/3

(/)max< 0.001

max= 0.82 e AÊÿ3

min=ÿ1.58 e AÊÿ3

Absolute structure: (Flack, 1983) Flack parameter = 0.06 (18)

Table 1

Selected geometric parameters (AÊ,_).

Sn1ÐC1 2.114 (8) I1ÐC1 2.135 (8) C1ÐSn1ÐC1i _{109.1 (5)}

C1ÐSn1ÐC1ii _{109.7 (3)} Sn1ÐC1ÐI1 112.4 (3)

Symmetry codes: (i) 1ÿx;1ÿy;z; (ii) 1ÿy;x;2ÿz.

H atoms were placed in calculated positions, with CÐH = 0.97 AÊ, and re®ned with a riding model, withUiso= 1.2Ueq(C). The absolute

structure was determined on the basis of 492 Friedel pairs.

Data collection:SMART(Bruker, 1999); cell re®nement:SAINT

(Bruker, 1999); data reduction: SAINT; program(s) used to solve structure:SHELXS97 (Sheldrick, 1990); program(s) used to re®ne structure: SHELXL97 (Sheldrick, 1997); molecular graphics:

ORTEP-3 (Farrugia, 1997); software used to prepare material for publication:SHELXL97.

We thank CPNq, FAPERJ and FUJB, Brazil, for ®nancial support.

References

Bruker (1999).SADABS, SMARTandSAINT. Bruker AXS Inc., Madison, Wisconsin, USA.

Burnett, L. A., Howie, R. A., Garden, S. J., Ru®no, H. & Wardell, J. L. (1998).

J. Chem. Res. M, pp. 1801±1843. Farrugia, L. J. (1997).J. Appl. Cryst.30, 565. Flack, H. D. (1983).Acta Cryst.A39, 876±881. Sheldrick, G. M. (1990).Acta Cryst.A46, 467±473.

Sheldrick, G. M. (1997).SHELXL97. University of GoÈttingen, Germany.

Figure 1

The molecule of (I), showing the labelling scheme. Non-H atoms are shown as 50% ellipsoids and H atoms as small circles. The view is downc

supporting information

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Acta Cryst. (2002). E58, m105–m106

supporting information

Acta Cryst. (2002). E58, m105–m106 [doi:10.1107/S160053680200274X]

Tetrakis(iodomethyl)stannane

R. Alan Howie, Janet M. S. Skakle and James L. Wardell

S1. Comment

The asymmetric unit of the title compound, (I), consists of Sn in the 2 b s pecial positions of the space group P421c along

with, in the 8 e general positions, C, I and two H atoms of a single representative iodomethyl group. As a consequence,

relatively high D2 d symmetry is imposed upon the molecule as a whole, which is shown in Fig. 1, and results in the very

compact presentation of symmetry unique bond lengths and angles in Table 2. The bond distances are much as would be

anticipated for a molecule of this type. The bond-angle data show that there is no real distortion of the tetrahedral

coordination of Sn. However, the Sn1—C1—I1 angle of 112.4 (3)° is clearly attributable to the physical bulk of the I

atom.

S2. Experimental

Compound (I), prepared as described by Burnett et al. (1998) (m.p. 348–349 K) and recrystallized from CHCl3, provided

crystals suitable for analysis.

S3. Refinement

H atoms were placed in calculated positions, with C—H = 0.97 Å, and refined with a riding model, with Uiso = 1.2Ueq(C).

Figure 1

The molecule of (I) showing the labelling scheme. Non-H atoms are shown as 50% ellipsoids and H atoms as small

circles. The view is down c of the tetragonal cell. [Symmetry codes: (i) 1 - x, 1 - y, z; (ii) 1 - y, x, 2 - z; (iii) y, 1 - x, 2 - z].

Tetrakis(iodomethyl)stannane

Crystal data [Sn(CH2I)4] Mr = 682.40 Tetragonal, P421c a = 9.4019 (5) Å c = 7.4051 (4) Å V = 654.58 (6) Å3 Z = 2

F(000) = 588

Dx = 3.462 Mg m−3

Mo Kα radiation, λ = 0.71073 Å Cell parameters from 3436 reflections θ = 3.1–30.5°

µ = 11.33 mm−1 T = 298 K Block, colourless 0.40 × 0.20 × 0.20 mm

Data collection

Bruker SMART 1000 CCD area-detector diffractometer

Radiation source: fine-focus sealed tube Graphite monochromator

φ and ω scans

Absorption correction: multi-scan (SADABS; Bruker, 1999) Tmin = 0.416, Tmax = 0.928

6440 measured reflections 1191 independent reflections 1044 reflections with I > 2σ(I) Rint = 0.030

θmax = 32.6°, θmin = 3.1° h = −12→14

supporting information

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Acta Cryst. (2002). E58, m105–m106 Refinement

Refinement on F2 Least-squares matrix: full R[F2 _{> 2σ(F}2_{)] = 0.038} wR(F2_{) = 0.105} S = 1.08 1191 reflections 21 parameters 0 restraints

Primary atom site location: structure-invariant direct methods

Secondary atom site location: difference Fourier map

Hydrogen site location: inferred from neighbouring sites

H-atom parameters constrained w = 1/[σ2_(F

o2) + (0.0512P)2 + 1.6332P] where P = (Fo2 + 2Fc2)/3

(Δ/σ)max < 0.001 Δρmax = 0.82 e Å−3 Δρmin = −1.58 e Å−3

Absolute structure: (Flack, 1983) Absolute structure parameter: 0.06 (18)

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 F}2_, conventional R-factors R are based on F, with F set to zero for negative F2_{. The threshold expression of F}2 _{> σ(F}2_{) 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.

Sn in 2 b s pecial positions of space group P-42 (1)c i.e. molecule has -4 site symmetry. Anisotropic displacement parameters refined for all non-H atoms. H in calculated positions and refined with a riding model.

Absolute structure from 492 Friedel pairs.

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

x y z Uiso*/Ueq

Sn1 0.5000 0.5000 1.0000 0.04091 (18)

I1 0.44403 (8) 0.77733 (7) 0.68654 (11) 0.0749 (2)

C1 0.3508 (7) 0.6061 (8) 0.8344 (13) 0.0552 (18)

H1A 0.2745 0.6429 0.9092 0.066*

H1B 0.3098 0.5385 0.7502 0.066*

Atomic displacement parameters (Å2₎

U11 _U22 _U33 _U12 _U13 _U23

Sn1 0.0360 (2) 0.0360 (2) 0.0507 (4) 0.000 0.000 0.000

I1 0.0710 (4) 0.0710 (4) 0.0827 (4) 0.0096 (3) 0.0129 (3) 0.0293 (3)

C1 0.041 (3) 0.049 (3) 0.075 (5) −0.004 (3) −0.008 (3) 0.006 (3)

Geometric parameters (Å, º)

Sn1—C1 2.114 (8) C1—H1A 0.9700

I1—C1 2.135 (8) C1—H1B 0.9700

C1—Sn1—C1i _{109.1 (5) I1—C1—H1A 109.1}

Sn1—C1—I1 112.4 (3) I1—C1—H1B 109.1

Sn1—C1—H1A 109.1 H1A—C1—H1B 107.9