1,1,3,3-Tetra-tert-butyl-2,2-diisopropyl-4,4-diphenyl­cyclo­tetra­silane

Kuribara, T.; Kyushin, S.

doi:10.1107/S160053681205074X

Volume 69
Part 1
Page o149
January 2013

Received 22 November 2012
Accepted 13 December 2012
Online 22 December 2012

Key indicators
Single-crystal X-ray study
T = 173 K
Mean (C-C) = 0.004 Å
R = 0.048
wR = 0.095
Data-to-parameter ratio = 16.1
Details

1,1,3,3-Tetra-tert-butyl-2,2-diisopropyl-4,4-diphenylcyclotetrasilane

Takayoshi Kuribara ^a and Soichiro Kyushin ^a ^*

^aDepartment of Chemistry and Chemical Biology, Graduate School of Engineering, Gunma University, Kiryu, Gunma 376-8515, Japan
Correspondence e-mail: kyushin@gunma-u.ac.jp

The molecule in the structure of the title compound, C₃₄H₆₀Si₄, lies on a twofold rotation axis that passes through the two Si atoms, resulting in a planar cyclotetrasilane ring. The dihedral angle between the cyclotetrasilane ring and the phenyl ring is 68.20 (5)°. The Si-Si bonds [2.4404 (8) and 2.4576 (8) Å] are longer than a standard Si-Si bond (2.34 Å) and the C-Si-C bond angle [97.07 (14)°] of the phenyl-substituted Si atom is smaller than the tetrahedral bond angle (109.5°). These long bonds and small bond angle are favorable for reducing the steric hindrance among the bulky substituents.

Related literature

For background to and applications of phenyl-substituted oligosilanes, see: Hinch & Krc (1957); Matsumoto & Tanaka (2008). For a related structure of a cyclotetrasilane without phenyl groups, see: Kyushin et al. (1995).

Experimental

Crystal data

C₃₄H₆₀Si₄
M_r = 581.18
Monoclinic, C 2/c
a = 11.9477 (9) Å
b = 17.6585 (12) Å
c = 17.0422 (13) Å
= 104.9394 (8)°
V = 3474.0 (4) Å³
Z = 4
Mo K radiation
= 0.19 mm^-1
T = 173 K
0.50 × 0.40 × 0.20 mm

Data collection

Rigaku R-AXIS IV imaging plate diffractometer
Absorption correction: multi-scan (REQAB; Jacobson, 1998) T_min = 0.910, T_max = 0.963
8534 measured reflections
2917 independent reflections
2899 reflections with I > 2(I)
R_int = 0.025

Refinement

R[F² > 2(F²)] = 0.048
wR(F²) = 0.095
S = 1.24
2917 reflections
181 parameters
H-atom parameters constrained
_max = 0.24 e Å^-3
_min = -0.20 e Å^-3

Data collection: CrystalClear (Rigaku, 2003); cell refinement: CrystalClear; data reduction: CrystalClear; program(s) used to solve structure: SIR2004 (Burla et al., 2005); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 (Farrugia, 2012); software used to prepare material for publication: SHELXL97 and Yadokari-XG 2009 (Kabuto et al., 2009).

Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: IS5224 ).

Acknowledgements

This work was supported in part by Grants-in-Aid for Scientific Research from the Ministry of Education, Culture, Sports, Science and Technology, Japan, and the Japan Society for the Promotion of Science. This work was also supported by the Element Innovation Project of Gunma University.

References

Burla, M. C., Caliandro, R., Camalli, M., Carrozzini, B., Cascarano, G. L., De Caro, L., Giacovazzo, C., Polidori, G. & Spagna, R. (2005). J. Appl. Cryst. 38, 381-388.
Farrugia, L. J. (2012). J. Appl. Cryst. 45, 849-854.
Hinch, R. J. & Krc, J. Jr (1957). Anal. Chem. 29, 1550-1551.
Jacobson, R. (1998). REQAB. Private communication to the Rigaku Corporation, Tokyo, Japan.
Kabuto, C., Akine, S., Nemoto, T. & Kwon, E. (2009). J. Crystallogr. Soc. Jpn, 51, 218-224.
Kyushin, S., Sakurai, H. & Matsumoto, H. (1995). J. Organomet. Chem. 499, 235-240.
Matsumoto, H. & Tanaka, R. (2008). Jpn Kokai Tokkyo Koho JP4132933.
Rigaku (2003). CrystalClear. Rigaku Corporation, Tokyo, Japan.
Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.

organic compounds