(3aR,8aR)-2,2,6,6-Tetra­methyl-4,4,8,8-tetra­phenyl­tetra­hydro-1,3-dioxolo[4,5-e][1,3,2]dioxasilepine

Hijji, Y.M.; Hudrlik, P.F.; Hudrlik, A.M.; Butcher, R.J.; Jasinski, J.P.

doi:10.1107/S160053680804227X

Volume 65
Part 1
Page o135
January 2009

Received 9 December 2008
Accepted 11 December 2008
Online 17 December 2008

Key indicators
Single-crystal X-ray study
T = 293 K
Mean (C-C) = 0.009 Å
Disorder in main residue
R = 0.054
wR = 0.119
Data-to-parameter ratio = 7.3
Details

(3aR,8aR)-2,2,6,6-Tetramethyl-4,4,8,8-tetraphenyltetrahydro-1,3-dioxolo[4,5-e][1,3,2]dioxasilepine

Yousef M. Hijji,^a Paul F. Hudrlik,^b Anne M. Hudrlik,^b Ray J. Butcher ^b ^* and Jerry P. Jasinski ^c

^aDepartment of Chemistry, Morgan State University, Baltimore, MD 21251, USA,^bDepartment of Chemistry, Howard University, 525 College Street NW, Washington, DC 20059, USA, and ^cDepartment of Chemistry, Keene State College, 229 Main Street, Keene, NH 03435-2001, USA
Correspondence e-mail: rbutcher99@yahoo.com

The title compound, C₃₃H₃₄O₄Si, is a dioxasilepine compound, an effective chiral dopant for the determination of high helical twisting powers in liquid crystals. Its structure consists of a five-membered dioxolo ring fused to a seven-membered dioxasilepine ring which contains two sets of phenyl rings in a twisted butterfly shape attached to the two Csp³ atoms in the ring opposite each other. Two methyl groups are attached to the Si atom in the ring and two additional methyl groups are attached to the Csp³ atom in the dioxolo ring (one of which is disordered) and which lies in an envelope pattern. The dihedral angles between the mean planes of the phenyl ring pairs are 85.9 (2) and 83.5 (1)°. The dihedral angles between the mean planes of the dioxolo ring and the two pairs of butterfly shaped phenyl rings are 46.2 (1), 67.7 (1), 35.6 (7) and 83.5 (1)°.

Related literature

For a related structure, see: Madison et al. (1998). For dioxasilepines as chiral dopants in liquid crystals, see: Kuball & Hofer (2000); Kuball et al. (1997). For puckering parameters and pseudo rotation parameters, see: Cremer & Pople (1975); Rao et al. (1981).

Experimental

Crystal data

C₃₃H₃₄O₄Si
M_r = 522.69
Orthorhombic, P 2₁ 2₁ 2₁
a = 10.008 (2) Å
b = 17.081 (3) Å
c = 17.271 (3) Å
V = 2952.4 (9) Å³
Z = 4
Mo K radiation
= 0.11 mm^-1
T = 293 (2) K
0.56 × 0.32 × 0.16 mm

Data collection

Siemans P2 diffractometer
Absorption correction: refined from F (SHELXL97; Sheldrick, 2008) T_min = 0.786, T_max = 0.982
2819 measured reflections
2819 independent reflections
1693 reflections with I > 2(I)
3 standard reflections every 97 reflections intensity decay: none

Refinement

R[F² > 2(F²)] = 0.054
wR(F²) = 0.119
S = 1.04
2819 reflections
388 parameters
14 restraints
H-atom parameters constrained
_max = 0.24 e Å^-3
_min = -0.18 e Å^-3

Data collection: XSCANS (Siemens, 2000); cell refinement: XSCANS; data reduction: SHELXTL (Sheldrick, 2008); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL.

Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: HG2455 ).

References

Cremer, D. & Pople, J. A. (1975). J. Am. Chem. Soc. 97, 1254-1358.
Kuball, H. G. & Hofer, T. (2000). Chirality, 12, 278-286.
Kuball, H. G., Weiss, B., Beck, A. K. & Seebach, D. (1997). Helv. Chim. Acta, 80, 2507-2514.
Madison, J., Clausen, R. P., Hazell, R. G., Jacobson, H. J., Bols, M. & Perry, C. C. (1998). Acta Chem. Scand., 52, 1165-1170.
Rao, S. T., Westhof, E. & Sundaralingam, M. (1981). Acta Cryst. A37, 421-425.
Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.
Siemens (2000). XSCANS. Bruker AXS Inc., Madison, Wisconsin, USA.

organic compounds