Received 9 December 2008
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: email@example.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)°.
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).
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 ).
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