title: The polyoctahedral silsesquioxane (POSS) 1,3,5,7,9,11,13,15-octaphenylpentacyclo[9.5.1.1(3,9).1(5,15).1(7,13)]octasiloxane (octaphenyl-POSS).
abstract: Solvent-free single crystals of 1,3,5,7,9,11,13,15-octaphenylpentacyclo[9.5.1.1(3,9).1(5,15).1(7,13)]octasiloxane (abbreviated as octaphenyl-POSS), C48H40O12Si8, were obtained by dehydration/condensation of the tetrol Si4O4(Ph)4(OH)4. The powder pattern generated from the single-crystal data matches well with the experimentally measured powder pattern of commercial octaphenyl-POSS. The geometry of the centrosymmetric molecule in the crystal was compared with that in the gas phase, and had shorter Si-O bond lengths and a broader range of Si-O-Si bond angles. The average Si-O bond length [1.621 (3) Å], and Si-O-Si and O-Si-O bond angles [149 (5) and 109 (1)°, respectively] were within the same range measured previously for octaphenyl-POSS solvates.
authors.affiliation: Department of Chemistry, Temple University, 1901 North 13th Street, Philadelphia, PA 19122, USA.
authors.forename: Parameswara Rao
authors.initials: PR
authors.lastname: Chinnam
authors.affiliation: Department of Chemistry, Temple University, 1901 North 13th Street, Philadelphia, PA 19122, USA.
authors.forename: Michael R
authors.initials: MR
authors.lastname: Gau
authors.affiliation: Research and Development, Hybrid Plastics, 55 W.L. Runnels Industrial Drive, Hattiesburg, MS 39501, USA.
authors.forename: Joseph
authors.initials: J
authors.lastname: Schwab
authors.affiliation: Department of Chemistry, Temple University, 1901 North 13th Street, Philadelphia, PA 19122, USA.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Zdilla
authors.affiliation: Department of Chemistry, Temple University, 1901 North 13th Street, Philadelphia, PA 19122, USA.
authors.forename: Stephanie L
authors.initials: SL
authors.lastname: Wunder
keywords: POSS; crystal structure; nanocomposites; octasiloxane; polyoctahedral silsesquioxanes