The crystal and molecular structure of hexacyclo[10,3,1,02,10,03,7,06,16,09,14]hexadecane, an ethano-bridged diamantane

Abstract

The structure of a hydrocarbon, m.p. 110-115 °C, obtained from two different cyclooctatetraene dimers by hydrogenation followed by aluminum halide rearrangement, has been determined to be an ethanodiamantane, hexacyclo [10,3,1,02'1°,03'7,06'xs,0°'14]hexadecane. The crystals are monoclinic with unitcell dimensions: a = 9.151 + 0.001, b = 6.510 + 0-001, c = 19.733 +_ 0.003 ./~ and fl = 98.62 + 0.02 °. The space group is P21]e with four molecules in the unit cell. The structure was solved by a straightforward application of the symbolic addition procedure and refined by full-matrix least-squares methods with anisotropic thermal parameters for the carbon atoms and isotropic thermal parameters for the hydrogen atoms. The final R value is 0.044 for 1615 observed reflections. The average standard deviation in the C-C bond distances is 0-002 A and that in the C-H bond is 0.02 ~. The C-C bond distances lie in the range 1.516-1.552 A (mean 1.534 A), and the bond angles range from 99.2 to 114.5 ° (mean 109"1°). The molecule has seven six-membered rings; the mean torsion angle in all of them is greater than the value of 56 ° found in cyclohexane itself. The cyclopentane ring is in the envelope conformation with the puckered atom deviating 0.4/~ from the plane of the remaining atoms.

Crystal and molecular structure of 2-aminoadamantane-2-carboxylic acid hydrobromide

“…The room temperature form is disordered. The structures of congressane (Karle & Karle, 1965), diadamantane (Alden, Kraut & Taylor, 1968), tetramantane (Schleyer, Osawa & Drew, 1968) and an ethanobridged diadamantane (Rao & Sundaralingam, 1972) have also been reported.…”