Ionization efficiencies of C3H6, C4H8, C6H12, C2H6O,and C3H8O isomers

Ionization efficiencies of 14 organic compounds have been measured in the wavelength region from 105 to 134nm using an ionization chamber. The compounds examined are cyclopropane, propylene, l-butene, isobutene, cis-and trans-2-butenes, cyclohexane, 1-hexane, tetramethylethylene, ethyl alcohol, dimethyl ether, n-, and iso-propyl alcohol, and ethyl methyl ether. The ionization efficiencies of cyclopropane and cyclohexane monotonically increase with increasing photon energy, but those for the others show a peak or a shoulder in the wavelength region of the present work.     

Molecular and Crystal Structure of Magnolol—C18H18O2

Magnolol, 2, 2′-dihydroxy-5, 5′-diallylbiphenyl (C₁₈H₁₈O₂) was isolated from the heartwood of Taiwan sassafras, Sassafras randaiense (Hay.) Rehd. (Lauraceae) and characterized by single crystal X-ray diffraction. It crystallized in monoclinic P 2₁/C. The cell parameters are a=10.905(3), b=8.834(4), c=16.103(9) Å, β=106.76°(3), z=4. The structure was solved by direct method. The dihedral angle between two benzene rings is about 45′ which seems to be the best arrangement for intra- and inter-molecular H-bondings. O … O distances are ～2.6 Å which indicate very strong H-bonding. The solid structure can be discribed as a helix chain of molecules connected through H-bonds parallel to b-axis.