| Title: | Hetero-double-helix formation by an ethynylhelicene oligomer possessing perfluorooctyl side chains |
| Author(s): | Amemiya R; Saito N; Yamaguchi M; |
| Address: | "Department of Organic Chemistry, Graduate School of Pharmaceutical Sciences, Tohoku University, Aoba, Sendai 980-8578, Japan" |
| ISSN/ISBN: | 1520-6904 (Electronic) 0022-3263 (Linking) |
| Abstract: | "Monomeric to pentameric (P)-ethynylhelicene oligomers possessing perfluorooctyl side chains were synthesized. The circular dichroism (CD) and vapor pressure osomometry (VPO) studies indicated the formation of a helix-dimer for the (P)-pentamer, for example, in trifluoromethylbenzene at 5 degrees C at concentrations above 2 x 10(-6) M. Compared with a (P)-pentamer possessing decyloxycarbonyl side chains, the perfluorooctyl (P)-pentamer exhibited lower solubilities in organic solvents, formed a thermodynamically more stable helix-dimer, and exhibited a mirror image CD spectrum. The perfluorooctyl (P)-pentamer formed a hetero-helix dimer with a decyloxycarbonyl (M)-pentamer but not with a (P)-pentamer. It indicated higher stability of the hetero-helix dimer over the homo-helix dimers" |
| Keywords: | Acetylene/analogs & derivatives/*chemical synthesis/chemistry Circular Dichroism Fluorocarbons/*chemistry Hydrogen Bonding Molecular Structure Osmosis Polycyclic Compounds/*chemical synthesis/chemistry Pressure Solubility Thermodynamics Volatilization; |
| Notes: | "MedlineAmemiya, Ryo Saito, Nozomi Yamaguchi, Masahiko eng Research Support, Non-U.S. Gov't 2008/08/30 J Org Chem. 2008 Sep 19; 73(18):7137-44. doi: 10.1021/jo8010057. Epub 2008 Aug 26" |
