クラウンエーテルの分子形態におよぼす置換基の効果

概要

論文の詳細を見る
Dipole moments of crown ethers 3x-cmwn-x, ((CH_2CH_2O)x, x = 4,5,6) and their benzene group substitute crown ethers were measured in toluene over the temperature range of 25 to 50℃ in order to investigate the effect of a benzo moiety on the crown ring conformation. The dipole moments μ_<unit> for the repeating unit-(CH_2CH_2O)- at 35℃ were 1.168D(12C4), 0.915D(B12C4), 1.358D(15C5), 1.059D(B15C5), 1.083D(18C6), 0.899D(B18C6). The very similar values of μ_<unit> observed for 18C6 and for poly(ethylene oxide) (μ = 1.049-1.058D) suggest that 18C6 behaves like the acyclic polyethers. It was shown that the ring flexibility is depressed by the benzo moiety. The dipole moments computed by the molecular mechanics calculations for the crown ethers and their benzene group substitute crown ethers are compatible with the experimental results.
東京女子大学の論文
2004-03-10