Utilization of Ionic Liquid for Preparation of Difluorocyclopropanes for Spectroscopic Studies

• Main Authors: Cha-Wen Chang, 張嘉文
• Other Authors: May-Fan Ding
• Format: Others
• Language: zh-TW
• Published: 2004
• Online Access: http://ndltd.ncl.edu.tw/handle/dby955

碩士 === 靜宜大學 === 應用化學研究所 === 92 === The preparation of 1-aryl-2,2-difluorocyclopanes in various solvents were investigated. Although, the yields were not much difference in the different solvents. However, the advantages of low vapor pressure and easily recycle, the ionic liquids were need for our preparation propose. The study on the substituent-induced chemical shifts (SCS) of C(α,β,γ) of the 13C NMR spectra. The correlation between SCS and Hammett constants (σ+) shows that the substituent effect via field effect on the Cγ (slope=-0.67, r2=0.860), and on the Cβ (slope=+1.02, r2=0.840). No correlation can be made for Cα. The 19F chemical shifts demonstrate more effect by the substituent on the benzene ring (F1, slope=+0.45, r2=0.920; F2, slope=+0.49, r2=0.932). The fragmentation of this series in the mass spectrometer under electron impact condition. The [M-CF2]+ was particular peak in the series. The molecular ions of donating group often be base peak. The [M-R-HF]+ of withdrawing group often be base peak.