- 作者: 朱時宜; 林渭川
- 作者服務機構: Contribution from the Department of Chemistry, National Taiwan University, Taipei, Taiwan
- 中文摘要:
PMR spectrum of N, N-dimethylnitrosoamine (DMNA) showed no apparent solvent effect in the media of aliphatic solvents. While in the aromatic solvents, both the α- and β- lines of DMNA experience a larger upfield shift on dilution. Furthermore, the shift of α- line is large than that of β- line, suggesting that the stereo-specific association between the benzene ring and DMNA molecules occurs.
Using NMR technique, the equilibrium constants of association complexes with aromatic donors were determined and their relative magnitude were found to be:
Mesitylene > p-Xylene > Toluene > Benzene > Chlorobenzene~ Bromobenzene
The sequence for the upfield shift of α-methyl1 protons in the pure complex were found to be:
Benzene>Toluene>p-Xylene>Mesitylene
white for β-methyl protons in the pure complex, the upfield shift is relatively insensitive to the variation of methylsubstituted benzenes.
All these phenomena can be satisfactorily explained by using the one-electron theory of ring current proposed by McWeeny and Martin. - 英文摘要: --
- 中文關鍵字: --
- 英文關鍵字: --