CH_3 COCH_2 COCH(CH_3)_2 およびCH_3 COCH_2 COC(CH_3)_3のラマン、赤外およびNMRスペクトル

摘要

2-metyl 3,5-hexanedione and 2,2-dimethyl 3,5-hexanedione molecules should be expected to have a Cs symmetry for a rigid structure, and a C3v symmetry for a non-rigid one, respectively. However the obtained vibrational spectra can be assigned neither according to the selection rules of Cs nor according to those of non-rigid C3v. This seems due to the appearance of tautomerisms. However the proton NMR spectra of these molecules strongly support non-rigid C3v model with the rotating CH3,CH2, CH and CO groups in their molecules, respectively.