AbstractThe chloroacetones CH2Cl. CO. CH3, CHCl2CO. CH3, CH2Cl. CO. CH2CL CHCl2CO. CH2Cl, and CHCl2CO. CHCl2 have been prepared. Their Raman spectra as well as those of several other chloroketones and chloroacid chlorides have been determined. A comparative study of these spectra reveals that the specific bending frequencies for the groups CH3 and CH2Cl, as deduced for the chloropropanes, show a characteristic shift to lower values if these groups are directly attached to the carbonyl group; the “CCl3 frequency” is shifted to a higher value. An intense Raman line at 350 cm−1, which has been found in the spectra of several chloropropanes and chloropropenes containing a CHCl2 group, is particularly strong and characteristic in carbonyl compounds possessing the configuration CHCl2CO. ‐ or CHCl2CHCl. CO.‐. The carbonyl group frequency shows highly different values for groups of compounds such as saturated ketones (1730‐1760 cm−1), unsaturated ketones (1710‐1720 cm−1), and acid chlorides (1780‐1820 cm−1). v(CO) gradually Increases with an increasing substitution of chlorine for hydrogen in the molecule of saturated ketones. In unsaturated ketones, in which C O and CC are conjugated, v(CO) and v(CC) are lowered and their Intensity is enhanced.