Knowledge Bank

“Infrared spectra for the series $CF3CCX$ (where $X = H, D, F, Cl, $Br, and I) have been taken in the range 2.5-38 microns. Assignment of the fundamentals is made on the basis of band type, position and frequency relationships. The coupling of the $A1$ fundamentals is traced as the C-X stretching frequency varies from $3325cm-1$ in $CH3CCH$ to $770cm-1$ in $CF3CCI$. The $CF3$ asymetric stretching vibration is remarkably constant at $1170-1180cm-1$, and the $CFa$ asymmetric deformation mode varies from 600 to $620cm-1$.”