CH2 stretching region of the Raman spectra of the 2,2,2-d3-ethyl amine and 3,3,3-d3-propionic acid in D2O at different pD values at 5°C (blue curve) and 60°C (red curve). Band marked with (*) at 2918 cm−1 in 2,2,2-d3-ethylamine is most likely due to Fermi resonance of the νsCH2 with the overtone of the CH2 scissoring. The splitting between symmetric and asymmetric CH2 stretches in CD3-CH2-ND3+ at pD = 0.7 and 6.6 is unusually small, ~ 19 cm−1 (an additional indication that νsCH2 is up-shifted due to Fermi resonance) In gly and propionic acid CH2 scissoring is at a significantly lower frequency than in ethylamine which removes the condition for Fermi resonance.