Chemistry
How Isotopic Substitution Alters Vibrational Frequencies in Raman Spectroscopy
Quick fact
Replacing a hydrogen atom with deuterium nearly halves the stretching frequency (e.g., C–H ~3000 cm⁻¹ → C–D ~2200 cm⁻¹) because the vibrational frequency depends on the inverse square root of the reduced mass.
Why this is interesting
Have you ever wondered why changing one isotope in a molecule can shift its Raman signal? The answer lies in the delicate balance between mass and motion.