Rovibrational effects on nuclear shielding of apex nuclei in bent molecules

摘要: The isotope shifts of non‐end nuclei with lone pairs are generally larger than those without pairs. Using the bent triatomic molecule as a prototype, we examine mass and temperature dependence mean bond angle deformation displacement along due to centrifugal stretching anharmonic vibration. We find that 〈Δα〉 determines whether shielding apex nucleus will be normal [(dσ0/dT)<0] or abnormal. dominant contribution rotation in hydrides can lead opposing effects on while shifts. performed similar calculations for trigonal pyramidal molecules order explain observed abnormal 15N 31P nuclear NH3 PH3.