Comparison of conformation and vibrational properties of ?C(O)-S- and ?C(O)-O- compounds

MARÍA ELIANA DEFONSI LESTARD; DIEGO MAURICIO GIL; MARÍA EUGENIA TUTTOLOMONDO; AIDA BEN ALTABEF

Jena

Conferencia; XXIV International Conference on Raman Spectroscopy; 2014

Universidad de Jena

The functional group idea is useful to understand the chemistry of biological macromolecules. Atoms and functional groups poseess characteristic and additive properties that in many cases exhibit a remarkable transferability between different molecules. Knowledge of the structural properties and conformational preference of simple molecules containing distinct functional groups is therefore of prime interest. As follow up of studies for -C(O)S- and -C(O)O-compounds in this work, a comparison is presented of conformational and vibrational properties of R1C(O)SR2 (R1=CF3,CH3 and R2=CH2CH3, CH3) and R1C(O)OR2 (R1=CF3, CCl3,CH3 and R2=CH3, CH2CH3, CH2CF3, SiCH3) which includes the use of vibrational spectroscopy (FTIR-gas and liquid phase, Raman liquid phase, Figure 1) and quantum chemical calculations (B3LYP and MP2 methods). The behavior of hyperconjugative interactions with changing substituents and their relationship to vibrational properties is studied with the NBO program to understand how this group affects the change of substituents.