The detection of molecules in space, is based on their spectroscopic features and high resolution spectral data is needed to allow an unambiguous identification of them. Many of the molecules detected in space are complex organic molecules containing chains of carbon atoms and which therefore show a high degree of molecular flexibility. The high number of low energy conformations and the presence of large amplitude motions on shallow potential energy surfaces are peculiar to this kind of systems.. The presence of a high number of stable conformers - often interconverting through small energy barriers - usually gives rise to very complex spectra, which represent a challenge for spectroscopic and computational methods. We will give examples of rotational spectroscopy of highly flexible organic molecules of astrophysical interest such as methylacetate [1], methylaminoethanol and biological building blocks like C4 sugars [2] studied in the isolated conditions of a free jet expansion in the 60-78 GHz region. The interpretation of their rotational spectra with appropriate models is essential to correctly predict their spectral features at higher frequencies.
Flexibility in complex organic molecules: a challenge for spectroscopy and computational methods
MELANDRI, SONIA
2012
Abstract
The detection of molecules in space, is based on their spectroscopic features and high resolution spectral data is needed to allow an unambiguous identification of them. Many of the molecules detected in space are complex organic molecules containing chains of carbon atoms and which therefore show a high degree of molecular flexibility. The high number of low energy conformations and the presence of large amplitude motions on shallow potential energy surfaces are peculiar to this kind of systems.. The presence of a high number of stable conformers - often interconverting through small energy barriers - usually gives rise to very complex spectra, which represent a challenge for spectroscopic and computational methods. We will give examples of rotational spectroscopy of highly flexible organic molecules of astrophysical interest such as methylacetate [1], methylaminoethanol and biological building blocks like C4 sugars [2] studied in the isolated conditions of a free jet expansion in the 60-78 GHz region. The interpretation of their rotational spectra with appropriate models is essential to correctly predict their spectral features at higher frequencies.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
