Site-Specific Assignments of C-H and C-D Vibrations in Gaseous 1-Butanol by High-Resolution Cavity-Enhanced Raman...

Area of Science:

• Physical Chemistry
• Spectroscopy
• Molecular Physics

Background:

• C-H and C-D vibrations are key Raman probes for molecular analysis.
• Site-specific vibrational analysis is challenging due to overlapping modes and isotope effects.
• 1-Butanol is a model molecule for studying complex vibrational spectra.

Purpose of the Study:

• To assign gas-phase vibrational spectra of 1-butanol and its isotopologues.
• To elucidate site-specific C-H/C-D vibrational modes and Fermi resonances.
• To develop a robust framework for site-specific Raman analysis.

Main Methods:

• High-resolution cavity-enhanced Raman spectroscopy.
• Selective deuteration of 1-butanol isotopologues.
• Quantum chemical calculations and polarization-dependent measurements.

Main Results:

• High-resolution Raman spectra of 1-butanol and deuterated isotopologues were obtained.
• All major spectral features were assigned, elucidating site-specific vibrations.
• Isotope-induced shifts in frequency and intensity were quantified.

Conclusions:

• Fundamental understanding of 1-butanol's vibrational landscape was advanced.
• A robust framework for site-specific Raman analysis of complex organic molecules was established.
• This research guides the design of Raman-based imaging probes.