The complexes between CH3OH and CF4. Infrared matrix isolation and theoretical studies

Area of Science:

• Physical Chemistry
• Spectroscopy
• Computational Chemistry

Background:

• Understanding molecular interactions is crucial in chemistry.
• Matrix isolation spectroscopy is a powerful technique for studying weakly bound complexes.
• Computational chemistry provides insights into molecular structure and bonding.

Purpose of the Study:

• To identify and characterize the complex formed between methanol (CH3OH) and tetrafluoromethane (CF4).
• To investigate the structural and spectral properties of the complex in argon and neon matrices.
• To compare experimental findings with theoretical predictions.

Main Methods:

• Fourier Transform Infrared (FTIR) spectroscopy was used to identify the complex in argon and neon matrices.
• Ab initio calculations at the MP2 level of theory with a 6-311+G(2df,2pd) basis set were performed.
• Atoms in Molecules (AIM) theory was employed for topological analysis of charge density.

Main Results:

• Three fundamental vibrations (OH, FCF, CO) were observed for the complex.
• The OH stretching vibration showed a red shift in neon and a blue shift in argon.
• Theoretical calculations identified two hydrogen-bonded structures and one non-hydrogen-bonded structure.
• Experimental and theoretical data suggest that only the non-hydrogen-bonded complex is trapped in the matrices.
• The observed spectral shifts were attributed to the matrix material's influence on vibrational frequencies.

Conclusions:

• The methanol-tetrafluoromethane complex exists as a non-hydrogen-bonded species in argon and neon matrices.
• Matrix effects significantly influence the vibrational frequencies of the complex.
• Computational methods successfully predicted the complex's structure and spectral properties.