Abstract
The rotational spectrum of the binary complex formed between 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP) and 1,4-dioxane was investigated using a chirped pulse Fourier transform microwave spectrometer. HFIP is known to be an exceptional solvent that catalyzes the epoxidation of olefins by hydrogen peroxide. The addition of 1,4-dioxane can severely reduce HFIP’s ability to boost the epoxidation rate, possibly through its intermolecular interactions with HFIP. It is therefore of considerable interest to examine the non-covalent interactions between HFIP and 1,4-dioxane in detail. Theoretical conformational searches were carried out for the binary HFIP···1,4-dioxane complex and 17 minimum energy structures were identified. Seven of them are within an energy window of 7 kJ mol−1, while the three lowest energy ones are within 1.4 kJ mol−1. Experimentally, only the rotational spectrum of the most stable conformer was detected and assigned. To understand the non-observation of the other low energy conformers in the supersonic jet expansion, subsequent analyses were performed to estimate the conformational conversion barriers. The detected conformer contains a trans HFIP subunit which is hydrogen-bonded to an O atom of 1,4-dioxane and is further stabilized by weak F···H attractive interactions. The intermolecular interactions in HFIP···1,4-dioxane were analyzed and visualized using QTAIM, NCI and SAPT approaches and the interaction energies compared to the HFIP dimer and related complexes of HFIP and 1,4-dioxane with water.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.