Peroxides as Host Compounds: An Investigation of the Host Ability and Selectivity of Di-(9-(p-trifluoromethylphenyl)xanthen-9-yl) Peroxide in Anisole/Methylanisole Mixtures
Year: 2025
Type: article
Abstract: The present investigation focused on the complexation behavior of a peroxide, specifically di(9-(p-trifluoromethylphenyl)xanthen-9-yl) peroxide (H), as a host compound for the potential guest species anisole (ANI) and 2-, 3- and 4-methylanisole (2MA, 3MA and 4MA) through crystallization experiments from each of these organic solvents. The results obtained demonstrate that H has the ability to form 1:1 host:guest inclusion complexes with each of ANI and 4MA, while no enclathration was observed when the potential guests were 2MA and 3MA. Furthermore, it was established from crystallization experiments from mixed guests that H possesses an overwhelming affinity for ANI followed by 4MA; equimolar mixed guest experiments showed the host selectivity to thus be in the order ANI > 4MA > 3MA > 2MA. Importantly, H was also shown to have the ability to separate 20:80 ANI/2MA and 60:40 4MA/2MA mixtures, in favor of ANI and 4MA, respectively (high selectivity coefficients, K, were calculated in these two instances). Single crystal X-ray diffraction (SCXRD) analyses indicated that 4MA engages in one (host)C–H···π(guest) and one (guest)C–H···π(host) interaction, while the overwhelming selectivity for ANI was attributed to the existence of two stabilizing (host)C–F···π(guest) bonds to each guest molecule. Furthermore, thermoanalytical experiments demonstrated that the ANI-containing inclusion complex was significantly more stable than that with 4MA, explaining the host selectivity witnessed in the mixed guest experiments. Molecular modeling at the molecular mechanics and density functional theory levels showed that the geometries adopted by H in the crystals obtained without guest inclusion, as well as for the complexes with ANI and 4MA, are essentially the same, and correspond to a conformer that is 13.4 kJ·mol–1higher in energy than the global energy minimum conformer for the peroxide.
Source: Crystal Growth & Design
Institution: Nelson Mandela University
Language: English
Subfield: Physical and Theoretical Chemistry
Field: Chemistry
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $4,500
OpenAlex ID: W4412774633