2,5-Dichloro-1-(ROSO2)benzene [R = C6H5, C6F5, and CH2(CF2)4H]: Synthesis, molecular structure, and solubility in supercritical CO2 |
| |
Authors: | Michael E. Wright Casey E. Gorish Mark A. McHugh |
| |
Affiliation: | a Research Department, Chemistry Division, NAWCWD-US NAVY, China Lake, CA 93555-6100, United States b Department of Chemical and Life Science Engineering, Virginia Commonwealth University, 601 West Main Street, Richmond, VA 23284, United States |
| |
Abstract: | Highly crystalline phenyl 2,5-dichlorobenzenesulfonate (PDBS, Tmelt = 86-87 °C) and pentafluorophenyl 2,5-dichlorobenzenesulfonate (FPDBS, Tmelt = 120-122 °C) were synthesized. Single-crystal X-ray molecular structure determinations show that both compounds have similar three-dimensional molecular structures; however, PDBS crystals are thin platelets and FPDBS crystals form hexagonal tube-like structures that are predominately hollow at one end. PDBS crystals exhibit offset π-stacking of the phenoxy-rings that form complete two-dimensional layers each two molecules thick. Hydrogen-bonding interactions are calculated at ∼3.2 Å between the C6-hydrogen and the sulfonyl-oxygen of a neighboring molecule. On the other hand, for FPDBS, π-stacking of the dichloro-substituted ring as well as dipole-dipole interactions of the fluorinated-phenoxy rings appears to be the predominate intermolecular interactions. Neither structure exhibits any kind of side-on interaction of the phenyl rings. PDBS and FPDBS exhibit melting point depressions of 26 and 40 °C, respectively, in the presence of supercritical CO2. Although both sulfonates exhibit high solubility in CO2, much lower pressures are needed to dissolve FPDBS compared to PDBS. For example, at 100 °C FPDBS dissolves at 4750 psia and PDBS dissolves at 11,000 psia. The solubility data reinforce the observation that fluorinating a compound can significantly lower the conditions needed to dissolve that compound in CO2. |
| |
Keywords: | Supercritical CO2 solubility Crystal engineering Fluorination effects |
本文献已被 ScienceDirect 等数据库收录! |
|