TY - JOUR
T1 - Benzophenone as a Probe of Local Cosolvent Effects in Supercritical Ethane
AU - Knutson, Barbara L.
AU - Sherman, Steven R.
AU - Bennett, Karen L.
AU - Liotta, Charles L.
AU - Eckert, Charles A.
PY - 1997
Y1 - 1997
N2 - The n → π* shift of benzophenone has been used to quantify solute-cosolvent interactions in supercritical ethane. Dilute solutions of benzophenone in cosolvent/supercritical ethane mixtures were studied at 35°C from 50 to 100 bar over a range of cosolvent concentrations. The following cosolvents were chosen for investigation on the basis of their varying abilities to interact with benzophenone: 2,2,2-trifluoroethanol, ethanol, chloroform, propionitrile, 1,2-dibromoethane, and 1,1,1-trichloroethane. In the supercritical systems investigated here, hydrogen bonding of protic cosolvents to the carbonyl oxygen of benzophenone is the primary mechanism of the n →π* shift. The results of this investigation are consistent with a chemical-physical interpretation of cosolvent effects in supercritical fluids in the presence of strong specific solute-cosolvent interactions. The experimental results for the ethane/TFE/benzophenone system were analyzed by using integral equations in order to study the assumptions of the chemical-physical model. This combination of spectroscopic data with radial distribution function models provides a powerful tool for understanding cosolvent effects.
AB - The n → π* shift of benzophenone has been used to quantify solute-cosolvent interactions in supercritical ethane. Dilute solutions of benzophenone in cosolvent/supercritical ethane mixtures were studied at 35°C from 50 to 100 bar over a range of cosolvent concentrations. The following cosolvents were chosen for investigation on the basis of their varying abilities to interact with benzophenone: 2,2,2-trifluoroethanol, ethanol, chloroform, propionitrile, 1,2-dibromoethane, and 1,1,1-trichloroethane. In the supercritical systems investigated here, hydrogen bonding of protic cosolvents to the carbonyl oxygen of benzophenone is the primary mechanism of the n →π* shift. The results of this investigation are consistent with a chemical-physical interpretation of cosolvent effects in supercritical fluids in the presence of strong specific solute-cosolvent interactions. The experimental results for the ethane/TFE/benzophenone system were analyzed by using integral equations in order to study the assumptions of the chemical-physical model. This combination of spectroscopic data with radial distribution function models provides a powerful tool for understanding cosolvent effects.
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U2 - 10.1021/ie9600809
DO - 10.1021/ie9600809
M3 - Article
AN - SCOPUS:0031095894
SN - 0888-5885
VL - 36
SP - 854
EP - 868
JO - Industrial and Engineering Chemistry Research
JF - Industrial and Engineering Chemistry Research
IS - 3
ER -