Benzophenone as a probe of local cosolvent effects in supercritical ethane

Journal Article · Sat Mar 01 04:00:00 EST 1997 · Industrial and Engineering Chemistry Research

DOI:https://doi.org/10.1021/ie9600809· OSTI ID:458466

Knutson, B L; Sherman, S R; Bennett, K L; Liotta, C L; Eckert, C A ^[1]

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1. Georgia Inst. of Technology, Atlanta, GA (United States)

The n {yields} {pi}* 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 {yields} {pi}* 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.

• Sponsoring Organization: USDOE, Washington, DC (United States)
• DOE Contract Number: FG22-91PC91287
• OSTI ID: 458466
• Journal Information: Industrial and Engineering Chemistry Research, Journal Name: Industrial and Engineering Chemistry Research Journal Issue: 3 Vol. 36; ISSN IECRED; ISSN 0888-5885
• Country of Publication: United States
• Language: English

Related Subjects

40 CHEMISTRY
BENZOPHENONE
CHEMICAL SHIFT
ETHANE
MATHEMATICAL MODELS
ORGANIC SOLVENTS
PROBES
SUPERCRITICAL GAS EXTRACTION