Characterization of supercritical fluid solvents using solvatochromic shifts

Journal Article · Thu Jun 19 00:00:00 EDT 1986 · J. Phys. Chem.; (United States)

DOI:https://doi.org/10.1021/j100404a046· OSTI ID:5332884

Yonker, C R; Frye, S L; Kalkwarf, D R; Smith, R D

Solvatochromic probe molecules, with absorbances in the UV region, were used to examine the cybotactic region of pure and mixed supercritical fluid solvent systems. This approach allowed determination of the relative polarity-polarizability of these fluids and comparison with conventional solvents. The position of maximum absorbance was seen to be density dependent. The solvatochromic shift for the most polar fluid studied, supercritical ammonia, was the most sensitive to changes in solvent density, and at moderate densities it approached that observed for tetrahydrofuran. Supercritical CO/sub 2/, N/sub 2/O, and CCl/sub 3/F showed smaller spectral shifts over a comparable density range. In mixed fluid solvents (CO/sub 2/-methanol) the spectral shift approached that seen for pure methanol as the percentage of methanol was increased.

• Research Organization: Pacific Northwest Lab., Richland, WA
• DOE Contract Number: AC06-76RL01830
• OSTI ID: 5332884
• Journal Information: J. Phys. Chem.; (United States), Journal Name: J. Phys. Chem.; (United States) Vol. 90:13; ISSN JPCHA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
ABSORPTION SPECTRA
ALCOHOLS
AMMONIA
CARBON COMPOUNDS
CARBON DIOXIDE
CARBON OXIDES
CHALCOGENIDES
CRITICAL PRESSURE
CRITICAL TEMPERATURE
DATA
EXPERIMENTAL DATA
EXTRACTION
HYDRIDES
HYDROGEN COMPOUNDS
HYDROXY COMPOUNDS
INFORMATION
METHANOL
NITROGEN COMPOUNDS
NITROGEN HYDRIDES
NITROGEN OXIDES
NITROUS OXIDE
NUMERICAL DATA
ORGANIC CHLORINE COMPOUNDS
ORGANIC COMPOUNDS
ORGANIC FLUORINE COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
PRESSURE DEPENDENCE
SEPARATION PROCESSES
SOLVENT EXTRACTION
SOLVENT PROPERTIES
SPECTRA
SUPERCRITICAL GAS EXTRACTION
THERMODYNAMIC PROPERTIES
TRANSITION TEMPERATURE
ULTRAVIOLET SPECTRA