Organic chemistry in supercritical water

The knowledge of supercritical fluids dates back to 1861 when the critical conditions of carbon dioxide were established. Over the last two decades, the use of water as a critical solvent has been under development because of the unusual properties exhibited near the critical point. This dissertation describes to use of subcritical and supercritical water as a solvent for synthetic organic chemistry.; A supercritical fluid can be described as a fluid with a single phase where the distinction between a liquid and gas can no longer be made. Water's critical point is at 374{dollar}spcirc{dollar}C and 220 atmospheres where the critical density is 0.322g/mL. The properties of water change dramatically around the critical point. For example, the dielectric constant of water decreases from a room temperature value of around 80 C{dollar}sp2{dollar}/NM{dollar}sp2{dollar} to a value of 5 C{dollar}sp2{dollar}/NM{dollar}sp2{dollar} at the critical point. This is around the value for many organic solvents like benzene and toluene and they, with oxygen, become completely miscible in all proportions at or the near critical point.; Using the unique properties of supercritical water, these labs were able to perform traditional synthetic organic oxidations in water. Incorporating water into synthetic applications associated with bulk chemical processing can minimize hazardous waste. The organic compound p-xylene can be oxidized to terephthalic acid in good yields (65%). The compound fluorene can be extracted from coal tar and oxidized to fluorenone in a single, batch reactor process using subcritical water as the solvent. Subcritical water has also been shown to be useful in the complete hydrolysis of polyester to terephthalic acid and ethylene glycol. Other synthetic organic reactions have been shown to work in supercritical water such that it has been shown to be a viable solvent for organic chemistry.; In unrelated work, the chemistry of iron carbonyl sulfides and selenides was studied. Polysulfides and polyselenides will react with iron carbonyl in an oxidative decarbonylation pathway to give dianionic clusters such as ({dollar}rm Fesb6(CO)sb{lcub}12{rcub}Ssb6rbrack sp{lcub}2-{rcub}{dollar} and ({dollar}rm Fesb5(CO)sb{lcub}14{rcub}Sesb2rbrack sp{lcub}2-{rcub}.{dollar} Other metals like nickel and palladium have been inserted into these compounds to form mixed metal species like ({dollar}rm NiFesb4(CO)sb{lcub}12{rcub}Ssb 4rbrack sp{lcub}2-{rcub}.{dollar}...