| Room temperature ionic liquids (RTILs) have recently gained recognition as possible environmentally benign alternative chemical process solvents. They are nonvolatile and non-flammable. The superoxide ion is a safe and mild oxidizing agent that has several potential applications.; In this dissertation we show that a stable superoxide ion (O2 •-) can be electrochemically generated in certain RTILs as long as the structure and purity of the RTIL is controlled. We also show that the superoxide ion in RTIL can be used to destroy polyhalogenated aromatic hydrocarbons, which represent a major environmental problem.; Selective oxidation of organic compounds is vital for manufacturing value-added chemical intermediates. Here we show that O2•- reacts with primary and secondary alcohols to give the corresponding carboxylic acids and ketones, respectively. The yields depend greatly on the structure of the RTIL and its level of purity. When 1-butyl-3-dimethylimidazolium hexafluorophosphate, [bmim][HFP], was used, the average yield of benzhydrol to benzophenone was 50%. That is, only half of the electrochemically generated superoxide ion went on to participate in the desired reaction, while the other half reacted with [bmim][HFP] as indicated by the detection of the corresponding ketone. In comparison, when purified 1-butyl-2,3-dimethylimidazolium hexafluorophosphate, [bdmim][HFP] was used the average yield of benzophenone increased to 98%. Equally significant was that no degradation products were detected in this case.; The superoxide ion was used to activate dissolved CO2 in RTILs. This is a first step toward the synthesis of carbmates and organic carbonates from the corresponding amines.; Most of the previous electrolysis experiments have been conducted in a standard two-compartment cell. The potential difference across the fritted glass used to separate the cathode and anode compartments in [bmim][HFP] was very high compared to the potential difference between the solvent and the electrode. An electrochemical reactor utilizing NafionRTM membrane as a separator between the cathode and anode compartments was constructed and used to conduct synthesis processes in RTILs. The use of Nafion RTM the potential difference by more than 4 fold. This reduces the energy needed for electrolysis remarkably in addition to enhancing mass transfer.; We used electrochemical techniques, particularly, double potential step chronoamperometry, to determine the pseudo first order rate constant for the homogeneous reaction between the superoxide ion and primary and secondary alcohols in RTILs at different temperatures. The activation energy for the reaction was then determined using the Arrhenius method. |
