Reaction products and rates were measured for the gas-phase reactions of selected first row transition metal ions (Ti+, V+, Fe+, Co+, Ni+, Cu+, Zn+) and both CO and CO2 using a flowing afterglow instrument. The formation and description of products formed and reaction mechanisms are presented and discussed as well. Ab initio calculations were used to produce potential-energy surface diagrams for selected reactions as a tool to further understand the reaction mechanisms, thermochemistry, and reaction kinetics. Reactions with CO are slow and typically yield complexes of the form M(CO)n+ (n = 1-2), with the second CO molecule appearing to be added faster than the first one. Reactions with CO2 also yield the formation of clusters; however, in the case of Ti+, the reaction produces the oxide TiO+ ion efficiently. An interesting observation was also the formation of metal doubly charged ions. Some dications were easily obtained as the major ion by changing the ionization conditions in the sputter ion source. We are proposing an ionization mechanism for the formation of the dications.

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Nuclear magnetic resonance (NMR) techniques were used to study crown ether-water interactions in solvents of low dielectric constants such as chloroform and carbon tetrachloride. Water forms a 1:l complex with a number of crown ethers including 12-crown-4, 15-crown-5, 18-crown-6, dicyclohexano-18-crown-6, dichclohexano-24-crown 8, and dibenzl-24-crown-8 in chloroform. Among these crown ethers, the 18-crown-6-HzO complex has the largest equilibrium constant (K=545) and 97% of the crown is complexed to water in chloroform. Addition of carbon tetrachloride to chloroform lowers the equilibrium constants of the crownwater complexes. The partition coefficients of crown ethers (D = crown in waterkrown in solvent) between water and organic solvent also vary with solvent composition. At room temperature, the D value for 18-crown-6 is about 0.25 between water and chloroform and the value increases to 48 between water and carbon tetrachloride. NMR studies of cesium-crown ether-water interactions in chloroform in the presence of picric acid turned out to be complicated for spectral analysis. Some results were obtained but with large uncertainties. N M R studies of crown-water interactions in supercritical C02 using a capillary tubing technique was also not successful due to experimental difficulties. Instead, Fourier-Transform Infrared (FT-IR) spectroscopy was used to study crown-water interactions in liquid and supercritical C02 using a high-pressure view-cell with diamond windows.liquid and in supercritical C02 were studies under various experimental conditions. Water forms a 1: 1 complex with 18-crown-6 at low ligand concentrations and a 112 sandwich complex at high ligand concentrations. Spectral analysis indicates that the 1 : 1 complex has two forrns, one with both hydrogen atoms of the H20 molecule bonded to the oxygen atoms of the host cavity and the other with only one hydrogen bonding between water and the cavity oxygen. The equilibrium constant of the single hydrogen bond 18-crown-6-H20 complex decreases from 2 l*2 to1 3rtl L mol-' with an increase in temperature fiom 25 "C to 60 "C at 200 atm C02. The equilibrium constant of the double hydrogen bond complex decreases from 14k2 to 2*1 from 25 "C to 60 "C under the same C02 pressure. The enthalpis of the reaction for the single hydrogen bond and the double hydrogen bond complexes were determined to be -12*2 KJ mol-' and -38h3 KJ mol-', respectively. Density shows little effect on the equilibrium constants of the crown-water complex in supercritical C02. The crown-water complex can be regarded as a Lewis acid-base complex with the crown being the electron donor and the water as the electron acceptor. This Lewis acid-base complex formation mechanism may provide a means of introducing insoluble hydrophilic acids into supercritical CO2 for chemical reactions and separations.Several techniques were used to characterize complex formation between tri-nbutylphosphate (TBP) and some inorganic acids using NMR and other methods. TBP forms complexes with aqueous acids such as...