Novel metal containing polymers: characterization, radiation chemistry, and evaluation of utility for electron lithography

Polymeric dicarboxylato-dioxouranium(VI) species have been synthesized by two different methods. An equilibrium controlled solution relation has been devised where bis(acetato)dioxouranium(VI) undergoes an acid interchange reaction with a simple dicarboxylic acid. The materials synthesized in this manner have been characterized by several methods. An end group analysis is possible by high resolution nuclear magnetic resonance detection of the acetate reactant fragment. The concentration of acetate relative to bridging ligand can be used to calculate number average molecular weights. The gel permeation chromatographic method has been calibrated with poly[(3,3-dimethylpentanedioato)(dimethylsulfoxide)dioxouranium(VI)] and gives a simple relation of molecular weight versus milliliters of retention volume. Inclusion of the respective intrinsic viscosities and a comparison to the universal calibration curve, based on polystyrene, shows no significant difference. The net radiation chemistry of the polymeric materials has been evaluated with gel permeation chromatography. Solid samples were irradiated with 137Cs gamma radiation and the change in molecular weight with dose determined. These studies indicate that many of the uranium containing polymers possess unusually high sensitivities to radiation