Mixtures of a radiation polymerizable poly(ethylene glycol)-dimethacrylate, a plasticizing solvent and a neodymium salt have been studied using FTIR and UV-VIS spectroscopy. The solvents used are propylene carbonate (PC) and dimethyl sulfoxide (DMSO) and the salts are neodymium bis-(trifluoremethanesulfonyl)-imide (TFSI) and neodymium nitrate. While the macroscopic properties of the electrolyte change radically on polymerization, the local environment of the neodymium ion is unchanged. The neodymium ions are coordinated to the ether oxygens of the polymer or solvated by the plasticizing solvent depending on which solvent is used. Complex formation of the anions is observed for the nitrate ion but not for TFSI in the concentration range studied.