Over the 2 hours, a maximum Mw of 4950 g/mol was observed (Fig. ). The limited molecular weight of the polymer is likely a result of polymer precipitation at that chain length with these reaction conditions. While the molecular weights obtained with this method are relatively low, this precipitation polymerization does provide a self-protection mechanism against reductive degradation of the polymer. This feature contrasts to homogenous chemical initiation methods such as photoredox catalysis or chemical reduction which could potentially react with and reduce the polymer, rather than just the monomer. Finally, it was observed that the distribution of polymer molecular weight decreased over the reaction, resulting in a more uniform Đ (Fig. ). This is likely a result of lower molecular weight oligomers converting to longer-chain polymers and precipitating from solution. Next, the optimized conditions (Table , entry 10) for the synthesis of poly-4 were applied to monomers 1 and 3. Specifically, the monomers were dissolved in a solution of acetonitrile so that the initial monomer concentration was 0.04 M. An undivided cell was used in the ElectraSyn ® reactor equipped with two glassy carbon electrodes and an Ag/AgCl reference electrode. The supporting electrolyte was nBu4NPF6 (0.1 M in acetonitrile, 15 mL) and the polymerizations were initiated by applying a constant potential of -2.0 V versus Ag/AgCl. The reactions were run for 4 hours at room temperature with stirring. As in the synthesis of poly-4, poly-1 and poly-3 also precipitated during the reaction. Poly-1 was isolated in 83% yield, with GPC analysis indicating a Mw of 6580 g/mol and a Đ of 3.08 (Fig. ). The formation of poly-3 is also notable in that the carboxylic acid functionality was tolerated (Fig. ). Evidence for the stability of the carboxylic acid group under these conditions can be observed by the characteristic carbonyl stretch present in the infrared spectrum of poly-3 (Fig. ). Poly-3 was isolated in a synthetically useful yield of 59%. Aqueous GPC analysis of poly-3 combined equimolar quantities of NaOH per carboxylic acid indicated a Mw of 8530 g/mol and a Đ of 1.31. Poly-3 was soluble in water when the carboxylic acid groups were deprotonated by equimolar quantities of NaOH (Fig. ). Successful preparation of poly-3 represents a significant advance in producing water-soluble polysulfides, few of which have been made by inverse vulcanization. Aqueous solubility of sulfur rich polymers may provide benefits in sorption of valuable metals in aqueous media, as previously shown by Jenkins and co-workers, so this behavior for poly-3 was investigated further (vide infra).