Running the reaction open to air (even for a mere 2 hours) resulted in a substantial amount of insoluble material. IR analysis of this insoluble fraction revealed unreacted alkenes (S13) and an overall lower fraction of carbon and sulfur by elemental analysis when compared to the soluble fraction (S13). In contrast, running the reaction under nitrogen in a rigorously dry reaction vessel overcame this issue. Control experiments indicated that water can interfere with the reaction and result in insoluble material (S12-S13), so reactions were subsequently run under a nitrogen atmosphere under anhydrous conditions. The preferred protocol for making oligomer 1 was therefore the direct reaction of equal masses of sulfur and DCPD at 140 °C, stirred vigorously for 2 hours under an atmosphere of nitrogen. The resulting material (1) formed a flexible solid on cooling to room temperature (Fig. ). Importantly, 1 was fully soluble in chloroform, which met the goal of accessing a solution-processible pre-polymer. This product was stable for more than 8 months and no elemental sulfur crystallised over this period.