reaction hypotheses because it is readily produced in polymerization experiments. One suggested role of 5 is as an intermediate in the hypothesized formation of 7. The structure 5 is known to undergo photochemical isomerization to 6. The cis-and trans-forms of 5 are also possible starting points for the Völker and Umemoto models (12, 13 and 14) shown in Figure . Mamajanov and Herzfeld have furthermore suggested that polymerization of 5 results in polyaminoimidazole (18 or 19) via an intermediate such as 20 (Fig. , pathway 5). Other structures proposed to form from 5 include the linear polymers 21 and 22 (Fig. , pathway 6). 12 Figure 5. Two pathways for polymerization of diaminomaleonitrile (5) proposed in literature. Polyaminomalononitrile (23). Figure shows the two last pathways that we consider.