The structure and attempted topochemical polymerization of single crystalline 1,1,4,4-bis(pentamethylene)-1,2,3-butatriene

The photo-initiated solid-state topochemical polymerization of 1,1,4,4-bis( pentamethylene)-1,2,3-butatriene (1) was attempted unsuccessfully. Since 1 readily polymerizes in the liquid state, a structural study was undertaken to better understand its inertness in the solid-state. 1 crystallizes in th e monoclinic space group P2(1)/n with a = 6.4597(6), b = 10.8914 (10), c = 8.4396(8) Angstrom, beta = 100.168(2)degrees, V = 584.44(9) Angstrom(3), an d Z = 2. The crystal structure reveals that while the alignment of the pi-s ystems in the solid-state is acceptable for supporting the targeted polymer ization reaction, the reaction centers are located too far apart to allow t he reaction to take place. Additionally, comparison of the molecular struct ure of 1 with the limited number of other structurally characterized butatr ienes has provided insight into the steric and electronic influences played by the substituents attached to the cumulene moiety.