Diacetylenes copolymerization

Finally, reference should be made to copolymerization in this series. The diacetylene 142 is (homo)-polymerizable by high-energy radiation, whereas 143, though structurally very similar, is not. This difference in reactivity is apparently due to the difference between the crystal axial lengths in the direction in which polymerization would be expected to proceed this length is 4.37 A for 142 and 4.55 A for 143 (216). The two monomers are miscible in all proportions in the... 

Patel, G. N., Miller, G. G. Copolymerization of diacetylenes in the crystalline solid state — a method for recording latent finger prints. Preprint 1976... 

Little has been reported on the formation of organogermanium dendrites and related hyperbranched products. Recently, Tang et al. described the synthesis of hyperbranched materials based on the diacetylene l,l-diethynyl-2,3,4,5-tetraphenyl-germole, 130. The homopolymerization of 130 to homopolymer 131 and and copolymerization with 1-octyne, 132, to copolymer 133 was accomplished (Scheme 39). 

An interesting class of metal-induced cross-linking gel was reported by Hecht [68]. A poly(triazole-pyridine) 68 was prepared by AABB CuAAC copolymerization of a pyridyl diacetylene 69 and a chiral aryl diazide 70 (Scheme 20). Due to the repulsive interactions between the nitrogen lone-pair electrons on the triazole and pyridine units [69], the polymer tended to adopt a helical conformation in the absence of metal ions. On the other hand, metallogels 71 were formed when Zn (II), Fe(II), or Eu(III) ion was added to a solution of the polymer in acetonitrile. It was believed that the 2,6-bis(triazolyl)pyridine ligands chelated to the metal ion to form a hexacoordinate metal complex, which then led to a metal-promoted cross-linked 3D network that entrapped acetonitrile solvents. 

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