Preparation and properties of isomeric polyphenylacetylenes

Abstract

Polyphenylacetylenes were prepared using ferric acetylacetonate and (i‐Bu)2AlH, RhCl[(C6H5)3P]3 and thermal initiation. Color, infrared spectra, softening temperatures, ultraviolet fluorescence, solubility, and crystallinity are described. A method is presented for assigning to these three macromolecular species predominantly cis, trans, and cis–trans copolymer structures, respectively. The dominantly cis polymer is believed to form in a transoid conformation which can easily be transformed to a more helical arrangement which exhibits a degree of crystallinity. Pyridine promotes the isomerization of cis to trans structure. The rhodium phosphine is thought to effect chain growth by repeated additions of the acetylenic CH of monomer across a terminal triple bond. Phenylacetylene thus behaves as a bifunctional molecule in this system. Color, polymer conformation, and crystallinity appear to be strongly interrelated.

Advanced syntheses and microfabrications of conjugated polymers, C60-containing polymers and carbon nanotubes for optoelectronic applications

“…The syntheses of soluble poly(methylacetylene) and poly(phenylacetylene) have been reported by using rhodium compounds as the catalyst [255,256]. These polymers can be regarded as polyacetylene grafted with methyl or phenyl side groups.…”

Precise synthesis of monosubstituted polyacetylenes using Rh complex catalysts. Control of solid structure and π-conjugation length

“…Previously, Kern (1969) 8) has reported that the Wilkinson catalyst, RhCl(PPh 3 ) 3 , can be used to polymerize the ethynylbenzene (EB) monomer, although the color of the resulting poly(ethynylbenzene) polymers depended on the polymerization conditions. Recently, analogues of the Wilkinson catalyst, e. g. [Rh(norbornadiene)Cl] 2 , were extensively developed in order to selectively produce cis-PEB even at room temperature 12,18,21,22) , although the complete cis-polyacetylene can be generated at a lower temperature, ca.…”

Substituted polyacetylenes

“…A pioneering work was done by Kern as early as the 1960s, 57 in which monomer 1 was polymerized with RhCl 3 -LiBH 4 and (Ph 3 P) 3 RhCl. The selective formation of cis-transoidal structure was confirmed by Furlani and Feast using 1 H and 13 C NMR, 58 and it was found by Tabata that Et 3 N works as an effective cocatalyst in the [(nbd)RhCl] 2 -catalyzed (nbd: 2,5-norbornadiene) polymerization.…”