Synthesis of π-conjugated polymers via regioregular organometallic polymers 2. Transformation of titanacyclopentadienecontaining polymer into poly(ρ-phenylene) derivative

Article abstract of DOI:10.1002/aoc.1593

The transformation of a regioregular organometallic polymer possessing titanacyclopentadiene-2,5-diyl units into a poly(ρ-phenylene) derivative by means of a novel polymer reaction method is described. The organotitianium polymer was prepared by the polymerization of 1,4-diethynyl-2,5- dioctyloxybenzene and a low-valent titanium complex, generated in situ from titanium(IV) isopropoxide and isopropylmagnesium chloride, and was subjected to the reaction with 3-bromo-1-propyne followed by the protonation. Consequently, a polymer consisting of the substituted phenylene-1,4-diyl units could be produced in a high yield,which is soluble in organic solvents such as chloroform. The number-average molecularweight and themolecular weight distribution of the polymer were estimated as 4800 and 1.8, respectively (GPC, polystyrene). The UV-vis absorption spectrum of the polymer exhibited the absorption maximum (λmax) at 329 nm, which was bathochromically shifted by 53 nm compared with that of a model compound, 1,4-bis(2-methoxyphenyl)-2- methylbenzene (λmax = 276 nm). Copyright