Poly[(2,2′,5′,2″-tetramethoxy-p-terphenyl-5,5″-ylene)propylene]: Synthesis and physical properties of a novel amorphous regularly segmented conjugated polymer

A new regularly segmented conjugated polymer with methoxy-substituted p-terphenylene units tethered by their meta positions along the polymer main chain was synthesised using the Suzuki cross-coupling reaction. The small size of the connector and lack of long lateral chains lead to a high density of rigid electrooptically active moieties in the structure. However, this molecular architecture produces a very soluble and amorphous polymer with relatively high Tg. The optical properties of samples with different degrees of polymerisation were investigated using UV–visible absorption, steady state and time-resolved photoluminescence emission spectroscopies. Their absorption and emission properties are rather insensible to Mn after reaching a modest DP, to the aggregation state, either solution or neat film, and to annealing. The contorted polymer chain forms a very stable morphology and substantially hinders interactions between chromophores, thus diminishing the formation of aggregated species that are commonly observed in other electrooptically active polymers.