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Several crosslinkable oxetane‐functionalized copolymers, containing regio‐regular segments of 3‐hexylthiophene, are synthesized using the Grignard metathesis polymerization. The optical and electrochemical properties of the new polymers, both in the soluble and crosslinked forms, are reported. These polymers are used in the preparation of organic photovoltaics upon blending with PCBM as electron‐acceptor. The effect of the crosslinking of these copolymers, once the blend films are formed, on the devices performance is also studied. In particular, the insertion of the oxetane‐functionalized thiophene comonomers leads to a decrease of the devices performance, which is further decreased upon crosslinking of the copolymer. However, the stability of the devices overall improves upon crosslinking of the copolymer. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014, 52, 652–663

Light-emitting diodes based on blends of the two green-emitting polymers, poly(9,9-dioctylfluorene-alt-benzothiadiazole), F8BT, and poly(9,9-dioctylfluorene-alt-bithiophene), F8T2, show efficiencies that lie in between those of the devices based on the neat polymers (with a maximum efficiency of approximately 4 cd/A for the devices with magnesium cathodes based on F8BT), except for the blend with 5% by weight of F8T2, which is more efficient than the device based on neat F8BT (a maximum efficiency of approximately 5 cd/A is obtained). In view of the lower photoluminescence efficiency of F8T2, we attribute this improvement to the improved hole transport brought about by F8T2, though is surprising that 5% by weight, is enough to significantly improve the charge balance within the emissive layer. A detailed photophysics study was carried out for the neat polymers and their blends and no clear evidence for energy transfer between the components was found. This unanticipated devices performance improvement points to the need of a deeper screening of available conjugated luminescent polymers.

(CNB-EDT-TTF)6Ag∼7.91I∼9.15 (CNB-EDT-TTF = 5-cyanobenzene-ethylenedithio-tetrathiafulvalene) is reported as the first bilayer conducting salt with a polymeric anion. The anion is a silver-deficient iodoargentate layered polymer with a composition close to Ag7.95I9.19, as deduced from single crystal X-ray diffraction. In spite of disorder in the silver iodide polyanion layer, and the large unit cell with six inequivalent donor molecules, this compound presents clear metallic properties down to 1.5 K, comparable to those of the β′′-type 4:1 salts of this donor with small discrete anions, with room temperature electrical conductivity in the range of 3–10 S/cm and thermoelectric power of ∼100 μV/K.