A novel naphtho [2,3-b:6,7-d′]dithiophene (NDT)-based copolymer, poly [4,9-bis(2-ethylhexyloxy)naphtho[2,3-b:6,7-d′]dithiophene-2,7-diyl-alt-1,3-(5-heptadecan-9-yl)-4H-thieno[3,4-c]pyrrole-4,6-dione] (P1), was synthesized and characterized for use in polymer solar cells. We systematically investigated the synthesis, thermal stability, optical and electrochemical properties, field-effect carrier mobilities, and photovoltaic characteristics of the resulting polymer. The properties of the NDT-based polymer were compared with those of poly[4,8-bis(2-ethylhexyloxy)benzo-[1,2-b:4,5-b′]dithiophene-alt-1,3-(5-heptadecan-9-yl)-4Hthieno[3,4-c]pyrrole-4,6-dione] (P2) prepared via the same synthetic procedure. Polymer solar cells made from the new polymer, P1, yielded a power conversion efficiency of 4.0% with a short-circuit current density of 11.54 mA/cm 2 , an open-circuit voltage of 0.69 V, and a fill factor of 0.50 under AM 1.5 G irradiation (100 mW/cm 2 ).

Palladium substituted in cerium dioxide in the form of a solid solution, Ce 0·98 Pd 0·02 O 1·98 is a new heterogeneous catalyst which exhibits high activity and 100% trans-selectivity for the Heck reactions of aryl bromides including heteroaryls with olefins. The catalytic reactions work without any ligand. Nanocrystalline Ce 0·98 Pd 0·02 O 1·98 is prepared by solution combustion method and Pd is in +2 state. The catalyst can be separated, recovered and reused without significant loss in activity.

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