Competition between Ultrafast Energy Flow and Electron Transfer in a Ru(II)-Loaded Polyfluorene Light-Harvesting Polymer.

This Letter describes the synthesis and photophysical characterization of a Ru(II) assembly consisting of metal polypyridyl complexes linked together by a polyfluorene scaffold. Unlike many scaffolds incorporating saturated linkages, the conjugated polymer in this system acts as a functional light-harvesting component. Conformational disorder breaks the conjugation in the polymer backbone, resulting in a chain composed of many chromophore units, whose relative energies depend on the segment lengths.

Color purity in polymer electrochromic window devices on indium-tin oxide and single-walled carbon nanotube electrodes.

Dual polymer absorptive/transmissive electrochromic (EC) window devices have been assembled using the solution-processable and high-EC-contrast polymer PProDOT-(CH(2)OEtHx)(2) as the EC material, along with a non-color-changing electroactive polymer, poly(2,2,6,6-tetramethylpiperidinyloxy-4-yl methacrylate) (PTMA), as the counter electrode material. Indium-tin oxide (ITO) and highly transmissive single-walled carbon nanotube (SWNT) film coated glass electrodes are used as electrode substrates. The use of the EC/non-color-changing polymer combination allowed us to construct window devices that rapidly switch between magenta and highly transmissive (>95% T for ITO and approximately 79% T for SWNT) states with large optical modulation (>71% DeltaT for ITO and 66% DeltaT for SWNT).

Conformational locking for band gap control in 3,4-propylenedioxythiophene based electrochromic polymers.

We report a tethered poly(3,4-propylenedioxythiophene) derivative with a built-in polymer conformation restriction which locks the conjugated chain at a specific dihedral angle, thus providing a handle in which to tune the optical and electronic properties of the material.

Electrooxidative coupling of furans and silyl enol ethers: application to the synthesis of annulated furans.

The preparation of annulated furan systems as key synthetic intermediates through the application of a two-step annulation involving an electrochemical ring closure between a furan and a silyl enol ether has been studied. The reaction was shown to be quite general for the formation of six-membered rings in good yields and was tolerant of a variety of different functional groups. The ring closure was highly stereoselective, leading to the formation of cis-fused systems.