Ruilian Wu

A zirconium-promoted methylenation of aldehydes, ketones, and enones

Abstract Treatment of zirconocene dichloride with dibromomethane and zinc affords an organometallic intermediate which rapidly methylenates aldehydes, ketones, and enones at room temperature.

Approaches to Orthogonally Fused Conducting Polymers For Molecular Electronics

Molecular electronics-based computing instruments possess tremendous technological potential. There is the hope of developing single molecules that could each function as a self-contained electronic device. Thus, one can envision computing systems with molecular-sized electronic elements and operational efficiencies far exceeding that of present systems.3 Recently, Aviram of the IBM Corporation has suggested that molecules which contain a pro-conducting (non-doped or non-oxidized system, hence insulating) polymer which is fixed at a 90° angle via a non-conjugated sigma bonded network to a conducting (doped or oxidized system) should exhibit properties which would make it suitable for interconnection into future molecular electronic devices.4 These devices may be useful for the memory, logic, and amplification computing systems. The molecule 1 (in doped form) is an example of this pro-conducting/sigma/conducting type of molecule.

Orthogonally fused conducting oligomers for molecular electronic devices

Described is the synthesis of two spiro core segments of orthogonally arranged conducting systems and the adhesion of oligomeric branching units to the core segments. The final systems are to have a potentially conducting chain fused perpendicularly to a second potentially conducting chain via a sigma bonded network. These systems may be suitable for incorporation into future molecular electronic devices. One of the core segments synthesized is based on a thiophene conducting group and it is formed by a zirconium‐promoted bis(bicyclization) of bis(diyne) systems. The second is a phenylene‐based system that is derived from fluorene. Terminal bromide groups provide the linkage points for further extensions of the chains via palladium‐catalyzed cross coupling methods. Four thiophene trimers are added in a single operation to spiro‐fused cores to afford the target molecules. A spiro‐fused thiophene‐based monomer system is converted to a spiro‐fused heptamer that is 25 A long. The synthesis of a mixed phenylen...