No abstract

We report the synthesis of a series of random copolymers composed of phenyleneethynylene and 3,7-di-tert-butylnaphthalene units by alkyne metathesis with simple catalyst systems, formed from Mo(CO) 6 and 4-chlorophenol in situ. These novel copolymers give rise to efficient (Φ ) 0.16-0.76) blue solid-state emission (λ max ) 422-443 nm) which can be fine-tuned according to their naphthalene content differing greatly from that of standard dialkyl-PPE (λ max 500-520 nm). The effective and blue-shifted solid-state emission is a result of disrupting the solid-state alignment thereby diminishing π-π interactions of the copolymers in addition to the efficient interruption of planarization of the conjugated backbone. Electroluminescent multilayer devices showed low turn-on voltages (5.5 V) and a maximum brightness of 100 cd/m 2 .

Gold nanowell electrode arrays, with a nanowell depth of approximately 600 nm, have been prepared using commercially available anopore membranes as templates. Electrodes were prepared by forming a copper film on anopore, followed by electrodeposition of gold throughout the pore and finally removal of the copper to expose the nanowells. The electrodes were characterized by atomic force microscopy, scanning electron microscopy, and electrochemical methods. Dodecanethiol self-assembled monolayers were found to passivate the electrode.

We report studies on the perturbations induced by the evaporation of copper metal overlayers on dodecanethiol and octadecanethiol self-assembled monolayers (SAMs). Monolayers were characterized after deposition on a gold substrate from an ethanolic solution, after heat treatment alone, after acid treatment alone, after physical evaporation of a submonolayer copper layer alone, and after deposition of an optically thick copper layer followed by stripping with a nitric acid solution. The monolayers were studied using cyclic voltammetry, grazing-angle IR spectroscopy and X-ray photoelectron spectroscopy. Cyclic voltammetry revealed that the gold electrodes are passivated by the formation of the monolayers. The degree of passivation does not decrease with exposure to <6 N nitric acid solutions or after copper deposition and removal with nitric acid. The IR studies indicate that the deposition of metal induced a reorganization, interpreted as increased disordering, of the monolayer, that is similar to heat treatment alone. X-ray photoelectron spectroscopy experiments showed no evidence of bond formation between carbon and copper upon deposition of the copper layer on the SAM.