Sharon Gould

Three-dimensional characterization of conducting polymer arrays using secondary ion mass spectrometry

Image depth profiling with dynamic secondary ion mass spectrometry (SIMS), using ion microscopy and digital imaging, provided high spatial resolution 3D images of patterned polymer films prepared from [Ru(Me4bpy)2(vpy)2]2+ and {Fe[(CH2Br)2bpy]3}2+. Although 3D SIMS has been widely applied to semiconductor device characterization, this study represents a first attempt to characterize conductive polymer arrays. The SIMS studies were useful in localizing the polymer domains, and the extent of polymer mixing within the film structures. Volume‐rendered images and reconstructed local area depth profiles indicated that electropolymerization of the poly‐Fe complex was not limited to the channels in the poly‐Ru resist produced by optical lithography. Quantification of the SIMS image depth profiles required consideration of detection system nonlinearities, ion yield variations (especially transients at the film/substrate interface), and native and sputter induced roughness of the polymer films.

Reductive electropolymerization of complexes containing an aldehyde-substituted derivative of 2,2′-bipyridine

Abstract Polypyridyl complexes of Fe II and Zn II containing the ligand 4-methyl-2,2′-bipyridyl-4′-carboxaldehyde(4-CH 3 -4′-CHO-bpy) have been prepared. Upon electrochemical reduction of these complexes coupling reactions occur at the ligands, yielding thin metal-complex-containing polymeric films on the electrode surfaces. The polypyridyl ligands that form in a polymerized film of [Zn(4-CH 3 -4′-CHO-bpy) 3 ] 2+ have been isolated following chemical degradation and characterized using fast atom bombardment mass spectrometry and 1 H nuclear magnetic resonance. These and other results are consistent with a mechanism for polymerization that involves radical—radical coupling at the aldehyde substituents following reduction. The coupling occurs with the formation of a 1,2-diol linkage between the bipyridine ligands which creates a basis for network polymerization.