Andrew G. Gilicinski

On the relative power of electrophilic fluorinating reagents of the NF class

Abstract Electrochemical measurements have been employed as a measure of the relative chemical reactivity of a series of NF class electrophilic fluorinating reagents. A correlation has been found between the potential for the first one-electron reduction of the reagents and their observed reactivity in synthetic fluorination reactions. Comparative electrochemical data in acetonitrile and dimethylformamide are reported.

Study of Silicon Surface Roughness by Atomic Force Microscopy

Progress is reported in developing reliable methodology for imaging silicon surfaces with the atomic force microscope (AFM). A new form of AFM, known as tapping mode AFM, has been found to provide the best quality data for surface roughness determinations. Commercially available colloidal gold spheres have been used to fabricate tip characterization standards and are used to report tip size with roughness data. Power spectral density calculations are shown to provide a useful roughness calculation based on lateral wavelength.

The Effects of Chemical Vapor Cleaning Chemistries on Silicon Surfaces

This study explores the effects of two chemical vapor cleaning chemistries on silicon surfaces. The silicon surfaces are not significantly roughened by exposure to either process. Trace amounts of fluorine are found on the surfaces exposed to 1,1,1,5,5,5-hexafluoro-2,4-pentanedione (HFAC). A thin silicon nitride film forms on the silicon surface as a result of exposure to the HMDS process and is attributed to the H 2 /N 2 plasma treatment used in the first step of the process.

New Metal Complex Oxygen Absorbents for the Recovery of Oxygen

Emerging non-cryogenic technologies for the separation of air use zeolites and microporous “molecular sieve” carbons as moderately selective nitrogen and oxygen adsorbents, respectively.1,2 While the zeolites have a thermodynamic affinity for N2, use of carbons relies on a kinetic selectivity for the passage of oxygen into the micropores. It is well known that certain coordination compounds of cobalt and iron reversibly react with oxygen under near ambient conditions.3,4 Since this is a chemical rather than a physical interaction as is seen with zeolites and carbons, it should be possible to use such metal complexes as O2 equilibrium sorbents for air separation. We have been conducting a long term research effort to prepare such metal complex oxygen carriers for use in future generation non-cryogenic air separation devices.5 The primary interest in such complexes is in their use in pressure or temperature swing processes for the production of inert gas (N2,Ar) and oxygen.6,7 For these applications, the oxygen complex could either be used as a circulating liquid or as a solid sorbent. In order to be useful in a commercial process an oxygen complex has to satisfy several requirements. It must (a) bind O2 rapidly and reversibly, (b) have a high stability (>1 year lifetime), and (c) be accessible via simple synthetic techniques at minimal cost.