I. Applications of fourier transform ion-cyclotron-resonance mass spectrometry to the studies of the isomers of the organometallic distonic ion and the reactivity of cobalt iodide. II. Analysis of polymers by matrix-assisted laser desorption/ionization--time-of-flight
Abstract
The study of organometallic distonic ion, Fe(p-benzyne) +, and it achieved by CID and ion-molecule reactions with selected alkenes and alkyl halides. The distonic ion, Fe(p-benzyne) + demonstrates unique reactivity toward most of these reagents unlike those of its isomers. In most reactions, it is seen that the charged metal center plays the major role, while the radical site is mostly inert. Other attempts have been made to generate and investigate new organometallic species with different charged metals or different ligands, such as iodoaniline or cyclopentadienyl. The unique reactivity of CoI+ with alkanes is studies. It is proposed that a C-H insertion followed by β-hydrogen transfer yields the dehydrogenation product. The iodine atoms appears to suppress the isomerization of the CoI(alkene)+ complex to a hydrido π-allyl complex ion. The most unique reaction observed is the selective 2,3-dehydrogenation of n-butane with CoI+. The use of metallocenes in polymer analysis by MALDI-TOF is first reported. Ferrocene and nickelocene cationized the polystyrenes and polyethylene glycols, while cobaltocene cationized only the polyethylene glycols. The higher molecular weight polymers achieved higher signal intensities than the low molecular weight polymers. In fact, PS 13700 had the highest signal intensity with very little if any metal cluster signals. In analyzing polymers by MALDI-TOF it is important to utilize metal salts as cationizing agents. The effect of the concentration of the cationizing agent, AgTFA, is studied. The results show that for low molecular weight polymer the concentration of the cationing agent does not significantly alter the signal intensity or the abundance of metal clusters. On the other hand, for high molecular weight polymers the concentration plays a major role in the signal intensity and the formation of metal clusters.
Degree
Ph.D.
Advisors
Regnier, Purdue University.
Subject Area
Analytical chemistry|Chemistry|Polymers
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