Synthesis and characterization of distonic radical, biradical and carbene ions
Abstract
The synthesis and characterization of distonic radical, biradical and carbene anions were studied with the use of a flowing afterglow-triple quadrupole instrument. A new synthetic strategy for gas-phase synthesis of negative ions with multiple open valence sites was developed. This method, which is based on the reaction of organic anions with molecular fluorine, allowed effective synthesis of a series of negative ions of biradicals and triradicals that are of great theoretical importance. These include the negative ions of trimethylenemethane; m- and p-benzyne; $\alpha$,3-dehydrotoluene; $\alpha$,3-dehydrostyrene; 3,5-dehydrophenyl; 1,3,5-trimethylenebenzene and 3-oxyphenylcarbene anions. The regioselective synthesis of these ions permitted negative ion photoelectron spectroscopic determinations of the electron affinities and singlet-triplet gaps in the corresponding biradicals (doublet-quartet gaps in triradical species). In addition, characterization of these ions using ion-molecule reactions and tandem mass spectrometry yielded a wealth of new chemical information concerning the radical- and spin-state related reactivity of these ions. Several gas-phase, ion-structure probes were also developed based on ion-molecule reaction mechanisms and ion fragmentation kinetics and energetics. In particular, application of the kinetic method resulted in unambiguous determination of the structures of some of the ions and in the measurement of important thermochemical data such as electron binding energies and gas-phase basicities of some of these ions.
Degree
Ph.D.
Advisors
Squires, Purdue University.
Subject Area
Organic chemistry|Chemistry|Analytical chemistry
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