| Thanks to recent advances in ionization, Fourier Transform Ion Cyclotron Resonance Mass Spectrometry (FT-ICR MS) has come to the forefront of mass analysis techniques in biochemistry and other chemically related fields thanks to the ultrahigh resolution and ultrahigh mass accuracy capabilities it affords. The FT-ICR mass spectrometer is also used as a self contained ion-molecule laboratory for the study of intrinsic gas phase chemistry of ions without interfering solvent effects. The ionization method that has allowed this is Electrospray Ionization (ESI), which allows for generating ions from species in solution a wide variety of solvents. This dissertation focuses on applying ESI coupled to FT-ICR MS to challenging structural problems in inorganic and biochemistry. Peptide phosphorylation and sulfation posttranslational modifications and sulfation or phosphorylation cofactors that differ in mass by less than 0.0095 Dalton are readily resolved by this method, which allows for rapid identification of the residues or cofactors. This isobaric pair can be resolved even in a mixture of the two peptides or two cofactors without resorting to chromatography. The same ultrahigh resolution and ultrahigh mass accuracy are applied to determining the formula and composition of silicate esters and their transition metal complexes in an actively reacting sol-gel polymerization. ESI FT-ICR MS is also used to determine the repeat unit and molecular identity of supramolecular gold and copper clusters using ultrahigh mass accuracy and the tandem mass spectrometric capabilities that can be conjoined with such instruments. ESI FT-ICR MS used in ion-molecule laboratory mode has revealed interesting dynamics of peptide ions in the gas phase thanks to unique photoaffinity labeling experiments detailed in this dissertation. Reaction mechanisms of square planar Rh(I) complexes have been revealed to proceed by dissociative, rather than associative, pathways in the gas phase. This is contrary to the bulk of square planar reactions in solution, which proceed by associative interchange. |
