Structural elucidation of organic molecules and analysis of petroleum fractions via ion -molecule reactions in a Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometer

Many mass spectrometric methods, such as exact mass measurement, collision-activated dissociation and H/D exchange reactions, have been successfully used for obtaining structural information on mixture components. However, these techniques don’t always allow the unambiguous identification of unknown compounds. Gas-phase ion-molecule reactions provide a powerful tool for obtaining molecular weight, structural, functionality and chemical reactivity information for molecules, including small organic molecules, drug intermediates, synthetic polymers and petroleum components. Chapters 3, 4 and 5 in this thesis address the issue of identifying two functional groups (N-oxide and diol) present in protonated analytes. The first study (Chapter 3) involves the identification of the aromatic tertiary N-oxide functional group via ion-molecule reactions with 2-methoxypropene (MOP) in an FT-ICR. The second study (Chapter 4) describes the identification of and differentiation between protonated aromatic and aliphatic tertiary N-oxide functionalities via ion-molecule reactions with tri(dimethylamino)borane (TDMAB) followed by sustained off-resonance irradiation collision-activated dissociation (SORI-CAD). The third study (Chapter 5) focuses on the differentiation of protonated stereoisomers (cis- and trans-diols) by using phenylboronic acid in the gas-phase. Chapters 6, 7 and 8 focus on the analytical utility of selective chemical ionization (CI) reactions combined with laser-induced acoustic desorption (LIAD) mass spectrometry for petroleum analysis. Chapter 6 discusses the gas-phase reactions of ClMn(H2O)+ with polar and nonpolar hydrocarbons in an FT-ICR mass spectrometer. The differentiation of isomeric hydrocarbons is also discussed in this chapter. Chapter 7 extends the applicability of LIAD/ClMn(H2O)+ CI to the analysis of real petroleum products (base oil fractions). Chapter 8 introduces a preliminary study on molecular weight distribution of asphaltenes by LIAD/EI mass spectrometry

Part 1, Synthesis and spectroscopic characterization of Ru(3,8-dibromo-1,10-phenanthroline)₃(PF₆)₂ ; Part 2, Magnetic field and temperature effects on the emission properties of d- and 1- tris(2,2\u27-bipyridyl)ruthenium(II) complexes

In first section . . . resulted in the first synthesis of Ru(3,8-dibromo-1,10-phenanthroline)₃(PF₆)₂, which could be used as a cross-linking core to generate metal-centered star-shaped hyperbranched assemblies. In second section . . . the purpose of our investigation is to clarify whether the luminescence properties demonstrate difference due to different physical properties. --Abstract, page iii

Ru(II) Tris(3,8-Dibromo-1,10-phenanthroline)—A New Versatile Core for the Divergent Synthesis of Hyperbranched Systems

We report the first synthesis of Ru(II) tris(3,8-dibromo-1,10-phenanthroline) bishexafluorophosphate (1), and we demonstrate its utility as a building core for the divergent synthesis of hyperbranched systems by coupling with phenylacetylene in the preparation of Ru(II) tris(3,8-diphenylethynyl-1,10-phenanthroline) dihexafluorophosphate (2)

Ion-Molecule Reactions for the Differentiation of Primary, Secondary and Tertiary Hydroxyl Functionalities in Protonated Analytes in a Tandem Mass Spectrometer

A mass spectrometric method utilizing gas-phase ion-molecule reactions of 1-butanethiol and di-tert-butyl peroxide has been developed for the differentiation of primary, secondary and tertiary hydroxyl functionalities in protonated analytes in a FT-ICR mass spectrometer

Ru(II) Tris(3,8-Dibromo-1,10-Phenanthro1ine): A New Versatile Core for the Divergent Synthesis of Hyperbranched Systems

We report the first synthesis of Ru(II) tris(3,8-dibromo-1,lO-phenanthroline) bishexafluorophosphate, and we demonstrate its utility as a building core for the divergent synthesis of hyperbranched systems by coupling with phenylacetylene in the preparation of Rum tris(3,8-diphenylethynyl- 1,lO-phenanthroline) dihexafluorophosphate

Data-Dependent Neutral Gain MS3: Toward Automated Identification of the N-Oxide Functional Group in Drug Metabolites

We report here an automated method for the identification of N-oxide functional groups in drug metabolites by using the combination of liquid chromatography/tandem mass spectrometry (LC/MSn) based on ion-molecule reactions and collision-activated dissociation (CAD). Data-dependent acquisition, which has been readily utilized for metabolite characterization using CAD-based methods, is adapted for use with ion-molecule reaction-based tandem mass spectrometry by careful choice of select experimental parameters. Two different experiments utilizing ion-molecule reactions are demonstrated, data-dependent neutral gain MS3 and data-dependent neutral gain pseudo-MS3, both of which generate functional group selective mass spectral data in a single experiment and facilitate increased throughput in structural elucidation of unknown mixture components. Initial results have been generated by using an LC/MSn method based on ion-molecule reactions developed earlier for the identification of the N-oxide functional group in pharmaceutical samples, a notoriously difficult functional group to identify via CAD alone. Since commercial software and straightforward, external instrument modification are used, these experiments are readily adaptable to the industrial pharmaceutical laboratory

The reactivity of metallated nitrenium ions studied by FT-ICR

The reactivity of two metallatednitrenium ions toward various substrates was examined in the gas phase. The nitrenium ions were generated by a reaction of benzoyl azide with laser-ablated Mg+ or Cu+ in a Fourier transform ion cyclotron resonance mass spectrometer. The two nitrenium ions show drastically different reactivity. While the Mg-nitrenium ion reacts by radical mechanisms (e.g., H atom abstraction), the Cu-nitrenium ion follows non-radical pathways (e.g., metal ion transfer)