Dissertation

Investigation of reactive intermediates: Nitroxyl (HNO) and carbonylnitrenes

Chavez, Tyler A

2016

Overview

Membrane inlet mass spectrometry (MIMS) is a well-established method used to detect gases dissolved in solution through the use of a semipermeable hydrophobic membrane that allows the dissolved gases, but not the liquid phase, to enter a mass spectrometer. Interest in the unique biological activity of azanone (nitroxyl, HNO) has highlighted the need for new sensitive and direct detection methods. Recently, MIMS has been shown to be a viable method for HNO detection with nanomolar sensitivity under physiologically relevant conditions (Chapter 2). In addition, this technique has been used to explore potential biological pathways to HNO production (Chapter 3). Nitrenes are reactive intermediates containing neutral, monovalent nitrogen atoms. In contrast to alky- and arylnitrenes, carbonylnitrenes are typically ground state singlets. In joint synthesis, anion photoelectron spectroscopic, and computational work we studied the three nitrenes, benzoylnitrene, acetylnitrene, and trifluoroacetylnitrene, with the purpose of determining the singlet-triplet splitting (ΔEST = E S – ET) in each case (Chapter 7). Further, triplet ethoxycarbonylnitrene and triplet t-butyloxycarbonylnitrene have been observed following photolysis of sulfilimine precursors by time-resolved infrared (TRIR) spectroscopy (Chapter 6). The observed growth kinetics of nitrene products suggest a contribution from both the triplet and singlet nitrene, with the contribution from the singlet becoming more prevalent in polar solvents.

• Publisher: ProQuest Dissertations & Theses
• Subject: Organic chemistry
• ISBN: 9781369474817, 1369474814