Synthesis, mass spectrometry, and nuclear magnetic resonance characterization of Di-Guerbet esters

Several Di-Guerbet esters (DGE) suitable for lubricant applications were sy nthesized from branched Guerbet alcohols and Guerbet acids. The mass spectr a of DGE under electron-ionization and positive chemical-ionization (PCI) c onditions were recorded. Gas chromatography-mass spectrometry, especially i n PCI mode with methane as reagent gas, is an effective method for analyzin g DGE. In methane positive chemical-ionization mass spectrometry, the DGE g ive molecular ion peaks. In both PCI and EI modes, some other characteristi c ions including up to four McLafferty rearrangement products with high m/z are observed. Thus identification of both hydrocarbon moieties is possible . The DGE were also characterized by H-1- and (1)3C nuclear magnetic resona nce.