MASS-SPECTROMETRIC INVESTIGATION OF 2-METHOXYETHANOL AND 2-ETHOXYETHANOL CLUSTERS - MAGIC NUMBERS AND STRUCTURAL IMPLICATIONS

In this paper, we present the results of our mass spectrometric invest igations for van der Waals clusters of 2-methoxyethanol and 2-ethoxyet hanol. The cluster mass spectra were acquired for a variety of expansi on conditions and electron energies. The protonated alkoxyethanol clus ter ions {AE}(n)H+ form the dominant cluster ion series. A number of f ragment ions, that may arise from an unprotonated and/or a protonated alkoxyethanol molecular ion, were solvated by additional alkoxyethanol molecules. The {AE}n{H2O}(m)H+ ions were observed with significant in tensities only for n greater-than-or-equal-to 5 in neat as well as mix ed alkoxyethanol/water expansions. It was also found that {AE}n{H2O}(m )H+ cluster ions which satisfy the condition n = 2 (m + 2), for m = 1 and 2, have enhanced ion intensities. Various models that may explain the behavior of {AE}n{H2O}(m)H+ are discussed.