PART I: FIELD DESORPTION MASS SPECTROMETRY OF ALKALI METAL CRYPTATES. PART II: STEREOCHEMICAL DIFFERENTIATION OF ALCOHOL DERIVATIVES BY VARIOUS MASS SPECTROMETRIC TECHNIQUES.

摘要

Part I. Field desorption (FD) mass spectra have been obtained from a series of alkali metal cryptates formed from {2.2.2}-, {2.2.1}- and {2.1.1}-cryptands with Li(u27+), Na(u27+) and K(u27+) salts of Cl(u27-), Br(u27-), I(u27-), OTs(u27-) and BPh(,4)(u27-). Stabilities of these complexes under FD conditions are compared with their thermodynamic stabilities in solution. Differences in these stabilities are attributed to the lack of solvation of ions under FD conditions. A marked anion effect is also observed in FD spectra. This effect is correlated with the recombination energy of the released cation and anion in the gaseous state. Part II. Acid phthalates from isomeric alicyclic alcohols have been studied by field desorption (FD) and electron impact (EI) mass spectrometry. Isomeric acid phthalates gave identical FD spectra and EI spectra. The use of these methods for distinguishing stereoisomers of this type thus proved to be unsuccessful. However, the field ionization (FI) spectra of cis- and trans-4-t-butylcyclohexyl 9-fluorenylmethyl carbonate show distinguishing features. The trans-isomer undergoes a rearrangement reaction which involves mainly the transfer of the benzylic hydrogen to carbonyl oxygen, whereas the cis-isomer transfers either the benzylic hydrogen or a readily available hydrogen from the 2-position in the cyclohexyl ring. This divided pathway gives rise to an additional ion for the cis-isomer (m/z 138) which is the major qualitative difference in the spectra. The EI spectra for both isomers are simple and closely related to each other. Source: Dissertation Abstracts International, Volume: 42-08, Section: B, page: 3262. Thesis (Ph.D.)--University of Windsor (Canada), 1981.