Negative ion laser mass spectrometry of aromatic nitro compounds and their use as solid-state chemical ionization reagents

Ion-molecular reactions in the negative ion laser mass spectra of aromatic nitro compounds

“…This observation clearly indicates that formation of (M + 15)" involves removal of an aromatic hydrogen; i.e., the (M + 15)' ion corresponds to ( + 16 -H)". This implies that (M + 15)" ion formation in aromatic nitro compounds involves substitution of an oxygen atom for a ring hydrogen, probably via a nucleophilic substitution as suggested earlier by our group (19).…”

“…To facilitate identification of nitro-PAHs by laser mass spectrometry, the present study has focused on understanding the negative ion laser mass spectrometry of nitro-substituted aromatic hydrocarbons, specifically the role of ion-molecule reactions. The present study is an extension and amplification of results reported as a preliminary communication (19).…”

Electrochemical studies of sulfur-nitrogen compounds. 3. S3N3O-, S3N3O2-, and S4N5O- ions and S4N4O2, S3N2O, Ph2CNSNSO, and S(NSO)2

“…S(NSO)2 was produced by the reaction of PPN+S3N3" with S0C12.14 Ph2CNSSNCPh2 was prepared from Ph2CNSiMe3 and S2C12 in diethyl ether. 15 The procedures used for purification and drying of acetonitrile16 and for the preparation and purification of supporting electrolytes17 have been described elsewhere. PPN+C104" was made from commercial PPN+C1" (Alfa) and perchloric acid in a way similar to that of the other supporting electrolytes17 and recrystallized from ethanol.…”

“…This is a new area of activity typified by observations such as the apparent nucleophilic substitution (eq 1) seen in secondary ion (2) mass spectrometry14 and the oxygen displacement reaction (eq 2) observed in laser desorption of polynuclear aromatic hydrocarbons. 15 In some cases reactions accompanying desorption complicate the analysis, as in the examination of thiamine hydrochloride from glycerol matrix, where hydrogenolysis apparently occurs. 16 The Hünsdiecker reaction17 is a thermal decarboxylation; the prototype (eq 3) involves the silver salt of the acid in the presence of halogen and mercuric oxide.…”

Mass spectrometric investigation of silver ion promoted carbon-carbon bond scission

“…This is a new area of activity typified by observations such as the apparent nucleophilic substitution (eq 1) seen in secondary ion (2) mass spectrometry14 and the oxygen displacement reaction (eq 2) observed in laser desorption of polynuclear aromatic hydrocarbons. 15 In some cases reactions accompanying desorption complicate the analysis, as in the examination of thiamine hydrochloride from glycerol matrix, where hydrogenolysis apparently occurs. 16 The Hünsdiecker reaction17 is a thermal decarboxylation; ions observed in SIMS independently by a direct thermal process and characterizing individual mass-selected ions via the gas-phase fragmentations.…”