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Laser desorption mass spectrometry of squaric acid and its salts
Author(s) -
Byrd Gary D.,
Fatiadi A. J.,
Simons D. S.,
White V E.
Publication year - 1986
Publication title -
organic mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.475
H-Index - 121
eISSN - 1096-9888
pISSN - 0030-493X
DOI - 10.1002/oms.1210210204
Subject(s) - chemistry , squaric acid , adduct , mass spectrum , polyatomic ion , alkali metal , dimer , mass spectrometry , ion , desorption , salt (chemistry) , analytical chemistry (journal) , inorganic chemistry , organic chemistry , chromatography , adsorption
The laser desorption mass spectrometry of the oxocarbon squaric acid (3,4‐dihydroxy‐3‐cyclobutene‐1,2‐dione) and its salts of the form A 2 C 4 O 4 (A = cation) is described. Both positive and negative ion spectra were obtained. The positive ion spectrum of the acid is characterized by an ion corresponding to loss of CO from [M + H] + . The negative ion spectrum shows an intense [M − H] − peak in addition to a dimer species. The alkali salt spectra contain [M + A] + in the positive mode and [M − A] − and an intense [C 4 HO 4 ] − in the negative mode. The smaller alkali salts also have an [M + H] + adduct ion. Unlike the alkali squarates, the ammonium salt shows ions corresponding to losses of neutrals from the molecular adduct in the positive ion spectrum and a dimer species in the negative ion spectrum. Molecular weight information was obtained in all cases. A (bis) dicyanomethylene derivative of potassium squarate was also studied. Some field desorption mass spectrometry results are presented for comparison.