SASSINE, ANDREMARTINS JUNIOR, HELIO A.LEBRE, DANIEL T.VALLI, FELIPEPIRES, MARIA A.F.VEGA, OSCARFELINTO, MARIA C.F.C.2014-07-152014-07-302014-07-152014-07-302008SASSINE, ANDRE; MARTINS JUNIOR, HELIO A.; LEBRE, DANIEL T.; VALLI, FELIPE; PIRES, MARIA A.F.; VEGA, OSCAR; FELINTO, MARIA C.F.C. An electrospray ionization Tandem mass spectrometric study of p-tert-butylcalix[6]arene complexation with ammonium hydroxide, and ammonium and sodium ions. <b>Rapid Communications in Mass Spectrometry</b>, v. 22, p. 385-393, 2008. DOI: <a href="https://dx.doi.org/10.1002/rcm.3352">10.1002/rcm.3352</a>. Disponível em: http://repositorio.ipen.br/handle/123456789/5097.0951-4198http://repositorio.ipen.br/handle/123456789/5097The formation of complexes involving p-tert-butylcalix[6]arene with neutral and charged species has been investigated by tandem mass spectrometry combined with electrospray ionization. Complexes of p-tert-butylcalix[6]arene with NH4+ ions were observed in the ratios 1:1, 2:1, and 3:1, together with the complexes of p-tert-butylcalix[6]arene with NH4OH and Na+ ions in the ratios 1:1:1, 2:1:1, and 3:1:1. A single 1:1 complex of p-tert-butylcalix[6]arene with Na+ ions was observed. In addition, a doubly charged complex of p-tert-butylcalix[6]arene with NH 4OH, Na+, and NH4+ ions in the ratio 6:1:1:1 was observed. The identity of each complex was determined by mass analysis of product ions formed by the application of a declustering potential over the range 20-220 V and by observation of product ion mass spectra wherein the collision energy was varied from 5 to 50 eV. Fragmentation of the complexes is characterized by the facile loss of the ammonia molecule, sodium and ammonium ions, loss of neutral p-tert-butylcalix[6]arene, and successive neutral losses of C4H8 from the six tert-butyl groups in each p-tert-butylcalix[6]arene molecule.385-393closedAccesscalixarenesammonium hydroxidessodium ionsmass spectroscopyionizationmolecular structureArtigo de periódico2210.1002/rcm.3352https://orcid.org/0000-0001-7028-0878https://orcid.org/0000-0002-4712-4057