title: Tandem mass spectrometry of metal nitrate negative ions produced by electrospray ionization.
abstract: M(NO(3))(x)(-) ions are generated by electrospray ionization (ESI) of metal solutions in nitric acid in negative ion mode. Collision-induced reactions of these ions are monitored in a tandem mass spectrometer (MS) of quadrupole-octopole-quadrupole (QoQ) geometry. For Group 1 and 2 elements, the M(NO(3))(x)(-) ions dissociate into NO(3)(-) and neutral metal nitrate molecules. These elements also form some M(x)(NO(3))x+1- clusters, especially Li(+). Metal nitrate ions from transition elements and Group 13 elements fragment into oxo products and also undergo internal electron transfer to leave the M atom in a lower oxidation state. To calibrate the collision energy, the dissociation energy of O-NO(2)(-) is found to be 5.55 eV, about 0.76 eV lower than a value derived from thermochemistry. The product ions from Fe(NO(3))(4)(-) ions have low formation thresholds of only 0.5 to 2 eV.
authors.affiliation: Department of Chemistry, Ames Laboratory, United States Department of Energy, Iowa State University, Ames, Iowa 50011, USA.
authors.forename: Fumin
authors.initials: F
authors.lastname: Li
authors.forename: Matthew A
authors.initials: MA
authors.lastname: Byers
authors.forename: R S
authors.initials: RS
authors.lastname: Houk