Electron ionization mass spectrometry of aryl- and fluoroalkyl-substituted nickel(II) β-diketonates and monothio-β-diketonates

Abstract

Electron ionization positive-ion mass spectra are reported for 18 substituted nickel(I1) (3-diketonates and monothio-Pdiketonates, Ni"(RCXCHCORf),, where X = 0 or S; R = phenyl, 2-thienyl, 5-methyl-2-thienyl, or 2-naphthyl; and R' = difluoromethyl, trifluoromethyl, pentafluoroethyl, or rz-heptafluoropropyl. Each mass spectrum contains a prominent molecular ion, [NiL,]', which, for P-diketonates, fragments mainly by elimination of the odd-electron R" species; the resulting ion decomposes by losses of one or more even-electron neutral species to yield ions containing nickel(I1). In contrast, the major fragmentation of the molecular ion of monothio-P-diketonates is loss of NI'L to yield an abundant Lf ion. Furthermore, while most ions contain nickel(II), some prominent ions contain nickel (1) On a determine les spectres de masse des ions positifs par ionisation Clectronique de 18 P-dicetonates et monothio-Pdicetonates de nickel(II), Ni"(RCxCHCOR'),, dans lesquels X = 0 ou S; R = phenyle, 2-thiknyle, 5-methyl-2-thienyle ou 2-naphtyle; et R' = difluoromethyle, trifluoromethyle, pentafluoroCthyle ou n-heptafluoropropyle. Chaque spectre de rnasse comporte un ion moleculaire important, [NiL?]'., qui, pour les P-dicetonates, se fragmente principalement par elimination de l'espece R" a tlectron celibataire; l'ion qui en rksulte se decompose par perte d'une ou de plusieurs espkces neutres comportant un nombre pair d'electrons, pour fournir des ions contenant du nickel(I1). Par opposition, la fragmentation principale de l'ion moleculaire des monothio-P-dicetonates comporte une perte de NI'L qui conduit B un ion [Traduit par la redaction]

Electron ionization mass spectrometry of aryl- and fluoroalkyl-substituted palladium(II) β-diketonates and monothio-β-diketonates

“…-. tonates (1,2). For such complexes the decomposition would result in a formal reduction of the metal to its +I oxidation state.…”

“…Our recent efforts in characterizing the mass spectral behavior of volatile transition metal chelates under electron ionization (EI) conditions have included the examination of fluorinated P-diketonates and monothio-P-diketonates of cobalt(II1) (1) and nickel(I1) (2). The mass spectra of these complexes showed interesting differences, which could be attributed to the relative stabilities of the +3, +2, and +1 oxidation states of the metals, and also to the relative acid hardness of the metals in these oxidaion states, according to the Hard and Soft Acid and Base (HSAB) principle (3)(4)(5)(6).…”

Mono- and Mixed Metal Complexes of Eu3+, Gd3+, and Tb3+ with a Diketone, Bearing Pyrazole Moiety and CHF2-Group: Structure, Color Tuning, and Kinetics of Energy Transfer between Lanthanide Ions

“…In fact, only two compounds were used as a ligands, namely, fore mentioned 4,4-difluoro-1-phenylbutane-1,3-dione (1), and 4,4-difluoro-1-(thiophen-2-yl)butane-1,3-dione (2). Complexes with Al 3+ [30], Zr 4+ [31], Mn 2+ [32], Co 2+ [33], Ni 2+ [34] and Pd 2+ [35] were reported up to date.…”