ANALYSIS OF TRANSITION-METAL COMPOUNDS CONTAINING TETRATHIAFULVALENE PHOSPHINE-LIGANDS BY FAST-ATOM-BOMBARDMENT MASS-SPECTROMETRY - LIMITATIONS AND THE DEVELOPMENT OF MATRIX ADDITIVES FOR THE DESORPTION OF MULTIPLY-CHARGED COMPLEXES

A series of new complexes incorporating the functionalized tetrathiafu lvalene (TTF) ligands ortho-(CH3)(2)(P(C6H5)(2))(2)TTF (o-P2) and (P(C 6H5)(2))(4)TTF (P4) have been prepared and studied by fast atom bombar dment mass spectrometry (FABMS). The mononuclear o-P2 complexes [M(o-P -2)(2)](BF4)(2) (M = Fe, Pd, Pt) and [Co(o-P2)(2)(NCCH3)(2)](BF4)(2) w ere synthesized from reactions of the free ligand with the fully solva ted BF4- salts [M(NCCH3)(n)](BF4)(2) (M = Fe, Co, n = 6; M = Pd, Pt, n = 4). The dinuclear P4 complex, [Pt-2(P4)(NCCH3)(4)](BF4)(4), was pro duced by reacting the free ligand with PtCl2(NC7H5)(2) followed by abs traction of the chlorides with AgBF4 in acetonitrile. Reaction of [Pd( NCCH3)](BF4)(2) with 1 equiv of P4 produces the polynuclear compound f ormulated as [Pd(P4)](n)(BF4)(2n), which was characterized by infrared , H-1, and P-31{H-1} NMR spectroscopies and elemental analysis. The us e of FABMS in this study was undertaken in order to elucidate the chem ical options of multiply charged cations in the desorption process fro m the liquid matrix to the gas phase. The use of additives to the FAB matrix (m-nitrobenzyl alcohol) was demonstrated for the P4 complexes w hich do not give spectra in this medium due to a high positive net cha rge. The addition of triflic acid (HOTf or CF3SO3H) to the FAB matrix/ analyte solution was shown to assist in the MS analysis of cationic co mplexes with up to six charges and a mass range up to m/z 4000. When H OTf is added, bound OTf- anions are formed and are attached to the cat ionic complex, lowering the net charge to +1. The method of using matr ix additives as opposed to chemically synthesizing the OTf- compounds is a convenient in situ method which produces species that are capable of being analyzed by FABMS.