Mass spectrometry of polystyrene and polypropene ruthenium complexes. A new tool for polymer characterization

The use of organometallic fragments as cationization reagents for matrix-assisted laser-desorption-ionization time-of-flight mass spectrometry (MALDI-TOF-MS) of polystyrene (PS) and polypropene (PP) is reported. Reaction of [Ru(C5H5)(NCCH3)(3)][PF6] (1a) with PS samples of numerical mass average M-n 1430-135000 in a ratio [Ru]/[PS] = 1/1 to 3/1 favours effective ionization of the polymer by MALDI-MS techniques and leads to an increase in signal intensity over that obtained by use of Ag+ salts. PP samples of M. 2700 and 6100 are ionized after reaction with the trinuclear ruthenium pentahydride derivative (RuC5Me5)(3)H-5, thus affording the first observation of MALDI-MS signals for this polymer. Reactions of the cations [Ru(C5H5)(NCCH3)(3)](+) and [Ru(C5Me5)(NCCH3)(3)](+) with 1,3-diphenylpropane and of (RuC5Me5)(3)H-5 with 1-eicosene were studied as models for the corresponding reactions with PS and PP, respectively. (C) 2002 Elsevier Science B.V. All rights reserved.