Characterization of an Insoluble Poly(9,9-diphenyl-2,7-fluorene) by Solvent-Free Sample Preparation for MALDI-TOF Mass Spectrometry

• Published in: Analytical chemistry (Washington) Vol. 74; no. 15; pp. 3777 - 3782
• Main Authors: Trimpin, S, Grimsdale, A. C, Räder, H. J, Müllen, K
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 01.08.2002
• Subjects: Analysis; Applied sciences; Exact sciences and technology; Organic polymers; Physicochemistry of polymers; Polymers; Properties and characterization; Scientific imaging; Structure, morphology and analysis; Arylene polymer; Time of flight mass spectroscopy; Sample preparation; Insoluble compound; Molecular structure; Spectrum analysis; Mass spectrum; Matrix assisted laser desorption ionization; Experimental study
• ISSN: 0003-2700; 1520-6882
• DOI: 10.1021/ac0111863

The application of solvent-free sample preparation for matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) allowed the characterization of an insoluble fraction of poly(9,9-diphenylfluorene) that was previously hindered by the lack of suitable characterization methods. The MALDI mass spectrometric analysis gives valuable mechanistic information about the heterogeneous polymerization process of the insoluble high molecular weight fraction of the polymer. The fragmentation appearing even under moderate desorption and ionization conditions of this rigid backbone analyte is identified as a multiple loss of the bulky phenyl side groups and can be avoided by applying the new MALDI matrix 7,7,8,8-tetracyanoquinodimethane. A specialized fragmentation study by postsource decay MALDI-TOF MS reveals a molecular weight dependent change in fragmentation mechanism from an exclusive cleavage of side groups from long polymer chains to an additional cleavage of the polymer backbone of short polymer chains.