García-Martínez Joaquín C, Atienza Carmen, de la Peña Milagros, Rodrigo Ana C, Tejeda Juan, Rodríguez-López Julián
Area de Química Orgánica, Facultad de Química, Universidad de Castilla-La Mancha, Avda. Camilo José Cela, 10, 13071-Ciudad Real, Spain.
J Mass Spectrom. 2009 May;44(5):613-20. doi: 10.1002/jms.1534.
An extensive study by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry (MS) of some first-generation and second-generation lanthanide(III)-cored poly(phenylenevinylene) dendrimers is described. The complexes were obtained by self-assembly of suitably functionalized carboxylate dendrons around the lanthanide ion (La(3+), Er(3+)). Fourier transform infrared (FT-IR) spectroscopy gave reasonable evidence for the proposed structures. However, MS was used to ascertain unequivocally the complex formation. The most reliable results were found in the negative reflector mode, using 2-[(2E)-3-(4-tert-butylphenyl)-2-methylprop-2-enylidene]malononitrile (DCTB) as matrix. Well-defined and highly resolved base peaks corresponding to negative ions of Gn(4)La and Gn(4)Er were found in all cases, with an excellent match between the theoretical and observed isotope distributions. However, the 3:1 stoichiometry used in the synthesis guarantees an empirical formula Gn(3)Ln for the complexes.
