کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1195352 964327 2006 8 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
ESI-FTICR-MS Studies on Gas Phase Fragmentation Reactions of ArPd(PPh3)2I Complexes
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی آنالیزی یا شیمی تجزیه
پیش نمایش صفحه اول مقاله
ESI-FTICR-MS Studies on Gas Phase Fragmentation Reactions of ArPd(PPh3)2I Complexes
چکیده انگلیسی

Gas-phase fragmentation reactions of [ArPd(PPh3)2]+ were studied by electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI-FTICR-MS). The results of sustained off-resonance irradiation collision-activated dissociation (SORI-CAD) experiments provide detailed insights into mechanisms for the gas-phase fragmentation reactions of these complex ions. The PC bond cleavage mediated by palladium is investigated in the gas phase. There are two competitive fragmentation pathways for the complex ions [ArPd(PPh3)2]+ (Ar = p-OCH3-C6H4, p-CH3-C6H4, p-tBu-C6H4, p-NH2-C6H4, p-COCH3-C6H4, and p-F-C6H4) of electron-donating and electron-withdrawing aromatic iodides. Path A proceeds through reductive elimination of [ArPd(PPh3)2]+ to produce the product ion [PPh3Ar]+. Path B mostly proceeds via phenyl migration from the triphenylphosphine ligand to the palladium center by cleavage of the phosphorusphenyl bond to give a palladiumphenyl intermediate, and subsequent reductive elimination of the intermediate to yield a product ion [PPh4]+. The result of deuterium-labeling experiments provides evidence for the phenyl shift between the palladium center and the coordinated ligand through cleavage of the PC bond. The complex ions [(o-CH3-C6H4)Pd(PPh3)2]+, [(o-2,6-Me2-C6H3)Pd(PPh3)2]+, and [(C10H7)Pd(PPh3)2]+ display more fragmentation pathways, two of which are similar to those of the ions [ArPd(PPh3)2]+ (Ar = p-OCH3-C6H4, p-CH3-C6H4, p-tBu-C6H4, p-NH2-C6H4, p-COCH3-C6H4, p-F-C6H4), and the third pathway involves loss of one molecule of benzene and one PPh3 ligand. The electronic effect and steric effect of the aryl groups also exhibit different influences on the fragmentation pathways.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of the American Society for Mass Spectrometry - Volume 17, Issue 11, November 2006, Pages 1582–1589
نویسندگان
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