Ligand size distribution of phenanthroline-functionalized polyethylene glycol-iron(II) complexes determined by electrospray ionization mass spectrometry and computer simulation

Ákos Kuki, Miklós Nagy, Lajos Nagy, Miklós Zsuga, Sándor Kéki

Research output: Contribution to journalArticle


The complex formation in solution, and the gas-phase dissociation of a phenanthroline-terminated poly(ethylene glycol) with Fe2+ ions were investigated. The size distribution of poly(ethylene glycol)-α-monomethyl-ω-5-[1,10]phenanthroline (mPEG_phen) was determined by electrospray ionization mass spectrometry (ESI-MS). Based on the measured ligand size distribution of mPEG_phen by ESI-MS, the 1:3 complex formation (Fe2+/mPEG_Phen) was computer-simulated as a pure random assembly process. The simulated distribution fits excellently to that of the complex Fe(mPEG_phen)32+ determined from the ESI-MS intensities. In addition, the collision-induced dissociation (CID) of the Fe(mPEG_phen)32+ complex was also studied by tandem mass spectrometry (ESI-MS/MS) and by computer simulation, as well. The ESI-MS/MS intensity distribution of the Fe(mPEG_phen)22+ formed from Fe(mPEG_phen)32+ by the loss of an mPEG_phen ligand under CID conditions fits quite well to the calculated one.

Original languageEnglish
Pages (from-to)1561-1564
Number of pages4
JournalJournal of the American Society for Mass Spectrometry
Issue number9
Publication statusPublished - Sep 1 2010


ASJC Scopus subject areas

  • Structural Biology
  • Spectroscopy

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