Mass spectrometry is an excellent tool not only to characterize dendrimers with respect to molecular mass and the presence of defects, but also offers experiments to examine dendrimers and their non-covalent complexes with respect to their reactivity under environment-free conditions as isolated ions. One highlight of our work is the detailed analysis of fragmentation mechanisms of Frechet dendrons which exhibit "self-immolative" fragmentation cascades that commence at the focal point, but then quickly proceed into the periphery.

Another example is the detailed analysis of the host-guest complexes of Frechet dendrimers with a dicationic viologen core. From the fragmentation reactions - and in particular their sequence - evidence for backfolding was obtained. The larger and more electron-rich the branches are, the better the dications are stabilized.

Finally, H/D exchange experiments provide evidence that crown ethers are capable of migrating from one side chain to another in POPAM complexes. This behavior was coined the "spacewalk" of the crown ethers.

Forth generation POPAM dendrimer/crown ether complex. H/D-exchange experiments unravel the crowns to migrate between different branches on the dendrimer surface.

 

Related Publications

• 189

  Multivalency in the Gas Phase: H/D-Exchange Reactions Unravel the Dynamic 'Rock 'n Roll' Motion in Dendrimer-Dendrimer Complexes
  Z. Qi, C. Schlaich, C.A. Schalley
  Chem. Eur. J. 2013, 19, 14867-14875

---

• 144

  Host-Guest Chemistry of Dendrimers in the Gas Phase
  Z. Qi, C.A. Schalley
  Supramol. Chem. 2010, 22, 672-682

---

• 133
  Dynamic Motion in Crown Ether-Dendrimer Complexes: A "Spacewalk" on the Molecular Scale
  H.D.F. Winkler, D.P. Weimann, A. Springer, C.A. Schalley
  Angew. Chem. 2009, 121, 7382-7386; Angew. Chem. Int. Ed. 2009, 48, 7246-7250
  DOI: 10.1002/ange.200902437, 10.1002/anie.200902437

---

• 127

  Dendrimer Disassembly in the Gas Phase: A Cascade Fragmentation Reaction of Fréchet Dendrons
  B. Baytekin, H.T. Baytekin, U. Hahn, W. Reckien, B. Kirchner, C.A. Schalley
  Chem. Eur. J. 2009, 15, 7139-7149

---

• 115

  Characterization of Self-Assembled Metallodendrimers in Solution, in the Gas Phase, and at Air/Solid Interfaces
  H.T. Baytekin, M. Sahre, A. Rang, M. Engeser, A. Schulz, C.A. Schalley
  Small 2008, 4, 1823-1834

---

• 95

  Mass Spectrometry as a Tool in Dendrimer Chemistry: From Self-Assembling Dendrimers to Dendrimer Gas-Phase Host-Guest Chemistry
  C. A. Schalley, B. Baytekin, H.T. Baytekin, M. Engeser, T. Felder, A. Rang
  J. Phys. Org. Chem. 2006, 19, 479-490

---

• 97

  Designer Dendrimers: Branched Oligosulfonimides with Controllable Molecular Architectures
  O. Lukin, V. Gramlich, R. Kandre, I. Zhun, T. Felder, C. A. Schalley, G. Dolgonos
  J. Am. Chem. Soc. 2006, 128, 8964-8974

---

• 91

  How useful is mass spectrometry for the characterization of dendrimers? "Fake defects" in the ESI and MALDI mass spectra of dendritic compounds
  B. Baytekin, N. Werner, F. Luppertz, M. Engeser, J. Brüggemann, S. Bitter, R. Henkel, T. Felder, C. A. Schalley
  Int. J. Mass Spectrom. 2006, 249, 138-148

---

• 83

  A Combined ESI- and MALDI-MS(/MS) Study of Peripherally Persulfonylated Dendrimers: False Negative Results by MALDI-MS and Analysis of Defects
  T. Felder, C. A. Schalley, H. Fakhrnabavi, O. Lukin
  Chem. Eur. J. 2005, 11, 5625-5636

---

• 77

  Gas-Phase Host-Guest Chemistry of Dendritic Viologens and Molecular Tweezers: A Remarkably Strong Effect on Dication Stability
  C. A. Schalley, C. Verhaelen, F.-G. Klärner, U. Hahn, F. Vögtle
  Angew. Chem. 2005, 117, 481-485; Angew. Chem. Int. Ed. 2005, 44, 477-480
  DOI: 10.1002/ange.200461872, 10.1002/anie.200461872