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Abstract No.: T1
Speaker: Helmut Schwarz
Session: Tutorial T1
Presentation date: Sun, Aug 27, 2006
Presentation time: 17:00 – 17:45

On The Spin-Forbiddeness Of Gas-Phase Ion-Molecule Reactions: A Fruitful Intersection Of Experimental And Computational Studies

Helmut Schwarz1

1 TU Berlin, Sekr. C 4, Berlin, Germany

Correspondence address: Helmut Schwarz, TU Berlin, Department of Chemistry, Sekr. C 4, Strasse des 17. Juni 135, Berlin, 10623 Germany.

Web site: http://www.chem.tu-berlin.de/Helmut.Schwarz/

Keywords: Calculations, Ab Initio; Dissociation, Thermal; Fourier Transform IR (FTIR); Ion Beam; Ion-molecule Reactions; Metal Ion Chemistry; Organometallics; Reaction Mechanisms.

The effects of spin changes on the efficiencies and product distributions of gas-phase ion-molecule reactions are analyzed, and the examples discussed include metal- as well as non-metal containing systems, with some emphasis on various types of bond activation relevant in homogeneous and heterogeneous catalysis as well as enzymatic processes. Of particular importance are reactions concerning the seemingly trivial conversion RH + <O> → ROH. Further, the (rather new) concept of multi-state reactivity pattern will be outlined, and it will be shown that this paradigm is much more important than generally acknowledged. As expressed by Harvey et al. in a related context "spin-forbidden reactions can end up being as fast as spin-allowed ones, or slower or faster! The devil is in the detail."

Recommended readings:
1. H. Schwarz, Int. J. Mass Spectrom. 237, 75 (2004).
2. J. N. Harvey, R. Poli, K. M. Smith, Coord. Chem. Rev. 238/239 347 (2003).
3. R. Poli, J. N. Harvey, Chem. Soc. Rev. 32, 1 (2003).
4. J. C. Weisshaar, Acc. Chem. Res. 26, 213 (1993).
5. P. B. Armentrout, Science 251, 175 (1991).