Events & Seminars > Event Details

Where:

4:00 pm
Room 304, Chemistry Building

Metal-mediated C-N bond coupling in the gas phase: Experiment and computational chemistry in concert

Speaker:

Professor Helmut Schwarz
Technical University of Berlin

Hosted by: Professor Brent Gunnoe

Thermal C−N coupling processes mediated by transition-metal complexes have been investigated in gas-phase experiments combined with computational methods, and mechanistic aspects and elementary steps of these ion/molecule reactions are described.
Three mechanistic variants of C-N bond coupling reactions have been identified: i) M(CH3)+ ions of the zinc triad react with ammonia in an SN2 reaction under C–N coupling, yielding protonated methylamine, CH3NH3+, and a neutral metal M which serves as a novel leaving group; in contrast, the cationic amides, M(NH2)+, do not afford C–N bond formation in the reaction with methane. ii) NH2+ transfer from Ni(NH2)+ to ethene takes place in the reaction of mass-selected Ni(NH2)+ with C2H4 thus forming N-protonated ethylideneamine; in addition, dehydrogenation of the substrate under C–N bond coupling and Ni(C2,H4,N)+ formation are observed as a minor reaction channel. iii) A high valent iron-nitrido dication [LFeN]2+ is described that is capable to undergo N-atom transfer to 1,3-butadiene as well as to act in an unparalleled nitrile-alkyne metathesis reaction with alkynes to generate RCN at ambient conditions.

Recommended literature:
[1] R. Kretschmer, M. Schlangen, H. Schwarz, Chem. Eur. J. 2012, 18, 40.
[2] R. Kretschmer, M. Schlangen, H. Schwarz, Chem. Asian J. 2012, 7, 1214.
[3] R. Kretschmer, M. Schlangen, M. Kaupp, H. Schwarz, Organometallics 2012, 31, 3816.
[4] J. P. Boyd, M. Schlangen, A. Grohmann, H. Schwarz, Helv. Chim. Acta 2008, 91, 1430.