Niko Pavliček, Ingmar Swart, et al.
Physical Review Letters
Rearrangements that change the connectivity of a carbon skeleton are often useful in synthesis, but it can be difficult to follow their mechanisms. Scanning probe microscopy can be used to manipulate a skeletal rearrangement at the single-molecule level, while monitoring the geometry of reactants, intermediates and final products with atomic resolution. We studied the reductive rearrangement of 1,1-dibromo alkenes to polyynes on a NaCl surface at 5 K, a reaction that resembles the Fritsch–Buttenberg–Wiechell rearrangement. Voltage pulses were used to cleave one C–Br bond, forming a radical, then to cleave the remaining C•–Br bond, triggering the rearrangement. These experiments provide structural insight into the bromo-vinyl radical intermediates, showing that the C=C•–Br unit is nonlinear. Long polyynes, up to the octayne Ph–(C≡C)8–Ph, have been prepared in this way. The control of skeletal rearrangements opens a new window on carbon-rich materials and extends the toolbox for molecular synthesis by atom manipulation.
Niko Pavliček, Ingmar Swart, et al.
Physical Review Letters
Lorel M. Scriven, Katharina Kaiser, et al.
JACS
Wolfram Steurer, Bruno Schuler, et al.
Nano Letters
Leo Gross, Bruno Schuler, et al.
Physical Review B - CMMP