Conformational changes of single molecules induced by scanning tunneling microscopy manipulation: A route to molecular switching

A detailed experimental and theoretical investigation of the processes invo lved in the manipulation of individual specially designed porphyrin-based m olecules by scanning tunneling microscopy at low temperature is presented. On a stepped Cu(211) surface, the interaction between tip and molecule was used to locally modify in a reversible way the internal configuration of a single molecule, thus drastically changing the tunneling current passing th rough it. Model calculations confirm that this manipulation realizes the pr inciple of a conformational molecular switch. DOI: 10.1103/PhvsRevLett.86.6 72.