"Naked" iron-5,10,15-triphenylcorrole on Cu(111): observation of chirality on a surface and manipulation of multiple conformational states by STM.

A new member of the metalloporphyrinoid class, the one-carbon short corrole, has been developed in the past decade to a very accessible and easily tunable compound with many potential applications in material science and catalysis. Other than for the structurally related iron porphyrins, all attempts to prepare and study the "naked" iron triphenylcorrole molecule (FeTPC) in bulk have failed. Here, we demonstrate stabilization of FeTPC as adsorbates on a surface. Local investigations by means of scanning tunneling microscopy reveal that along with the adsorption of FeTPC in a saddle conformation, surface induced chirality is the result. Using scanning tunneling microscopy as a local manipulation tool, individual molecules can be controllably switched between different orientations and conformations. Even conformations which are unfavorable during the adsorption process are feasible. The presented experiments demonstrate that metalated corroles are a highly interesting class of metalloporphyrinoids for local investigations but, in comparison with the well established class of porphyrins, add an additional degree of experimental freedom via chirality.