Conformations of a long molecular wire with legs on a Cu(100) surface

The adsorption on Cu(1 0 0) of a long molecular wire constituted of a 2.5 n m conjugated board equipped with four lateral legs is investigated using sc anning tunnelling microscopy (STM). The legs are free to rotate when the mo lecule approaches the surface. Experimental images are analysed and compare d to calculated images based on an optimisation of the geometry of the legs in order to extract the conformation of the adsorbed molecule. The adsorpt ion is dominated by the interaction of the molecular board with the metal s urface which forces the legs to rotate and to twist around their attaching bond to the board. (C) 2001 Elsevier Science B.V. All rights reserved.