A large variation in electrical resistance induced by an electrochemical surface charge is observed for the ultrathin films of indium tin oxide ͑ITO͒. A decrease and increase in resistance is noticed when the negative and positive surface charge is applied to the ITO thin films, respectively. An increase in total effect-size is obtained with a decrease in film thickness. Two contributions are considered to account for the measured effect: the variation in the carrier density and the modification of the charge carrier mobility. The first contribution, which is estimated from the Hall-effect measurements and applied surface charge density, can explain only a small fraction of the observed variation in electronic transport. The correlation of the other contribution ͑i.e., a variation in the electron mobility͒ with the film morphology and the local electronic states is examined by scanning tunneling microscopy and spectroscopy studies. Scanning tunneling spectra suggest that a local variation in charge carrier density exists on the grain surfaces and at the grain boundaries. Upon electrochemical surface charging, this local variation in density of states should result in an increase in the electronic roughness of the surface and a deeper penetration of the applied electric field at the grain boundaries. Thus, it is considered that a pronounced surface and grain boundary scattering of the conducting electrons is responsible for the large ͑electric͒ field effect observed in highly conducting oxides such as ITO.

A series of tripodal MIII complexes (M = Ga, Mn, Fe) functionalized with three methylsulfanyl end‐groups for deposition on Au(111) were synthesized. The structures were designed to build rigid three‐dimensional molecular structures that stand on their own with multiple attachments on the metallic surface. The coordination compounds are based on a trensal [(tris(2,2′,2"‐salicylideneimino)triethylamine)] Schiff base ligand which provides stable metal complexes. The molecular structures of GaIII, FeIII, and MnIII complexes were determined by single‐crystal X‐ray diffraction crystallography. Magnetic properties depend on the coordinated metal ion and vary from a diamagnetic GaIII complex to paramagnetic high‐spin FeIII and MnIII complexes. A submonolayer of the GaIII complex deposited on Au(111) was studied in a preliminary ultra‐high‐vacuum scanning tunneling microscopy (UHV‐STM) investigation.

The realization of molecular electronics demands a detailed knowledge of the correlation between chemical groups and electronic function. It has become obvious during the last years that the conformation of a molecule and its coupling to the connecting electrodes plays a crucial role in its conductance behavior and its electronic function, e.g., as a switch. Knowledge about these relationships is therefore essential for future design of molecular electronic building blocks. We present a new three-dimensional molecule, consisting of three identical molecular wires connected to a headgroup. Due to the well-defined spatial arrangement of the molecule in a nonplanar geometry, it is possible to investigate the conductance behavior of these wires with respect to their position and coupling to the surface electrode with the submolecular resolution of a scanning tunneling microscope. The experimental findings are supported by calculations of the electronic structure and conformation of the molecule on the surface by density functional theory with dispersion corrections.

Tripodal facial and meridional Ru(II) complexes comprising three conjugated legs with acetyl-protected thiol end groups are designed, synthesized and isolated for investigation on a gold surface. Preliminary ultrahigh vacuum scanning tunnelling microscopy (UHV STM) measurements of a monolayer of facial isomer deposited on Au(111) are presented.

The microwave spectra of