This project aims at combining inorganic and organic materials in hybrid nanoelectronic structures for addressing a set of key problems in solid-state physics: (1) the magnetic ordering of 2D spin systems and their interaction with conduction electrons, (2) the coherent transport properties of organic molecules, and (3) reliable electronic characterization of single nanostructures. For all objectives we will integrate top-down and bottom-up (self-assembly) techniques, benefitting from strong collaborations with leading chemistry groups. For Objective 1, we will apply self-assembled monolayers of organic paramagnetic molecules on various substrates. This geometry offers great tunability for the nature, density and ordering of spins, and for their interaction with underlying electrons. We will study (many-body) phenomena that lie at the very heart of solid-state physics: the Kondo effect, RKKY interaction, spin glasses and the 2D Ising/Heisenberg model, addressing open questions concerning the extension of the Kondo cloud, RKKY-Kondo competition, and the relevance for high-Tc superconductivity. For Objective 2, molecular monolayers are inserted in an electron interferometer, allowing a systematic study of molecular charge coherence. We will study how coherence depends on the molecule s characteristics, such as length and chemical composition. For Objective 3 we will attach single nanostructures (quantum dots) by an innovative self-assembly method to highly-conductive, selectively metallized DNA molecules, bridging the gap between nano and micro. A crucial advantage compared to conventional (top-down) nanocontacting schemes is the high control and reproducibility afforded by sequence-specificity of DNA hybridization, enabling a wide range of fascinating experiments.