The synthesis of dinuclear ruthenium alkenyl complexes with {Ru(CO)(P i Pr 3 ) 2 (L)} entities (L = Cl À in complexes Ru 2 -3 and Ru 2 -7; L = acetylacetonate (acac À ) in complexes Ru 2 -4 and Ru 2 -8) and with π-conjugated 2,7-divinylphenanthrenediyl (Ru 2 -3, Ru 2 -4) or 5,8-divinylquinoxalinediyl (Ru 2 -7, Ru 2 -8) as bridging ligands are reported. The bridging ligands are laterally π-extended by anellating a pyrene (Ru 2 -7, Ru 2 -8) or a 6,7-benzoquinoxaline (Ru 2 -3, Ru 2 -4) π-perimeter. This was done with the hope that the open π-faces of the electron-rich complexes will foster association with planar electron acceptors via π-stacking. The dinuclear complexes were subjected to cyclic and square-wave voltammetry and were characterized in all accessible redox states by IR, UV/Vis/ NIR and, where applicable, by EPR spectroscopy. These studies signified the one-electron oxidized forms of divinylphenylene-bridged complexes Ru 2 -7, Ru 2 -8 as intrinsically delocalized mixed-valent species, and those of complexes Ru 2 -3 and Ru 2 -4 with the longer divinylphenanthrenediyl linker as partially localized on the IR, yet delocalized on the EPR timescale. The more electron-rich acac À congeners formed non-conductive 1 : 1 charge-transfer (CT) salts on treatment with the F 4 TCNQ electron acceptor. All spectroscopic techniques confirmed the presence of pairs of complex radical cations and F 4 TCNQ *À radical anions in these CT salts, but produced no firm evidence for the relevance of πstacking to their formation and properties.

The concept of nanoparticles (NPs) as building blocks offers new possibilities to produce complex and tailored structures from the nano- to the mesoscale. In order to control a “polymerization” of particles, knowledge of the mechanism and kinetics of the reaction are necessary. We show that controlled assembly of cetylpyridinium chloride-stabilized gold NPs utilizing induced dipole–dipole interactions can lead to the formation of defined one-dimensional structures in solution. Three different shaped NPs (cubes, octahedra, and truncated cuboctahedra) were investigated individually. The assembly process is analogous to a step growth polymerization and is quantitatively describable with kinetics of a polyesterification. In situ kinetic studies reveal that there is an ideal particle size and shape for the induced dipole-driven assembly. Even small changes in size have remarkable effects on the assembly behavior. We further demonstrate that the transition from oriented assembly to oriented attachment requires a critical particle size (critical interface area) resulting from a size-dependent energy barrier for the crystallographic fusion. A combination of ideal size, shape, and degree of destabilization enables controlled oriented attachment of gold NPs in solution to chainlike structures under ambient conditions.

Single nanowires and networks are considered as promising candidates for miniaturized memristive devices for brain-inspired systems. Moreover, single crystalline nanostructures are useful model systems to gain a deeper understanding in the involved switching mechanism of the investigated material. Here, we report on hydrothermally grown single crystalline Nb3O7(OH) nanowires showing a complementary resistive switching (CRS) behavior. The CRS characteristics can be related to an oxygen vacancy migration at the electrode/metal hydroxide interface. Therefore, an oxygen plasma treatment is used to reduce the oxygen vacancy content, resulting in a total reduction of the device conductivity. Furthermore, temporal resolved current–voltage measurements demonstrate the dependence of the destructive readout process of the resistance states on the voltage amplitude and polarity.

Colloidal crystals are arguably one of the most promising candidates when it comes to the fabrication of nanostructured metamaterials. Especially mesocrystals show exciting new properties that emerge from their inherent directional oriented assembly. With this work, the electrical conductivity of well‐defined micrometer‐sized platinum nanocube‐based mesocrystals is demonstrated and tuned through the variation of different capping agents. Herein, a method is presented to reproducibly quantify the intrinsic resistance of individual mesocrystals through electrical nanoprobing and focused ion beam deposition contacting. A thermally activated tunneling mechanism is identified as the main effect for electron propagation. In addition, the mesocrystals are altered through organically linking and mineral bridging the individual nanoparticles. This results in an increase in mesocrystal rigidity and, more importantly, conductivity by seven orders of magnitude while retaining shape, structure, and composition. In addition, these observations are transferred onto multicomponent superstructures in the form of binary mesocrystals. There, it is demonstrated that the electrical properties could be tuned through the ratio of nanoparticles incorporated into a mesocrystalline host system while simultaneously maintaining potential catalytic or superparamagnetic features of the guest particles.

Three binary charge-transfer (CT) compounds resulting from the donor 2,2′ : 6′,2′′ : 6′′,6-trioxotriphenylamine (TOTA) and the acceptors F4TCNQ and F4BQ and of a pyrene-annulated azaacene (PAA) with the acceptor F4TCNQ are reported.