The sustainable development of IT-systems requires a quest for novel concepts to address further miniaturization, performance improvement, and energy efficiency of devices. The realization of these goals cannot be achieved without an appropriate functional material. Herein, we target the technologically important electron modification using single polyoxometalate (POM) molecules envisaged as smart successors of materials that are implemented in today's complementary metal-oxide-semiconductor (CMOS) technology. Lindqvist-type POMs were physisorbed on the Au(111) surface, preserving their structural and electronic characteristics. By applying an external voltage at room temperature, the valence state of the single POM molecule could be changed multiple times through the injection of up to 4 electrons. The molecular electrical conductivity is dependent on the number of vanadium 3d electrons, resulting in several discrete conduction states with increasing conductivity. This fundamentally important finding illustrates the far-reaching opportunities for POM molecules in the area of multiple-state resistive (memristive) switching.

An ew base metal catalyzed sustainable multicomponent synthesis of pyrroles from readily available substrates is reported. The developed protocolu tilizes an air-and moisture-stable catalyst system and enablest he replacement of themutagenic ahaloketones with readily abundant 1,2-diols. Moreover,the presented method is catalytic in base and the sole byproducts of this transformation are water and hydrogen gas. Experimental and computationalm echanistic studies indicatet hat the reactiont akes place through ac ombineda cceptorless dehydrogenation hydrogenautotransfermethodology.Multicomponent reactions are valuable sustainable processes for the construction of complex molecules in one pot from three or more substrates. This strategy merges severale lementary reaction steps, which leads to minimization of the amount of waste, and simplifies the workup and purifications teps. [1] Pyrroles represent prominent and important chemicalm otifs in medicinal, agro, and advanced materials chemistry.C lassical synthetic routes suffer from drawbacks mainly resultingf rom the generation of substantial amounts of waste produced during the multi-stepp re-functionalization of substrates or byproduct formation. [2] Accordingly,t here is ac ontinuous need to develop new catalytic systems that allow the direct and atom-economic conversion of renewable and readily available substrates to pyrroles.Alcohols can be obtained from renewable biomass resources and presentp romising sustainable feedstock chemicals. The utilization of alcohols as substrates in the synthesis of fine chemicals will hence contributen ot only to the reduction of toxic chemical waste but also to decrease CO 2 emissions by avoidingthe use of carbon fossil sources. [3] One of the key concepts for alcoholf unctionalization is hydrogen autotransfer (HA), which has become ap owerful tool for utilizing abundant alcohols as building blocks for environmentally benign CÀC and CÀNb ondf ormations, releasing water as the only byproduct (Scheme 1A). [4] Ar elatedc oncept is acceptorless dehydrogenation(AD), which permits the conversion of alcohols to car-Scheme1.Acceptorless dehydrogenation and hydrogen autotransfer catalysis.

The understanding of the molecular state of vanadium-oxo clusters (polyoxovanadates, POVs) in solution and on surface is a key to their target application in catalysis as well as molecular electronics and spintronics. We here report the results of a combined experimental and computational study of the behavior of nucleophilic polyoxoanions [V IV 10 V V 8 O 42 (I)] 5− charged balanced by Et 4 N + in water, in a one-phase organic solution of N,N-dimethylformamid (DMF) or acetonitrile (MeCN), in a mixed solution of MeCN−water, and at the hybrid liquid−surface interface. The molecular characteristics of the compound (NEt 4 ) 5 [V 18 O 42 (I)] (1) in the given environments were studied by microspectroscopic, electrochemical, scattering, and molecular mechanics methods. Contrary to the situation in pure water, where we observe great agglomeration with a number of intercalated H 2 O molecules between POVs that are surrounded by the Et 4 N + ions, no or only minor agglomeration of redox-active POVs in an unprecedented cation-mediated fashion was detected in pure DMF and MeCN, respectively. An inclusion of 1% water in the MeCN solution does not have an effect significant enough to reinforce agglomeration; however, this leads to the POV•••POV interface characterized by the presence of the Et 4 N + ions and a small number of H 2 O molecules. Water amounts of ≥5% trigger the formation of higher oligomers. The deposition of compound 1 from MeCN onto an Au(111) surface affords nearly roundshaped particles (∼10 nm). The use of DMF instead of MeCN results in bigger, irregularly shaped particles (∼30 nm). This change of solvent gives rise to more extensive intermolecular interactions between polyoxoanions and their countercations as well as weaker binding of ion-pairing induced agglomerates to the metallic substrate. Lower concentration of adsorbed molecules leads to a submonolayer coverage and an accompanied change of the POV's redox state, whereas their higher concentration results in a multilayer coverage that offers the pristine mixed-valence structure of the polyoxoanion. Our study provides first important insights into the reactivity peculiarities of this redox-responsive material class on a solid support.

The [VO{(OCH)CCHOCHC[triple bond, length as m-dash]CH}] with two terminal alkyne functionalities exhibits excellent reactivity towards (bio-)organic azides. The designed synthetic protocol for the generation of triazol-modified Lindqvist hexavanadates grants access to bio-"clicked" polyoxometalates with spectroscopically detectable V nuclei.