Diamondoid-modified DNA

We prepared novel C5-modified triphosphates and phosphoramidites with a diamondoid functionally linked to the nucleobase. Using primer extension experiments with different length templates we investigated whether the modified triphosphates were enzymatically incorporated into DNA and whether they were further extended. We found that all three modified nucleotides can be incorporated into DNA using a single-nucleotide incorporation experiment, but only partially using two templates that demand for multiple incorporation of the modified nucleotides. The modified phosphoramidites were introduced into oligonucleotides utilizing DNA synthesizer technology. The occurring oligonucleotide structures were examined by circular dichroism (CD) and melting temperature (Tm)measurements and were found to adapt similar helix conformations as their unmodified counterparts

Secondary Phosphine Oxide Preligands for Palladium-Catalyzed Câ\u80\u93H (Hetero)Arylations: Efficient Access to Pybox Ligands

C–H arylations of oxazolines were accom- plished with a well-defined palladium catalyst de- rived from a secondary bisdiamantyl phosphine oxide. The single-component secondary phosphine oxide (SPO)-palladium complex enabled C–H activa- tions with aryl bromides and challenging aryl chlor- ides in the absence of directing groups, setting the stage for the step-economical synthesis of pybox li- gands under racemization-free reaction conditions

Diamondoid Hydrazones and Hydrazides: Sterically Demanding Ligands for Sn/S Cluster Design

A series of new adamantane and diamantane hydrazides was synthesized and coupled with organo-functionalized Sn/S clusters of the general type [R¹Sn₄S₆] (R¹ = CMe₂CH₂C­O­Me) to form diamondoid-decorated Sn/S clusters. The new ligand precursors as well as the resulting hybrid compounds were analyzed by NMR spectroscopy, mass spectrometry, and single-crystal X-ray diffraction, and first insights were gained in the installation of sterically highly demanding and at the same time rigid mono-, di-, and trifunctionalized diamondoid ligands on tetrelchalcogenide cages

Monochromatic Photocathodes from Graphene-Stabilized Diamondoids.

The monochromatic photoemission from diamondoid monolayers provides a new strategy to create electron sources with low energy dispersion and enables compact electron guns with high brightness and low beam emittance for aberration-free imaging, lithography, and accelerators. However, these potential applications are hindered by degradation of diamondoid monolayers under photon irradiation and electron bombardment. Here, we report a graphene-protected diamondoid monolayer photocathode with 4-fold enhancement of stability compared to the bare diamondoid counterpart. The single-layer graphene overcoating preserves the monochromaticity of the photoelectrons, showing 12.5 meV ful width at half-maximum distribution of kinetic energy. Importantly, the graphene coating effectively suppresses desorption of the diamondoid monolayer, enhancing its thermal stability by at least 100 K. Furthermore, by comparing the decay rate at different photon energies, we identify electron bombardment as the principle decay pathway for diamondoids under graphene protection. This provides a generic approach for stabilizing volatile species on photocathode surfaces, which could greatly improve performance of electron emitters

Diamondoid Coating Enables Disruptive Approach for Chemical and Magnetic Imaging with 10 nm Spatial Resolution

Diamondoids are unique molecular nano-materials with diamond structure and fascinating properties such as negative electron affinity and short electron mean free paths. A thin layer of diamondoids deposited on a cathode is able to act as an electron monochromator, reducing the energy spread of photo-emitted electrons from a surface. This property can be applied effectively to improve the spatial resolution in x-ray photoemission electron microscopy (X-PEEM), which is limited by chromatic aberration of the electron optics. In this paper, we present X-PEEM measurements reaching the technological relevant spatial resolution of 10?nm without the need of expensive and complex corrective optics. Our results provide a simple approach to image surface chemical and magnetic information at nanometer scales by employing diamondoids

Hybrid metal-organic chalcogenide nanowires with electrically conductive inorganic core through diamondoid-directed assembly.

Controlling inorganic structure and dimensionality through structure-directing agents is a versatile approach for new materials synthesis that has been used extensively for metal-organic frameworks and coordination polymers. However, the lack of 'solid' inorganic cores requires charge transport through single-atom chains and/or organic groups, limiting their electronic properties. Here, we report that strongly interacting diamondoid structure-directing agents guide the growth of hybrid metal-organic chalcogenide nanowires with solid inorganic cores having three-atom cross-sections, representing the smallest possible nanowires. The strong van der Waals attraction between diamondoids overcomes steric repulsion leading to a cis configuration at the active growth front, enabling face-on addition of precursors for nanowire elongation. These nanowires have band-like electronic properties, low effective carrier masses and three orders-of-magnitude conductivity modulation by hole doping. This discovery highlights a previously unexplored regime of structure-directing agents compared with traditional surfactant, block copolymer or metal-organic framework linkers