A polyterpyridinyl building block-based nutlike hexagonal bismetallo architecture with a central hollow Star of David was assembled by a stepwise strategy. This nanoarchitecture can be viewed as a recursive mathematical form that possesses a supramolecular corner-connected cyclic structure, i.e., a triangle or rhombus at various levels of scale or detail. The key metallo-organic ligand (MOL) with four uncomplexed free terpyridines was obtained by a final Suzuki cross-coupling reaction with a tetrabromoterpyridine Ru dimer. The molecular metallorhombus was prepared by reacting the MOL with a 60° bis-terpyridine and Fe(2+). The giant hollow hexagonal nut with a diameter of more than 11 nm and a molecular weight of ca. 33 kDa was obtained in near-quantitative yield by mixing the two types of multi-terpyridine ligands with Fe(2+). The supramolecular architecture was characterized by NMR ((1)H and (13)C), 2D NMR (COSY and ROESY), and DOSY spectroscopies, high-resolution electrospray ionization mass spectrometry, traveling-wave ion mobility mass spectrometry, and transmission electron microscopy.
Five- and six-pointed star structures occur frequently in nature as flowers, snow-flakes, leaves and so on. These star-shaped patterns are also frequently used in both functional and artistic man-made architectures. Here following a stepwise synthesis and self-assembly approach, pentagonal and hexagonal metallosupramolecules possessing star-shaped motifs were prepared based on the careful design of metallo-organic ligands (MOLs). In the MOL design and preparation, robust ruthenium–terpyridyl complexes were employed to construct brominated metallo-organic intermediates, followed by a Suzuki coupling reaction to achieve the required ensemble. Ligand LA (VRu2+X, V=bisterpyridine, X=tetraterpyridine, Ru=Ruthenium) was initially used for the self-assembly of an anticipated hexagram upon reaction with Cd2+ or Fe2+; however, unexpected pentagonal structures were formed, that is, [Cd5LA5]30+ and [Fe5LA5]30+. In our redesign, LB [V(Ru2+X)2] was synthesized and treated with 60° V-shaped bisterpyridine (V) and Cd2+ to create hexagonal hexagram [Cd12V3LB3]36+ along with traces of the triangle [Cd3V3]6+. Finally, a pure supramolecular hexagram [Fe12V3LB3]36+ was successfully isolated in a high yield using Fe2+ with a higher assembly temperature.
Three generations of metalated trigonal supramolecular architectures, so-called metallo-triangles, were assembled from terpyridine (tpy) complexes. The first generation (G1) metallo-triangles were directly obtained by reacting a bis(terpyridinyl) ligand with a 60° bite angle and Zn ions. The direct self-assembly of G2 and G3 triangles by mixing organic ligands and Zn , however, only generated a mixture of G1 and G2, as well as a trace amount of insoluble polymer-like precipitate. Therefore, a modular strategy based on the connectivity of ⟨tpy-Ru -tpy⟩ was employed to construct two metallo-organic ligands for the assembly of G2 and G3 Sierpiński triangles. The metallo-organic ligands L and L with multiple free terpyridines were obtained through Suzuki cross-coupling of the Ru complexes, and then assembled with Zn or Cd to obtain high-generation metallo-triangular architectures in nearly quantitative yield. The G1-G3 architectures were characterized by NOESY and DOSY NMR spectroscopy, ESI-MS, TWIM-MS, and transmission electron microscopy.
In recent years, modeling and simulation of materials have become indispensable to complement experiments in materials design. High‐throughput simulations increasingly aid researchers in selecting the most promising materials for experimental studies or by providing insights inaccessible by experiment. However, this often requires multiple simulation tools to meet the modeling goal. As a result, methods and tools are needed to enable extensive‐scale simulations with streamlined execution of all tasks within a complex simulation protocol, including the transfer and adaptation of data between calculations. These methods should allow rapid prototyping of new protocols and proper documentation of the process. Here an overview of the benefits and challenges of workflow engineering in virtual material design is presented. Furthermore, a selection of prominent scientific workflow frameworks used for the research in the BATTERY 2030+ project is presented. Their strengths and weaknesses as well as a selection of use cases in which workflow frameworks significantly contributed to the respective studies are discussed.
Bimetallic nanostructures are a promising candidate for plasmon-driven photocatalysis. However, knowledge on the generation and utilization of hot carriers in bimetallic nanostructures is still limited. In this work, we explored Pt position-dependent photocatalytic properties of bimetallic Au nanobipyramids (Au NBPs) with single-molecule fluorescence imaging. Compared with all-deposited core–shell nanostructures (aPt-Au NBPs), single-molecule imaging and simulation results show that the end-deposited bimetallic nanostructures (ePt-Au NBPs) can maintain a strong electromagnetic (EM) field and further promote the generation and transfer of energetic hot electrons for photocatalysis. Even though the Pt lattice is more stable than Au, the strong EM field at the sharp tips can boost lattice vibration, where enhanced spontaneous surface restructuring for active reaction site generation takes place. Significantly enhanced catalytic efficiency from ePt-Au NBPs is observed in contrast to that of Au NBPs and aPt-Au NBPs. These microscopic evidences offer valuable guidelines to design plasmon-based photocatalysts, particularly for bimetallic nanostructures.
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