“Nanoobjects” by Self-Assembly Concomitant with Modifications under Alterable Boundary Conditions: Incorporation of Paramagnetic Metal Centers (Cu2+) in Ring-Shaped Molybdenum-Oxide Based Clusters The authors thank Prof. D. Gatteschi, University of Florence (Italy), for helping with the interpretation of the ESR spectrum, and Dipl.-Chem. A. Berkle and Dr. J. Hockemeyer, University of Bielefeld (Germany), for their collaboration. C. R. thanks the Alexander von Humboldt Foundation for her fellowship. Financial support by the Deutsche Forschungsgemeinschaft and the Fonds der Chemischen Industrie is gratefully acknowledged.

2001 ◽  
Vol 40 (21) ◽  
pp. 4034 ◽  
Author(s):  
Achim Müller ◽  
Erich Krickemeyer ◽  
Hartmut Bögge ◽  
Marc Schmidtmann ◽  
Paul Kögerler ◽  
...  
Keyword(s):  
Boundary Conditions ◽  
Molybdenum Oxide ◽  
Self Assembly ◽  
Financial Support ◽  
Metal Centers ◽  
Esr Spectrum ◽  
Alexander Von Humboldt ◽  
Paramagnetic Metal ◽  
University Of Florence ◽  
Deutsche Forschungsgemeinschaft

First gravity data aquired by the transportable absolute Quantum Gravimeter QG-1 employing collimated Bose-Einstein condensates

2021 ◽  
Author(s):  
Waldemar Herr ◽  
Nina Heine ◽  
Marat Musakaev ◽  
Sven Abend ◽  
Ludger Timmen ◽  
...  
Keyword(s):  
Measurement Uncertainty ◽  
Financial Support ◽  
Gravity Data ◽  
German Research Foundation ◽  
Local Gravity ◽  
German Research ◽  
Measurement Concept ◽  
Bose Einstein ◽  
Absolute Quantum ◽  
Deutsche Forschungsgemeinschaft

<p>The transportable Quantum Gravimeter QG-1 is designed to determine the local gravity to the nm/s² level of uncertainty. It relies on the interferometric interrogation of magnetically collimated Bose-Einstein condensates in a transportable setup consisting of a sensor head and an electronics supply unit.<br>In this contibution we introduce the measurement concept and discuss it's impact on the measurement uncertainty. We are reporting on the first gravity data taken with the device over the course of three days thereby validating the operability and the measurement concept applied in QG-1.<br>We acknowledge financial support from "Niedersachsisches Vorab" through "Förderung von Wissenschaft und Technik in Forschung und Lehre" for the initial funding of research in the new DLR-SI Institute. Funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under Germany's Excellence Strategy - EXC-2123 QuantumFrontiers - 390837967 and under Project-ID 434617780 - SFB 1464.</p>

scholarly journals Pyramidal Heteroanion-Directed and Reduced MoV-Driven Assembly of Multi-Layered Polyoxometalate Cages

2018 ◽  
Author(s):  
Qi Zheng, ◽  
Manuel Kupper ◽  
Weimin Xuan ◽  
Hirofumi Oki ◽  
Ryo Tsunashima ◽  
...  
Keyword(s):  
Self Assembly ◽  
Electronic Materials ◽  
Electronic Devices ◽  
Mixed Valence ◽  
The Self ◽  
Model Structure ◽  
Redox Titration ◽  
Metal Centers ◽  
Redox Active ◽  
Tetrabutyl Ammonium

The fabrication of redox-active polyoxometalates (POMs) that can switch between multiple states is critical for their application in electronic devices, yet, a sophisticated synthetic methodology is not well developed for such cluster types. Here we describe the heteroanion-directed and reduction-driven assembly of a series of multi-layered POM cages 1-10 templated by 1-3 redox-active pyramidal heteroanions. The heteroanions greatly affect the selfassembly of the resultant POM cages, leading to the generation of unprecedented three-layered peanut-shaped - 4, 7 and 8 - or bulletshaped - 5 and 6 - structures. The introduction of reduced molybdate is essential for the self-assembly of the compounds and results in mixed-metal (W/Mo), and mixed-valence (WVI/MoV) 1-10, as confirmed by redox titration, UV-Vis-NIR, NMR spectroscopy and mass spectrometry. 11, the tetrabutyl ammonium (TBA) salt derivative of the fully oxidized 3, is produced as a model structure for measurements to confirm that 1-10 are a statistical mixture of isostructural clusters with different ratios of W/Mo. Finally, multilayered POM cages exhibit dipole relaxations due to the presence of mixed valence WVI/MoV metal centers, demonstrating their potential uses for electronic materials.

An azido-bridged [FeII4] grid-like molecule showing spin crossover behaviour

2021 ◽  
Author(s):  
Zhilin Guo ◽  
Maolin You ◽  
Yi-Fei Deng ◽  
Qiang Liu ◽  
Yin-Shan Meng ◽  
...  
Keyword(s):  
Self Assembly ◽  
Spin Crossover ◽  
Great Success ◽  
Metal Centers ◽  
Synthetic Strategy

Supramolecular self-assembly synthetic strategy provides a valid tool to obtain polynuclear Fe(II) complexes containing effective communications between the metal centers and achieve distinct spin crossover behaviour. Despite great success in...

scholarly journals Coordination-Driven Self-Assembly and Anticancer Activity of Molecular Rectangles Containing Octahedral Ruthenium Metal Centers

2011 ◽  
Vol 30 (12) ◽  
pp. 3242-3245 ◽  
Author(s):  
Vaishali Vajpayee ◽  
Young Ho Song ◽  
Yoon Jung Yang ◽  
Se Chan Kang ◽  
Hyunuk Kim ◽  
...  
Keyword(s):  
Anticancer Activity ◽  
Self Assembly ◽  
Metal Centers

Electron self-exchange of cytochrome c measured via13C detected protonless NMR

2013 ◽  
Vol 17 (01n02) ◽  
pp. 142-149 ◽  
Author(s):  
Stefano Cacciatore ◽  
Mario Piccioli ◽  
Paola Turano
Keyword(s):  
Cytochrome C ◽  
Exchange Rates ◽  
Mixing Time ◽  
The Self ◽  
Conformational Exchange ◽  
General Applicability ◽  
Metal Centers ◽  
Human Cytochrome ◽  
Paramagnetic Metal ◽  
Human Cytochrome C

The use of protonless 13C′–13C′ EXSY (COCO-EXSY) is proposed here to measure electron self-exchange rates. The experiment is compared to the commonly employed 1H and 15N EXSY experiments using as a reference system human cytochrome c. In COCO-EXSY, the exchange peaks are stronger than in the other experiments with respect to the self peaks and their intensity is less dependent on the choice of the EXSY mixing time. The use of 13C directed detection may be essential for all those cases where T2 relaxation is detrimental, as in the case of proteins containing highly paramagnetic metal centers, or rotating slowly in solution, or where the amide signals are difficult to detect due to chemical or conformational exchange. The proposed experiment has a general applicability and can be used to monitor exchange phenomena different from electron self-exchange.

scholarly journals Linked topological colloids in a nematic host

2015 ◽  
Vol 112 (15) ◽  
pp. 4546-4551 ◽  
Author(s):  
Angel Martinez ◽  
Leonardo Hermosillo ◽  
Mykola Tasinkevych ◽  
Ivan I. Smalyukh
Keyword(s):  
Boundary Conditions ◽  
Self Assembly ◽  
Structural Organization ◽  
Building Blocks ◽  
Elastic Coupling ◽  
Defect Structures ◽  
Two Photon ◽  
Colloidal Properties ◽  
And Topology ◽  
Orientational Ordering

Geometric shape and topology of constituent particles can alter many colloidal properties such as Brownian motion, self-assembly, and phase behavior. Thus far, only single-component building blocks of colloids with connected surfaces have been studied, although topological colloids, with constituent particles shaped as freestanding knots and handlebodies of different genus, have been recently introduced. Here we develop a topological class of colloids shaped as multicomponent links. Using two-photon photopolymerization, we fabricate colloidal microparticle analogs of the classic examples of links studied in the field of topology, the Hopf and Solomon links, which we disperse in nematic fluids that possess orientational ordering of anisotropic rod-like molecules. The surfaces of these particles are treated to impose tangential or perpendicular boundary conditions for the alignment of liquid crystal molecules, so that they generate a host of topologically nontrivial field and defect structures in the dispersing nematic medium, resulting in an elastic coupling between the linked constituents. The interplay between the topologies of surfaces of linked colloids and the molecular alignment field of the nematic host reveals that linking of particle rings with perpendicular boundary conditions is commonly accompanied by linking of closed singular defect loops, laying the foundations for fabricating complex composite materials with interlinking-based structural organization.

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