Self-assembly of non-macrocyclic triangular Ni3Ln clusters

2022 ◽  
Author(s):  
Tyson N Dais ◽  
Rina Takano ◽  
Takayuki Ishida ◽  
Paul Plieger
Keyword(s):  
Self Assembly ◽  
Structural Characterisation ◽  
Tetranuclear Complexes

The synthesis and structural characterisation of four new heterometallic tetranuclear complexes is reported. Three L3Ni3Ln type complexes, where Ln = La (C1), Eu (C2), and Gd (C3), have been fully...

Direct synthesis and structural characterisation of tri- and tetra-nuclear silver metallaknotanes by self-assembly approach

2008 ◽  
pp. 6191 ◽  
Author(s):  
Julien Bourlier ◽  
Abdelaziz Jouaiti ◽  
Nathalie Kyritsakas-Gruber ◽  
Lionel Allouche ◽  
Jean-Marc Planeix ◽  
...  
Keyword(s):  
Self Assembly ◽  
Direct Synthesis ◽  
Structural Characterisation

scholarly journals Reaction Monitoring and Structural Characterisation of Coordination Driven Self-Assembled Systems by Ion Mobility-Mass Spectrometry

2021 ◽  
Vol 9 ◽  
Author(s):  
Oscar H. Lloyd Williams ◽  
Nicole J. Rijs
Keyword(s):  
Mass Spectrometry ◽  
Ion Mobility ◽  
Self Assembly ◽  
Functional Materials ◽  
Ion Mobility Mass Spectrometry ◽  
Complex Species ◽  
Structural Characterisation ◽  
Analytical Technique ◽  
Complex Processes ◽  
Analytical Approaches

Nature creates exquisite molecular assemblies, required for the molecular-level functions of life, via self-assembly. Understanding and harnessing these complex processes presents an immense opportunity for the design and fabrication of advanced functional materials. However, the significant industrial potential of self-assembly to fabricate highly functional materials is hampered by a lack of knowledge of critical reaction intermediates, mechanisms, and kinetics. As we move beyond the covalent synthetic regime, into the domain of non-covalent interactions occupied by self-assembly, harnessing and embracing complexity is a must, and non-targeted analyses of dynamic systems are becoming increasingly important. Coordination driven self-assembly is an important subtype of self-assembly that presents several wicked analytical challenges. These challenges are “wicked” due the very complexity desired confounding the analysis of products, intermediates, and pathways, therefore limiting reaction optimisation, tuning, and ultimately, utility. Ion Mobility-Mass Spectrometry solves many of the most challenging analytical problems in separating and analysing the structure of both simple and complex species formed via coordination driven self-assembly. Thus, due to the emerging importance of ion mobility mass spectrometry as an analytical technique tackling complex systems, this review highlights exciting recent applications. These include equilibrium monitoring, structural and dynamic analysis of previously analytically inaccessible complex interlinked structures and the process of self-sorting. The vast and largely untapped potential of ion mobility mass spectrometry to coordination driven self-assembly is yet to be fully realised. Therefore, we also propose where current analytical approaches can be built upon to allow for greater insight into the complexity and structural dynamics involved in self-assembly.

Coordination arrays — Synthesis and characterization of tetranuclear complexes of grid-type

2004 ◽  
Vol 82 (10) ◽  
pp. 1428-1434 ◽  
Author(s):  
Garry S Hanan ◽  
Dirk Volkmer ◽  
Jean-Marie Lehn
Keyword(s):  
Metal Ions ◽  
Self Assembly ◽  
Metal Ion ◽  
Transition Metal Ions ◽  
Tridentate Ligands ◽  
H Nmr ◽  
Nitrogen Ligands ◽  
Metal Metal ◽  
Tetranuclear Complexes

A series of tetranuclear metal complexes of grid-type consisting of four bis-tridentate ligands and four divalent transition metal ions were synthesized and characterized. The 1H NMR spectra of diamagnetic complexes containing Zn(II), Cd(II), Fe(II), and Ru(II) was correlated to the radius of the metal ion. The UV–vis and electrochemical results indicated that the bridging ligand π* orbital and the dπ metal orbital are stabilized by complexation of more than one metal ion. Furthermore, the Co(II) and Fe(II) grids exhibit metal–metal interaction mediated by the bis-tridentate ligands as indicated by electrochemical and spectroscopic methods. These results provide guidelines for the design of larger grids bearing several metal centres in a square arrangement, which also represent potential components of molecular electronic devices.Key words: complexes with nitrogen ligands, octahedral metal ions, self-assembly, supramolecular chemistry.

Straightforward formation of dianionic acetonylate: self-assembly of mercury(II) with pyridyl donor ligands in acetone

2021 ◽  
Author(s):  
Kangsan Hong ◽  
Sangwoo Lim ◽  
Heehun Moon ◽  
Dongwon Kim ◽  
Dongwook Kim ◽  
...  
Keyword(s):  
Single Crystals ◽  
Self Assembly ◽  
Room Temperature ◽  
Donor Ligands ◽  
Tetranuclear Complexes

Self-assembly of Hg(ClO4)2 with new bidentate (L) in acetone at room temperature produces single crystals consisting of unusual discrete tetranuclear complexes [Hg4(ClO4)4(CH2COCH2)2L2]·CH3COCH3 via straightforward formation of dianionic acetonylate, -CH2COCH2- in...

Synthesis, Structural Characterisation and Self Assembly of Nanoparticles

2021 ◽  
Author(s):  
◽  
John D. Watt
Keyword(s):  
Lead Sulfide ◽  
Self Assembly ◽  
Palladium Nanoparticles ◽  
Hydrogen Absorption ◽  
Lead Chalcogenide ◽  
X Ray ◽  
Structural Characterisation ◽  
Size And Shape ◽  
Surfactant System ◽  
Branched Nanostructures

<p>This thesis is concerned with the synthesis, structural characterisation and self assembly of various nanocrystalline materials. These materials include gold, lead sulfide and lead selenide with substantial focus given to the noble metal palladium. The aim of this research was to obtain size and shape control over nanoparticles formed from solution phase synthesis for various applications. This was realised with chemical techniques using organic surfactants as growth controlling agents. The morphology, composition, internal crystal structure and applicable properties of the as synthesised nanoparticles were fully investigated to give a complete characterisation. Characterisation was carried out using a number of techniques including Super and High Resolution Transmission Electron Microscopy (SHREM, HREM), Synchrotron Powder X-Ray Diffraction (XRD), Selected Area Electron Diffraction (SAED) and Energy Dispersive X-Ray Spectroscopy (EDS).  The first chapter in this thesis focuses on the synthesis and self assembly of monodisperse gold nanoparticles into nanoparticle superlattices (NPSLs), an exciting new type of material. The nanoparticles were prepared using a well known chemical method at room temperature. They were then arranged into NPSLs by a simple evaporation technique. Intermediate structures to the SLs were isolated which gave an insight into their formation. This showed that the NPs first self assembled into an energetically unfavourable bilayer before forming the most thermodynamically preferred three dimensional structure. This behaviour was due to the presence of organic capping ligands.  The second chapter is concerned with the synthesis and characterisation of lead chalcogenide nanoparticles (lead sulfide and lead selenide). These are semiconductor materials which can provide a photocurrent when illuminated with infra-red radiation which makes them ideal candidates for solar cell technology. The nanoparticles were synthesised using a bench top solvothermal method. By varying the nature of the surfactant system, the precursor and the reaction time and temperature a wide range of nanoparticles with different sizes and shapes were prepared. A type of lead sulfide nanoparticles was then chosen for capping ligand exchange experiments. The new method developed here provides a facile route to water soluble lead chalcogenide nanoparticles and a means to more easily extract a photocurrent when used in solar cell applications.  The remainder of this thesis is focussed on the synthesis and structural characterisation of palladium nanoparticles. Palladium is a very important catalytic metal therefore control over its size and shape on the nanoscale is of primary concern. In the third chapter of this thesis various types of palladium nanoparticles were produced using solution phase techniques in a pressure reaction vessel. By varying the nature of the surfactant system, the precursor and the reaction pressure, temperature and time the size and shape of the resulting nanoparticles could be controlled. These included spherical and worm-like nanoparticles as well as novel pod-like and highly branched palladium nanostructures. These complex shapes were the first evidence of this kind of morphology for palladium and provide a new and exciting material for catalytic applications.  The final chapter in this thesis features a full structural characterisation and growth mechanism for the novel, complex palladium nanostructures along with an investigation into their catalytic and hydrogen absorption properties. The structural characterisation of a palladium tripod provides the first direct evidence of complex growth from a symmetrical nanoparticle core possessing the face centred cubic crystal structure. The growth of the highly branched palladium nanostructures is then tracked in real time. It is shown that the growth involves the formation of nuclei followed by tripod intermediates and finally highly branched nanostructures. By varying the nature of the surfactant system the kinetics of the reaction and hence the morphology of the resulting nanostructures can be controlled. A full growth mechanism is therefore proposed. The catalytic activity of the highly branched palladium nanostructures towards a simple organic transformation reaction is investigated. Finally, the hydrogen absorption and desorption properties of the highly branched nanostructures is explored. The results presented here regarding palladium nanoparticles are applicable to other industrially important noble metals such as gold, silver and platinum.  A final conclusion chapter is then presented along with ideas for future research.</p>

scholarly journals Microfluidics for Time-Resolved Small-Angle X-Ray Scattering

2020 ◽  
Author(s):  
Susanne Seibt ◽  
Timothy Ryan
Keyword(s):  
Self Assembly ◽  
Structural Evolution ◽  
Time Resolved ◽  
X Ray ◽  
Structural Characterisation ◽  
X Ray Scattering ◽  
Saxs Analysis ◽  
Kinetics Of ◽  
Ray Scattering

With the advent of new in situ structural characterisation techniques including X-ray scattering, there has been an increased interest in investigations of the reaction kinetics of nucleation and growth of nanoparticles as well as self-assembly processes. In this chapter, we discuss the applications of microfluidic devices specifically developed for the investigation of time resolved analysis of growth kinetics and structural evolution of nanoparticles and nanofibers. We focus on the design considerations required for spectrometry and SAXS analysis, the advantages of using a combination of SAXS and microfluidics for these measurements, and discuss in an applied fashion the use of these devices for time-resolved research.

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