Lanthanide-directed synthesis of luminescent self-assembly supramolecular structures and mechanically bonded systems from acyclic coordinating organic ligands

2016 ◽  
Vol 45 (11) ◽  
pp. 3244-3274 ◽  
Author(s):  
Dawn E. Barry ◽  
David F. Caffrey ◽  
Thorfinnur Gunnlaugsson

This review focuses on recent developments made in the area of lanthanide directed synthesis/formation of supramolecular self-assembly structures including the formation of complexes/bundles, helicates, MOFs and interlocked molecules.

2011 ◽  
Vol 64 (10) ◽  
pp. 1315 ◽  
Author(s):  
Christophe Lincheneau ◽  
Floriana Stomeo ◽  
Steve Comby ◽  
Thorfinnur Gunnlaugsson

In this short review, we focus on the recent developments within the field of coordination chemistry where mono- or multimetallic supramolecular self-assemblies are formed by employing structurally defined organic ligands, taking advantage of the high coordination requirements of the lanthanides. Such synthesis results in the formation of both structurally complex and beautiful self-assemblies. Moreover, as the lanthanide ions possess both unique magnetic (e.g. GdIII and DyIII) and luminescent properties, either in the visible (EuIII, SmIII and TbIII) or near-infrared regions (YbIII, NdIII, ErIII), these physical features are usually transferred to the self-assemblies themselves, allowing the formation of highly functional structures, such as coordination networks, as well as molecular bundles and helicates. Hence, examples of the use of lanthanide-directed synthesis of luminescent sensors, some of which are formed on solid surfaces such as gold (flat surface or nanoparticles), and imaging agents are presented. Moreover, we demonstrate that by using chiral organic ligands, lanthanide-directed synthesis can also give rise to the formation of enantiomerically pure self-assemblies, the structure of which can be probed using circularly polarized luminescence.


Author(s):  
Xiaodan Gu ◽  
Ilja Gunkel ◽  
Thomas P. Russell

To meet the increasing demand for patterning smaller feature sizes, a lithography technique is required with the ability to pattern sub-20 nm features. While top-down photolithography is approaching its limit in the continued drive to meet Moore’s law, the use of directed self-assembly (DSA) of block copolymers (BCPs) offers a promising route to meet this challenge in achieving nanometre feature sizes. Recent developments in BCP lithography and in the DSA of BCPs are reviewed. While tremendous advances have been made in this field, there are still hurdles that need to be overcome to realize the full potential of BCPs and their actual use.


2013 ◽  
Vol 20 (12) ◽  
pp. 1595-1608 ◽  
Author(s):  
D. Fernandez ◽  
I. Pallares ◽  
G. Covaleda ◽  
F. X. Aviles ◽  
J. Vendrell

2014 ◽  
Vol 10 ◽  
pp. 2858-2873 ◽  
Author(s):  
Robert Francke

Due to the fact that the major portion of pharmaceuticals and agrochemicals contains heterocyclic units and since the overall number of commercially used heterocyclic compounds is steadily growing, heterocyclic chemistry remains in the focus of the synthetic community. Enormous efforts have been made in the last decades in order to render the production of such compounds more selective and efficient. However, most of the conventional methods for the construction of heterocyclic cores still involve the use of strong acids or bases, the operation at elevated temperatures and/or the use of expensive catalysts and reagents. In this regard, electrosynthesis can provide a milder and more environmentally benign alternative. In fact, numerous examples for the electrochemical construction of heterocycles have been reported in recent years. These cases demonstrate that ring formation can be achieved efficiently under ambient conditions without the use of additional reagents. In order to account for the recent developments in this field, a selection of representative reactions is presented and discussed in this review.


2015 ◽  
Vol 7 (4) ◽  
pp. 421-445 ◽  
Author(s):  
James R. Barth ◽  
Tong Li ◽  
Wen Shi ◽  
Pei Xu

Purpose – The purpose of this paper is to examine recent developments pertaining to China’s shadow banking sector. Shadow banking has the potential not only to be a beneficial contributor to continued economic growth, but also to contribute to systematic instability if not properly monitored and regulated. An assessment is made in this paper as to whether shadow banking is beneficial or harmful to China’s economic growth. Design/methodology/approach – The authors start with providing an overview of shadow banking from a global perspective, with information on its recent growth and importance in selected countries. The authors then focus directly on China’s shadow banking sector, with information on the various entities and activities that comprise the sector. Specifically, the authors examine the interconnections between shadow banking and regular banking in China and the growth in shadow banking to overall economic growth, the growth in the money supply and the growth in commercial bank assets. Findings – Despite the wide range in the estimates, the trend in the size of shadow banking in China has been upward over the examined period. There are significant interconnections between the shadow banking sector and the commercial banking sector. Low deposit rate and high reserve requirement ratios have been the major factors driving its growth. Shadow banking has been a contributor, along with money growth, to economic growth. Practical implications – The authors argue that shadow banking may prove useful by diversifying China’s financial sector and providing greater investments and savings opportunities to consumers and businesses throughout the country, if the risks of shadow banking are adequately monitored and controlled. Originality/value – To the authors’ knowledge, this paper is among the few to systematically evaluate the influence of shadow banking on China’s economic growth.


Life ◽  
2018 ◽  
Vol 8 (4) ◽  
pp. 53 ◽  
Author(s):  
Hironori Sugiyama ◽  
Taro Toyota

Experimental evolution in chemical models of cells could reveal the fundamental mechanisms of cells today. Various chemical cell models, water-in-oil emulsions, oil-on-water droplets, and vesicles have been constructed in order to conduct research on experimental evolution. In this review, firstly, recent studies with these candidate models are introduced and discussed with regards to the two hierarchical directions of experimental evolution (chemical evolution and evolution of a molecular self-assembly). Secondly, we suggest giant vesicles (GVs), which have diameters larger than 1 µm, as promising chemical cell models for studying experimental evolution. Thirdly, since technical difficulties still exist in conventional GV experiments, recent developments of microfluidic devices to deal with GVs are reviewed with regards to the realization of open-ended evolution in GVs. Finally, as a future perspective, we link the concept of messy chemistry to the promising, unexplored direction of experimental evolution in GVs.


2018 ◽  
Vol 9 (1) ◽  
Author(s):  
Bo Song ◽  
Sneha Kandapal ◽  
Jiali Gu ◽  
Keren Zhang ◽  
Alex Reese ◽  
...  

2000 ◽  
Vol 72 (10) ◽  
pp. 1819-1834 ◽  
Author(s):  
John M. Prausnitz

At liquid-like densities, molecules of complex fluids can assume a variety of structures (or positions) in space; when the molecules contain many atoms as, for example, in polymers, that variety becomes very large. Further, when confined to a narrow space, it is possible to achieve structures that are not normally observed. Thanks to recent advances in statistical mechanics and molecular physics, and thanks to increasingly fast computers, it is now possible to calculate a fluid's structure, that is, the positions of molecules at equilibrium under given conditions. Calculation of fluid structure is useful because thermodynamic properties depend strongly on that structure, leading to possible applications for new materials. Three examples illustrate some recent developments; each example is presented only schematically (with a minimum of equations) to indicate the physical basis of the mathematical description. The first example considers the effect of branching on self-assembly (micellization) of copolymers (with possible long-range applications in medicine). The second and third examples consider the effect of confinement on fluid structure: first, crystallization in a narrow, confined space to produce a desired crystal structure (with possible applications for light-emitting diodes) and second, suppression of micellization of a diblock copolymer in a thin film (with possible application in lithography). Whenever possible, theoretical calculations are compared with experimental results.


2013 ◽  
Vol 66 (1) ◽  
pp. 9 ◽  
Author(s):  
Yi Liu ◽  
Zhan-Ting Li

The chemistry of imine bond formation from simple aldehyde and amine precursors is among the most powerful dynamic covalent chemistries employed for the construction of discrete molecular objects and extended molecular frameworks. The reversible nature of the C=N bond confers error-checking and proof-reading capabilities in the self-assembly process within a multi-component reaction system. This review highlights recent progress in the self-assembly of complex organic molecular architectures that are enabled by dynamic imine chemistry, including molecular containers with defined geometry and size, mechanically interlocked molecules, and extended frameworks and polymers, from building blocks with preprogrammed steric and electronic information. The functional aspects associated with the nanometer-scale features not only place these dynamically constructed nanostructures at the frontier of materials sciences, but also bring unprecedented opportunities for the discovery of new functional materials.


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