A Topological Approach to Molecular Chirality, Erica Flapan

2011 ◽  
pp. 137-152
2020 ◽  
Author(s):  
Daniel B. Straus ◽  
Robert J. Cava

The design of new chiral materials usually requires stereoselective organic synthesis to create molecules with chiral centers. Less commonly, achiral molecules can self-assemble into chiral materials, despite the absence of intrinsic molecular chirality. Here, we demonstrate the assembly of high-symmetry molecules into a chiral van der Waals structure by synthesizing crystals of C<sub>60</sub>(SnI<sub>4</sub>)<sub>2</sub> from icosahedral buckminsterfullerene (C<sub>60</sub>) and tetrahedral SnI4 molecules through spontaneous self-assembly. The SnI<sub>4</sub> tetrahedra template the Sn atoms into a chiral cubic three-connected net of the SrSi<sub>2</sub> type that is held together by van der Waals forces. Our results represent the remarkable emergence of a self-assembled chiral material from two of the most highly symmetric molecules, demonstrating that almost any molecular, nanocrystalline, or engineered precursor can be considered when designing chiral assemblies.


1993 ◽  
Vol 39 (131) ◽  
pp. 10-14 ◽  
Author(s):  
J. F. Nye

AbstractThe pattern of horizontal strain rate in an ice sheet is discussed from a topological point of view. In a circularly symmetric ice sheet, the isotropic point for strain rate at its centre is degenerate and structurally unstable. On perturbation the degenerate point splits into two elementary isotropic points, each of which has the lemon pattern for the trajectories of principal strain rate. Contour maps of principal strain-rate values are presented which show the details of the splitting.


2020 ◽  
Vol 9 (4) ◽  
pp. 1585-1595
Author(s):  
A. Divya ◽  
D. Sasikala
Keyword(s):  

Universe ◽  
2021 ◽  
Vol 7 (3) ◽  
pp. 75
Author(s):  
Richard Pincak ◽  
Alexander Pigazzini ◽  
Saeid Jafari ◽  
Cenap Ozel

The main purpose of this paper is to show and introduce some new interpretative aspects of the concept of “emergent space” as geometric/topological approach in the cosmological field. We will present some possible applications of this theory, among which the possibility of considering a non-orientable wormhole, but mainly we provide a topological interpretation, using this new approach, to M-Theory and String Theory in 10 dimensions. Further, we present some conclusions which this new interpretation suggests, and also some remarks considering a unifying approach between strings and dark matter. The approach shown in the paper considers that reality, as it appears to us, can be the “emerging” part of a more complex hidden structure. Pacs numbers: 11.25.Yb; 11.25.-w; 02.40.Ky; 02.40.-k; 04.50.-h; 95.35.+d.


Author(s):  
Alberta Ferrarini ◽  
Pier Luigi Nordio
Keyword(s):  

Science ◽  
1998 ◽  
Vol 282 (5397) ◽  
pp. 2247-2250 ◽  
Author(s):  
R. K. Kondru ◽  
P. Wipf ◽  
D. N. Beratan

Author(s):  
Subana Thanasegaran ◽  
Yi Yin ◽  
Yuichiro Tateiwa ◽  
Yoshiaki Katayama ◽  
Naohisa Takahashi
Keyword(s):  

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