Chiral filament

Figure 5.17 Temperature dependence of induced CD of 9-anthracenecarboxylate bound to chiral filaments of 2C12-L-GluCnN+ (22). Reprinted with permission from Ref. 83. Copyright 1994 by the American Chemical Society. 

Miyake I, Takanishi Y, Rao NVS, Kr M, Ishikawa K, Takezoe H (2005) Novel chiral filament in an achiral W-shaped liquid crystalline compound. J Mater Chem 15 4688 1694... 

In some cases, chiral resolution can be recognized by helical structure formation. A variety of helical filaments and fibers can be observed in the B7 phase, as shown in Fig. 10. The B7 phase is identified to be a polarization-modulated phase and the internal helical polarization modulation is responsible for the helix [15]. In contrast,... 

E. D. Lee, J. D. Henion, C. A. Brunner, I. W. Wainer, T. D. Doyle, and J. Gal, High-performance liquid chromatographic chiral stationary phase separation with filament on thermospray mass spec-trometric identification of the enantiomer contaminant (S)-( + )meth-amphetamine, Anal. Chem., 55 1349 (1986). 

A similar model can be considered even when a system of polymers forms microfibrils or filaments distributed with a constant interdistance. The separation of filaments can be controlled by the balance of several forces hydration, electrical doublelayer repulsion and van der Walls attraction. This conception derives from a paper by Elliot and Rome (1969) who interpreted in that way the interdistance control between muscle cell filaments. We do not know the exact shape of the isopotential surfaces corresponding to that system of forces in the vicinity of fibrils formed by a set of chiral pol5nners, but they must show in many cases a helicoidal symmetry. The complete system can closely resemble the model suggested by Rudall (1955). 

Electron microscopy studies revealed the successive states of self-assembly of 1 from nuclei to filaments and then to very long helical fibers of opposite chirality for the (L, L) 1 and (D, D) 1, whereas the achiral (M, M) 1 material showed no helicity (Figure 8) [16]. Thus, molecular chirality is transduced into supramolecular helicity which is expressed at the level of the material on nanometric and micrometric scales. 

The 1/33=0 result implies that it is difficult to produce an axial second-order polarization with an optical field parallel to the myosin/actin filaments and that the radiated SHG are contributed mainly from d =dacx and dis=dxzx- Note that the non-zero d i and dis suggest the chirahty in myosin/actin filaments inside a myofibril. This suggestion comphes with a previous conjecture, which states that the nonlinear optical properties in several biological materials (e.g. collagen matrix and muscle) are induced or enhanced by the chirality in their structure [68,69]. 

SEM micrographs are used to determine the nature of the deposit produced by the synthesis and to acquire a rough idea of the material quality (e.g. purity level). As illustrated, for example, in Figs 6.1 and 6.8, the information acquired by SEM is preliminary in fact, it is not possible to say whether the observed filaments are bundles of carbon nanotubes or micro-carbon fibers. In addition, in the case of carbon nanotubes data relative to the presence of single walls or multiwalls are not provided. The same applies for other parameters such as chirality, twisted angle, etc. 

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