Circular dichroism spectroscopy, chiral

Stephens PJ, Devlin FJ (2000) Determination of the structure of chiral molecules using ab initio vibrational circular dichroism spectroscopy. Chirality 12 172-179... 

A convenient method to demonstrate guest binding in mPE systems is circular dichroism spectroscopy (CD). CD is a method which allows the determination of chiral excess in a system [56]. In the absence of a chiral influence, the mPE helix exists as a racemic mixture of both M and P helices and displays no CD signal. Upon the addition of a chiral guest, diastereomeric complexes are... 

Vibrational Circular Dichroism Spectroscopy of Chiral Molecules... 

Stephens PJ, Devlin FJ, Aamouche A (2002) Determination of the structures of chiral molecules using vibrational circular dichroism spectroscopy. In Hicks JM (ed) Chirality physical chemistry. ACS Symposium Series, vol. 810, Chap. 2, Oxford University Press, New York, pp 18-33... 

Yang GC, Ha T, Fan E et al (2010) Determination of the absolute configurations of synthetic daunorubicin analogues using vibrational circular dichroism spectroscopy and density functional theory. Chirality 22 734—743... 

The first method of enantiomeric separation by direct crystallization is the mechanical technique use by Pasteur, where he separated the enan-tiomorphic crystals that were simultaneously formed while the residual mother liquor remained racemic. Enantiomer separation by this particular method can be extremely time consuming, and not possible to perform unless the crystals form with recognizable chiral features (such as well-defined hemihedral faces). Nevertheless, this procedure can be a useful means to obtain the first seed crystals required for a scale-up of a direct crystallization resolution process. When a particular system has been shown to be a conglomerate, and the crystals are not sufficiently distinct so as to be separated, polarimetry or circular dichroism spectroscopy can often be used to establish the chirality of the enantiomeric solids. 

In this experiment, we will simply be looking for chiral descrimination in ML binding to DNA. The two enantiomers are designated as A-ML and A-ML in Figure 8.7. After equilibrium, an excess of the enantiomer not preferentially bound (A-ML) to the DNA is found in analysis chamber B, which can be detected by circular dichroism spectroscopy. To carry out this experiment, you will use small volumes 1 ml in each A and B chamber. Bel-Art products (Pequannock, NJ, USA) sells a conveniently small dialysis cell for a price that is reasonable for a small inorganic lab section. Alternatively, SPECTRA/ POR j regenerated cellulose dialysis tubing is commercially available in 6.4 mm diameter. 

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