Emission detected circular dichroism

Emission Detected Circular Dichroism In some cases, it is possible to... 

Riehl JP, Muller G. Circularly Polarized Luminescence Spectroscopy and Emission-Detected Circular Dichroism. In Berova N, Polavarapu PL, Nakanishi K, Woody R, editors. Comprehensive Chiroptical Spectroscopy John Wiley Sons, Inc., New York 2012, pp. 65-90. 

Muller FC, Muller G, Riehl JP. Emission Detected Circular Dichroism from Long-Lived Excited States Application to Chiral Eu(ni) Systems. Chirality 2007 19 826-832. 

See also Biomacromolecular Applications of Circular Dichroism and ORD Chiroptical Spectroscopy, Emission Theory Chiroptical Spectroscopy, General Theory Chiroptical Spectroscopy, Oriented Molecules and Anisotropic Systems Circularly Polarized Luminescence and Fluorescence Detected Circular Dichroism Light Sources and Optics Luminescence, Theory Nonlinear Optical Properties Vibrational CD Spectrometers Vibrational CD, Applications Vibrational CD, Theory. 

In fluorescence-detected circular dichroism (FDCD) the difference in total emission intensity is used to monitor differences in circularly polarized absorption. This spectroscopic technique was developed in the early 1970s in the laboratory of Professor I. Tinoco at the University of California,... 

The differential emission of left and right circularly polarized light from luminescent molecular systems is called circularly polarized luminescence (CPL), and is at the basis of the corresponding spectroscopic technique (CPL spectroscopy) [23-25]. CPL spectroscopy should not be confused with fluorescence detected circular dichroism (see Sect. 6.1.6) in the latter technique the differential absorption of the circularly polarized components is detected through fluorescence measurements, owing to the different extent of photoexcitation that left- and right-handed light can produce on a chiral molecule. 

Unlike CD, the measurement of CPL is still mainly dependent on the use of custom-made instruments that have been designed, developed and improved by a limited number of research groups around the world over the last three decades [36,38,41,42,45,52,59-63]. However, the growing interest in developing chiral luminescent probes, and in particular Ln(in)-based systems, has resulted in the advertising and some availability of commercial instrumentation. The first commercial CPL spectrometer, which essentially consists of two CD spectrometers with the second one used as the emission spectrometer, was manufactured by JASCO Inc., the JASCO CPL-200. More recently, the company OLIS Inc. developed its Polarisation Toolbox to support fluorescence, polarisation of fluorescence, anisotropy, CPL, CD, and FDCD (fluorescence detected circular dichroism) measurements for its CD instrumentation. As of Febmary 2012, only CPL-related studies using the JASCO CPL-200 instrument have appeared in the hterature [64-67]. 

Electronic spectroscopy (see Electronic Spectroscopy), in one form or another, has been the principal method used for the detection of short-lived intermediates. UV-visible absorption was the initial spectroscopic method used with flash photolysis and flow systems, and for each of these methods it remains the most commonly used approach. For species in low-temperature matrices, many varieties of electronic spectroscopy have been used. These include UV-visible absorption and emission, fluorescence, magnetic circular dichroism (MCD) and magnetic linear dichroism, and photoelectron spectroscopy. It is unfortunate, therefore, that in many cases electronic spectroscopy yields little or no stractnral information. The exceptions are high-resolution spectra, where vibrational or rotational flne structure may be seen. 

The binding of synthetic ion channels and pores to lipid bilayer membranes often causes a change in intra- or intermolecular self-organization that is visible in sufficiently sensitive methods such as fluorescence (e.g. tryptophan emission) [14] or circular dichroism spectroscopy and can be used to determine the partition coefficient. Convenient methods of detection under relevant conditions are fluorescence resonance energy transfer (FRET) or fluorescence depth quenching (FDQ) [3, 4, 6]. Many fluorescent probes for the labeling of both synthetic ion channels/... 

The right panel in Figure 3 depicts 1/1(0) for (+)-catechin in mixtures of trifluoroethanol and 1-propanol that contain poly(L-proline) at a concentration of 0.90 mg/ml. In pure trifluoroethanol 1/1(0) is slightly less than one. At the opposite extreme of solvent composition, I/l(0) is greater than one and increases over a period of several days. The greatest sensitivity of 1/1(0) to solvent composition occurs near 25 75 trifluoroethanol 1-propanol, which is where the Form I - Form II interconversion is detected by circular dichroism. Measurements of the fluorescence of (+)-catechin in the mixed solvents, but in the absence of poly(L-proline), show no unusual dependence of emission on solvent. 

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