Linear and Circular Dichroism

LFnder the influence of a static electric field liquid crystalline solutions of PBLG become uniaxially oriented and show both linear and circular birefringence and linear and circular dichroism. Accordingly, the measured CD shows a dependence of the microscopic angle, a, that the fast optical axis of the oriented solution makes with respect to the plane of polarization of the polarizer in the CD instrument. When the film is reasonably thin (0.01-0.1 mm thick) or/and only partially oriented (less than 5% orientation), the apparent CD of oriented film of deoxyribonucleic acid is expressed by the equation (50) ... 

Ruban AV, Calkoen F, Kwa SLS, van Grondelle R, Horton P and Dekker JP(1997a) Characterisation of LHCII in the aggregated state by linear and circular dichroism spectroscopy. Biochim Biophys Acta 1321 61-70... 

An X-ray diffraction study of the proflavine—DNA complex gave direct evidence of intercalation, by showing one molecule of the aminoacridine stacked parallel to the base-pairs in a 1 3 ratio (Neville and Davies, 1966). Linear and circular dichroism studies of flowing solutions of all five monoaminoacridines (complexed to DNA) confirm that the acridine cations lie in planes parallel to those of the base-pairs Qackson and Mason, 1971). Finally, the free-energy of binding of aminoacridines to DNA was determined and found to be of the order... 

Ligand-field theory is concerned only with the low-lying electronic states of a d- or y block metal complex which can be described by the rearrangements of electrons within the d- or y shell. These states describe the magnetic properties (paramagnetism, g-values) and the ""d-d (or ""f-f ) electronic spectra (color, linear, and circular dichroism). 

The ultraviolet spectra of crowded olefins and substituted butadienes have been studied the sign of the Cotton effect has been related to the chirality of a series of w-molecular complexes of olefins with tetracyanoethylene the sign of the chiral-optical effects of non-planar heteroannular cisoid dienes is opposite to that predicted from the diene rule. Studies of linear and circular dichroism in mono-olefins and magnetic circular dichroism of conjugated olefins have been made, and the experimental ionization potentials of fourteen alkenes have been correlated with the inductive effects of substituents. ... 

The use of liquid crystals as orienting media in polarized infrared spectroscopy, though first demonstrated (as applied to solutes) in the late 1960s [310, 320], has received considerably less attention due to the fact that solvent absorptions severely limit the spectral range accessible to investigation, particularly with conventional dispersion instruments [1, 304], Infrared linear and circular dichroism (IR-LD and IR-CD, respectively) of liquid crystalline materials themselves have, of course, been studied extensively [2]. With the advent of commercial FTIR spectrometers, whose enhanced sensitivity and superior spectral subtraction capabilities allow for far greater precision in IR spectral measurements than is possible with dispersion instruments, activity in this field has picked up considerably [314,321 - 324] and has been reviewed recently [325]. 

Bauman D, Killet C, Boiadjiev SE, Lightner DA, Schonhofer A and Kuball H-G (1996) Linear and circular dichroism spectroscopic study of P, P -dimethylmesobilirubin-XIIIa oriented in a nematic liquid crystal. Journal of Physical Chemistry 100 11546-11558. 

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