Linear magnetic dichroism

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. 

MLDAD Magnetic linear dichroism in the angular distribution of photoelectrons... 

Equally important is the sensitivity to spin ordering referred to as x-ray magnetic linear/circular dichroism [5]. 

At 4.2 K the absorption coefficient of relatively pure single crystals between 1.6 and 0.8 im is only slightly higher than at 300 K [8]. For studies at 4.2 K in a magnetic field in order to determine the magnetic circular dichroism and the magnetic linear dichroism, see p. 265. 

Magnetic Circular Dichroism (MCD), Magnetic Linear Dichroism (MLD), Magnetic Linear Birefringence (Cotton-Mouton effect)... 

The magnetic linear dichroism is the difference in the optical density for linearly polarized light beams parallel and perpendicular to H, AD=D -Dx. 

The magnetic linear dichroism at 7.2 kOe at 8.3 and 5.7 K has been measured on EuSe films on CaF2 by Ferre [2]. The following values of AD = Dy-Dx (in 10 ) as a function of the photon energy are read from a figure in the paper ... 

The redox potentials of zinc-substituted phthalocyanines are shown to be linearly dependent on the total Hammett substituent constant.837 In 1987, Stillman and co-workers used the absorption and magnetic circular dichroism spectra of the zinc phthalocyanine and its 7r-cation-radical species to assign the observed bands on the basis of theoretical calculations. The neutral and oxidized zinc phthalocyanine complexes with cyanide, imidazole, and pyridine were used with the key factor in these studies the stability of the 7r-cation-radical species.838 The structure of zinc chloro(phthalocyaninato) has been determined and conductivity investigated.839... 

Probing Metalloproteins Electronic absorption spectroscopy of copper proteins, 226, 1 electronic absorption spectroscopy of nonheme iron proteins, 226, 33 cobalt as probe and label of proteins, 226, 52 biochemical and spectroscopic probes of mercury(ii) coordination environments in proteins, 226, 71 low-temperature optical spectroscopy metalloprotein structure and dynamics, 226, 97 nanosecond transient absorption spectroscopy, 226, 119 nanosecond time-resolved absorption and polarization dichroism spectroscopies, 226, 147 real-time spectroscopic techniques for probing conformational dynamics of heme proteins, 226, 177 variable-temperature magnetic circular dichroism, 226, 199 linear dichroism, 226, 232 infrared spectroscopy, 226, 259 Fourier transform infrared spectroscopy, 226, 289 infrared circular dichroism, 226, 306 Raman and resonance Raman spectroscopy, 226, 319 protein structure from ultraviolet resonance Raman spectroscopy, 226, 374 single-crystal micro-Raman spectroscopy, 226, 397 nanosecond time-resolved resonance Raman spectroscopy, 226, 409 techniques for obtaining resonance Raman spectra of metalloproteins, 226, 431 Raman optical activity, 226, 470 surface-enhanced resonance Raman scattering, 226, 482 luminescence... 

Thulstrup, E. W. Aspects of Linear and Magnetic Circular Dichroism of Planar Organic Molecules , Springer Berlin, 1980 No. 14 In Lecture Notes in Chemistry. 

In contrast to n-n transitions, the n-n transitions of heterocyclic compounds and carbonyl-containing rings are often polarized in a direction perpendicular to the plane of the ring. Linear dichroism of cytosine, adenine, and other nucleic acid bases has been measured on single crystals and in partially oriented polymer films.71 Magnetically induced linear dichroism provides a new tool for study of metalloproteins.72... 

Figure 3 Electronic absorption (A) and magnetic circular dichroism (B) spectra of the Type 1 Cu site of Achromobacter cycloclastes nitrite reductase (a) and spinach plastocyanin (b). Absorption data were obtained at 120 K for nitrite reductase and at 25 K for plastocyanin. MCD spectra were obtained at 4.2 K. Gaussian resolution of bands in the absorption spectra is based on a simultaneous linear least-squares fit of Abs, MCD, and CD data for each. MCD data from 5000 to 8000 cm have been multiplied by a factor of 5. (Reprinted with permission from Ref. 22. 1996 American Chemical Society)...

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