Optical activity magnetic circular dichroism

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... [Pg.457]

Studies involving temperature dependence of the oscillator strengths of the hypersensitive transitions and circular dichroism (CD) and magnetic circular dichroism (MCD) of optically active complexes may give some useful information from which the relative contributions of static and dynamic coupling mechanisms to the observed oscillator strengths may be ascertained. [Pg.610]

B Ligand field circular dichroism spectrum of optically active tetragonal copper(II) complex (adapted from Ref. 11 o). C Magnetic circular dichroism of the ligand field region of copper(II) complex in (A) scale normalized to 10 K Gauss (adapted from Ref. 11 n)... [Pg.8]

If the optical activity is induced by an external magnetic field it is proportional to the magnetic field strength, and one measures magnetic circular dichroism (MCD), commonly expressed as magnetic molar ellipticity per gauss. [Pg.142]

In an external magnetic field all matter becomes optically active. This observation was first made by Faraday in 1845 the magnetically induced rotation of the plane of polarized light is therefore referred to as the Faraday effect. In recent years, the common mode of study of this phenomenon has been the measurement of magnetic circular dichroism (MCD). Similarly to natural circular dichroism, magnetic circular dichroism is defined as the difference Af = fi, - of the extinction coefficients for left-handed and right-... [Pg.154]

Nonlinear optical activity phenomena arise at third-order and include intensity dependent contributions to optical rotation and circular dichroism, as well as a coherent form of Raman optical activity. The third-order observables are - like their linear analogs - pseudoscalars (scalars which change sign under parity) and require electric-dipole as well as magnetic-dipole transitions. Nonlinear optical activity is circular differential. [Pg.360]

Aside from the intrinsic circular dichroism originating from the molecular structure, a so-called induced optical activity may result when a molecule is situated in an asymmetric environment. Magnetic circular dichroism, for instance, maybe produced by applying an external magnetic field to an absorbing sample. Adsorption of pigment molecules on nucleic acids or protein molecules may also induce circular dichroism. [Pg.92]

Chiroptical measurements in the chrysanthemic acid series have shown that 1,2,2,3-tetra-alkylcyclopropanes have the same chiralities as, yet Cotton effects opposite to, those previously reported for corresponding 1,3-dialkylcyclopropanes. Magnetic circular dichroism of cyclopropane and c.d. studies of optically active derivatives indicate that configuration interaction is of considerable importance in the low-energy excited states. ... [Pg.5]

The quinone (37) has been synthesized and the circular dichroism, attributable to the isotopic substitution, measured. This represents only the second case of optical activity attributable to isotopic substitution other than by deuterium. Further analysis of the circular dichroism of a-diketones is discussed. The use of magnetic circular dichroism in the study of ketones and conjugated dienes has been fully discussed. [Pg.326]

In the presence of a static magnetic field any sample becomes optically active in a direction parallel to that of the magnetic field, and exhibits a circular dichroism to an extent proportional to the intensity of the applied field. Such an effect has nothing to do with molecular chirality and is called magnetic circular dichroism (MCD). Differently from what discussed for natural circular dichroism, the two... [Pg.138]