Units magnetic circular dichroism

A novel tribenzotetraazachlorin fused with a Cgo unit and three 15-crown-5 moieties (compound 114) has recently been prepared by Kobayashi et al. [96], As expected, the C6o unit and the macrocyclic core show strong electronic interactions. As shown by UV-Vis, magnetic circular dichroism, and mass spectroscopic methods, this compound undergoes edge-to-edge dimerization in the presence of K+ ions, while for Na+ ions, they are simply trapped inside the crown ether voids of 114. 

X-Band ESR spectra were obtained at 77 and 293 K with a JES-FE-3X spectrometer. The g-values were determined relative to Li-TCNQ(g = 2.0026) and the magnetic fields were calibrated by the splitting of Mn(II) in MgO(AH3 4 = 86.9 G). Magnetic circular dichroism (MCD) measurements, using a 11.7-kG magnet, were carried out on a Jasco J-20 spectro-polarimeter and are expressed in terms of molecular ellipticity, [0] = 2.303 (4500/7r) ( - r), with units of (deg cm2)/d mol. 

The electronic spectra of the five-membered ring compounds have been intensively studied by the experimental and theoretical works. These molecules are fundamental units in many important biological systems. Furthermore, their excitation spectra are benchmark examples for theoretical studies of molecular excited states [51,55-58]. For furan and thiophene, various types of excitation spectra were measured the vacuum ultraviolet (VUV) spectrum, electron energy-loss (EEL) spectrum and magnetic circular dichroism (MCD) spectrum. The SAC-Cl method offered consistent interpretations of these electronic spectra [51-53]. 

Suryanarayanan et al. (1972) have shown that the results obtained by magnetic circular dichroism are in good agreement with those of Holtzberg and Torrance (1971). The lattice parameter of the fee unit cells are 6.20 A for SmSe and 6.60 A for SmTe. Magneto-optical properties have been reported by Paparoditis and Suryanarayanan (1972). 

This contribution is sometimes referred to as the B term contribution to the Verdet constant. For molecules containing orbital degeneracies additional contributions arise (the A and C terms), in analogy with the closely related phenomenon - magnetic circular dichroism, discussed in O section Magnetic Circular Dichroism. For unit conversion factors, see O Table 11-9. 

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