Magnetic transition moments

In the /1-symmetry transition T+ - T00, the electric and magnetic transition moments can be described as ... 

In attempting to explain results from experiments that found positive results for the Vester-Ulbricht Hypothesis [65] (Table 1), Garay et al. hypothesized that the magnetic moment of the electron and the magnetic transition moment of the electronically excited optically active molecules could interact [128]. Thus, the... 

The conventional view is that the molecular basis of optical activity relates to an assumed non-zero scalar product of electric and magnetic transition moments that defines a rotational strength... 

In equation 23 Im means to take the imaginary part of the corresponding expression. In a series of related compounds for a particular magnetic dipole transition, as is the (n, tt ) excitation of 152-154, 156, 157, the magnetic transition moment is approximately constant, but the electric transition moment may vary widely. Then, if 0 represents the angle between the directions of the electric and magnetic transition moments, an equation... 

In applications of this relation, the contribution from the coupling with the magnetic transition moments M = is often neglected. The... 

Finally, it should be noted that for states and that are produced by mutual magnetic mixing, the contributions to the B terms are of equal magnitude but of opposite sign. Whether the contribution of the energetically lower or the hi er transition to the B term is positive depends on the orientation of the electric transition moment relative to the magnetic transition moments and... 

Inherently chiral chromophores Chromophore itself is twisted and chiral and, therefore, the 7t—7t and/or n—it transitions become CD active, because both electric transition moment and magnetic transition moment < M 0> take nonzero values. The CD intensity of this group is stronger than that of group (a). 

Exciton-coupled CD8, The systems have two or more chromophores, which are placed in chiral positions to each other. Each chromophore exhibits intense tt—tt transition generating a large electric transition moment , and at the same time, these moments make a large magnetic transition moment... 

In both cases (b) and (c) the rotatory strength will be expressed in terms of the energies and of the scalar products of the electric and magnetic transition moments involved. 

The d-d transitions may be either magnetic dipole allowed or forbidden, but are generally (by symmetry) electric dipole forbidden. This may seem contradictory as they appear in the normal absorption spectrum with a finite but small intensity, but we shall consider this in detail later. Thus at this stage, the d-d transitions are characterized solely by their magnetic transition moments... 

For the purpose of finding the angular distribution of the products in magnetic predissociation, we choose the Z axis along the magnetic field direction. Here we shall consider only the case in which the magnetic transition moment is along the molecular axis to demonstrate the method of calculation. Other cases can be treated similarly. In this case, Eq. (150) becomes... 

The calculation of the angular distribution of products in magnetic predissociation is similar to that in photodissociation. In the above derivation, we have only demonstrated the calculation of the angular distribution for the case of the magnetic transition moment being along the molecular axis other cases can be treated in a similar manner as those in the photodissociation and will not be discussed here. Notice that when Hfi is independent of / values, Eq. (164) yields P v = 2. 

The optical activity in valence excitations of chiral metal complexes has been effectively treated using the model of an achiral chromophore (metal ion) in a chiral environment (ligands) and this model appears also appropriate for XAS in view of the core nature of the initial orbital state. The zero-order electric and magnetic transition moments arise from different transitions and must be mixed by some chiral environmental potential (V ). Considering the case of a lanthanide ion, and taking tihe electric dipole transitions for the Z.2,3 edge as Ip—Kj), a first-order perturbation expression for the rotational strength looks like ... 

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