First-Order Spin-Orbit Coupling

Table 4. States arising in ionisation from / free-ion configurations with first-order spin-orbit coupling. (Only multiplet components with normalised intensity > C.l are listed) ...

States Arising in Ionization from f" free-ion-configurations with first-order spin-orbit coupling [9]. 

Ab initio SCF and Mbller Flesset calculations with flexible valence basis sets including 4f orbitals are carried out for the ground and first excited spin states of the Co(NH3)52 and Co(NH3)5 complexes. The results of the calculations in conjunction with a first-order spin-orbit coupling model yield an estimate of 10" for the electronic transmission factor in the Co(NH3)5 exchange reaction using an apex-to-apex approach of reactants, thus providing a mechanism characterized by only a modest degree of non-adiabaticity, consistent with the experimental kinetic data. 

The values in parentheses correspond to a weak shoulder before the first maximum. Though its distance is too large to be due to first-order spin-orbit coupling in the selenium atom, it may be the spin-forbidden transition to Ti or a symmetry-forbidden transition i.e. the precursor band ) to Ti intensified by intermediate coupling and vibronic effects. 

In order to settle a controversy over the effects of deuteriation on the radiative lifetimes of aromatic hydrocarbons, some systems have been examined, using two independent techniques. Table 7 shows the rr values obtained from phosphorescence lifetimes and quantum yields. Evidence for the intramolecular nature of the deuterium isotope effect on rr comes from the lack of sensitivity to solvent. Although no definitive evidence as to the origin of the isotope effect is put forward, it is suggested that there may be two important contributing mechanisms to the 7i -> S0 radiational process, an isotope-independent and an isotope-sensitive one. The isotope-insensitive mechanism is almost certainly first-order spin-orbit coupling. It therefore remains to determine the nature of the other process, which will only be important when spin-orbit coupling is inefficient.1886... 

First-Order Spin-Orbit Coupling Selection Rules... 

First-order spin-orbit coupling mechanisms... 

Table 9.3. First-Order Spin-Orbit Coupling Selection Rules D

We therefore turn to the second triplet possibility, EJin d ). First-order spin-orbit coupling splits this orbitally degenerate state as sketched below. We include the D h symmetry labels and also values of the cylindrical quantum number which measures the total parallel angular momentum [22]. 

---