Singlet-triplet energy differences

Table 1. Bond lengths (A) and singlet-triplet energy differences (in kcal/mol) for triplet phosphinidenes ...

Table 2. Singlet-triplet energy differences (A sx) and singlet (BDEj), triplet (BDEx), and composite (BDEsx/xs) bond dissociation energies for phosphinidenes and their W(CO)5 complexes, calculated with BP/TZP...

The CNDO and CNDO/S methods apply the ZDO approximation to all integrals, regardless of whether the orbitals are located on the same atom or not. In the INDO method, which was designed to improve the treatment of spin densities at nuclear centers and to handle singlet-triplet energy differences for open-shell species, exchange integrals... 

An Arrhenius type plot of EDas a function of temperature will give the value of the energy gap A Est. The value thus obtained has been found to agree with the singlet-triplet energy difference 42 kJ (10 kcal) mol- obtained by direct spectroscopic methods for eosin in glycerol. 

Substituents effect dramatically also the bond dissociation energies of disilenes to the corresponding silylenes (Eq. 1), as is shown in Fig 12. which describes the correlation of the calculated dissociation energies for a series of substituted disilenes vs the sum of the singlet-triplet energy differences in the corresponding silylenes [20]. The theoretical background for the existence of such a correlation is discussed elsewhere [21]. 

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