Hydrocarbons lowest triplet energies, table

Table 5.4. Lowest Triplet Energies of Various Hydrocarbons...

Triplet state (cont d) intersystem crossing quantum yields, table of, 239-240 lifetime, 12 lowest triplet energies of carbonyls, table of, 224-225 of hydrocarbons, table of, 226 of various organic molecules, table of, 227... 

In aromatic hydrocarbons, short-lived ](it, it ) is the lowest excited state and energy gap between (n, it ) and 8(it, it ) states is large. Both these factors are conducive to fluorescence emission and in general aromatic hydrocarbons are good fluorescer. Sometimes, the prediction may not come true if a higher triplet state T2 is available near the St state such as in anthracene. In such cases, fluorescence and phosphorescence both are observed at low temperatures in suitable solvent medium specially when S, and T, are states of different symmetry type. Some data correlating AEst and 4[Pg.148]

Another example that illustrates the effect of the overlap density upon the magnitude of K j involves two conjugated hydrocarbons. Listed in Table 8.1 are the experimental values of the first IP, the EA, the first singlet excitation energy ( — g) and the first triplet excitation energy (Ej — Ec) for azulene 8.7 and anthracene 8.8 [6]. For simplicity of notation, the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) of 8.7 and 8.8 are denoted by the... 

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