Triplet–triplet energy transfer reaction to cis-stilbene: a dual thermal bond activation mechanism

The behavior of cis-stilbene in nonvertical triplet–triplet energy transfer (NVET) reactions was examined in detail. A quantitative influence of both the single and double bond torsions on the strong NVET character was clearly evidenced by using a thermal activation model. Moreover, this model appears as powerful and remarkably fits the experimental data. The results are supported by quantum chemical DFT calculations.