Isomerization and electronic relaxation of azobenzene after being excited to higher electronic states

First-principle-based MD description of azobenzene molecular rods

“…We have therefore used DFT B3-LYP/cc-pVTZ level of theory for the next computations, since it provides reliable results and is more computationally convenient than cc-pVQZ. We remark that according to previous computational studies [35] and experimental characterisations [36,37], our calculations did provide not equal bond lengths for the two benzene rings. For trans-1-DA, we observe shorter and longer bonds alternating each other.…”

“…Anyway, we are quite confident that the obtained DFT structure is reliable, since other studies [39,40] on push-pull para-substituted 1-DAs show that the geometry (especially in the central moiety) is not particularly affected by the presence of the substituents [35,39,40]. In Table 4, we report the optimized (equilibrium) values for the selected parameter for trans-and cis-thio-1-DA, obtained with three different basis sets.…”

“…MP2 does not show such behavior. Concerning with this aspect, CASSCF gives different pictures, depending on the active space: data obtained at CASSCF(10,8)/6-31G(d) level [35] agree with HF and DFT ones, data obtained at CASSCF(14,12)/6-31G(d) level [38] agree with MP2 ones. In the cis conformer, the differences in bond lengths of the same ring are less surprising, since they have been documented at all the different levels of theory applied so far.…”

Ultrafast photoisomerization and its single-shot pump pulse efficiency of trans-azobenzene derivative: Compound for photosensitive DNA

“…We assume that the intermediate state in the π-π* excitation (360 nm pumping) is different from that in the n-π* excitation as well as the difference of the initial isomer. This is because the practical potential-energy barrier [17] from the different excited state S m i (i=1 or 2, m=T or C) to the isomerization pathway is different in each case, depending on the isomerization mechanisms such as rotation, inversion or concerted inversion processes [4][5][6][7]18] . 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 …”

Femtosecond photoisomerization of azobenzene-derivative binding to DNA

“…However, we have no knowledge of ultrafast electronic excited-state dynamics of the AzD binding to DNA (AzD-DNA) as well as the AzD, though for Az related compounds extensive studies on photoisomerization mechanisms such as rotation, inversion and concerted inversion processes have been carried out to clarify the relation between these processes and the excitation bands [9][10][11].…”